Volvo S80 1999 - Strange, Stubborn Problem..

vick1w · Post by **vick1w** » 06 Aug 2009, 04:23

Hi, here is my story..

After running 2-3 minutes, 3 out of 6 Spark plugs stop getting signals and the car shakes, the Oxygen Sensor comes on, the "Urgent Repair needed" comes on.

After testing and taking it to three mechanics, including Volvo Dealer..

1. Changed the Front O2 Sensors.
2. Changed the Spark plugs
3. Changed the Air intake hose.
4. Volvo dealer put it on the scanner and changed the above accordingly.
5. Replaced 3&4 Coils - Scanner showed defective.
Still the car has a miss fire and rumbles and shakes.

the strange problem is this..

When I put a cheap Scanner and Reset the O2 Code.. the car works fine for couple of minutes and back to the shaking and mis-firing.

the only other possible problem could be the main computer, because when I reset the O2 Code, the car work perfect for 2-3 minutes and than starts the mis-fire..

three Volvo Garage Visits and after $$$$ of money and still, the same problem.. could it be the main computer that regulate the intake air/gaz flow???

can anyone out there had this kind of problem and possible resolution

appreciate your input

Post by **vegasjetskier** » 06 Aug 2009, 08:52

It could be the main computer. What codes are you gettting?

vick1w · Post by **vick1w** » 07 Aug 2009, 03:24

That is what I am suspecting as well, as far as the code, I got P0132, but after clearing that Code, and even with the O2 Indication up on the dash, there is no code showing..

a new computer is expensive, but I am not sure if I can find a used one or even if its worth to put a used one in. but with Volvo, specially this one in MOntreal, they will test and replace parts as per code, and even if it does not fix the problem, they will still charge me for that part and labor, eventually they might find the problem, but the bill will be in the thousands..

so is it possible to put a used computer, provided I can find one..?

Post by **vegasjetskier** » 07 Aug 2009, 04:28

vick1w wrote:That is what I am suspecting as well, as far as the code, I got P0132, but after clearing that Code, and even with the O2 Indication up on the dash, there is no code showing..

a new computer is expensive, but I am not sure if I can find a used one or even if its worth to put a used one in. but with Volvo, specially this one in MOntreal, they will test and replace parts as per code, and even if it does not fix the problem, they will still charge me for that part and labor, eventually they might find the problem, but the bill will be in the thousands..

so is it possible to put a used computer, provided I can find one..?

I believe the computer is linked to each specific car via software and only the dealer can program it (something to do with preventing thefts). I've read that the dealers will not put a used computer in - they make you buy a new one then they link up to the main computer in Sweden to program it to work with your car.

vick1w · Post by **vick1w** » 09 Aug 2009, 04:52

Thanks for the info.

I stopped by the garage, and at least he narrowed down the problem to heating. here is what we did with him,

When the car is cold and the O2 code reset. the card work like a clock, all 6 coils receive signal and the car is working normal.

but when the car warms up, one by one the coils stop receiving signals and the car goes rough, only 1,2,3 of keep receiving signals and 4,5,6 coils stop. leave the car to cool down and restart again, same symptoms.

seems that when car heats up, a signal or a sensor is going bad, no code shows on the scanner, until the O2 light comes up.

we repeated this three times on Friday, so left the car at the Garage for further tests, could be a faulty wire, switch? but it so difficult to find which one.. the saga continues.....

Post by **mvsuzr** » 11 Aug 2009, 07:28

Here's a couple of ideas:

Run it on a scanner and see if the problem starts when the controls go from "open loop" to "closed loop". This might help pinpoint the sensor(s) that are failing.

Check your wiring harnesses and make sure everything is tight and nothing has moved near a heat source. Intermittent connections can cause weird problems.

Try this one carefully or run it by a mechanic: Disconnect a sensor like the MAF, then run the car and see if it helps. I had an older escort that had a bad air sensor, and would hardly run. When I unplugged the sensor, the "limp home" mode took over and it ran fine... Replacing the sensor fixed the problem.
(Use this with care, it could potentially cause more problems!)

Good luck.