DIY Car Maintenance and Repair

Links

2007-01-26T17:34:00.000-08:00

This is a lazy update. I'm collecting all the useful bookmarks from the multiple computers that I use.

Engine Oil and Filter

http://minimopar.knizefamily.net/oilfilterstudy.html
http://www.corolland.com/oil-filters.html

Suspension
http://www.se-r.net/car_info/suspension_tuning.html

Auto Tech
carbible

Mazda 626 vibration and rpm idle speed

2006-12-31T00:53:00.000-08:00

I think the vibration may be due to low idle speed.

I've noticed that the idle rpm drops slightly when I put the car into D or R from P or N.

When the car is cold, the idle rpm is 1500 and drops to 1350-1400 when in D or R. (with brakes applied) There is no noticeable vibration.

When the car is fully warmed up, I can't estimate what the rpm is because the tach gauge scale is so coarse. I know it drops by about 100-150 rpm for D/R. Then the vibrations happen. If I step on the gas a little bit and the brakes are still applied, the vibrations go away.

The wrong size belt on a Jetta

2006-12-14T21:56:00.000-08:00

Another friend spent three days trying to put on a serpentine belt on a newly purchased 2000 VW Jetta GLX (V6 engine). The old belt was badly worn and missing some ridges. He got a replacement belt from some independent VW shop, but he just couldn't get it on. So we went to pep boys and got the right belt. We brought the old belt to verify the correct size.

The V6 Jettas are packed with stuff and useless plastic cover pieces. (I hate how luxury or wanna-be luxury cars dress up the engine compartment with stylish plastic pieces.) There's not much room to work on the belt. He fished his hand down a narrow opening that was about the same width as a video tape, and installed the belt on by feel on all the pulleys. It took him several hours to complete the job in freezing weather at night!

I had recommended removing the wheel and side cover. This page has lots of pictures on removing the belt and tensioner. Here are lots of DIY procedures for a V6 Jetta.

Engine Vibrations

2006-12-11T21:52:00.000-08:00

I changed the side engine mount on the Mazda 626. At first it seemed the vibrations went away, but after a while I noticed the vibrations again. Now I'm starting to realize the vibrations are dependent on more than just the transmission gear setting and rpm.

1. Occurs when I'm applying the brakes to hold the car at a stop and
-in D gear
-car is fully warmed up
-car has been driven for a few minutes

2. Does not occur in P or N at any rpm.
3. Does not occur when engine is cold and rpms are high even when car is stopped in D gear.

So do the other mounts (transmission and rear) need to be replaced?
Is the engine centered on the rear mount? Is the engine mispositioned on its mounts? There was a TSB.
Is the problem due to the torque converter?

To see if the problem is still due to the engine mounts, I'll warm up the car until the vibrations occur, then I'll jack up the engine/transmission a little bit to see if the vibrations go away.

High-Centered an Audi S4 on a Column Lift

2006-12-09T14:42:00.000-08:00

This week was extremely busy. I got involved in several car projects.

The most interesting event was that I had "high-centered" my friend's Audi S4 on a single column lift. He brought his car to the class for an oil change. According to him, several shops charged $90 for an oil change!

Mobil 1 5W30 $6 per quart or $23 for a 5 gallon jug at Walmart. S4 needs 6.7 quarts.
Filter $5-$6

The oil change itself was quite easy. The S4 has the oil filter and drain plug in the most convenient location of any car that I've worked on. They're just in front of the left tire below the headlamps. I removed a plastic cover on the bottom which was held in place by about 5 screws and 2 plastic fasteners.

When he backed the car away the service bay, we heard a loud clunking sound. WTH?!
It was already 10PM and past the time when everyone should get out of the class. I discovered the bottom plastic cover was not fully secured - I had asked someone else to put it back on while I was hurrying to return the tools and cleanup. Even with the cover fully secured, the clunking was still present.

So, I flagged down one of the instructors to diagnose the problem. The noise sounded like something was rubbing against an axle or wheel. They put the car up on a 4 post lift which has no center column, and manually spinned each wheel to try to make the clunking sound. I don't think we heard the sound. Then they asked Andy to get in the car and run the car in 2nd gear while it was up on the lift. The sound came from the driveshaft rubbing against the catalytic converter's heat shield.

