might be my motor!!! pictures!

[mitch500]

what do you guys think of this ?. compression numbers seemed low arent they supposed to be 190 across, is this only when the motor is warmed up because the numbers were 140-150 across all six cylinders with the motor out of the car cold.? oh and whats that black box to the right of the DME.

http://i140.photobucket.com/albums/r...EEK/Clutch.jpg
http://i140.photobucket.com/albums/r...yandClutch.jpg
http://i140.photobucket.com/albums/r...SSNEEK/DME.jpg
http://i140.photobucket.com/albums/r...NEEK/Plugs.jpg
http://i140.photobucket.com/albums/r...EK/Engine1.jpg
http://i140.photobucket.com/albums/r.../EngineTop.jpg
http://i140.photobucket.com/albums/r...ineFront-1.jpg

[browntown]

If you do it on a cold motor, add some oil to the cylinder, and it goes up, then your rings might not be good. Doing a compression test on a warm motor will not reveal this as everything is nice and expanded with a nice coat of oil on the cylinder walls giving an artificially high result. This info is brought to you by unsubstantiated internet reading, and should not be taken as law.

Now that I search there is decent amount of sites that tell you to do it warm too, in fact more than the cold. Huh. I'm no help.

[mitch500]

thanks,anyones else?

[grib]

thanks,anyones else?

You may want to get a better shot of those plugs - it is difficult to really see the tips in that light.

What were your compression numbers? Not just the overall numbers, but the relation to each other is important as well.

I have an S52 that appears to be in great shape (very clean head, oil pan and internals - but have not completed/started it yet) that tested these numbers cold:

# 1 - 179 lbs
# 2 - 175 lbs
# 3 - 170 lbs
# 4 - 173 lbs
# 5 - 170 lbs
# 6 - 174 lbs

Bentley lists the compression specs as:
Minimum Compression 142-156 psi
Maximum Difference between cylinders: 7psi

So "technically" mine would not pass (delta between 1 and 3/5), however 2 PSI could be attributed to error in the gauge. We'll see how it runs.

[browntown]

7 psi differential is like 5%, most things I've read say 10% variance is okay.

[LINUS]

Before you get too far into thinking about buying parts, do yourself/have it at least leakdown tested instead of just a simple compression test. That way you'll find out if your problem is valves/upper end or rings/bottom end. If you are only doing this one time, paying to have it done might be the smarter money. I don't know what one costs, the shop I use lets me use all tools and a hoist on Saturdays for $15/hour. Just make sure the shop you use knows up front that this is for your own information, and that they aren't going to be doing the labor. Just to make sure you get an accurate result.

[mitch500]

this is the last message the guy sent me, this is what he stated about the compresion test.

"I did a compression test however my tester had seen better days.. it worked but gave me lower than expected numbers as it has done this before.. The engine ran awesome before so please don't let these numbers fool you.. 140-150 1 and 2.. 3 and 4 were down at 100-110 and 5 and 6 were around 140-150... again the motor ran great in the car so I am sure it's just the tester.. or i am not doing it right..?! Everything is there.. the oil is clean.. Let me know what you think..""

[Mike325]

You should always do the comp test with the motor warm. Sounds like you should get the comp tested with a good tester.

[grib]

140-150 1 and 2.. 3 and 4 were down at 100-110 and 5 and 6 were around 140-150

If those are the actual compression numbers, I have a difficult time believing that the motor ran well. 100 to 150 is a huge difference between cyl. I guess you can hope that is gauge is malfunctioning? I'd pass on this one unless it is super cheap.