Why is my compression so high?

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rodufuso
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Joined: 13 Jul 2020, 07:20
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Why is my compression so high?

Post by rodufuso »

Hi I have recently done a compression test due to smoke out the exhaust, that i'm pretty sure is oil.The smoke is a white/blue but I have an air-cooled 2.0 so its not coolant. The compression was between 130 and 150, 130 being the weakest cylinder #1 Compared to charts and other info this seems too high?Cylinder one also had the lovely surprise of an oily spark plug, so I'm looking for a leak but my compression is either ok or the test was flawed somehow, I did each cylinder twice. I also think the oil has been over filled by a mechanic (long story as to why i couldn't do it) so I'm thinking this might be a problem with the smoke but doubt it has messed up my compression readings? Any ideas?? Thanks

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937carrera
Posts: 3436
Joined: 05 Apr 2015, 19:29
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Location: N Yorks.

Re: Why is my compression so high?

Post by 937carrera »

Nope, not too high, but pretty good.

The smoke is probably oil burning as a consequence of valve guide wear on the cylinder with the oily plug.

Some things to do:
1. Drain any excess oil off so it isn't overfull
2. Start the engine, note if there is smoke on startup, which clears, or continues all the time
3. See if there is a puff of smoke when accelerating after running on the overrun for 20 seconds or so
4. Put the details of your van in your signature.

Welcome :)
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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