When I lifted the car with the single column lift, the column had pushed the exhaust pipe up against the heatshield, bending it against the driveshaft. This happened because the center of the car was slightly lower than the lift points on the sides of the car. I should have placed "cheater blocks" or angled the lift blocks at the end of each crossarm of the lift. This would have created a clearance between the column and the car's underbody.

The instructor bent back heat shield into the correct place with a pry bar and the driveshaft no longer rubbed against it.

Broken transmission on 1999 Subaru Outback

2006-12-03T01:16:00.000-08:00

My friend called me about his broken car. It won't shift into any gear except R.

Posssibilities:

1. broken shift fork
2. broken linkages
3. broken transmission mount?

Things to do:

Drain fluid - see if there's metal bits coming out.
Examine linkages - check for missing parts
Examine mounts per Haynes manual

Removing the side engine mount on 626

2006-12-02T00:33:00.000-08:00

I decided to remove the passenger side engine mount for inspection. I used a 24" breaker bar and penetrating oil to get the bolts and nuts loose.

For one nut, I used an impact wrench for the first time. Man..that was handy - I'm going to get myself a cordless impact wrench off ebay! Since I'm going to be doing the tire rotations myself, this tool should pay for itself after 4-5 uses. Although I get "free" tire rotations at the tire shop, it's really too much of a hassle because I have to wait at least 1 hour.

I noticed the thru-bolt had very little clearance in the engine mount bracket hole. I had to fine tune jacking up the engine's oil pan to pull the bolt out through the bracket's mounting hole. When I got the bolt out, the engine mount center was at the very edge of the mounting hole. I wonder whether or not the engine is not centered on its mounts. There was a TSB on Alldata about the engine not being centered on the rear mount. This does sound sound easy or fun to center or "neutralize" the mounts.

When I pulled the mount out, the rubber had cracks in it and some separation from the metal. I decided to get a new mount, but none of the local part stores had it in stock. So I had to put back in the old mount.

Today, I ordered an OEM mount from alleurasianautoparts.com. I searched through several online parts stores, and decided to go with an OEM mount. I've read anecdotal stories of cheap aftermarket mounts failing within a few months. I'll pay a little extra so I don't have to redo the job later.

I hope replacing this one mount will cure most of the vibration at idle problems. If not, then I'll replace the transmission mount, which isn't too difficult to take out. I'm not touching the rear mount - that's too much work for a car that I'll probably get rid off in less than a year. I want to fix the vibration problem because that's the most noticeable problem.

Mazda Vibration in Gear

2006-11-26T15:08:00.000-08:00

I posted this on mazda626.net.

I have a 97 626 Automatic 4 cyl. Why does the car vibrate when I'm stopped at a stop light and the transmission is in "Drive"? The vibrations goes away when I put the transmission in neutral or park. I'm trying to figure out whether or not the problem is due to cracked engine mounts. I see a crack on the passenger side top mount, but I can't see whether there's any cracks in the rear firewall mount and driver side top mount (near the battery).

I have read some posts from people with similar problems and suggested solutions.

Some posts say the problem is bad idle. My idle speed in park or neutral isn't noticeably less than the idle speed in drive. I revved the engine up to 1000 rpm in park/neutral and the car did not exhibit more vibrations. So I don't think it's idle speed related.

I've also connected a vacuum gauge to the PCV valve vacuum hose and didn't see anything abnormal. The needle was steady. Perhaps I should repeat the vacuum test and put the car in drive with the brakes applied?

So I suspect the engine mounts are the culprits, but the rear one and driver side top one is hard to inspect and to take out. If I just replace the top passenger side one, I'm not sure if that will help or not.

Damn idiots in class

2006-11-24T00:49:00.000-08:00

I don't claim to be an expert in auto repair, but I know enough to figure who is a fucking idiot and who knows their stuff well. I hate it when these fucking idiots in class start tinkering around my car without my consent. I don't mind helpers, but I hate unsolicited help from people who are likely to do more harm to my car than me.

1. There's always a guy who always floats between various groups in the class. He helps a little bit, but always disappears when it's time for cleanup. He also liked fixing other people's car without their person or presence. He replaced a PCV valve on another guy's car when the owner briefly stepped away. The owner wanted to do it by himself. In another case, he broke the spark plugs or wires on another car. I gave him the evil eye to keep him away from my car.

