Question, When sitting in traffic I have experienced twice this scenerio.
While stopped in drive, car warmed up, Water temp increasing, all of a sudden the car would surge and rpm's become erratic. Then there is a miss fire when you start driving. Car kinda chugs a bit. Now if you let the car sit for a hour or so it runs just fine. This has only happened when the car finds the water temp climbing. I also now have the water level light comming on every once in a while. Antifreeze levels are fine. I've never had it overflow on to the ground. Never overheated. Just kinda weird. No smoke out the exhaust, no sticky oil, no ses light, I'm at a loss. F.Y.I , car is 94 a4 lt-1 107,000 miles. Suspect motor work done, No idea if the opti has been replaced. Anything else I can give for info let me know. Thanks in advance.


Jim

 

About the Coolant light coming on and off.... I have a 95 Z28 and when my coolant lever sensor was going out it did the same thing. As soon as the coolant got to a certain temp it began to turn the low level light on and off..

I took it out to clean it and it never worked again ever since. I finally disconected. Do a search I am not the only one with the same problem.


Marvin

 

Jpack- As far as the level light is concerned, get a new sensor. They go bad often. Be sure the coolant level is correct. Next, check the operation of the fans. See if it comes on by itself as the temp rises, and that it comes on when you engage the AC. Then have the sensors scanned to see what temp the PCM sees from it's sensor and compare that to the temp gage in the instrument cluster. Remember, the gage uses a different sensor then the PCM. Not absolutely sure about your problem but I've seen defective coolant temp sensors that make the PCM think the engine has not warmed up and causes the engine to run poorly. Since it takes very little effort to scan it, it's worth the time.

Dave