We had a minor gasket cover leak that we had repaired. I drove my '15 Jeep Wrangler less than 5 min to the store and back the first day I had it back. The next day I took it on a longer trip and, all of the sudden, fluid spurted out of the coolant system, a bunch of lights came on (husband says fluid got into the fuse box, elsewhere), and all shut down. When we got out to check on things, my husband discovered that the coolant cap was loose.
Shop says it’s not their fault because they didn’t touch our coolant system. They think the fan stopped working and it overheated. But the temperature guage didn’t read hot until all of the sudden and the guage moved over until it was almost pegged.
They also say there’s air in the oil, so we must have blown a head gasket.
Thoughts?
What was this minor gasket cover leak that you refer to and does this leak involve motor oil or coolant?
Air in the oil needs a bit more explanation also as that makes no sense. Not trying to be combative at all. Just trying to form an opinion and need some details.
No oil or coolant from the leak. Was wicking down the side of the motor onto the O2 sensor, which is how we found the leak.
Not sure I have the air detail correct. Shop said it’s an indication that we blew a head gasket.
I don’t mind questions!
What’s a gasket cover leak?
The gasket for the valve cover is leaking?
Air in the oil is BS. Air can get whipped into the oil but not from a head gasket leak, that would be from way overfilling the oil pan. If the oil has a brown, milkshake kinda look, then that would be from coolant in the oil and that would be most likely from a head gasket.
A blown head gasket could be caused by overheating the engine and that could have happened if the radiator cap was left off. But replacing a cover rail gasket would not involve removing the radiator cap.
Look at the oil now, does it appear normal?
Check the coolant level, is it low?
If the oil looks normal and the coolant can be filled up, do that and try to start the engine and see if it runs.
Worse case, the engine is not blown in the short time you drove it unless there was no oil in the oil pan. You may need new head gaskets which would be worth doing in this vehicle.
Coolant or water in the engine oil indicates significant engine damage, more than just a leaking head gasket. Multi-layer stainless steel head gaskets won’t leak unless the cylinder heads are warped.
One of the signs of head gasket failure is coolant in the oil or vice versa. Another sign of a head gasket failure is combustion pressure forcing coolant out of the radiator cap because head gasket failure allows much higher pressure to enter the cooling system than the radiator cap is intended to hold so it blows coolant all over the place. Have a competent shop do a compression check or a lookdown test, IN the leak down test the air pressure will show you where the air is going when it leaks out of the cylinder.
Yep. You are all correct. Major engine damage. Air was in the coolant system. I had misspoken about that. We have to get a new motor. Thanks to everyone for their comments.
I strongly urge you to get a second opinion on the engine. Overheating does not cause major engine damage. Unless you ran it out of oil or oil and coolant got mixed, your engine is OK. All you need is a head gasket.
But I’m not there to look at it myself. Car repair is a business transaction and any good business transaction calls for second opinions and multiple quotes. I suggest you find another mechanic and pay to have a second look, it could save you a lot of money.
I have seen a couple dozen vehicles towed in that overheated, the engines had no compression. The head gaskets were intact, the cylinder heads were warped. Stainless steel multi-layer head gaskets don’t fall apart like the old composite gaskets of the previous century.
I disagree with that sentiment, and I wouldn’t be surprised if some other forum members also disagree.
I have to respectfully disagree that engine overheating due to lack of coolant issues does not cause major damage. I’ve seen multiple engines that were fried to the point of being economically unsalvageable.
I have seen engine damage from overheating, but there were other factors as well, mostly when the oil get contaminated with coolant and the driver continues to drive the vehicle until it won’t run any more. But I have not seen simple overheating do any more damage than blowing a head gasket and sometimes warping the heads.
But keep in mind that my recommendation was to get a second opinion. I’ll stand by that.
I disagree with that . . .
Just a few months ago, a vehicle in the shop was leaking coolant
The MLS head gasket was leaking coolant externally from just one corner . . . nothing got into the crankcase. I used the block tester, which I’ve mentioned many times on this website
The only problem was the head gasket
I used my straight edge. No warped head. Nothing was warped at all. Everything was well within specs
The only thing it needed was that head gasket . . . and of course new head bolts, intake bolts and valve cover gasket(s)
Was the head gasket leak result of a severely overheated engine caused by driving without coolant?
I have seen engines wiped by overheating due to lack of coolant, stuck thermostat, and even by a failed water pump belt.
Compression near nothing, scored cylinder walls and pistons, seized rings, and so on and no coolant in the motor oil.
I even saw a motorcycle air-cooled engine seize up once and that was caused by nothing more than running it at a speed that it was never designed to be run at. Matter of fact, that bike used to belong to me and I was right beside the guy I traded it to on another bike when it happened. Engine screaming one second and the next nothing but screeching rear tires when the engine locked up. (1941 Harley Servi-Car or meter maid trike as they are called)
Not at all
The vehicle was in for a regularly scheduled service
No overheating
No driving without coolant
In fact, the coolant level was still within the marks
I only noticed the coolant leaking as part of my normal inspection
It was . . . as some of us agreed in another recent discussion . . . simply the mechanic observing a problem that the vehicle operator/owner was unaware of 
My sons Nissan (2.5L) blew a head gasket. Never overheated, never run low on coolant. It just started seeping coolant into the engine, none in the oil though.
I am sorry to hear you had to get a new engine. For a long time I have wondered why the engines aren’t shutdown by the ECM at a temperature low enough to prevent catastrophic damage to engine. with a suitable warning period of course so you can safely get off the road. I have seen lots of engines economically destroyed by low oil and high temperature overheating that could have been safely prevented by a better ECM program.