2. This old guy in another class came to watch me do an alternator test. He had some strong ideas on the direction of current measured by the VAT-40. I politely disagreed with him and tried to ignore him. But the old fart didn't take the hint. Instead he started probing around my car. I told him to stop and go away.

Fixed Saturn shifter bushing!

2006-11-23T01:04:00.000-08:00

I used a C-clamp to push the bushing onto the ball joint of the shift lever. I didn't think it was too difficult, but my dad couldn't do it because he had trouble twisting his body into the right position.

After cleaning up and putting the console back together, my friend and I went on a drive to fully recharge the battery. The battery had enough power to crank the motor after one month of sitting in the garage. We drove up Doherty road up to San Ramon. Doherty road had little traffic and it was perfect for test driving the Saturn after being out of service for two months.

Mazda 626 service items

2006-11-21T12:50:00.000-08:00

1. Retest Alternator - I'm still getting inconsistent readings. 20A on alternator cable with no load is weird. Alternator is probably marginal.

2. Test Front Struts - n/a

edited after 11/22 class

I just don't get these kids..

2006-11-17T12:34:00.000-08:00

who modify their cars to such an extent that it's become unreliable and needs constant tinkering. Some of these same kids drive like "ass-hats". They think nothing of doing clutch dumps at redline, burning up the clutch, shifting at redline on a regular basis, blowing up the engine, street racing, and driving recklessly on mountain road thinking that they're Takumi of Initial D.

My question is how can they afford to abuse their car? If you had to work hard to earn money, would you blow it away like that? I've noticed a Lemmings or sheep-like mentality among these car nuts. Once something is deemed "cool", everyone wants to get it. The standard for coolness for the import is "JDM-tite yo". WTH do they spend several thousands of dollars for a tired engine or transmission from Japan that has no verified mileage? On top of that, they need to buy the ECU and do all the wiring to get it to work. And then the ECU needs to be retuned to accept the lower octane gas in the US, especially in California (91 Octane max). Such non-ODBII ECU's will not pass smog tests in certain states.

Case 1: Car catches on fire after street racing. Car has aftermarket fuel rails, pumps, turbo, and modified engine management.

Case 2: Car engine blows up after driving near redline for most of its 80K miles. Just 80K miles!

I'm not against modding or performance driving. I like doing things in moderation.

VAT-40 Amperage scale

2006-11-15T22:34:00.000-08:00

When I did the alternator test on the Subaru with the help of other students, I suddenly realized that I had been reading the wrong amperage scale on the VAT-40 for the entire time in the class!! There is a red and blue amperage scale. The VAT-40 has a rotary switch to set it to different modes. In "Starting" mode, the correct amperage scale is the red scale (0-500A). In "Charging" mode, the blue scale (0-100A) is the correct one. I had been doing the alternator test with the VAT-40 set to the "starting" mode and reading the blue scale. So when I thought the amperage was 20A, the alternator was really putting out 100A. I should have set the mode to charging and read the more detailed blue scale.

I think the Mazda's alternator is probably ok. I'll remeasure it next week.

The Subaru alternator put out about 80A at 14V and 2500 rpm. Spec was 65A or more at 14.1V. The front mounted alternator allows easy access to the thick B+ cable, so I clipped the current probe onto that cable.

Other completed tasks:

Tire rotation
CV boots inspection

I noticed some tissue stuffed into the exhaust pipe near the junction of the left and right exhaust manifolds. I took a picture of it and will ask the dealer mechanics about it.

Measured specific gravity of battery cells. The results seem to vary depending on how much electrolyte was drawn into the hydrometer.

Update on Saturn, 626, Subaru

2006-11-15T12:45:00.000-08:00

Saturn:

My dad removed the broken shifter bushing. He used a screwdriver to pry it off the ball joint at the bottom of the shift lever. My dad installed the bushing onto the cable but couldn't get it on to the ball joint. I loaned him some small C-clamps to finish the job.

