Getting hot while idling

[sweetiieheart]

2006 Aveo LS - we've had a lot of work done on it in the last half year, including thermostat housing replaced, brake pads replaced, spark plugs and wires replaced, air filter replaced. Basically the car was paid off and now it's wanting to be a douche.

Alright, now what's happening is when we're idling the car starts heating up. We have to be driving for at least 30 minutes for it to happen. Oh, and if the A/C is on, it's less likely to do that, plus, when we start moving again, it cools down back to normal again. I'd also like to add in that sometimes we smell a burning rubber smell, when stopping or slowing down. It's random. It's got enough coolant, so it can't be that either, and there's no leaks that we're noticing.

We were going to take it to a shop today, but well, finances got in the way of that. The reason we were going to do that, is because we've read so many different things it can be. If we could just fix this on our own, without having to take it to a shop, that'd be grand.

By the way, I say "we" because it's my boyfriends car.

[avguy]

Either the fan isn't working, the coolant is low, or the pump isn't pushing like it should. A blockage is another possibility, but you probably would have seen this happen long ago if that were the case. And I'm assuming you would have at least checked that the fan works, and comes on when it gets hot, correct?
What exactly does "starts heating up" mean? Just over 1/2 way; 3/4; more than 3/4? Also would expect this to be an automatic tranny, because 30 minutes is about the right amount of time for the trans fluid to come up to full temp. And the fully hot trans cooler is probably pushing the coolant temp and causing it to go higher.
Is the overheat consistent, or different readings at various times? Next question - did a fairly reasonable amount of time go by after the t-stat housing was replaced where there was no overheating? If overheating started happening right after it was replaced, then there may be air still in the system, especially if the heater was not turned on while refilling. If that's the case, pull the reservior cap while cold, turn the heater on full, warm it up parked, watch the coolant level, and hopefully it will drop and require a good amount to be added.
But if that's not not the case (i.e. no air), then do you know when the water pump was changed? Often it's done along with the timing belt, but not always. If you don't know, then it could be that the WP is heading South.

[sweetiieheart]

Either the fan isn't working, the coolant is low, or the pump isn't pushing like it should. A blockage is another possibility, but you probably would have seen this happen long ago if that were the case. And I'm assuming you would have at least checked that the fan works, and comes on when it gets hot, correct?
What exactly does "starts heating up" mean? Just over 1/2 way; 3/4; more than 3/4? Also would expect this to be an automatic tranny, because 30 minutes is about the right amount of time for the trans fluid to come up to full temp. And the fully hot trans cooler is probably pushing the coolant temp and causing it to go higher.
Is the overheat consistent, or different readings at various times? Next question - did a fairly reasonable amount of time go by after the t-stat housing was replaced where there was no overheating? If overheating started happening right after it was replaced, then there may be air still in the system, especially if the heater was not turned on while refilling. If that's the case, pull the reservior cap while cold, turn the heater on full, warm it up parked, watch the coolant level, and hopefully it will drop and require a good amount to be added.
But if that's not not the case (i.e. no air), then do you know when the water pump was changed? Often it's done along with the timing belt, but not always. If you don't know, then it could be that the WP is heading South.

The fan, from what we've noticed does turn on at times.

We've put coolant in, and it's at a good level.

It goes up to 3/4 or all the way hot.

The housing was replaced at least 3-4 months ago, and has been doing fine until the last two weeks.

We drove about 200+ miles to the beach when this first happened. Once we started the A/C up, and let it cool down some, and then drove, it cooled down to the normal temp, which is a little over 1/4 of the gauge thing.

Water pump/timing belt has never been changed.

[avguy]

... We've put coolant in, and it's at a good level.
.... It goes up to 3/4or all the way hot....
Water pump/timing belt has never been changed.

Just to clarify, was it at a "good level" during the overheating? How much coolant is being added and how frequently?

"All the way hot" is a blown head gasket in the very near future (hopefully it hasn't happened already). That's around a 1,000 repair, unless you can DIY

This '06 probably has way over 60K miles? If so, the timing belt-related parts are old, tired, and getting ready to quit. And the bent valves that come with that failure will be a 1.5 - 2K repair if done in a shop.

