Coolant temp sensor blow out

[Dm03n]

Help. Trying to understand. Has anyone ever heard of the brass temp sensor blowing out of the engine head?

A mechanic replaced my engine, drove it 35 miles and the coolant temp sensor blew out. The temp gage showed 220ish just before it blew dumping all the coolant out. Was able to screw the sensor back in, (temp gage pinned out past 280 and now detects temperature difference but not actual temp accurately) put coolant in, let it cool, and drove it to the next rest stop.

Is it possible for that sensor to blow out without stripping the threads because an engine got too hot?

 

[Rickf]

Is it possible for that sensor to blow out without stripping the threads because an engine got too hot?

Yes, any sensor that is multi-piece can have the center take off.

I've had an a/c high pressure sensor blow out, it left the threaded part in place.

 

[WP29P4A]

I would say no. The only way I can see that happening is if the sensor was not tightened or was the wrong size. You said you were able to screw it back in which would indicate that it is still in one piece. If threads are not damaged than it was very likely only screwed in a couple turns and the heat and pressure was enough to turn it and pop it out.

 

[Dm03n]

Yes, any sensor that is multi-piece can have the center take off.

I've had an a/c high pressure sensor blow out, it left the threaded part in place.

Everything was intact though. The threads from the adapter (cyl head to sensor) and threads on sensor.

I would say no. The only way I can see that happening is if the sensor was not tightened or was the wrong size. You said you were able to screw it back in which would indicate that it is still in one piece. If threads are not damaged than it was very likely only screwed in a couple turns and the heat and pressure was enough to turn it and pop it out.

It didn't make sense to me either outside of an improper installation. Now my heads are pissing oil/coolant out the driver side.

 

[WP29P4A]

Oil and coolant together are not a good sign, possibly indicates bad head gasket or cracked head. Is the oil sensor lose also?

 

[fast 99]

Where is it leaking from? If it was actually 280 that isn't good. Like others suggested the sensor probably wasn't tight. The shop that did the work will have some liability on this. At this point stop doing anything, take it back.

 

[Dm03n]

Oil and coolant together are not a good sign, possibly indicates bad head gasket or cracked head. Is the oil sensor lose also?

Didn't notice it but I'll have to double check. Checked the valve cover gasket and it's not from there, but there was metal flakes mixed with oil sludge underneath. It appears to be coming from the driver back side of the motor and going down the exhaust pipe and blowing up onto my booster, master, and firewall. 90% sure it's head gasket. Hoping it's not worse.

Where is it leaking from? If it was actually 280 that isn't good. Like others suggested the sensor probably wasn't tight. The shop that did the work will have some liability on this. At this point stop doing anything, take it back.

I did he, and kept it a week. Mechanic said it needed a new temp sensor (reading improperly) and tachometer but it was drivable. At this point he's hiding behind a no labor warranty and will not do anything about it.

 

[fast 99]

At this point start thinking the motor may be damaged and what the options are. A new motor especially can be quickly damaged without coolant. It will have higher ring drag during break in. Already sounds like your mechanic has denied responsibility.

 

[Snoots]

Scratch that mechanic off of your list. Get an inspection mirror and also check the freeze plug on the back of the head.

 

[Dm03n]

At this point start thinking the motor may be damaged and what the options are. A new motor especially can be quickly damaged without coolant. It will have higher ring drag during break in. Already sounds like your mechanic has denied responsibility.

He definitely has. I wanted to see if anyone has ever had that sensor pop out for anything other than it being improperly installed. Going to end up going through the entire engine at this point.

Scratch that mechanic off of your list. Get an inspection mirror and also check the freeze plug on the back of the head.

I will check that as well thank you.

 

[fast 99]

He definitely has. More or less is it worth it to take legal action if the motor has catastrophic failure.

Legal action, kind of depends on what your time is worth. The cause of the failure and resulting damage will need to be proven. A second [professional] opinion might be needed. That's why I suggested stop working on it.

 

[Vbb199]

You don't reckon the thermostat just didn't open and a already poorly threaded CTS was the first thing to go when it pressurized, do ya?


Edit: oh poo, im late to the party

I kept reading, smh I hate seeing mechanics rip people off

 

[Dm03n]

You don't reckon the thermostat just didn't open and a already poorly threaded CTS was the first thing to go when it pressurized, do ya?


Edit: oh poo, im late to the party

I kept reading, smh I hate seeing mechanics rip people off

Unfortunately it was the first thing I checked. Both hoses were hot.

 

[SirRobyn0]

He definitely has. I wanted to see if anyone has ever had that sensor pop out for anything other than it being improperly installed. Going to end up going through the entire engine at this point.

I will check that as well thank you.

The only way I've seen a sensor leave the block on it's own is a 2 piece sensor where the center pops out, or it's not tightened down and unscrews on it's own.

At the shop occasionally we do non-warrantied work. Such as would be the case if the customer supplied the part. However if we did something negligent, we'd take care of it because it was our fault, because it's the right thing to do even if it cost us a motor. You can take anyone to small claims for any reason, but if you want to have any chance, you'll need to get a second professional opinion and have documentation of that with you. Even still the mechanic can claim you should have stopped driving the truck and had it towed thereby attempting to pin it back on you. It sucks that mechanic is not taking responsibility and guys like that give the industry bad marks.

Anyhow whatever you do, the best of luck to ya!

 

[WP29P4A]

Just a thought, coolant has something in it that feels oily. Is it possible that the coolant sprayed onto the frame area and left behind an oily film? Maybe not oil and coolant? hopefully.