Hey all
I was away from home when my daughter called me and said her car was smoking/Check engine line on/AC not working.

My immediate thought was that the a/c compressor seized and the smoking was the belt being forced around the pulley.

Told her to turn off the a/c.

Then a day or two later she calls me again that the car is smoking and the car stopped. Thinking that when the car was smoking earlier it damaged the belt and the belt lasted a day, but finally broke and not running the alternator, the car stopped because it was running on the battery solely.


Got home today and I clearly see that the uspect belt is fine and some whitish grease looking stuff at the radiator neck.

There is a crack at the neck and this stuff is oozing out of the crack. Undid the cap and the internals of the cap just came apart.

The check engine like has a code of p0117, which corroborates the overheating.

Here is the question.

Do you all think the engine's computer shut the engine off to save itself, or the engine stopped because it seized the engine?

I added a lot of water to the radiator and was able to drive it to the shop with no perceived problems. Even the A/C worked.

I checked the oil dipstick and saw no signs of water intrusion there either. My only explanation to the whitish stuff is oil being mixed with coolant. Head Gasket?

 

the smoking was more than likely the car overheating and boiling the coolant out. I would replace the radiator and anything that is leaking. You might be alright. The code you describe is the coolant sensor saying you're out of coolant or overheating. The ecu doesn't shut itself down. Let us know how it goes

 

yeah I concur that the "smoke" was steam. Since I wasn't present when it was smoking I can't confirm. She did say today that it smelled sweet to her.

I've seen the symptom of the a/c not working before on my cars that were running hot. I assume that the ecu is sensing it is hot and is turning off any accessories that would labor the engine even more.

Had I had more info I would have been able to assist her remotely better.

the question is
Did the engine shut off from the ECU shutting the engine down, or did the engine seize temporarily at its hottest point?

I guess a leak down test and compression tests after the radiator is replaced will let us know if the head gasket blew and/or the cylinder walls are scored to high heaven.

 

well you're overthinking the ecu. haha It's not as complex and intelligent as you might imagine. Unless you're using an aftermarket tuning system your vehicle wont shut itself down when it over heats. Wouldn't hurt to test the compression. It more than likely got to hot and shut down due to heat not the ecu. Anytime you notice smoke or your car going well above the over heating point most would typically stop running the car?

 

i would also test the cooling system make sure it is even operating correctly. The radiator may have cracked due to the thermostat sticking and or boiling the coolant. If you dont maintain pressure in the cooling system, it wont work correctly and will lead to over heating everytime. Also make sure the fans work

 

"most would typically stop running the car?" yep MOST would, unfortunately for me, my daughter didn't know what that gauge was for, nor did she recognize the difference between smoke and steam...

Like I said there was an obvious crack in the radiator at the neck. was that caused by the overheating (failed cap), or did the overheating happened because of the crack letting coolant out? Who knows.

at this point, step 1 is a new radiator, then test the fans for function. then a combustion gas test at the radiator.

The white grease looking stuff worries me as that, to me, looks like the result of oil mixing with coolant under pressure.

sigh

 

white grease/paste can occur from the ethyl glycol (coolant) drying or being heated/leaking etc

 

Yes, compression test to see if the head gasket is still sealing.

 

Good news. It appears that the head gaskets and heads are fine.

Mechanic replaced the radiator, cap and one fan. The fan was the most likely culprit, as well as the faulty cap. Without the fan turning on, the coolant overheated and with the faulty cap, the pressure wasn't released, thus the radiator cracked.

The whitish grease looking stuff at the crack is still unknown. Our guess is that the previous owner used some radiator sealer of some sort; as the pressure is it NOT climbing out of control, the temperature is right and there is no water in the oil pan.

tomorrow I'll scope out the front three cylinders and see how bad they are.