marcelxv

I've been dealing with this issue for the last 3 months now, I've got crazy odd overheating issues, where sometimes I'll hit about 2/3 of the thermostat, and other times I can be all the way up near or in the red, but once I start pacing my driving a little slower, it'll instantly drop back down to normal operating temps. I've replaced the water pump, radiator, thermostat, and all hoses, and still having this issue. There's dry coolant all on the bottom of the engine, but no puddles or wet spots, but water will occasionally shoot out of my FULL reservoir once I shut the car off. I have to usually pour half a gallon of coolant or water into the car before I decide to go anywhere, and it takes around 3 hours to fully deplete that coolant/water before I have to fill it up again. As a daily driver, this has become a severe problem, as I can't really go driving for longer than 2 and a half hours without symptoms starting to pop up. I've taken it to a shop, where they said it tested negative on 3 different tests as a faulty head gasket, but that's the only thing left I could think of that it might be. I took it to another shop where they offered to try 'Blue Devil' head gasket sealer, which I opted for. I picked up the car yesterday and could instantly tell it was running healthier than I had ever heard it before. I had a clean consistent idle, and my pops sounded more distinct rather than just little bangs, and my cooling fans come on way more often. However, just today I was going out on a little drive to continue testing the sealer as the shop recommended I do, and the overheating came right back. I hardly drive with the A/C on, but I had it on for around 10 minutes today and noticed the issue popped up way sooner than my usual 3 hours.
Again I've been dealing with this for 3 months now, all the mechanics I've tried reaching out to say it does or doesn't sound like a head gasket issue, but I have no symptoms of a typical head gasket issue, no milky oil, and no exhaust smoke. I've been quoted around $4,000 or more to get the head gasket replaced, otherwise I'm looking at a whole new engine. Looking for any help as I'm trying to save as much money as possible and can't afford a fix at that price.

LeX2K

First step is to pressurize the cooling system and look/listen for leaks. If you don't find any then the cylinders need to be pressurized this is a definitive test if there is a leak into the cooling system you'll find it. You driving the car over and over again means there is a good chance you have a head gasket issue.

HG fixes in a can at best do nothing, I've torn down engines that were given the treatment it makes a mess.

MikeFig82

iTrader: (13)

Does it look like the reservoir is leaking coolant from the top?

The actual lid to the reservoir should be facing the radiator. If it's facing the engine it's in the wrong position.

Incorrect


Correct

marcelxv

I'm not too sure how this would relate to my issue, but my coolant lid is facing the correct direction. The best conclusion I've come to so far is that maybe there's something in the system that's literally blocking the coolant and sending it back the other way. I'd assume it's getting to the point where there's so much pressure in the system it sends it back to the reservoir or out the other end of the reservoir lid

MikeFig82

iTrader: (13)

The way it works correctly is the left side is the pick up tube. So when the engine is off and drawing vacuum to replenish. It's not drawing in air into the system. Vice versa if the lid is flipped it would now just be drawing in air into the system. Since the draw hose is now connected to the vent side of the cap.

This happened to me I'd taken my car for inspection. I couldn't figure out why I was loosing coolant. It seems since any quick lube place will fidget with your engine to sell you something. The first picture is from another member somehow his got flipped backwards as well. The over heating seemed to even melt the pickup tube all together.

So have you also replaced the radiator cap?

GrizzlyMan

I feel your pain. I used to have a Honda car with the exact same problem. I went crazy tried everything and never was able to spot the problem, ended selling the car to a mechanic that never worked on it before. About four techs saw the vehicle, specialist, old school, left the car for days with a mechanic and let him drive it.

(maybe) You may have to cut your losses, trade it (of course dont say a word), and move on.

I think Scotty Kilmer has said the sealant may need a second dose to finally work, sometimes does not work the first time it is put in use.

**the other thing that comes to my mind is a laggy relay and/or fan. Warm up the car,drive it a bit, bring it back, pop the hood and let it idle (monitoring the temps) and see when the fan kicks in and strong the fan sounds. Followed by let it idle with the A/C on and if not mistaken the fan should come on instantly. Noticing it is a 2007, the fans can be going out or one of the relays is not working properly.

good luck

davidbusta

iTrader: (1)

When my car had overheating issues I had the coolant flushed to remove any possible air that could be in the cooling system and I also replaced the radiator cap with a new one. I haven’t had an issue with that ever since.

Armadous1

Coolant temperature sensor. Test it. Boil water on stove and ohm it out before going into water and while it's in water.

Protholl

marcelxv

Decided to just get the engine swapped, found a guy who collects ISx50s, and got an engine with 52k miles less so that should get taken care of. Thanks for the help

Crickets

Just saw this post. Couple of things I did when I had a similar problem on a 2007 RX400h back in 2018. Moot point now but perhaps it might help another member going forward:

1. performed a leak down test. Found head gasket leaked ever so slightly. Two annual doses of K-Seal ST3501, every 6 months, resealed and still reseals the gasket for leak-free daily driving.

2. The coolant gasket just below the install manifold leaked. Ended up replacing it.

Car has been running since (albeit by adding K-Seal every 6 months). And no leak under the intake manifold since then.

MrHarris

iTrader: (1)

bars leaks head gasket repair - the one that sells for around $36, i tried it and just used like 1/8th of the recommended amount and it seemed to really help/fix my leaking issues..

MrHarris

iTrader: (1)

is the “coolant gasket” what they call the intake manifold gasket? (They as in what Amazon calls it on their website)

Crickets

I don’t remember the name. What I recall is a coolant tube running under the Intake manifold. I replaced a gasket in the general area underneath the intake manifold.

2013FSport

iTrader: (2)

OP, hope that solves your problem. I'm surprised the leak wasn't found.

Its super important that all three parts of the cap seal.
1) at the neck
2) at interior, to rated pressure
3) vacuum ring
If either 2 or 3 have debris in them, when hot the engine can push fluid out to the reservoir and overheat. If #1 leaks while hot, it makes a mess and the engine won't pull a vacuum to refill the block from the reservoir during cool down. Any external leak will prevent the block from pulling a vacuum during cool down and prevent it from topping itself off. With air inside, hot spots can boil fluid which then pushes coolant out.

The block must pass pressure test or it just won't refill itself during cool down.

Anyone with rust or debris in the coolant system flush it until its clean as it can easily stick the vacuum flap in the cap open and screw up everything even though the engine has no leaks.