I brought my Treg to the dealer with an overheat story. Of course, what I describe to the service desk never gets through to the mechanic. My overheat was on a hill climb 3+ hours into a drive into the high sierras of CA. I requested a coolant flush with my regular service appt...they tell me that the Treg holds pressure and they test drove it and found nothing wrong. I tell the service desk, why did you test drive it? You couldn't possibly have recreated the condition on a local drive.
Over the next few weeks, I continue to slowly lose coolant and I overheat again on the 5hr+ trip into the sierras. I describe it to their desk again and meet with technician, he says "It's gonna be a tough case." I left it at that and did some good 100k maintenance of my own t-stat, water pump, belt. Problem persists, slow coolant loss.
Last weekend, I overheat a third time and prior to taking it in for a service, I deploy my new air purge tool and see that the reservoir is not holding pressure. I report this to service desk, it it written on my work order. I call to see how its' going 4 hrs into my service and tech had reported to service desk that my car is holding pressure and the service should be over soon.
Is it possible that a positive pressure test would seat the failing gasket, where a negative vacuum pressure test would fail?
I drove straight down to meet with service manager and he brings in his head mechanic. We cordially discuss my failed test and their description of a passing positive air pressure test. I show them my air purge tool and request that they flush my coolant and report on the coolant reservoir holding pressure in a vacuum. I had to describe my overheat to them again, since they had mentioned a road test and the codes being non specific, they even ask me if I really overheated, like I imagined boiling over the reservoir and spattered all that coolant around to deceive them?
The head mechanic asked if the temp gauge just went up a little or did it redline? I accused him of wanting me to torch this engine. He complained that it could be a number of things and that I might be dissatisfied with them for replacing the turbo or EGR and not fixing the problem. They know full well I have an extended warranty but they want to avoid condemning a part and being wrong about it. Why wouldn't they just want to get it right?
If it is the turbo, they should be able to isolate it and presure test it? Same with any other component like the EGR? Everyone I speak with says head gasket, like it is obvious. The dang codes should even tell them which bank is losing exhaust into my coolant since P011300 Intake air temp bank 1 sensor 1 circuit is high and P220100 NOx performance Bank1 sensor 1. I also have P023800 Tubocharger boost sensor (A) high inpiut, P010400 Mass or Volume Air Flow intermittent.
Head mechanic looks at these codes and say, your scan tool is aftermarket and these codes are non-specific. It could be anything...this is when he started saying he would be guessing if he condemned the turbo...and I would be disappointing we wasted money on it.
Anyone want to render an opinion?