I have a 1994 Acura Legend. Recently it has been overheating and is apparently low on fluid. I had an engine swap done at the dealership 50k miles ago ( they also replaced my radiator, heater core, water pump and associated lines). There are no apparent leaks and after I drive it for a while its down about a quart. There is no condensation coming out of the exhaust so I doubt its water jackets. I have done a combustion test to check and see if its the head gasket but the test confirmed that the head gaskets are fine. I revved it in my driveway increasing the heat to around 180 degrees and there is no dripping. I check underneath my car before I leave every morning / night and it's clean as well. Before I leave I make sure to fill it with mixed Anti-Freeze and after driving it for a day or two it routinely overheats and acts low on fluid. I'm baffled as to how its losing fluid and overheating as it is. Any all help would be greatly appreciated.
Both fans are working perfectly as intended. Forgot to include that.
September, 25, 2012 AT 5:27 AM
Somewhere there is a leak in the cooling system and a pressure test on the system should show you where it is coming from. A dye test would make it easier o detect.
Did you check the interior carpets for signs of coolant? A leak at the heater core would not leak outside.
September, 25, 2012 AT 5:35 AM
Interior carpets are fine and the heater core is sealed up tight. Didnt notice any leaks from it. I'll have to get a pressure test done. Another possibility is that the engine overheats when the thermostat fails to open completely and I've just been adding excess amounts of anti-freeze? I'm an armature mechanic at best lol. Completely baffled with this.
September, 25, 2012 AT 5:48 AM
Is the recovery tank overflowing or depleting?
You mentioned a combustion test, you mean a compression test or a chemical test to detect presence of carbon in cooling system?
September, 25, 2012 AT 5:51 AM
Chemical test to detect carbon / emissions. It came back clean. The recovery tank seems to stay the same but when the car overheats the radiator's basin is low on fluids. Or so I think, unless I've been over-filling it? Doubtful though. I appreciate the help! Thanks so much.
September, 25, 2012 AT 5:59 AM
When overfilling occurs, the only thing you would notice is that the recovery tank would overflow but the radiator should not be affected. There should be no air in system, meaning when you remove the radiator cap, it should show full.
How long has this been going on and losing a quart after how much driving time?
September, 25, 2012 AT 6:03 AM
Minimal driving time. I drive to college. Maybe a 40mile round trip doing 55-60 top speeds. The radiator itself is losing coolant then. It has been doing this for maybe a week. The radiator fluid doesn't have oil and the oil doesn't have water / coolant. I checked both.
September, 25, 2012 AT 6:09 AM
This is maybe 4x a week. I never go long distances. I used to drive it pretty far but lately its been having issues. It has never redlined or overheated. I always pull over / turn the heat on to cool the engine.
September, 25, 2012 AT 6:17 AM
Coolant would always leave a trail when leakages occurs and your leak is neither too large nor small so you most probably is not going to see any dripping onto the floor.
Under such circumstances it should be depleting the recovery tank as well but you mentioned it is not. When was the checmical test done?
Did you try bleeding the system to see if there are any changes in symptoms of the coolant loss?
September, 25, 2012 AT 6:32 AM
I just did it this morning actually because I'm completely baffled. An interesting thing happened actually. I totally forgot about this until now but this is what made me thing it was the thermometer not opening completely. I had drained 3 inches of radiator fluid as the test says. I left the cap off and placed the chemical tester where my radiator cap should be. About a minute into it the radiator fluid started overflowing into the test tube. I assumed the thermometer hadn't opened completely and if this had been happening on the road the fluid would have drained as I drove. I turned my car off, drained an inch more of fluid and reset the tube. I ran my car for two more minutes and it tested clean. (Temperatures were perfectly fine throughout these tests I made sure to monitor them.) Thus the fluid hadn't boiled over.