The only easy thing you can do is either find an actual coolant leak, or try a new thermostat (yes, you could test it first). I didn't mention that because it was replaced recently, and it's most likely not the problem.
Beyond that, if he intends to keep this vehicle, it needs to get into a shop NOW, unless you can find a leak, or if replacing the t-stat truns out to be a miracle cure. And I would ask the shop if they can try to evaluate if it has a blown HG, before doing anything else. You're between a rock and a hard place, and have no wiggle room.

[Daox]

You need to be sure that the coolant fan is coming on. After a drive, let it idle (leave A/C off) and if the coolant temp gets much above halfway and no fan turns on you've probably found your problem. It sounds like everything else is working properly.

FYI, turning on the A/C turns on a separate fan which will also cool the engine coolant down.

[petrified.rabbit]

You need to be sure that the coolant fan is coming on. After a drive, let it idle (leave A/C off) and if the coolant temp gets much above halfway and no fan turns on you've probably found your problem. It sounds like everything else is working properly.

FYI, turning on the A/C turns on a separate fan which will also cool the engine coolant down.

this, you will likely be replacing the coolant temp / fan switch

[sweetiieheart]

Just to clarify, was it at a "good level" during the overheating? How much coolant is being added and how frequently?

"All the way hot" is a blown head gasket in the very near future (hopefully it hasn't happened already). That's around a 1,000 repair, unless you can DIY

This '06 probably has way over 60K miles? If so, the timing belt-related parts are old, tired, and getting ready to quit. And the bent valves that come with that failure will be a 1.5 - 2K repair if done in a shop.

During the overheating when we checked, it was still between the min and max line. It goes up only when the car is stopped, and we're sitting, or it's turned on, without the engine being on. Once we start driving again, it's fine.

It has about 92k miles.

You need to be sure that the coolant fan is coming on. After a drive, let it idle (leave A/C off) and if the coolant temp gets much above halfway and no fan turns on you've probably found your problem. It sounds like everything else is working properly.

FYI, turning on the A/C turns on a separate fan which will also cool the engine coolant down.

I think it might be the coolant fan, because when the A/C is on, it's fine, or when we're moving. If it gets hot, and we then turn on the A/C, it cools down.

this, you will likely be replacing the coolant temp / fan switch

Thank you.


Thank all of you for your help. I really like his car, it's similar to one I used to have when I was able to drive. My Scion XA 2006 - and it was navy. Freakin' loved that car. Also miss driving like crazy.

[avguy]

The OP said it goes up anywhere from 3/4 to H, just idling at a stop. It doesn't make sense to me that it could be going up so fast and that high with just a fan not coming on. But maybe it's not hwppening the way I'm thinking it is. And I certainly hope you guys are right, because that would be the easiest and least expensive repair for them.
For the OP, if you can hang on a coolant temp / fan switch yourself, and that fixes the problem that would be great. But if not (or it doesn't fix it), you really need to get it into a shop asap, because running it in the H zone, is just asking for a really bad outcome. Hope the easy fix works for you!

[sweetiieheart]

Just to update everyone, avguy was right, kind of.

Head gasket is cracked, but not completely blown. Thankfully a friend of my boyfriend's Mother is going to be fixing it for us, and all we had to do was buy the parts. The head gasket, bolts, oil, filter, and antifreeze. They quoted us $1,100.00ish at the car shop, and the labor part was $760, rest was parts. We were able to get the parts at O'Reilly's for close to $200.00 all together. He paid for the head gasket, and I paid for everything else.

Good[maybe bad news] - the folks at the car shop thought we were married.

[avguy]

I get no satisfaction on being right, when the outcome is $$ out of your wallet. But at least it's hopefully getting fixed right. No idea about this repair guy's knowledge and ability, but I think you need to ask him about checking if the head is warped. It's very common for these alu heads to warp, and need milling at a machine shop. He may know all about this, check it, and have it milled true if necessary. But he also might not, which is why you need to ask in advance. If the head goes back on warped, you will be doing this whole thing again real soon, which is about the last thing you need. And thank you for posting your outcome, as painful as it was. Many never follow-up, and don't give others the chance to get valuable information.