Date registered: Jun 2007
Vehicle: Ex 202.028, 124.028, 107.045 (with 117.967), 129.067; now 163.154, 203.764, 129.066
Location: So. Cal.
Mentioned: 0 Post(s)
Quoted: 45 Post(s)
Hanno: I will assuredly walk away, but not without at least trying to get some manner of resolution if the problem is indeed with the valves. I do want to get a definitive (or at least very strong) third party diagnosis, though, before proceeding. I had a long talk with the mechanic and was able to get a commitment at least not to charge any top end R/R if the block is indeed the problem, but at the same time am skeptical that some fiddling around could be done with the valve seals and guides at disassembly to give the appearance that no problem existed in the first place. Since the machine shop is contracted by the mechanic, he could go ahead and have them fulfill their end of the warranty, and he still gets a new job by replacing the block (if he even does so). This way he's not out the labor for the first time around. Perhaps too elaborate of a scheme, but given how this has dragged on, not an unreasonable way to think.
Dolucasi: Well, I went there to collect the car and it had a puff of smoke. Just like on the day I picked it up after the head job in April, he said "that's all the junk that's built up in the motor, it will burn off." I said, "you told me that the first time and it never went away." I did ask specifically why he felt that the rings were at issue when the plugs were fouling and the compression was supposedly good. His answer was that all six plugs were fouled and that it's "impossible" that all of the valve seals were done improperly.
You mention this leakdown test. Is this, along with a compression test, a definitive means of diagnosing whether the problem is with the top end or bottom end of the motor? I want to be able to go there in a couple of hundred miles with some neutral but very clear data indicating where the problem is on the motor. If the bottom end is strong, I want to be able to say confidently, "I think you need to take the head off and focus on that instead of the block."
I'm not sure I will proceed with the bottom end at this shop (or at all) if this is indeed the problem, despite the offer not to incur any further top end expense. As Hanno suggested, there is a time to walk away.
Trevor: I'm not a mechanic but is there any way to determine the condition of the piston rings while the head is off and the block in situ? Or are we limited to what can be assessed visually, which now that I think about it, would only be the crowns and cylinder walls, correct? Nevertheless one of my contentions was, why didn't they see a problem with the bottom end during the month+ they had the car torn down? Oil burning is a difficult pill to swallow after all the work I had done, and all the more so when the car didn't burn anything before this episode.