Making Sense of Compression Test Results OM603

[oilslick]

1991 350sdl
1- 440 psi
2- 420 psi
3- 420 psi
4- 435 psi
5- 460 psi
6- 425 psi

Oil out the tail pipe. I installed new seals in the turbo about a month. Now I am watching oil drip steadily from the tail pipe. I've suspected significant blowby through the breather tube so I thought I'd just check the compression. If I have read correctly in other posts and forums then my compression results are pretty good. Too good for an engine with 275k. I was not able to test through the injector ports because my test adapter was too deep. I left the injectors in and tested through the glow plug holes. I did not test with any glow plugs installed.

My next move I guess will be to remove the turbo, again, and see what, if anything, has gone wrong with it. This car starts and runs smoothly and quietly. The oil consumption has varied over the last month from 1qt in 1200 miles to 1qt in 100 miles just recently. Crossover is wet with oil but looking down into the intake valves (intake removed of course) they don't look wet in fact, it look clean down in the intake ports.

While I'm tinkering with this '91 I've pulled out the '84 SD and started driving her again. Man, that 5cyl Turbo sounds so nice. What an engine!