Discussion and questions related to the course Practical Reflash Tuning
Hi to all ...
I tuned a w210 e55 5.4 engine (10.5/1 compression )
Fitted with some kind of root supercharger , no intercooler with boost of 6 psi +methanol kit
Afr at wot 12 .
Timing advance 13-16 deg
It was light detenation around 4700 rpm , thats was eliminating by adjusting methanol spry to be earlier .
Problem that we got , at wot run sligtly engine oil comes out of oil dipstick ! What can cause this problem ?
Excessive crank case pressure.
Thank you sir
Is excessive crank case pressure result of boost or detenation ?
Can you please give more details ?
For diagnostic purposes, you should run a compression test (or better yet a leakdown test) and determine if you have one or more cylinders with issues.
Another useful tool is to stick a borescope into the spark plug hole of a cylinder and see what it looks like? I use this little USB borescope if I have any concerns:
There's a variety of situations that can lead to the dipstick popping up. Ultimately it's crankcase pressure however you will always have some crank case pressure and when you add boost this gets worse. I've had a number of older engines where the oring that holds the dipstick in had lost its tension because it had become hard and brittle due to heat. That's the best case scenario and a new dipstick can fix the issue. The more sinister possibilities include a broken ring land on a piston or the side melted out of a piston due to detonation.
As David has suggested, a compression and leak down test is the next step.
Thanks David , Andre ... Yes we lost compression at cylinder 1,2 may headgazket cause it !
Detenation took place at 2 runs before we solved it , can be fast enogh to damage the engine !?