Coolant resevior rubbed against drive pullys and belts. Flashing check engine light

I stupidly did not properly replace my coolant reservoir after cleaning it. Found out today after my check engine light came on. The drive pullys rubbed against it enough to almost make a hole in the reservoir. After putting the reservoir back in the correct location, the check engine light stayed on. There is engine hesitation upon acceleration and the check engine light starts flashing even with mild acceleration. When I went to get it checked, I was told cylinder 3 misfire was the code. I suppose it is possible that the current problem is unrelated to the initial stupidity, but seems unlikely. Any suggestions?

2002 Impala 3.8L

I can’t see any relationship between the coolant reservoir rubbing the drive pulleys and your cylinder 3 misfire. If you didn’t get your coil packs wet while removing the reservoir…I just don’t see any connection. Have you checked to see that your spark plug wires are secure?

Don’t feel too badly about this. You made a mistake but that does not make you stupid at all. Even the best mechanics have made mistakes; some minor and some not so minor.

The current problem is likely not related to the resevoir bottle and the first thing to consider would be something like spark plugs and/or wires; especially if the plugs have been in there a long time and the wires are originals.

One thing that is important is to not drive it when the check engine light is flashing. To continue to do so can cause unburnt fuel to build up and cause your catalytic converters to overheat, eventually damaging or destroying them, and possibly even causing a fire.

I also don’t see how your problem could be directly related to the reservoir problem, but let me ask you this: Why did you clean the reservoir? Was it full of an oily scum? If so, you may have other problems, such as a bad head gasket, which certainly could be the cause of the misfire. How does your oil look?

Thanks for the responses. The oil looks ok. The resevior looked pretty nasty and so did the coolant right under the radiator cap. After draining the coolant, the rest looked fine though.

I went ahead and replaced the spark plug wire and spark plug for cylinder 3 today because it was a fairly cheap and easy thing to do. Drove it for 5 minutes and it seemed a little better, but I still had hesitation when I attempted to accelerate really quickly and the check engine light started flashing again. Thinking about trying some sea foam or other type of cleaner next.

Maybe another cylinder is acting up or the coil has gone bad for that particular cylinder.
With ignition components it often works like a line of dominos. Tip one and the rest fall.
In this case a bad spark plug can lead to a failing wire which can lead to a failing ignition coil.

Verify whether or not the CEL is coughing up the same code and if it is the same code, (and assuming the engine is mechanically sound) the coil could be suspect or the fuel injector.

swapped the coils to see if the problem would move to another cylinder. When accelerating heavily the check engine light flashed, but then went off. Thought the code would still be stored when I went to go check it with a reader, but there was nothing there. I guess for now, I will continue driving it until the code comes on and stays. Just don’t want to mess up my cat by having really bad misfires though.


I suspect the guy that tried to retrieve the codes was incompetent or used a POS tool

He should have trying to retrieve stored fault codes

There may not have been any current fault codes to retrieve

He may also have been using a POS tool which wasn’t capable of retrieving the codes from your car

Your spark plugs are due every 100K. Unless I hear otherwise, I’ll assume you’ve already reached 100K, or more, by now. I would replace all of them.

If that doesn’t help, you need a pro to take over.

Read out codes and live data
Read out freeze frame data
Fuel pressure test
Fuel injector balance test

Was the plastic coolant bottle jammed into the pulleys, so they couldn’t move freely, or just rubbing against them? If the latter, I doubt the doubt the CEL is related. Good idea in any event to replace the plastic bottle with a new one. In the meantime, monitor the coolant level and when driving, the engine temp gauge for any signs of overheating.

If this were my car, first thing I’d do is bring all the routine maintenance suggested in the owners manual up to date. Will probably save you time and money and aggravation in the long run.

If it is of any help to your ego, I should say that one time I rotated the tires on my car, and got a phone call in the middle of the operation, and in the process forgot to fully tighten the lug nuts on one of the wheels. Made for an interesting driving experience on my way home from work on the freeway the next day!

The misfire moved from cylinder 3 to cylinder 5 after swapping the coils. Went ahead and replaced the offending coil and it all appears to have fixed the problem. Thanks everyone for your help!!



Glad to hear it and appreciate you letting us know.