Hi Genvibers,
I’m wondering if there are still some folks here. It used to be my main source of information when the time came to fix my Vibe, so hopefully some people are still here! I’m having a problem that I can’t manage to resolve myself and for which I’m now clueless, so I’m trying here if you guys can give me some help.
My car is a 2005 Pontiac Vibe with the base engine. There is a smell of exhaust that enters the cabin when the car is on idle (at a red light for instance) and the heater fan is on (whether it’s for the A/C in summer or for the heater in winter). When I’m driving with the fan on, there is no smell and when I’m on idle and turn the fan off, there is no smell either.
Several research pointed out a leak somewhere in the exhaust system starting in the exhaust manifold. To troubleshoot it, I taped a shopvac in blowing mode in the exhaust pipe, and I sprayed soapy water all along the exhaust line. I could detect small leaks at both donut gasket, the rear flange and the one between the exhaust manifold and the first catalytic converter. The leaks were not that bad, and one would assume that there is a certain amount of leak all the time in these joints, but anyway, not seeing anything else I decided to replace both donut gaskets. It was a hard job because the bolts and springs were rusted. But with a lot of effort, PB Baster and heating, I managed to replace both donuts and their bolts & springs. I took this opportunity to repaint all the line from the resonator up to the tail pipe since this section is aftermarket and was rusted (living in Canada). By the way, I need to specify that I couldn’t find any leak on the exhaust manifold, despite it’s not easy to check for leak on it. In addition, I’m not hearing any clicking noise characteristic of exhaust manifold leaks.
Then, I reinstalled everything and I tightened the bolts as much as I could. Unfortunately, the smell problem in the cabin was still there. It is maybe slightly lower than before, not sure, but it’s still there. I checked again with the shopvac and the soapy water and I could still see bubbles near the donut gaskets. I was a bit frustrated, but I started wondering if it’s possible to completely remove any small crack there. After all, these are mobile parts so should we expect absolutely zero bubble when pushing string air from a shopvac? I would certainly like to check on another car without issue to see if I can see bubbles the same way…
So now I’m kind of clueless on what could be the problem. The donuts and bolts are new, I can’t see any leaks in the exhaust manifold, I don’t know where to look now. I discussed that with my local garage and the guy said that he would not know what to do more than what I did… This is why I’m now asking the community, in the hope that someone here has seen this problem before.
Hope to read you folks!