I have a problem with my VOLVO 960 wagon during mountain driving only. Climbing long steep mountain highways for more than 2 miles at temperatures higher than 90 Fahrenheit leads to a sudden and rather fast increase of the temperature gauge reading into the red region. The only way to get the temperature reading back is to switch the AC off and to start the heater, which is rather unpleasant at those high summer temperatures. I have as well the impression, that under those conditions the car looses quite some power and becomes more noisy. My car is 4 years old and did not show this problem when it was new. The dealer was never able to reproduce the problem. Indeed, driving in heavy traffic in the summer with a lot of stop and go and idling in front of traffic lights while having the air condition on leaves the temperature gauge very steady at its normal condition. This is even true with temperatures above 115 Fahrenheit. The dealer has replaced the thermostat and the cap of the coolant reservoir, but without any change in this behaviour. The problem was checked several times, but without any success. No readings were ever found on the car computer.

Can you give me any advice on what this problem can come from. This behaviour is especially strange, because I have never seen the temperature gauge of a car moving so fast from normal to red (about 30 seconds). In case of such an event, I have always seen the fan running, and the dealer has checked that the second speed works, and the hoses were hot, but not rock hard. I have never seen coolant coming out anywhere.

This is a puzzle! I can't give you an answer, but it is important to know that overheating in this car with the aluminium block is extremely hazardous. This is why Volvo also installed a coolant level warning light....it wasn't to be glitzy. So if it was occur again, respond immediately with what you did previously. Do not wait. That said, the cooling sysyem is one of the most simple in design and operation in the car.

If there is any loss of coolant, put the system under a coolant pressure test, both cold and hot engine. If the coolant hasn't been changed in 30K (miles), change it with Volvo coolant and a new thermostat. Hoses and pump would be unlikely culprits at this age. It also may be that you would want to downshift to the '3' position while driving up those steep hills. This will keep the engine rev'd, fluids flowing and the tranny not working so hard.

Rainer,

The only thing I can think of is that your missing either the belly pan, or the air dam. These two thinks keep debris from flying up an messing the bottom of your car up as well as helping it cool. These are two plastic pieces located directly under the engine, and directly under the radiator below the air intake. What is your coolant guage showing are you full. I have a 96 960 sedan which is basically the same exact car that you have except for yours is a wagon and mine is not. I have my car on a track at least once a week at 120+ mph and have never reached above midpoint on my temp guage. When my air dam did fall off I noticed that the car would run a little hotter.

Brandon

You might want to think about putting in an oversized radiator in your car if you are going to put that type of load on your engine. If not, turn off the AC before you climb the hills.

Norfleet,

Were talking about a car that is made to cruize above 100 mph on the autoban. I have pushed my 96 960 to its limits and only twice had the car jump past the middle mark. One time the radiator hose blew up, as it was 4 years old an these hoses need replacing once in a while. The second time was when I didn't have the air dam in and the car just ran a little past the middle mark. I think his coolant is either old or non volvo.

Brandon