Club 80-90 Forums

Well I've finally solved the problem of the worn valve seats/inlet valves and low compression which has dogged my van for the past 3 years - lead fuel additive.
I've never used it 'cause I was told not to, that now appears to have been a mistake.

Not all engines were built to run lead free! I have one of them - 1982 CU T25/bay - my engine doesn't have hydraulic tappets! So it's a mix of two engines!!!!

I've read the threads on here saying that VW designed engines in the early '70s to be run on unleaded for the US market etc.

Just thought I would share this in case somneone else is having valve seat/compression problems which can't be explained.

Yep there is a lot of miss information about unleaded mostly relevant to the Bay windows. But all T25's where designed to be able to use unleaded.
As you said you have a mix n match of bits there.

Going on from the other thread.. I'd say any valve seat issues are more likely to the poor cooling thats occuring.. seats will receed with overheating etc.. even earlier aircooleds can run unleaded fine as the quality of the valves and valve seats has to be better becuase they see higher tepmeratures generally than watercooleds from the same era.. IF the cooling system is all in place and working correctly..

Double post Sorry

^ What he said ^

Can think of at least one CJ engined T25 that is running just fine on unleaded.


Tinware and cooling, it's important.


Good articles on fuel here:
http://www.vw-resource.com/leaded.html" onclick="window.open(this.href);return false;
http://www.vw-resource.com/octane.html" onclick="window.open(this.href);return false;