I think this is surely one of those issues where the best practice is to adjust on a cold engine because of the nature of the metal parts and the changes in dimensions with heat (no argument there). Certainly they didn't wait overnight to adjust the valves, would they? (before my time). I'm thinking of back in the day when you'd take your car to a mechanic for a service. So the 'correct' clearance for the first valve you do is different from the last valve.Īlthough I don't think many could argue that the 'correct' way, or 'book' way is with the engine dead cold, wouldn't there be some convention to adjusting them warm? As it cools down those critical dimensions are changing. The problem I see with adjusting valves on a hot engine is that everything starts cooling down the moment the engine is shut down.

And it's not very fun to do hot - you best wear cloth gloves to avoid getting burned. However I only ever alter them hot if they are way off and then I'll check them the next chance I get cold to see what they read then. I have checked valves hot before - but only in certain circumstances - valves that are unusually noisy when warmed up and also when I suspect a valve of having tightened down to zero clearance. I have never heard of a mechanical engineer on this site – maybe one will show up.Īrgue it up boys and girls PhD here in Mathematics Wow - boy will the knuckledgragon purists appear on this one - along with some others that seem to believe that everything should be done like the factory in 1939. Then run hot to same temp and adjust hot. I am sure that the lash is much less but how much less could easily be accomplished by adjusting at 004 when cold then run it until it is hot them measure it - I t might come down almost to zero but all VW's clash even after hot. I am not so sure that adjusting while cold is the real answer - although 99% of the vw hobbyists and mechanics claim that.Įach piece of metal expands at a different rate and value and the car performs at 200 or when it is hot so the best would be to adjust while hot.

Sure it can be done but wont be acurate wait till you can do it when its cold so it is uniform.ĭo it when the engine is cold, why second guess it? View original topic: Warm valve adjustmentĬan I adjust the valves when the engine is still warm? If so what setting? 1972 Beetle 1600cc. :: View topic - Warm valve adjustment Forumsįorum Index -> Beetle - Late Model/Super - 1968-up -> Warm valve adjustment

Ej20 engine valve adjustment