Overheat when in traffic, gone after fuse and relay reseat

[PandaBear]

This weekend I was driving to Vegas from Norcal and when I was along I-5, getting off for gas, the engine temp gauge raise well above 1/2, and when I started driving again, it goes down to 1/2.

So, I drove carefully from Lost Hill to Bakersville, park my car in the airport, and get a rental to Vegas. On my way back, I am careful to avoid any traffic until I got home.

When I was stopping for gas the few times and popped the hood, I can see the coolant overflow tank bubbling. I was once stupid enough to use a towel to open the radiator cap and the steam poped out and a fountain of boiling coolant continue for 2 seconds. I know, it is so stupid I should have shot myself. I then add some new coolant and the boiling continue at the next gas stop.

This stopped after I reseated my cooling fan fuse under the dash's fuse box, the cooling fan fuse under the hood in the fuse box, and then reseat the fan relay under the hood. I make sure this is the case by letting the car sit and warm up, and the fan (both fans) turned on.

So I have a few question:

1) What could cause this? will this come back again?

2) I stopped the engine at traffic and make sure the temp gauge never exceed into the red zone, do you think I have warp my block?

3) When I added warm coolant (about 90F) after I open a hot radiator (probably 220F inside), do you think I have warp the block?

4) THe car feels more rough than before. I know it has a bit of a valve lash or piston slap like sound before, but it is stronger now, should I worry? It is more obvios above 3k rpm.

5) I just changed the ATF (yes, it is an auto teg) 2k miles ago but I am concerned that it has overheated as well, and ATF usually gets cooked pretty easy, should I change it again?


Any suggestion? If the engine is warpped I probably will just drive this car for some more and then swap the engine/transmission. It has 180k miles on it and is a 97. I just got a house so money is a bit tight, if things aren't broken I would rather keep it for a while.

 

[The Critic]

If you overheat in traffic, it's generally caused by a cooling fan that is not operating when it's supposed to. Since there is little or no airflow to a radiator when the car is at a standstill, the fan is required to push air through the radiator to allow for adequate cooling, correct me if I'm wrong.

It looks like you've found your problem.

As for the rest, I don't know. You're probably fine. My mother drove the 96 Saturn for 10-12 miles on a hot day with a busted serpentine belt tensioner, yes serpentine belt drives the water pump. No clue if the water pump was completely "shut off" during the whole time, the alternator was though, as the light came on.

Fwiw, it has been 3K+ since the incident and I've seen no coolant loss, and no signs of coolant in the oil.

If anything, the engine oil/filter should be changed immediately after overheating. This is where synthetic oil could've been useful.

As for the ATF, if it looks OK I'd leave it alone. It should be fine. And for the coolant, test the mixture to ensure that it's 50/50 and make sure that your cap works properly.

 

[PandaBear]

Additional info:

The oil is synthetic blend (Maxlife) and I am about due to change it anyways

The ATF is SF ATF Z1 from Molakule, it has been in the transmission for 2k or so, I guess it is ok since it is a blend? for another 25k?


Is engine sound a good indicator of warpped block? I am afraid of the murphy's law, if I didn't find the root cause (i.e. which relay or which connector is loose) then it will happen again.

 

[eljefino]

What kind of car is this? You might have sensor trouble that causes the computer to think it's colder than it really is, and not want to turn on the cooling fan when necessary. This particularly plagues Saturns it seems. Depending on the model year the dash temp gauge will be at normal when the antifreeze is boiling away.

If you have air conditioning on, the radiator fan should always run. If it doesn't, I would suspect a relay or wiring problem or a flaky fan motor.

A bad coolant temp sender will also cause a poor fuel mix which might explain your rough running.

 

[Drew99GT]

Good catch on the coolent temp sensor eljefino. That would likely also cause a check engine light after a while.

Panda, I seriously doubt you warped anything. Hard to warp a block; you'd likely warp the heads first. However, it would have to be like 280 for a while, coolent guage well into the rad and steam pouring out. You indicated bubbling in the overflow. What temp or where was the needle on the coolent temp guage at that point, into the red??? If not, I would also suspect a bad radiator cap. It shouldn't have been boiling, even if it got to perhaps 230-240.

 

[PandaBear]

Acura Integra 97, that shows that things do wear out or fail no matter what brand and model it is.

The radiator fan doesn't always run with the AC on, but I will double check on it.

Forgot to mention that when this problem happens, I was driving at 110F heat in the desert, getting off a run at 90mph and right into stop and go traffic, not the best environment for cooling system glitch.

What I am not sure, is how reliable are the electrical components like relays and sockets under high temp and high milage. From what I saw, the blade type connections that the fuse and relay use should be very reliable.

 

[CBDFrontier06]

The fan may only run if the A/C compressor is actually engaged, so don't jump to any conculsions if the fan isnt turning when the A/C is on.

Go ahead and change your oil, as when it reaches boiling temperatures it loses it's ability to lubricate. This is why I don't see the point behind synthetic blend oils....half or more of the oil in your pan can't tolerate the temperatures that a full syn can, so if it's overheated, it's still trash.

I'd also get a coolant flush and refill to assure you have maximum protection against boiling. As coolant ages and becomes contaminated, it loses it's ability to protect.

Depending on how hot your heads got, your plugs may not have fared well, so you might consider changing them as well. I can't think of anything else that would be making it run rough besides having developed a head gasket leak due to overheat, so keep your eye on coolant level and the color / consistency of your oil.

