M52B28 Compression Test Results!! Normal?

[Jordan125629]

So I recently put up a thread explaining how my 98 328i suddenly began smoking on cold starts which is definitely oil burning (Blue Hue , Oil Smell) I was almost positive it would be a clogged CCV but Unfortunately its not, Im now assuming its Most likely Leaky Valve Seals, So I went ahead and rented a Compression Tester from Autozone , Fired up the e36 and drove it around till It reached operating temperature and went ahead and removed Everything ( Spark Plugs, Coils, Fuel pump Fuse) I ran 2 separate tests and these were my results. Starting from closest to the front of the car. First test engine was still Hot, 2nd Engine had cooled off.



1st Test. 2nd Test

Cylinder 1 - 190 - 190
C2 - 190. - 195
C3. - 190. - 210
C4. - 195. - 210
C5. - 200. - 200
C6. - 210. -210


Now my questions are , why are they so high compared to others that Ive read usually around ( 140 - 180 psi )

Also upon visual inspection with spark plugs out , I noticed cylinder 3 had small noticeable oil droplets inside and had the dirtiest plug of them all, cylinder 4 also had a very dirty plug and oil residue inside. All other cylinders looked good.

What do you guys think? Are these bad numbers?

The Car runs amazing and pulls strong with no issues, just lots of blue smoke on cold starts or after its been sitting for hours.

Please any info is greatly appreciated!!

[gdavid]

I believe the most likely explanation between your compression measurements and others is the gauge you are using. When testing compression, the variation between your cylinders is typically more critical than the overall numbers, these gauges don't have to be exact (accurate), they really just need to be precise (consistent).

Your high numbers may very well be accurate, as carbon deposits in the head and on the top of the piston grow, the compression increases because there is less volume at top dead center. The valve stem seals definitely sound like they are the source of your blue smoke, it is a tedious job but it can be done without pulling the head. Based on the age of these cars, I would imagine that all of the original valve stem seals have gotten hard by now. Additives in good oil can extend their life but if the car has set for any long period of time unused and especially in harsh climates, the additives can't do their job.

I swapped drivetrains from my old daily driver which was side swiped to a clean shell a about a year ago, in the process resealed the engine including disassembling and cleaning the the head. I had about 1mm of even carbon deposits on top of all six pistons. The valve stem seals were hard and brittle, I did not overhaul the bottom end and my oil consumption dropped to about 1 quarts/5000 miles. I'm certain I lost a bit of compression by removing this much carbon.

[jclausen]

The compression is fine, if it smokes only on start up after sitting awhile and then that’s it, valve stem seals or worn valve guides

[spyderg0d]

Alot ges into compression test variables.. whether all plugs are in or just the 1. Throttle is open, if injectors are firing. How healthy the starter is can even make a difference. Plus wherever neglect the vanos happened to fall at in old used units can make a massive difference.

[Jordan125629]

Thanks for the reply’s guys, I’ve been stressing all week about this and reading thru tons of threads on related issues. It just seems so sudden for me, literally 1 day it’s perfectly fine then it sits all weekend (I left on a family weekend trip) and come Monday morning I fire her up and I see bunch smoke with nasty oil smell. Ever since that day I’m now getting blue smoke EVERY cold start.

Wouldn’t the Valve seals go bad over time? Starting with small increments of smoke eventually leading up to a lot more smoke?

I daily this car everyday and I would never see smoke on cold starts just vapor and smell of gas burning. Now it’s EVERYDAY I turn her on she’s letting out smoke and the shit smells bad. Once I drive and the car is at operating temp there’s no smoke whatsoever.
I have no problem changing the Valve seals, I just don’t want to go ahead and begin disassembling the head without knowing 100% that’s the issue.

So I currently have her parked and I’m driving around in my slow 323i lol

What other diagnostics should I run? Any suggestions or should I go ahead and just start ordering the Valve seals.

And again thanks for the Reply’s and Information guys I really appreciate it.

[JDStrickland]

The thing you want is less than 10% deviation among cylinders. By that measure, you are looking good.

[spyderg0d]

It very well could be a froze or gunned up cvv. Next time it's cold out and you are done driving for the day or night, take the oil cap off when you park. Then put it back on before you start the car the next day. .. if it doesn't smoke, you figured out the cvv gets clogged with ice or oil gunk when getting real cold.

[jclausen]

If it was a it of smoke I won’t worry about it, valve seals just wear out as do valve guides, unless it’s pouring out smoke I wouldn’t worry about it certainly the pcv system can cause it to smoke you try a higher grade oil what oil weight are you using now