4 replies to this topic

[Harrison541]

I've had oil leaks for a while, as you'd expect really, but last year I took the engine out to seal up some of the worst areas with new gaskets. It mostly worked, leaving a small drip from the timing chain cover, that gradually got worse and worse till 2 weeks ago when I replaced that gasket. Now oil seems to blow out of everywhere, some of the gaskets being only a year old.

 

The breathers are clean (although the one on the crankcase did look like an Americans arteries before cleaning it), and I can feel air moving through them if I take the hose off.

 

I was told that if the rings were worn then the pressures of combustion could be pressurising the oil and forcing it out, which would fit because the oil doesn't drip out when the engine is off.

 

I wanted to see what you lot thought, is it engine rebuild time??

 

[Cooperman]

Do a compression test, cylinder 'leak down' test, and oil pressure when 'hot' check (should be 50 psi at 4000 rpm as a minimum).

That will determine whether a full re-build is needed.

[Harrison541]

I did do a compression test not so long ago and the results were:
 
Dry/Wet
162/175
168/180
175/178
160/172
 
To me this shows slight wear but only a small amount. Although I was told that a compression test measures the peak pressure the engine can create, if there was a scratch lower down on the bore, it mightn't seal up fully towards the end of a power stroke, and could be leaking there. As long as it seals up tight in the top half of the bore then it will give a good compression reading?
 
The oil pressure is about 70PSI when cold and down to about 30PSI when up to temperature.

Edited by Harrison541, 17 May 2014 - 08:07 AM.

[Gremlin]

I'm guessing your crank case breather isn't plumbed into your inlet?

[Harrison541]

It's plumbed into the carb.