02-16-2013, 02:14 AM
Join Date: Apr 2010
My Ride: '02 330iT
| As some of you know I have been fighting with pinging since I built my car. The problem is I bought used engine and never ran it without the compressor.
I tried different ESS tunes, lowered the boost with 85mm pulley, tried octane booster but the engine would ping when going from cruising to boost and also under heavy load in higher RPMs.
I suspect the used engine had previous problems resulting in screwed up valve timing or higher than normal compression ratio (typical for overheated engines with repaired heads).
I gave up troubleshooting for few months to let the bank account recover
bought a tank of race gas ($20 per gallon of unleaded 104).
For the first time the car runs right.
From here the plan is to verify the bottom end is ok with compression and leakdown test.
If that's ok I'll check the valve timing.
Next step will be all sensors (O2, temperature, MAF) and valves (ICV, TB ...)
I expect that will solve the problem.
If not I'll look into meth/water AFTER the compressor.