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Join Date: Nov 2013
Location: Denver CO
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TrAvus Blue M5; Head Gasket Replacement
I had my M5 at the local shop looking over things. The main reason I had it into the shop was to locate leaking fuel lines. I got a strong smell of raw fuel after having her out a few weeks back. Turns out it was some lose hose clamps and old hoeses. But while it was there, I asked them to investigate what I suspected was a leaking oil return valve. I'd get a drop or two of oil on the garage floor after every drive. After cleaning the area, and checking the return valve, they confirmed this wasn't the main culprit. But still leaking slightly. They proceeded to drop the transmission for further investigation, and it turns out it is the head gasket... sweet. I've got a good leak around cylinder 6. Although oddly I didn't have any of the typical symptoms, overheating, oil in the coolant, missing coolant, smoke, etc. So, it seems I've avoided catastrophic failure.
I've got the car lined up to go to a local engine builder next week. He's fairly well known in the BMW community here in Colorado and someone I trust. But he’s a one man shop and I’ve had to wait two months before he had time to get to my car. So I want to do a more comprehensive engine service this go around
The plan so far is this;
Replace head gasket (of course) and rebuild the head. New Valves (at least intake), machining. I've asked him to review timing components and check the cylinders, rings, bore, etc.
What would you all recommend I include in the rebuild? Last year I had the oil pump, rod bearings and the s50 tensioner installed due oil pump failure. So it would seem the bottom end is in good shape. But we didn’t get as deep as checking pistons and rings. The bearings were in need of replacing but it's hard to say if that is because of the short time the engine ran without oil or they were just due. The crank showed some minor scoring on cylinder 4 but my mechanic polished it the best he could before putting the new bearings on.
So what would you do in this situation? I’d like to do the while you’re in there repairs. Had I done this when the oil pump was done I’d be enjoying the mountain passes right now. Instead of posting here. Basically, I don't want to be right back here in a years’ time wishing I’d done XY and Z. I’d like to bullet proof the engine (for a few years at least) this time around.