View Full Version : HELP, Got a wierd one for you guys

12-03-2009, 12:30 PM
Recently noticed that after my 99.5 A4 (2.8 30V) idles for 10-15 minutes, the thermostat gauge only goes up little over one quarter and stays that way, (instead of the common halfway point), if that isnt enough, the oil temp gauge goes up one quarter also, ... and my gas gauge will read correctly and then randomnly shoot down to empty, the low fuel alert beeps, then it randomnly shoots back up to the correct level. ???? Im hesistant to drive it, because I dont know if it will overheat or if its the guage cluster, it has 136K and has had all maintenance done on it, however it has sat for 6 months. ???????help, Im sure someone's seen this before.

12-03-2009, 12:59 PM
I am not sure how hot the oil/coolant is supposed to be after 10-15 minutes but for your fuel level, I would check your fuel sensor. I am not sure how the gauges on these are fed, I would think each gauge is independent of the other but, if someone could chime in it would make it more clear.

Also is the car idling correctly?


12-03-2009, 02:36 PM
Try replacing the coolant temp sensor. Its a very common problem on the B5. And like John Gutmannn said, fuel level sensor could be your culprit. I changed mine for the third time already but It's still doing it.. Im gonna change the connector this week so hopefully that would fix it. Better yet, get a hold of someone who has a VagCom in your area just to be sure. The regional section here should help.

Does your fuel gauge go to zero when you step on your brakes as well?

12-03-2009, 02:57 PM
check your sensors and thermostat, im doing mine right now actually

12-03-2009, 04:01 PM
Oil is normal. Gas gauge is likely the sender. Try thermostat and coolant temp sensor like has been said. That should be all you need to know.

12-04-2009, 05:33 AM
IF your gonna check your thermostat, when is the last time your did your TB?


12-04-2009, 12:39 PM
timing belt was done a year ago, its been sitting so hasnt been many miles, the car has had everything outside of the engine replaced . So is oil temp gauge at quarter level (first notch) normal? The gas gauge shoots up and down randomnly alerting the low fuel tone. As for the thermostat gauge, at idle its been consistently only going up one notch instead of two(halfway), and last night I drove it a couple miles and it never went up at all, I didnt notice any smoking or smell. Is it possible it can be something in the gauge cluster?? Also does anyone know any sites with detailed breakdown of this engine (2.8 AHA) and a walkthrough for thermostat and coolant temp sensor replacement?