 

[Tosh]

quote:

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Originally posted by PandaBear:
Forgot to mention that when this problem happens, I was driving at 110F heat in the desert, getting off a run at 90mph and right into stop and go traffic, not the best environment for cooling system glitch.

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This indicates that something was marginal for a while, and was just waiting for worse conditions. Smart of you not to continue and rent a car.

 

[johnd]

It might be as simple as a defective radiator cap-happened to me just about like you describe.

 

[Matt_S]

If I were you, I'd replace the cooling fan relay(s) and both those fuses, just to be on the safe side. Relays especially can malfuction in high temperatures as they age. I would guess that's most of the problem. To reassure yourself, replace the radiator cap too.

After that, run the engine up to temp and look for bubbles coming up into the coolant reservoir. That can indicate a head gasket leak, which may or may not indicate a warped cylinder head. If you have such a leak, that could continue to cause overheating, but would more likely do so under all operating conditions.

I wouldn't worry about the trans fluid, but change your oil to be safe.

 

[Jimbo]

quote:

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Originally posted by CBDFrontier06:
...

Go ahead and change your oil, as when it reaches boiling temperatures it loses it's ability to lubricate. This is why I don't see the point behind synthetic blend oils....half or more of the oil in your pan can't tolerate the temperatures that a full syn can, so if it's overheated, it's still trash.

...

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The normal viscosity of motor oil is specified at 100C, the boiling point of water. How does it lose the ability to lubricate at that temperature? There is an HTHS spec that is at 150C. There is no direct correlation between coolant and oil temperatures, especially when the overheating is at idle. The only reason to change the oil would be to check for coolant if a blown head gasket is suspected, doing a UOA. Full syn is of no benefit if coolant contamination is the problem.

 

[brianl703]

Check for signs of heat damage on the fuse and relay terminals and sockets. You might have a bad connection.

 

[OriginHacker21]

This sounds like my car - 04 Sunfire with the 2.2L Ecotec (similar to saturn?). According to engine temp guage and Scanguage - Engine operates at 190F. Redline at 290?

When I sit in traffic temperature goes up to 220F before I hear a fan turn on and cool the engine back down to 190F... I talked to a few people and they said this was "normal."

UOAs have always shown perfect - and coolant doesn't seem to be bubbling... Is this not normal???

 

[CBDFrontier06]

quote:

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Originally posted by Jimbo:

quote:

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Originally posted by CBDFrontier06:
...

Go ahead and change your oil, as when it reaches boiling temperatures it loses it's ability to lubricate. This is why I don't see the point behind synthetic blend oils....half or more of the oil in your pan can't tolerate the temperatures that a full syn can, so if it's overheated, it's still trash.

...

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The normal viscosity of motor oil is specified at 100C, the boiling point of water. How does it lose the ability to lubricate at that temperature? There is an HTHS spec that is at 150C. There is no direct correlation between coolant and oil temperatures, especially when the overheating is at idle. The only reason to change the oil would be to check for coolant if a blown head gasket is suspected, doing a UOA. Full syn is of no benefit if coolant contamination is the problem.

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I was referring to the boiling point of oil, not water. Do you know exactly how hot his engine really got? , because he doesn't. If it was hot enough to deposit boiling coolant into the reservior, I'd hazard a guess that the engine internals were considerably hotter than the boiling point of water.

 

[willkie]

On my 94 Legend there is a temp sensor in the radiator that fires the fans thru 3 relays. The
gauge in the dash has a different temp sensor in the upper part of the engine. There is another sensor next to the dash engine sensor that feeds the ecu.
Not sure if the Integra is laid out the same, but
if it is and the overheat happened after you slowed
down *loss of air flow} then look at the radiator
temp sensor and the fan relays *ac fan, radiator
fan relays and fan controler} If you are okay at speed *dash temp okay, normal warmup} then the water pump and the Tstat look good. The relays are the least trouble to replace. My radiator sensor has a variable resistor used for variable speeds on the fans, with AC compressor shutoff at 230 F*did AC shutdown}. The fan controler is under the dash on the legend. It also has an oil sensor that will run the fans for 15 minutes at engine shutdown if oil temp>198. You really need a manual to see
exactly how your Integra is laid out. On the Legend
both sensor and relays are known to go out or have intermitant failure. Hope this helps

 

[willkie]

quote:

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Originally posted by willkie:
On my 94 Legend there is a temp sensor in the radiator that fires the fans thru 3 relays. The
gauge in the dash has a different temp sensor in the upper part of the engine. There is another sensor next to the dash engine sensor that feeds the ecu.
Not sure if the Integra is laid out the same, but
if it is and the overheat happened after you slowed
down *loss of air flow} then look at the radiator
temp sensor and the fan relays *ac fan, radiator
fan relays and fan controler} If you are okay at speed *dash temp okay, normal warmup} then the water pump and the Tstat look good. The relays are the least trouble to replace. My radiator sensor has a variable resistor used for variable speeds on the fans, with AC compressor shutoff at 230 F*did AC shutdown}. The fan controler is under the dash on the legend. It also has an oil sensor that will run the fans for 15 minutes at engine shutdown if oil temp>198. You really need a manual to see
exactly how your Integra is laid out. On the Legend
both sensor and relays are known to go out or have intermitant failure. Hope this helps

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