[npanhuyzen]

So there are quite a few threads on overheat issues, but haven't found one quite like mine.

This started a few days ago when I found myself in unusually dense traffic. After about 30 minutes of driving the yellow overheat warning popped up. I pulled over and let the car idle for a while and then proceeded cautiously. After about another minute the yellow warning went Red. So I pulled over and shut the car down for about 5-10 minutes. Started her back up and received no warnings so cautiously finished my commute - no more warnings.

Coolant level was a tiny bit low, added about a cup and half of water to the reservoir.

Next day no issues.

When I got home I decided to see if I could reproduce the issue. Idled the car in the driveway for about 30 minutes with no overheat (fan came on after about a minute and stayed on the whole time). Cabin heat gives off nice hot air. Revved it to 2500 rpm for about a minute and the yellow popped on again.

- Turned off car.
- Checked the radiator - stone cold.
- Checked the reservoir - boiling hot, didn't try to turn off the lid as it was really steaming when I loosened it slightly.

When the car had cooled, I ran the water pump test (put cabin temp at 84, step on gas for 10 sec etc).

- Fan came on after about 5 seconds
- Water pump was running (confirmed by seeing water pumping into the reservoir).

Unfortunately I don't have anything to read the codes. But I'm suspecting its a stuck thermostat perhaps?

Anyone have any ideas?

[velociti]

Originally Posted by npanhuyzen

So there are quite a few threads on overheat issues, but haven't found one quite like mine.

This started a few days ago when I found myself in unusually dense traffic. After about 30 minutes of driving the yellow overheat warning popped up. I pulled over and let the car idle for a while and then proceeded cautiously. After about another minute the yellow warning went Red. So I pulled over and shut the car down for about 5-10 minutes. Started her back up and received no warnings so cautiously finished my commute - no more warnings.

Coolant level was a tiny bit low, added about a cup and half of water to the reservoir.

Next day no issues.

When I got home I decided to see if I could reproduce the issue. Idled the car in the driveway for about 30 minutes with no overheat (fan came on after about a minute and stayed on the whole time). Cabin heat gives off nice hot air. Revved it to 2500 rpm for about a minute and the yellow popped on again.

- Turned off car.
- Checked the radiator - stone cold.
- Checked the reservoir - boiling hot, didn't try to turn off the lid as it was really steaming when I loosened it slightly.

When the car had cooled, I ran the water pump test (put cabin temp at 84, step on gas for 10 sec etc).

- Fan came on after about 5 seconds
- Water pump was running (confirmed by seeing water pumping into the reservoir).

Unfortunately I don't have anything to read the codes. But I'm suspecting its a stuck thermostat perhaps?

Anyone have any ideas?

Water pump / thermostat is a common failure point, and the yellow warning quickly followed by red is a prime giveaway. Whichever one failed, you'll want to replace both. My indy shop suggested doing it by 60k miles, though some have had it go earlier, and many later or not at all.

[npanhuyzen]

That's definitely what I am thinking. Do you think the water pump problem is intermittent? Otherwise why would it run okay when doing the bleed procedure?

[450pirate]

In my thread below, my pump was running fine during the bleed procedure but it’s most likely on its way out....

[weehe126]

It's the electronics on the pump that seem to go bad rather than physically breaking. Random overheating is normal when the pump or thermostat are going bad.

[opjose]

Originally Posted by weehe126

It's the electronics on the pump that seem to go bad rather than physically breaking. Random overheating is normal when the pump or thermostat are going bad.

I experienced what he said above when mine went.

[npanhuyzen]

Thanks all. Before I go swapping out the pump and thermostat is there any electrical checks that I should do? Fuses seem okay (provided I'm checking the right ones!) any relays or sensors that could be the fault? I don't want to go through the work of the swap out just to find its an electrical problem.