Took my 850 brick to have it smog tested, when the technician, put it on the dyno. it over heated???? It has never done that before... he would not test it, so I filled up on antifreeze and drove home... everything worked fine. I replaced the fan relay and thermostat and every thing seamed ok... when I took it back to the test facility and the tech. put it on the dyno it over heated again????.. Every thing check out ok. Put in a radiator. The fan seams to run well. Could this be the problem???? Has anyone else had this problem???

FYI it has 157,000 miles.

I took mine through a large state inspection station, about 7 lanes!

When my car was dyno-tested, they rolled out a large, industrial strength external fan and placed it in front of the radiator, but I don't think all the cars that went through were treated to the fan! In fact, I'm pretty sure they DIDN'T use the exernal fan when they tested my kid's RWD '88 Merc which is equipped with a mechanical fan which varies directly with the engine's speed. I'm not sure that the sort of airflow that you get at highway speeds is the same as that provided by the car's electric cooling fans, which I think run at a constant speed. Has the tech done emissions testing on a Volvo before?

-Punxsutawney Phil

BINGO!!!!!!!!!!!!! Took it a station that does a lot of Euro. cars. He said that if the car is idling it is ok to let it stand, BUT, if you run the engine under load.. Like a smog test then you must provide moving air as the fan will not move enough air by it's self. 30 mph is the minimum.

Many thanks. the car passed AND KEEP IT' COOL..........

You can check the fan highspeed and lowspeed operation by grounding the yellow wire going into the fan relay for highspeed or the yellow/white wire for lowspeed operation. If the fan works when you ground one of these wires then both the fan and the relay are Ok. Is the temperature gauge on the dash working correctly? Meaning is the sensor from the motor working correctly? It could end up being the engine computer itself but I hope not. You can take it to a good independent shop that specializes in european cars and they can probably troubleshoot it pretty quick for you. A good scantool can manipulate the computer to test sensors and find the bad one quickly. Good luck ........ Mike