my compression and leak down test numbers

[aablown]

Guys,

I finally had compression and leak down test on my s14. Looks like it needs a little work but not bad for a 220+k engine. Let me know what you goes think. Everything below is from my shop. Ive read that the results below might indicate a bad exhuast valve?



Here are engine compression and leak down results from the E30 M3.

Compression
Cylinder #1- 190psi
Cylinder #2- 190psi
Cylinder #3- 180psi
Cylinder #4- 175psi
142-156psi is OE Rrange
Most likely cylinder head has been decked, every time you deck the cylinder head, you raise the compression of the engine, this is most likely best guess by mileage and without disassembly.

Leak down %
Cylinder #1- 38%
Cylinder #2- 22%
Cylinder #3- 24%
Cylinder #4- 15%

20% leak down is max acceptable per BMW.

Most likely due to wear and tear the cylinders have ovaled out, which is why we see acceptable compression but bad leakdown.

[M-technik-3]

Where was the air coming out of when you did the leak down test.

[aablown]

tech said the oil cap, so most likely bad rings. thoughts?

[M-technik-3]

Yup, that's correct. Still debating going the 2.5L route? 2.3L with 1st overbore isn't so bad. You'd be surprised what a fresh 2.3L runs like. I put a fresh engine in my white car and it made my red one feel dog slow. It's overdue for an Overhaul at 290K miles.

[aablown]

Nah the 2.8L route isn't in my budget, I'm already doing a complete low compression build on a s52. I'm just gonna replace the worm parts in the s14. If the block has to be bored and I need new pistons etc, I may debate on swapping a s5x in.

[bimmer8604]

Sounds like rings, mine were similar, a little lower in the 80-120 range, and failed the leak down test like woah. Once torn apart found carbon build up on all the valves. You should be able to do a stock rebuild on the s14 for what I nice s5x swap would cost, and the car would still be original.

Kyle

[steve68]

I think mine had 75,75,100,100, when the rings let go, the PO over heated it, bad, it ran for 4 or so months then gave up suddenly!!

[aablown]

I think mine had 75,75,100,100, when the rings let go, the PO over heated it, bad, it ran for 4 or so months then gave up suddenly!!

damn thats low, i guess mine isnt that bad, but still presents a problem, and im gonna go ahead and tear it apart

[steve68]

yes it died in my neighborhood, got it to fire up and put it in the garage, ended up tearing the motor down, did rings and bearings,