Links

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

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

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

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

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

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

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.