Join Date: Jul 2011
Location: Czech Republic
County: Hlavní město Praha
Turbo going mental in low revs
Right, I'm not really sure whether this should go in the engine forum or here, but here goes.
I just bought a used 2007 147 1.9 JTD 16v. When I was test driving it, it felt great and seemed to have no problem.
Now when I drove it home, I sensed an odd hesitation when accelerating in first and second at about 1200-2400 rpm. It would have a kind of stammering power delivery in that range, where the power would come in short lumps about half a second long. I investigated today and found that if I hold it at just over 2000 rpms (it does it sooner, but at 2k you can really feel it) in first or second, the engine won't maintain constant revs, and I can repeatedly hear the turbo "blow-off" sound, despite not removing my foot from the throttle. It almost feels like a cylinder isn't running. However, when I venture above 3000 rpm, the problem completely disappears and the engine feels tight as a drum.
When I let it idle, I can hear the engine coughing a bit. The exhaust seems to increase pressure for less than a second every 3 seconds or so. I also hear a kind of harsher tone when increasing revs from idle.
My theory is that the turbo is stuck in the high boost mode, or there might be a leak somewhere. I'm contacting the local alfa dealer, but as the car is used and the warranty is long gone, I'm a bit spooked and want to know what kind of issue I'm dealing with...
P.S. the search function revealed no people with similar symptoms.