Pressurize coolant system and check #6 and #8 cylinders (passenger bank) for coolant (and clean piston tops like Artie suggested).
2011 Lexus LX570 Intermittent Overheating
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- #22
Update: The shop pressurized the system and could not find any leaks. They said they added half a gallon of coolant to the system, which sounded like a lot to me. I’m trying to get a hold of the Lexus dealership to confirm they will check the cylinders, run a combustion test, and check the valley plate for a leak (i don’t think I trust that this Indy shop actually scoped the valley plate) before I drop the car off with them again.
They add half a gallon? I get worried if any of my Toyota even needs a cup of coolant. I hope it's not filling up cylinders.
Stop at almost any auto parts store and get a head gasket test kit, simple easy screws into the radiator. If you don't have a blown head gasket and you actually trust that they pressure tested the system (which I don't believe they did), I would do that myself. The coolant is obviously going somewhere. And I would not feel comfortable driving the truck until I knew exactly where.
I may be getting out over my skis here but I’m really curious on the age of the coolant and frequency at which it was changed.
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- #27
I could be wrong, but if it was a head gasket issue, would there not be other symptoms by now? I just dropped the car off at the Lexus dealership. I asked them what tests they ran last time and he said they pressurized the system and ran the car at various speeds to try to replicate the issue. Notably, the did not scope any part of the car and did not run any tests to see if there is a head gasket leak (even after having the car with them for over a week). Honestly somewhat shocking they were okay with returning the car to me without running these tests. They took the car for a second look and noted to scope the valley plate. Will report back with an update hopefully tomorrow afternoon ET.
I think water pump too but where is all that coolant going ? Valley area doesn’t hold that much, no coolant in the oil and if it was a head gasket it would be blowing steam big time.
My 4runner had a cracked overflow tank but the coolant in the radiator never dropped. I would put cardboard or something under the truck to see if you can find leaks especially if it's parked on grass or stone.
Coolant issues are pretty simple compared with other stuff and this is weird. How bout a faulty temp sensor? Does the truck actually overheat or is the gauge just tell you that. The engine may be fine.
My 4runner had a cracked overflow tank but the coolant in the radiator never dropped. I would put cardboard or something under the truck to see if you can find leaks especially if it's parked on grass or stone.
Coolant issues are pretty simple compared with other stuff and this is weird. How bout a faulty temp sensor? Does the truck actually overheat or is the gauge just tell you that. The engine may be fine.
I watched as a water pump failed and dumped massive amounts of coolant right in front of my eyes. Granted that was a Land Rover, but it happens. I like your idea of putting cardboard underneath to see if there are any visible coolant drips.
Headgasket can fail two ways, into the cylinder or external to the head and will leak down the block. Either way 1/2 a gallon is substantial and the truck shouldn't be driven until you can figure out where the coolant is going. Have you pulled all the plastic out of the engine bay and got in there with a flashlight and really looked around? Even if the coolant is drying it leaves a pink crust. Have you checked your radiator well since they have a bad history of failing.
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- #32
No white smoke coming out from the exhaust.
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- #33
I have not pulled all the plastic or checked your radiator well. Car is currently at the Pohanka Lexus of Chantilly dealership for the second time with this issue. If they try to report back saying they could not find the cause for this issue, I will be sure to confirm they did all of the above.
The time to check for this would be a cold start. It could be as little as a quick puff at start up if the leak isn’t bad.
Just curious—have these shops been charging you for finding nothing wrong?
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- #36
Update: They already looked at the car and provided me with a video indicating that they cannot find the coolant leak under pressure test and that they are moving on to head gasket. It’s not clear from the video that they checked the valley plate, but they certainly got under the car and opened up the plastic panels to have a look around…
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- #37
Indy shop has not. Dealership waived the diagnostic fee the first time since I got some unrelated work done on the car with them while they had it.
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- #39
Update: Lexus wants ~$1,000 to run the leak down test. I tried to confirm multiple times that the tech looked at the valley plate, but the service rep just kept telling me that he inspected the coolant jacket and that it is the same thing as the valley plate (I don’t think that is true). I am going out this afternoon to speak with the tech in person to confirm that he put a borescope down into the valley plate and had a good look around before I shell out a grand for a test that may be unnecessary. If I was having any other symptoms of head gasket issues, I would probably just roll over, but I’m not having any other issues that would suggest it is a head gasket issue.
Uh NO. I'd charge 1.5-2 hours at most for a 5.7 to scope under intake, pressure test cooling system, check leak down.
Where is this dealer? I'd like to send my résumé over.