Mazda:

Parts that should be fixed or replaced soon:

1. Leaking driver side inner CV boot. Perhaps a new clamp would fix it.
2. ~~Alternator isn't really up to spec.~~ Redo VAT-40 test
3. ~~Add more windshield wiper fluid.~~ Done 11/18
4. Radiator cap 16 psi

Wish list items:

1. Front struts R/R
2. Top engine mount R/R
3. Rear and Left engine mount remove and inspect.
4. Clean up grounds/ground wires
5. Test O2 sensors
6. Clean MAF, IAC, throttle body

I've very reluctant to disconnect the battery again because I'm not confident that the ECU will consistently overcome the rough idling/stall problem. Also since this is my wife's car, I don't want to deal with the flak "you messed up the car again!". But I need to disconnect it to replace the alternator.

Subaru:

Tonight, I'll rotate the tires and figure out a way to remove the spark plugs. The trick is to find the right set of extensions to access the spark plugs. I wonder if the Gear Wrench racheting wrenchs would be useful here.

If there's time, I'll do a battery and alternator test.

Mazda 626 passenger side CV joint

2006-11-09T15:06:00.000-08:00

This is the passenger side outer CV joint. The leak appears to be a slow, old leak.

Mazda 626 driver side CV joint leak

2006-11-09T14:50:00.000-08:00

I took this picture on 11/8/06 of the inner CV joint boot two weeks and about 200 miles after I had wiped away all the grease.

Mazda 626 Update

2006-11-06T11:53:00.000-08:00

On the day of the class, the idle problem improved all by itself. The car no longer stumbled while stopped at a traffic light. Also when I put the car into Park, the engine did not always stall out.

The instructor said that the ECU may have needed several ignition cycles to relearn its "operating parameters" for the specific car. When I disconnected and reconnected the battery, the ECU probably reseted itself and used factory defaults. Since the car is old, the factory settings could have lead to rough idle characteristics.

MAF sensor

I took out the MAF sensor and it had some carbon deposits on the front side. I didn't clean it because the instructor said MAF sensors are very touchy and sometimes cleaning it will make the probably worse.

IAC valve

The IAC valve is actually a stepper motor controlling a valve which bypasses the throttle plot. The computer adjusts the valve opening to vary the idle speed. The idle speed is increased when the engine is cold, when the A/C is on, when there is a load on the alternator, etc..I measured the IAC valve motor resistance - 9 ohms, which is within spec.

Distributor cap

There was some carbon around the contacts, but no shorts.

Spark plug wires

Measured the spark plug wire resistance
#1, 24", 7.03K
#2, 21", 5K
#3, 18", 6.2K
#4, 15", 4.08K

All wires are about 3K less than spec (16K/40"). Is this bad?

Ignition Coil

Primary side resistance was too low to measure with my DMM. I was unable to get a secondary side resistance measurement. The secondary output post is coated with a white dusty film. I cleaned it up with some sand paper.

Driver side inner CV joint

The grease leak is coming from the seam between the boot and metal shaft. I'll take a pic next week.

Subaru

2006-11-04T11:46:00.000-08:00

I'm here at the dealership for a free oil change. Yes there's free wireless internet here! They are also replacing the driver side window weatherstrip under warranty. The weatherstrip doesn't adhere completely to the window near the back and as a result I can hear wind noise while driving above 70 mph. I hope this will fix it.

Removing Water Pump Pulley Bolts

2006-11-01T00:18:00.000-08:00

A few months ago, a friend and I replaced the water pump in my Saturn. The biggest problem was figuring out how to remove the three bolts on the water pump pulley. On saturnfans.com, I found several methods:

1. Use a strap wrench to hold pulley while breaking loose the nuts.
Somewhat useful.
It was hard to hold on to the strap wrench while I applied torque to loosen the bolts. The wrench would have been more useful if it had a longer handle and better self-locking mechanism to lock the strap.

2. Keep the accessory belt on the pulley to provide resistance.
Useless.
The belt could not prevent the pulley from turning.

3. Jam screwdriver between two nuts and the frame.
N/A.
I couldn't see how this would work. The nuts have such a low profile that it was impossible to keep the screwdriver against the pulley nuts.

4. Use a wooden wedge.
This worked. I inserted a wedge between the pulley and subframe or crank pulley. Then I was able to break loose the pulley nuts.

