E36 M3 98 - Leak down and compression test input appreciated

[Gunner_27]

Hey guys

so just picked up an e36 m3 98 model with 173k miles.

Very well maintained, alot of work done, mechanic said the test results were ok but i personally am worried about CYL 3 and 6.

Compression

CYL1 185
CYL2 190
CYL3 165
CYL4 190
CYL5 185
CYL6 170

Leak down
CYL1 10%
CYL2 5%
CYL3 10%
CYL4 5%
CYL5 10%
CYL6 14%

so what confuses me is, cly 3 has a 165 comp but only 10% leak, while cyl 6 h has 170 comp but a 14% leak.... Should I be worried ? can I expect another 100k with proper maintenance ?

Mechanic did not perform wet test since he said it was not needed , everything looked ok.

input appreciated.

[BMRLVR]

Originally Posted by Gunner_27

Hey guys

so just picked up an e36 m3 98 model with 173k miles.

Very well maintained, alot of work done, mechanic said the test results were ok but i personally am worried about CYL 3 and 6.

Compression

CYL1 185
CYL2 190
CYL3 165
CYL4 190
CYL5 185
CYL6 170

Leak down
CYL1 10%
CYL2 5%
CYL3 10%
CYL4 5%
CYL5 10%
CYL6 14%

so what confuses me is, cly 3 has a 165 comp but only 10% leak, while cyl 6 h has 170 comp but a 14% leak.... Should I be worried ? can I expect another 100k with proper maintenance ?

Mechanic did not perform wet test since he said it was not needed , everything looked ok.

input appreciated.

He should have put some oil in to see if the numbers increased, that would rule out leaking valves and confirm the leakage is past the rings.

[Richbot]

with leakdown numbers like that you're liable to be down 20-30hp compared to a fresh rebuild for a street car not a big deal but I would rebuild

[Gunner_27]

Originally Posted by Richbot

with leakdown numbers like that you're liable to be down 20-30hp compared to a fresh rebuild for a street car not a big deal but I would rebuild

Thats the plan , but sometime down the line, just want to use this as is for a year or so unless things get bad.

[Gunner_27]

Originally Posted by BMRLVR

He should have put some oil in to see if the numbers increased, that would rule out leaking valves and confirm the leakage is past the rings.

he said.

We follow BMW specifications. While some of the tolerances are at the edge of spec, none out of spec. For this reason, we did not perform any further testing or diagnosis. The car fits inline with what we would expect a 180k mile car to be.

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