E30 Rebuild - Weekend #3

[RobertK]

So yeah.. as some of you guys know I'm new to the E30 community and I'm currently doing alot of work under the hood of a super cheap 87 325i I recently picked up for $400 a couple weeks ago.

To catch everyone up to weekend #3 the car had an oil leak at the cam seal, old timing belt, and was not well maintained overall when I drove it home. So my friend and I decided to go ahead and replace as many parts as we can while tearing the engine down for the timing belt replacement.

So far we've replaced the seal and the timingbelt with no problems and because the car was overheating at idle we decided to do a compression test to make sure the HG and head was good and here are teh results..

1 = 160psi
2 = 155psi
3 = 160psi
4 = 161psi
5 = 162psi
6 = 160psi

As far as I can tell it looks pretty good but I did want to get some opinions about piston #2 being @ 155psi considering the psi of the others. Should this be a concern?

[rwh11385]

IMO from class, that's completely fine. And here is it confirmed from another source:

Record the reading for each cylinder. If any of them vary 10 percent or more from each other a problem may exist in one or more cylinders. If the variance is greater than 10 percent, specialized testing equipment may be required to fully diagnose the problem.
If all cylinder readings are within 10 percent of each other, no further testing is required and compression is considered optimal.

http://www.motorage.com/motorage/article/articleDetail.jsp?id=16170

5psi is definately less than 10% of 160.

Close enough for me.

[Rob]

overheating at idle? check your cooling system, thermostat, fans, whatever...

[RobertK]

During the process of the timing belt replacement we went ahead and replaced the water pump and thermostat. We made sure to flush the cooling system before we tore the car down.

Right now we're at a stand still because we screwed the water pump pulley up so I'm waiting to hear back from Digitalwave about buying one from him and trying to get it here before the next weekend.

I've been taking pics as we progress.. I'll be sure to post them when I get home fom work.