Task list for tomorrow's class

2006-10-31T11:11:00.000-08:00

Re-measure current drain from battery when car is off. Check spec. Typical is 20 mA.
Remove airbox
Clean grounds
Add extra ground wires
Check intake hose, intake manifold gasket for leaks

Measure MAF sensor voltage
Clean MAF sensor
Clean throttle plate
Measure resistance of IAC valve terminals with connector removed
Clean IAC vavle
Inpect cap and rotor
Measure spark plug cable resistance
Check spark plug gap

ATF fluid condition

Tools/Supplies:

Anti-Seize
Brake Cleaner
TB cleaner
MAF cleaner
5' #6AWG wire
5 ring terminals
sandpaper
clean rags
T25 security bit
extra extensions
a known, good DMM
incense - probably not allowed in autoshop

Ah Ha

2006-10-29T14:07:00.000-08:00

I suddenly realized why the rough idle/stall problem occured after the transmission rebuild and after each time the battery was disconnected. The battery was probably disconnected when the transmission was rebuilt, therefor wiping the ECU's "learned" parameters.

If I had disconnected the battery prior to the transmission rebuild, the problem probably would have manifested itself.

Fixes for 626 rough idle, stalling

2006-10-27T21:36:00.000-07:00

I posted the rough idle and stalling problem on mazda626.net. From the responses I got and posts from people with similar problems, I'll clean the MAF and IAC. I'll reprint my post here:

I have two problems with my 1997 626 (2.0L, ATX).

1. When I come to a stop and the transmission is still in "Drive", the engine rpms drop below 650 rpm and stumbles a little bit before recovering.

2. When I change from "Drive" to "Park" or "Neutral", the engine rpms drop below 650 rpm and usually does not recover. The engine stalls.

My current problem may be related to a transmission rebuild done earlier this year and possibly the things that I did in an auto shop class. I'll use a timeline to summarize the background.

March 2006 - Rebuilt transmission. After rebuilt, problems #1 and #2 occur intermittently.

April 2006 - Replaced battery. After replacing the battery, both problems occured regularly. I took the car back to the shop for repair under their warranty. The shop had it for several days and found nothing wrong with the transmission. They did fix the problems and told me the cause was due to a corroded ground connection. I didn't asked them where it was. I only spoke to them over the phone because this was my wife's car who was a student in another city.

Summer 2006 - Replace spark plugs, air filter, flushed coolant, checked PCV valve.

October 4, 11, 18, 25 - I'm taking an introductory auto shop class and take the car into the shop to do basic maintenance and test procedures: engine compression test, cylinder leakage test, battery load test, alternator test, measuring manifold vacuum using the PCV vacuum line, cleared CEL for "warm up cat efficiency". If anyone is interested, I blogged about the tests and results.

I've noticed problem# 1 occuring again about 1-1.5 weeks ago.

In yesterday's class, I removed the battery and the battery tray to get a better look at the "driver side upper" transmission mount. When I removed the battery tray, I saw a ground connection that didn't look original. A bundle of 4 wires came off from a thick cable assembly and all four wires were crimped together onto a single large ground lug. The connection looked a bit corroded, so I used some sandpaper to buff it a little bit.

After the class, problem #2 occured repeatedly and #1 got worse.

Is it coincidence that problems #1 and #2 are happening again or caused by something I did during the shop class? The weather has been getting colder lately.

Problem #2 seems to occur regularly whenever the battery is removed and reinstalled. Is this stalling problem due to some parameter being lost in the engine/transmission controller's memory when the battery is removed?

I did test the resistance measured between the lug and other points on the chassis, result was 0-1 ohm. I'll go back and clean up that ground connection that I disturbed in the class.

I have browsed some related threads about the engine stalling and poor idle. Most of the posts suggest to clean the MAF, IAC. I don't know if doing these things will help because it just seems that problem #2 is related to r/r the battery. Perhaps some wires inside the cable assembly got affected when I disconnected the battery cables.

Thanks for reading. I appreciate any advice to diagnose this problem. I shudder to think that it's a transmission problem again because then I have to take the car back to the transmission shop that is located 360 miles away.

Rough Idle, Cutoff

2006-10-26T13:57:00.000-07:00

The rough idle, park engine cutoff problem has returned. I'll write more later.

1. Engine Mount Inspection Results

Confirmed Right engine mount is cracked.

