Troubleshooting overheating problem

Hello, I have a 2010 Gen III that I procured recently with about 210k miles on it. It has an overheating problem. I'm not seeing any white smoke in the exhaust, and I don't seem to be loosing coolant while it is running (though right now it doesn't run for long.)

It was doing the death rattle, and was overheating at high speeds (over 70mph.) I replaced the EGR valve, cleaned the intake manifold, and cleaned the EGR cooler. While doing this, I also replaced the PC valve, thermostat and water pump. The old water pump was definitely on the way out. The water pump I picked up was the ASIM water pump.

However, the car is still overheating.

I do not think I bled the car properly when I reassembled everything, and it overheated on a longer drive. It had seemed fine for a few hours, and then overheated. I got it home, but the car hit at least 250 at some point getting it home.

When I hold the large lower radiator hose that runs from the thermostat to the radiator, the temperature never changes on the hose, even after the car gets north of 200. I'm shutting the car off after it gets to 205 at this point. The radiator fans do cut on.

I seem to be able to drain the radiator easily, and when I refill with the bleeder valve open, fluid does come out the bleeder valve.

My hope is that this is indicating that maybe I had a bad thermostat when I picked up the replacement, or air was in the system causing the overheating after my first fluid replacement and the overheating tanked the replacement thermostat.

I would appreciate troubleshooting tips to try to narrow down the problem. How do I tell if the water pump is working versus the thermostat being the problem? Is this still a possible head gasket issue, even without the white smoke in the exhaust? Are there other causes it could be?

My theory of how it works right now is that if the hose on the bottom of the thermostat is not getting hot, then coolant isn't circulating, and that part of the problem is either going to be the thermostat or the water pump. Would that be accurate?

I did get the P0117 error code every so often, though it hasn't come back up again. I'm planning on replacing the ECT sensor.

Before the EGR cleaning, I was getting multiple cylinder misfires, but have not gottten that since the cleaning, even on the longer drive where the overheating started happening.

 

The EGR cooler did not look like it had ever been cleaned. It took me a few hours to get it clear.

The coolant that came out looked pretty clear, but there was also some coolant loss at some point. I guess the head gasket issue would be more evident at higher speeds as well?

 

The water pump is definitely running, that's a relief, I think. I'll test the thermostat when I pull it off. I have a new one as well.

Is the implication that there may be a hose gunked up somewhere preventing coolant flow?

I'm thinking that I should probably attempt a head gasket replacement. It looks like the parts aren't that expensive, and I will just need to be patient to get it done. That would also help me get solid diagnostic information (from what I've read) about whether the engine is actually shot or not. If it is, I should probably consider it a gonner, since I can't seem to find someone to replace the engine around here.

 

That does make sense. I'll add that to the list of things to do. Those videos make it seem entirely doable, just time consuming. It doesn't look that expensive to undertake, relative to what I've already put into the car, so worth at least attempting, I think. Time to go look for head gasket options.

 

I guess removing the head will also show proof of head gasket sealer and give me easier access to the coolant hoses to figure out what might be clogged up, if anything.

Is there a way to judge the okayness of the radiator?

 

Also, since I'm taking the car apart for the head gasket, I think I'll have better access to the coolant hoses to check those out and see if there is a problem there. If there's any guidance on that, things to think about, whatever, I'd appreciate it.

 

Getting everything disassembled now. Just took the replacement water pump off, and it does not spin at *all*. I don't know if it was bad to start with, or if overheating caused it to lock up, but that thing is toast. Whatever I thought was going on with the water pump looks like I was wrong.

 

I'm still taking it apart. Taking a brief break before tackling the last part of removing the head. I've pulled off a lot of coolant pipes, and no evidence yet. We'll see when I get the head off. But, if the water pump has been locked up, it would explain a lot. The first pump I pulled off was definitely going bad...it didn't have that freedom of spin and the feeling of wobble to it. This one, when I pulled it off, it looks like the spinning part of the pump got misaligned and wedged. I don't know if that was user error installing it, or if it just got banged around too much in shipping. Going to contact Asim tomorrow to see if I can get it replaced, under the assumption it broke while on the car.

I'm hoping between replacing the head gasket, ect sensor, water pump, thermostat and so on, it will resolve the issue.

There still *could* be a problem with the radiator itself, which I'm not sure how to test. If I dont' see sign of the good though, I think it unlikely there'd be goop in the radiator?

The shop said it would be a couple weeks before they get the head back to me. So it will still be a bit before I get it all back together again and see how this experiment went.

 

Sweet! No sign of any head gasket goop used! Pistons level off at the top of the block the same, so no bent arms!

Replacing this head gasket ought to do a lot for this car. And it is entirely likely that the overheating was related to the water pump both go rounds. It seems likey that when I get this put back together, I'll have a cat that should go for at least another 100k (well, I'll need a battery replacement at some point, but that feels relatively minor if this head gasket work and cooling system work pays off.)

 

The top of piston 1 has a goopy oily residue on top, 2-4 have hard carbon build up.

 

Thank you! It looks like it will be easier to do this after I've put the head back together from the videos I pulled up. Is that a correct interpretation?

 

I wasn't sure if I could easily isolate the radiator/heating core with all the hoses disconnected because the head is off. It would seem a good idea to me to flush as much as I can though while I have all that space to work with, I agree with that. I'll cover the block while doing the radiator flush to limit potential accidents.