Please help, mechanic can’t figure out unless it’s overheating in his shop but simply running it with air condition on will not overheat. I have replaced the radiator, thermostat, air pump, oxygen sensor, flushed the cooling system checked inside housing with camera and a $275 tune up.
The mechanic told me he can’t find anything wrong! But the first day it’s warmer out 79 degrees and I drive on the freeway all OK, but once I’m on the streets and idling at a stop light the thermostat starts climbing to the red zone. I call him when it’s happening he said turn heat on. It helps a little and I’m able to get car to shop.
He said he couldn’t get it to overheat but he can’t drive to freeway since it’s too far only 10 miles but nothing I can do.
Anyone have any idea what is going on?
True, but we don’t know that they were replaced for that reason. Customers often list everything that’s been done recently, whether or not it’s relevant to the current problem, because they don’t know whether it’s relevant.
Cooling system problems can sometimes be challenging to diagnose even with the vehicle at hand, even more so over the internet, and especially so without complete information. For example, does it overheat ONLY after it’s been driven on the highway? Does it overheat at idle with the A/C off? I’m sure there’s more, but it’s hard to think of all the relevant question when not actually working on the vehicle.
A faulty radiator fan system is one possibility, another is a faulty water pump, and there are others.
No, the temperature gauge needle climbs. This is not a house system with the thermostat and room thermometer together in one unit. On cars the thermostat is a device mounted in the engine, totally separate from the gauge in the instrument cluster.
If the symptom is truly intermittent, that can be frustrating for everyone involved. Some problems can not be evaluated unless they’re caught in the act.
If it does need to be driven at highway speed before the symptom appears, the mechanic can do that, but you would need to pay for the time involved to drive that far.
I have a lightly modded 2002 Chevy Cavalier I have an attachment to (2Dr) and believe it or not, it looks great, runs great (fast) even after 110K, but I had to replace the water pump twice because I had the same issues, had all other things replaced (they were due anyway), radiator, cooling system flush, thermostat etc… and it would still get really hot, turns out the water pump was going bad, at the time I had no idea, I thought the pump was just for the A/C, I was clueless. Anyhow I got it fixed and it still ran hot, not to red but still hot! Confused, my mechanic re did all of it, free of course (friend) and he was puzzled too. I guess it’s the simple things we overlook. So here is what I did
I filled the coolant reservoir to Full/Cold and then replaced the coolant cap, which turned out to be the problem! Turns out the cap wasn’t keeping it pressurized good enough in the reservoir and one of the lines had built up sludge in it that wasn’t cleared by a flush. Haven’t had a problem in 30K miles, with normal upkeep. Maybe check those items out, cost me about 30 bucks to fix it(reservoir cap, line and some antifreeze/coolant, besides the repairs that I would have needed anyway. By the way, the overheating only happened after idling on streets AFTER driving on a highway. Just an idea.
I was thinking of mentioning the pressure cap, and making sure the system was full with no air pockets, but I figured surely those bases would have been covered (silly me). If the person working on it did not check those items, then it’s absolutely time to find a mechanic who knows what he’s doing.
Yeah, No argument there. Sometimes simple things are forgotten though, almost as if we think “nothing in life is that simple to fix” I get an excuse because my mechanic is a good friend and family friend who goes to functions and all, so if he forgot something like that, I get a free brake job, or transmission flush or something to make up for it.
In OP case it wouldn’t be understandable unless the relationship between owner and mechanic was defined as more than business. In that case, it sure as shit should have been looked at. I truly hope that it isn’t a blown head gasket or something, but surely that would let oil be burned, dead giveaway. so I hope for the best for OP. Especially if he has an attachment to a car and doesn’t want to let it go, like myself.
2001 Pontiac Aztec? You must really like that car if you have wanted to keep it so long. I admire someone who can wear ugly well and like it.
You have to use the Occam’s Razor concept when trying to figure the problem out yourself, especially if your mechanic seems unable or unqualified to find the issue, and he does.
The simplest solution is probably the correct one. But it looks like you have done most of that. And a lot of the things that you have fixed needed to be done anyway after 16 years, so don’t look at it like you have thrown money away. But damn! An Aztec?
I agree with jz77817. But rather than a slight head or intake gasket leak, I would say that you have a cracked head or intake itself.
But that is just my opinion, man. I would be prepared to put the Aztec down and bury it in the back yard, or give it to someone that you do not like.
I’ll second Gary T’s suggestion: faulty electric radiator fan.
I had one fail on a VW rabbit. and it delivered the same symptoms: ran ok when driving around town, but if I slowed down after higher-speed driving it would overheat. The Rabbit had a temperature-controlled electric radiator fan (not belt-driven by the engine). The temperature-operated switch that ran the fan when the engine was hot had failed. When the motor was not working hard air coming in through the grill at 25 mph or so would keep it cool enough. When driving on the highway, 65-70 mph air coming in through the grill would keep it cool. Coming off the highway with the engine hot and slowing to 25 (or even stopping at a light) would let the hot engine overheat the water in the radiator.
I love my Aztec and if it’s not hot outside the gauge doesn’t read hot. Just stays in the middle. All the repairs were done when I started having issues. We are going to take the water pump out because the mechanic said it’s running hot reversed so maybe it was a faulty pump from the manufacturer.
Yes it’s like the breaking bad show and ever since that show was aired my Aztec logo keeps on getting ripped off.
The coolant is full no leaks anywhere. Today is a mild day and we ran it for 30 minutes and it was fine.
I’m going with the faulty electric fan switch/sensor mentioned up thread, based on my experience with an old Pontiac 6000 and a 95 Ford Contour I used to drive. Had a similar issue, turned out the fan switch/sensor was bad in both cars. With the Ford, the symptoms in the OP were identical in description.
ETA Shimmie you need to find a different mechanic and shop, this person/shop is either incompetent or (more likely) ripping you off big time.
