Hi all, I am new to here.

I have a 2000 S70 (2.3T) which lately I have been troubleshooting with an ODBII tool. I have the A/C off so that the cooling system is entirely controlled by ECU and engine temp.

At temperatures below 107 C, the fan remains completely off. At 108 C, the fan goes full speed and brings the temp down to 100 C and shuts down again. As I drive, the temp fluctuates between 90-108 C, but remaining above 100 most of the time as the other name for Bangkok is Traffic Jam Heaven. (A/C off as I want to test the system.)

My questions is, ain’t the fan suppose to be a 2 speed system? The Volvo dealer told me the lower speed only operates when A/C is on, but that does not make sense to me. Should it not be running at a lower speed first at around 100 C? Anyone have information on the cooling fan operating procedures?







Background info:

I see the fuel trim (with OBDII), increase gradually over the days as I drive till at hits 30%, then my car stalls and black smoke will be all over. I had to reset the ECU, bring the fuel trim to zero, and the cycle repeats. Sometimes if I am lucky, a code P1132 will be thrown (check engine light on) and the fuel trim will not hit 30% resulting in an un-drivable car. This problem has been with me over a year and Volvo Thailand has still till date not been able to fix this. They had replaced:

1. ECU
2. ETM
3. Thermostat
4. Vacuum hose and elbows
5. A whole bunch of gaskets all over.
6. Spark plugs gone bad with soot.
7. Up to 4 O2 sensors both front and back.
8. Water pump.
9. MAF Sensor.
10. Temp Sensor.
11. Turbo Valve.
12. My entire exhaust system.

... My conclusion that I have been trying to tell Volvo here but unable to communicate over is that, there is something wrong with the cooling system and thus when the ECU detect a slightly high operational temp, will increase fuel trim to bring down the temp. But since the temp is not going down on the average, the trim keep increasing until P1132 is thrown when O2 detects too rich situations.

And.. anyone here in Thailand?

 

Do you have any vaccum leaks at all?

 

Hi Tech.. .

Well, I don’t know if i can believe my Volvo dealers here now, but they claim there is no vacuum leak now. Previously, they had detected that the exhaust manifold gaskets had cracked and replaced it. And they had also replaced a gasket on the turbo.

 

I have an 854 2.3T and my fan works like yours. It only turns on high speed when it is really hot. Low speed does not turn on if the car is warm. Apparently low speed is only used to get air through the condenser and bring freon pressure down on the A/C high pressure side.

 

There has to be one somewhere or one of the new parts is bad.
A common leak that alot of people don't know about is in the hose form the MASS flow to the turbo. Where the valve is in the hose before the turbo. Usually it leaks around the valve.

 

Well... glad to hear form axelm that my fan is normal. And as for tech's comment on that hose.. i will check it out tomorrow, i have never checked that hose before. Carhas gone tothe workshop since yesterday.

 

Car has finally returned from the Volvo dealer. This time, they blamed it on some bad electrical connection. They said the O2 sensors were not properly connected and that they have fixed up the connectors.They claim the volatge levels meausred at ther O2 sensors were lower then normal (i think they meant the O2 heater line or something). They found no vacuum leak, no loose tubes.

Don't know if i can believe them. If all there is was a bad connection causing all my black smoke saga, i wonder why then did i paid for all the other replacements before.

Sigh....