Suspect Rear and Top mounts may be damaged. The Rear mount is by the firewall below the intake manifold. It seemss very difficult to r/r. The Top mount is under the ignition coil.

2. Cooling System Test
Radiation cap test result was 13 psi, but cap spec is 16 psi.
Pressurized cooling system to 16 psi, and found no leaks.

3. Driver side inner CV joint
Found a slight dab of new grease near CV boot end. I'm not sure if this is really new or a spot that I missed cleaning last week. I cleaned it up very carefully this time and will check it again in 2-3 weeks.

4. System Current Draw = 390 mA with ignition key OFF. This is OK.

5. Found broken wire clip just above passenger side inner CV joint. Replaced with tie-wrap.

6. Found non-OEM looking grounding point under battery tray. Four wires were connected to one lug. I sanded the chassis and lug to remove corrosion. Maybe this is what I shouldn't have touched and lead to the park stall problem. If it ain't broke, don't fix it.

Mazda 626 inspection plan

2006-10-24T18:32:00.000-07:00

For tomorrow's class, this is the to-do list in order of priority. There's no way I'll get all these things done, but the list will help me focus.

1. Jack up engine and inspect crack in top engine mount (passenger side)
2. Inspect driver side upper engine mount, below the ignition coil.
3. Inspect driver side inner cv joint to see if there's fresh grease.
4. Cooling system pressure test
5. starter voltage drop test
6. alternator wire resistance or voltage drop test
7. Ignition coil test
8. Measure spark plug wire resistance
9. Cap and rotor inspection
10. Adjust tire pressures
11. Find jumper location to do measure timing

I also ordered the replacement shifter bushing from Jerry on Ebay.

edited 11/1/06

Saturn Shifter Bushing

2006-10-21T23:33:00.000-07:00

A month ago, the shift lever suddenly became loose and could no longer shift gears. The lever was floating. The instructor for Auto 50B thought it might be a shifter bushing. I did further research on the saturnfans.com forums and learned that this was a common problem for the Saturn S-series.

I removed the console and parts of the lower dash to view the shift cable and shift lever linkages. Sure enough, I found the broken bushing for the cable that sends the up and down lever motion to the transmission. Thank goodness the problem was not due to a broken shift cable or broken linkage at the transmission end.

The bushing looks like plastic spindle that is pinned to the shift lever to allow it to spin. The spindle part is wrapped around by the shift cable's eyelet. The cap end of the bushing broke off so the cable eyelet was no longer secured to the bushing.

Unfortunately, Saturn does not sell this plastic piece by itself. I have to buy the shift cable assembly (~$200) to get it. The good news is that there is a guy on Ebay who is making and selling the bushings from Delrin or stainless steel. Here is his webpage.

Engine Mounts and CV joints

2006-10-19T00:24:00.000-07:00

Fluid levels

ATF level - ok. Color is light pink, which is normal. I'll be worried if it turns dark or has silvery particles in it.
PS level - ok. Orange color. I don't know if that's normal or not.
Oil - ok.
Coolant - ok.
Windshield Washer - Need to add.

Alternator Test

I can't conclude whether the alternator is ok or not. Measured battery voltage with engine off = 12.9V.

1. Using VAT40, placed a 20A load across battery terminals. Voltage at battery dropped from 14.2V to about 13V and alternator made a noisy whining sound. RPM at around 2000 rpm. By this test, alternator is no good. Alternator should provide 80A at 12V according to spec. But this spec doesn't make any sense to me. Should the alternator voltage remain at 14.2-14.7V at 2000 rpm with a load across battery? How much of the voltage drop is due to the resistance of the wire between the battery and alternator? It's hard to access "B" terminal on the alternator.

2. Alternator is good according to Haynes manual test. Turned on AC, defrost, radio, lights, and fan. Then measured battery voltage. 13.2V at idle and 14.2V above 2000 rpm.
I could not measure the "L" terminal voltage on the alternator with the connector on.

Inspect Engine Mounts

Used inspection mirrors.

1. Rear mount appears to have crack or large cavity above the thrubolt. Check new OEM mount to see if there is a cavity there by design. This mount is very hard to access.
2. Right mount has crack.
3. Front mount looks brand new. This is the one replaced by Wabbit Wepair earlier this year.
4. Bottom mount is aged and has some light wrinkles. I don't think it has cracks.
5. Top (Left) mount is hard to access and I didn't have time to check it.

