Hi all! I have a 1994 960 and now that it is summer time and the weather is finally get warm I have been noticing an issue with the car. After driving around lately not for anymore than 40-50 miles the coolant seems to just evaporate. For instance today I was out and about doing errands and I noticed the smell of coolant and the low coolant light came on the dashboard. Mind you, I have been smelling coolant (esp. when its hot out) now for a couple weeks, the car never overheats though... I add coolant (the Volvo stuff, of course) and continue on my way. I do know that the car had a heater core put in not much more than two years ago by a previous owner. I am not getting any fog on the windsheild and my floor mats are totally dry. Any thoughts or suggestions of things to check are much appreciated. -Matt

The usual culprits on these cars with the B6304 engine is the black, plastic, upper radiator hose connection. The plastic fatigues at the bottom, where the plastic neck connects to the radiator. It's hard to see and sometimes only leaks on hot shut down but check this area closely. If this area is leaking you will need to fix it asap since they are known to catastrophically let go and engine damage can occur.

The other culprit is a bad coolant reservoir cap. It's hard to tell if their cracked and you may never see any coolant in the engine compartment but it will evaporate on hot shutdown. Napa sells them for about $7 last time I bought one (the blue-green cap).

DEWFPO
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1998 S90 083,228 and 1995 964 154,100

Dear Matt,

May this find You well. You should check:
(a) clamps on heater hoses (which take coolant to/from the heater core): if the clamps have worked loose, coolant will drip out. As the hoses are close to the air intake, some vapor might find its way into the cabin
(b) the heater valve (in the heater hoses)
(c) the automatic transmission fluid (ATF; it should be a clear, rosy red). If the ATF is cloudy or milky, the in-radiator ATF cooler has failed. At once replace the radiator and flush the ATF. Water in the coolant will dissolve the glue adhering clutch material to the facings, ruining the tranny.
(d) cooling system integrity via a pressure test (this needs to be done carefully, i.e., with a modest amount of pressure [see Site FAQs]).

Hope this helps.

Yours faithfully,

Spook

It's either leaking externally somewhere, or it's going out the tailpipe. I had a similar issue with my '94 960. I was able to diagnose and pinpoint an external leak by examining the car after shutting down the hot engine. Since the closed cooling system was still under pressure, I could hear a faint hiss where the steam was coming out.

You didn't mention how many miles the car has, but my money would be on a head gasket that's letting go. That's what eventually sent my car to the scrap yard, since it wasn't worth the investment of pulling the head and replacing the head gasket. In my case, the coolant started seeping through the gasket at the rear of the head. The other possibility is that the gasket could allow the coolant to seep into the combustion chamber and there would be no visible sign of external leakage. In this scenario, depending on the volume, you would see some white smoke in the exhaust.

Good luck finding the problem. Hopefully, it's an easily-fixed external leak. BTW, how old is your radiator? They usually last around ten years and then start to fail. Assuming it has a plastic head, have you examined the hose inlet at the top for hair-line cracks? That's rather common for this car. If that's all it is, I have a new, in-the-box, CSF radiator that I never installed in my car.

rwregan- the car has 154,000 miles on it now. I just took it for a 100 mile road trip and on the way up there my low coolant light came on so I pulled over and added more then continued on my way. I did notice however when going to pass a truck a cloud of white smoke billowed out the exhaust pipe under heavy acceleration, this only happens under heavy acceleration though. On the way back from this trip I checked and filled the coolant before I left and it was still full when I got the car home. Did not over heat at all- either way. I did notice that the hoses behind the head on the fire wall that go into the heater core (black hoses X2 heater hoses?) appeared to be wet and you could see evaporated coolant on the top of the engine and the firewall- not alot though. That would explain the coolant smell in the cabin but not the smoke... Any other thoughts? Thanks!