Drove truck for a few miles severely overheating, how bad did we mess up?

Pull the fuel pump relay out. Fill the radiator full. Have someone crank the engine while you watch the coolant. If it goes like this, ___-___-___-___-___-, you have a leaking head gasket. If it shoots up and hits the hood, you REALLY have a leaking head gasket.

 

I knew a guy that drove his 500 cubic inch 1970 Cadillac El Dorado (the 6 years I knew him) with zero engine coolant (and he was proud of that fact). Maybe engine coolant IS overrated. I dunno

 

LOL.

 

I said the same, but he was changing the oil and saw a bunch of white/pink crust underneath. We traced it back to the WP and leaking weep hole. Truck never lost coolant though, so I think we both wish we just left.

 

If it was coming out the weep hole the seal was starting to leak, it was probably due for a new one. Its a shame this happened, you've just gotta deal with it and move on. If it warped the head, it might be cheaper to find a good used engine and swap it, if you have the skills, tools and time.

 

That's what I hear, especially with aluminum. Hopefully it's neither the gasket or heads and was just the air bubbles.

 

This is the last time I'll bug everyone about this, but I have another question.

In the manual, it makes it sound like there are 2 different temperature gauges in the truck, one for the radiator and one for engine temp. Is this true? If so, what are the chances the gauge was indicating that the truck had no water in it rather than the engine actually overheating? Just foolish wishful thinking on my part?

 

so i dont have a wiring diagram infront of me so dont take this as gospel but..... typically the gauge on the dash is for your coolant temerature. so if your radiator is empty it will read hot. The cylinder head temp sensor is what the engine computer uses to adjust A/F ratio/ and timing.

 

As was mentioned overheating is bad for uneven expansion. Overheating an iron block/aluminum head engine will likely stress the HG and a good way to crack the head. But it's also true these engines are tough and ruining a head gasket isn't the worst outcome.

 

Usually, if a temp sensor is exposed, it will not read hot but will actually read cold or won't read at all. That is what can be so ''dangerous,'' your engine is getting toasted but your gauge isn't telling you that expensive damage is occurring. A gauge that goes to cold means stop immediately and check your coolant level.

 

Probably a stupid question, but if I can get the wiring diagram (which I may have) what would I look for to determine which sensor it is? Thanks for all your help btw.

 

you would just be looking to see if the coolant temperature sensor was wired to the instrument cluster and the cylinder head temp sensor would be wired to the PCM. whats the latest with the truck? still having to add coolant?

 

No, last time I saw him it seemed to be fine, the coolant has stayed the same the last few days.

 

It is a coolant sensor

 

may have just had a bunch of air in the system. keep a close eye on it. If you can get your hands on a coolant pressure tester it would be a good idea to put it at 15-20 psi and leave it over night. if its the same in the morning you should be ok.

 

Not sure if it applies as I overheated my 4.0 to the red. And drove for about 10 miles before I realized it... Anyways... it also caused my transmission to overheat also and according to Toyota, the transmission is designed to purge itself of fluids/ pressure to protect itself (automatic not sure on manual) probably a good idea to have it checked out too especially if it starts to clunk when going into gear or seems to hunt more on the highways.

 

Any updates? @Drewski

 

Seems perfect now. He drives it all the time with no issues, so either got lucky or something will come up soon.