xxRiverHawkxx

Hello gang. I am currently in Largo Florida w/ my Audi. It has 197k on it - almost to 200k! Today we put a new O2 sensor in. My friend says there is four O2 sensors on the car. Is this correct. Also it was suggested to change out the water temperature sensor. My car is running rich and the plugs keep fouling out. Already put on new spark wires, fuel filter, rotors and distributor caps and now the O2 sensor. What will the water temp sensor do?

Thanks

5000CDQturbo

Hello There XXriver

I believe there is only two O2 sensors on the V8. Once this is changed try looking at the spark plugs again to see if there is fouling .

If Water sensor was not working it may give the engine a signal for rich fuel air mixture.

I would see if you can pull the codes first before you start spending lots of money on ideas .

see attached

dm
4.2 V8 summer car
5000cdqt winter car
Canada<ul><li><a href="http://www.sjmautotechnik.com/trouble_shooting/ecufv8.html">http://www.sjmautotechnik.com/trouble_shooting/ecufv8.html</a</li></ul>

audiqv8

Look under the car and see where the exhaust pipes forms a 'X' just before the catalytics converters. The O2 sensor is located there. It is a three wire O2 sensor (2) white wire, heating elements (1) black wire signal.

The 4.2L engine might have two O2 sensors.

The engine coolant sensor is located in the back of the right cylinder head (passenger side).

86 Coupe GT

4.2 only has one 02 as well.

audiqv8

I was thinking of the later A6-A8 which has a 4.2L engine.

You are refering to the older 92-93 Quattro V8

4x5x5

On a 1990 it should be a 4 wire, 3 in the main harness and an extra ground. There is only 1 sensor

xxRiverHawkxx

OK I am pretty sure my car has only 1 O2 sensor screwed into the back of the cat converter. We changed it out yesterday and the car seems to be performing much better. Took it on an early morning drive up Gulf Blvrd. The next small problem I need to resolve is why it hesitates when I push on the gas. I do not have a code tester but that would be interesting to see what failures are reading. I am going to replace that water sensor real soon since it is simple to do. By the way on my car (1990 V8 Quattro) it is located on the front driver's side on the engine block. Stay tuned for further updates as I try to push this car over the 200k mark OR into the gulf of mexico...

audiqv8

Is your temperature guage not working? Replacing the sensor on the "front driver's side on the engine block." will fix that problem. Quick test remove the connector and watch the dash temperature guage, it will start to go down if it was working. But if you are looking for the ECT (Engine Coolant Temperature sensor) then it is located on the rear right cylinder head. The ECT tell the ECU (Engine Control Unit) how hot the engine is and the ECU will adjust the fuel mixture.

BTW when was the last time that you changed the FPR (fuel pressure regulator)?

xxRiverHawkxx

All these damn sensors and gauges and control units!!! Yaaauurrgghh. What I want to do is to make the engine not run so rich and was advised to change out the water temp sensor. Some one pointed it out to me as being on the front driver side. Never changed the fuel pressure regulator nor did I know one ever existed... Just trying to push this car a little bit farther w/o busting my pocketbook.

audiqv8

Well as I have already stated the ECT is located at the rear right cylinder head.

For FPR go to the following link. Both the ECT and FPR can be causing your overly rich problem.<ul><li><a href="http://www.geocities.com/cobramsri/Regulator.html">FPR</a></li></ul>