I have been noticing coolant loss for the past month that has progressively become worse. Dropped the oil pan saturday to take care of another issue but I noticed no coolant in the oil. When I cut the truck off for a few minutes after driving it for a while, it seems to run rough for about 30 seconds, because I assume some coolant is getting into the combustion chamber and is having to burn off. My question being, which gasket can be leaking this much coolant (about a half gallon every 50 miles)? No coolant seems to be in the oil so could this likely still be a head gasket? Maybe a valley gasket? Truck been running great otherwise.
Disappearing coolant
- Thread starter kekule
- Start date
Any signs of leaking on the ground or driveway? Does it pressurize? (hard upper hose) .A valley gasket will cause it to drip somewhere.
It's possible that you have a leaking head gasket. I'm sure folks more knowledgeable than I can provide more detailed feedback here, but I can say that my Disco lost coolant via the head gasket without evidence of coolant in the oil or obvious drips on the ground. My leak was not as pronounced as yours, though. One half gallon every fifty miles seems like a lot. A pressure test might help identify the source of the leak.
The upper hose is hard. I thought it was leaking around the thermostat housing. I replaced the thermostat and seal( which was so brittle it just crumbled into pieces when I pulled it off), but it didn't stop the leak. To my surprise there was no visible coolant in the oil. One thing I do notice, and I am not sure if this is normal, is when I cut the truck off I can hear a pretty loud hiss coming from the expansion tank cap. I guess the cap is designed to release some pressure but I never noticed that loud of a hissing sound before. I guess a part of me wants it to be a simpler fix than a head gasket.
Sounds 100% headgasket.
Had this same issue in my 4runner, thought I couldn't notice a loss of coolant. If you have that rough idle at start and are loosing coolant thats most likely it.
Pull the spark plugs one at a time and crank it or use something to absorb coolant, [paper towel, pipe cleaner] place it into the chamber and youll see if theres coolant.
Had this same issue in my 4runner, thought I couldn't notice a loss of coolant. If you have that rough idle at start and are loosing coolant thats most likely it.
Pull the spark plugs one at a time and crank it or use something to absorb coolant, [paper towel, pipe cleaner] place it into the chamber and youll see if theres coolant.
Do a coolant pressure test, cap is 15 lbs. Anything over that and you are looking into valley gasket and /or head gaskets. That is if you absolutely have no leaks. Under throttle body, water pump weep hole, hoses, resevoir ( can be cracked and leak when hot ), and heater core (look for coolant in A/C weep lines on each side of tranny and on carpte under pass, side of console).