1997 850 overheating

cynlim · Post by **cynlim** » 05 Jan 2015, 18:12

My water reservoir bubble and hiss even after a short drive. The radiator was working fine after a new replacement in April. Is there air in the radiator? The water pump was changed two days ago

Post by **tryingbe** » 05 Jan 2015, 20:37

Sounds like a blown head gasket.

Was the car overheated badly?

Post by **erikv11** » 05 Jan 2015, 23:00

Agreed, could be a head gasket, it could also be as simple as a leaky cap on the reservoir, has the cap ever been changed?

Post by **misha** » 06 Jan 2015, 05:00

Remove the cap from expansion dish and let the engine idle.Wait untill it reach operating temperature and wait untill cooling fan kicks in.

Maybe you have air trapped in the system after recent radiator & water pump replacement.

If this not help,then you have a bad headgasket or replacement water pump is bad.

Did the car overheat before water pump replacement?

draser · Post by **draser** » 06 Jan 2015, 09:10

If coolant boils in exp. tank that means the cooling system is not pressurized. The pressure in cooling system prevents coolant to boil at 100 deg. Celsius. That said your system has leaks somewhere, most common places are, like said, rad. cap, hose clamps, water pp. If your engine starts, idles and runs okay your headgasket is good. However, the overheating needs fixed fast otherwise hg will go bad.

Post by **xHeart** » 06 Jan 2015, 10:08

misha wrote:Remove the cap from expansion dish and let the engine idle.Wait until it reach operating temperature and wait until cooling fan kicks in. [watch fluid circulating through the expansion tank - practice safety!]

Misha's method works for releasing trapped air.
You may want to run few cycles.
I prefer using Volvo's fluid for few $ more.

Was the thermostat ever replaced? ...Sensor?

cynlim · Post by **cynlim** » 06 Jan 2015, 18:48

Yes, the car was overheated badly and almost died on the road two days after I took it back from the painter's. The expansion tank was all brown and the mechanic found a blockage at the tiny hose on the tank. He flushed the radiator and put in several gallons of water. The cap on the expansion tank was not changed but he recommended to change the water pump. It was not leaking before that. He said the trapped air has been released. After that the temperature gauge is on midpoint and stays there when I drive but the engine oil and abs lights keep coming on and off. There is a vibration which can be felt on the steering wheel. My new set of volvo spark plugs were soaked in oil. I have them cleaned and put them back. It starts fine now with much less noise from the engine but the expansion tank still hisses after a short drive. I'm just wondering if the oil pump or switch that's triggering the oil lamp or is it the ignition switch. I didn't have these problems before the car was left in the paintshop for three weeks. The first time I drove out of the painter's I felt something wrong with the car, it seemed to rattle on reverse gear. The painter told me he opened the bonnet and flushed the engine compartment with water and cleaned the wheels with some polish and liquid chemicals. Could he have caused some damage with water and chemicals leaking into the brakes? The abs lights stayed on permanently for a couple of days, now its coming on and off randomly.