CV Joints

I discovered fresh gobs of grease deposited around the driver side inner CV joint. Boot did not appear to have crack. Perhaps boot was a universal one and doesn't fit well. Gas station monkeys replaced this axle 2 years ago. I cleaned up most of the grease and will monitor it.

On passenger side outer CV, I found some old grease and dirt along edge of boot. I didn't see any obvious cracks.

Got New Tires

2006-10-18T13:08:00.000-07:00

I got new BFG Precept Touring tires on Monday. $317.30. I didn't get the optional full replacement warranty for $40 extra at America's tires.

It was about time to get new tires. The car had 3 different makes of tires for the past 3 years. The sidewalls were beginning to crack on two tires and very low tread depth on the third tire.

Tonight I'm going to auto shop class!

To do next week

2006-10-12T03:43:00.000-07:00

Inspect engine mounts
Redo Alternator Test
Check ATF fluids
Inspect underbody -cracks in boots
Starter Voltage Drop test
Verify if front struts need replacement

check all fluids
pressure test cooling system and cap
adjust tire pressure

Edited 11/1/06

Cylinder Leakage, PCV valve, Manifold Vacuum

2006-10-12T03:05:00.000-07:00

I used the lift outside the main indoor area. These lifts were a bit strange. There was a center column and 4 movable arms. At the end of each lift arm was an adjustable metal pad. These pads can be adjusted so that there is a slight upward angle to keep the car's underbody from impacting the lift's arms.

Cylinder Leakdown Test

21mm crankshaft bolt

Measured 12%, 24%, 14%, 6% for cyls 1,2,3,4

Firing order 1-3-4-2

The nice feature on the Mazda is that there is already a hole in the wheel well cover to access the crankshaft bolt. I turned the bolt until the timing mark lined up with the TDC marking for cyl 1. The timing mark is found on a ring between the two concentric crankshaft pulleys.

To put the next cylinder in the firing order at TDC, I turned the bolt 180 deg. (720/# cylinders). Putting a long screwdriver down the spark plug hole helps indicate when TDC is reached. It's hard to estimate if I've turned the bolt 180 deg because of the limited room to turn the rachet.

As for the leakage, I couldn't feel or hear any air from the exhaust, oil filler hole or dipstick tube. I also didn't see any bubbles in the coolant at the radiator cap. I didn't take off the air filter (intake valves) because it's too troublesome to remove the air box cover. So I don't know the source of the leakage. The only hissing air sound was from the spark plug well where the air hose was plugged in. What's that from? Was it from the other cylinders since I had removed all the spark plugs at the same time?

Manifold Vacuum

Use PCV vacuum source

20" vacuum

Needle varies between 20-21". Needle steady for about 0.5 secs, then vibrates for 1-2 secs, and repeats the entire cycle. Applying pressure to the vacuum fitting could make needle steady at 20".

PCV Valve Check

PCV valve check. It's OK.
Why does air come out of the oil filler hole?

Compression, Battery Load, Starter, Alternator

2006-10-05T03:30:00.000-07:00

Compression Test

To disable fuel and ignition, remove fuel pump relay and ignition coil (primary side) connector. Haynes manual says it can be done by removing HV side cable and grounding it to chassis.

Measured 185, 185, 185, 190 psi for cyls 1-4

Battery Load Test
Car is off
Connect VAT40 to battery terminals and set load current to 150A. Measure battery voltage 10.9V. This is greater than min limit 9.6V. PASS

Starter Draw Test

Disable fuel and ignition (see above)
11.4V at 80A

Alternator Test

Reg. Voltage 14.1V-14.7V

At 2krpm, voltage = 14.2V with no extra load

As I increased the load from 0A to about 20A, the voltage drops below 14V!! Is this normal?
Instructor said this indicates alternator will go bad. Typical life is 80,000 miles. Car has 123K miles. But alternator puts out enough current to charge up battery, so it's ok to not replace it if car is not used frequently.

Redo test with lights on, rear defrost, heat fan, radio on. See if voltage is below 14.1V at 2Krpm.

It's better to do the compression check and alternator test with 2 persons.