CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

96 Corsica V6 chugging problem

This problem has been going on for about 4 1/2 months. I’ll try to describe more specifically the problem. When I start the car, it turns over fine, but when I put my foot on the gas pedal there is a non-response or a delayed response. Then when I shift into gear there is a hesitation to move either forward or backward, even with applying even pressure to the gas pedal. The hesitation is usually followed by an “over-rev” sound, and lack of control over the speed (if I weren’t holding down on the brakes) for a moment or two. This continues for 30-60 seconds of driving time. A few times the car has died before I was able to switch between the brake and the gas enough to keep the pressure on. After the 30-60 seconds, the car drives fine, even when idling at a stop. I had a new fuel pressure regulator (non-OEM) and a fuel filter (OEM) put in by a local shop. Then I put a mass airflow sensor in myself about a month and a half ago. I haven’t worked on the car or had it worked on since a month ago, when I brought it into a second (more highly respected) local shop and the problem wouldn’t recreate itself for them. They tested a bunch of things, and said the car tested fine and to bring it back when the problem gets worse. The respectable thing about that treatment by the second place is that they didn’t charge me, though they spent at least an hour or so testing and inspecting various things. I can give more info about the various issues that the car has besides the chugging problem if it would be helpful. Just looking for a little direction. Thanks

It sounds like you may have two different problems. It’s kind of hard to tell from your description, but it sounds like the car will stall on you, and it also sounds like when you put the car in gear that it won’t move for a few seconds, even if you rev the engine.

The stalling could be a number of things. Is the check engine light on? Have the codes been read?

The not moving is kind of worrisome. Have you checked the transmission fluid? Is it full? Has it ever been changed on this vehicle?

I assume that idling time does not help, that you cannot just run the car in idle for a few minutes when you start it up and the problem goes away. If that is not the case, try just warming the car up before driving it.
Otherwise is there any difference in dry weather vs. wet weather? I had a similar surge and stall problem with my Ford Taurus and it turned out the fuel filter was getting wet and grounding out in wet weather. I also replaced the mass air flow sensor because that was a likely cause for the problem. I had the car towed twice and no one could find anything wrong with it - because the car had dried out by the time anyone got a chance to look at it. My problem was a stolen and missing radio antenna and the resulting hole. It took a year or so for the problem to start up, but that was the problem. I solved it with some duct tape over the hole.

Thanks for the quick response. To clarify more, when I put the car in gear the transmission shifts fine and the car will move, it’s just that the chugging continues and makes the car bounce a little as it’s backing up or pulling forward. I’ve never driven the car very long in reverse. It feels like it will die sooner if I don’t switch it to drive fairly quickly. I have experimented by leaving the car in park and just revving the engine. The problem does not go away as quickly if I do this, and usually results in a pretty big over-rev before it settles down.

The check engine light came on once, for less than a day. I got the code checked and it said, “Definition H02S12 circuit condition (heated oxygen sensor bank 1 sensor 2) Explanation The powertrain control module uses the oxygen sensor to calculate the Air/Fuel ratio in the exhaust. Probable cause 1. Oxygen sensor defective 2.Fuel system running very rich or lean-check other codes first 3. Engine misfire condition-repair 4. Fuel pressure very high or low-fuel pump or pressure regulator.”

The transmission fluid is full. I don’t know if it has been changed. When I bought the car in Dec 2009 my mechanic said the trans fluid was black. I’ve since looked at it and I never see any color close to black, but I suspect there is a need to get the fluid changed just to be sure. I’ve asked a number of mechanics whether or not to do a trans fluid flush or just drain and refill. There are differing opinions-the reason for not flushing seems to be that the car has 205K miles on it and flushing it might cause more damage than good if the transmission isn’t causing problems. I don’t know. I just hope I can get to the bottom of this soon because the 2 attempts to fix the problem have cost me over half of what I bought the car for, and in the meantime the front brakes are at less than 20%. Should I trust the code and replace the O2 sensor? Thanks

As I described in my reply to “oblivion”'s post, idling seems to be a little worse than driving because of the really loud over-rev that results.

Thanks for sharing your experience. I live in Minnesota and the problem was the same in sub-zero degree weather, as in 50 to 70 degree weather. The problem does not change in snowy, rainy or dry weather. Thanks for your response. Let me know if you have any more thoughts with this added info.