1987 4wd Manual Overheated: Now what?

[momentum]

HI TV Family,

Recently my van overheated for the first time while chasing powder. After realizing the van was running extremely hot, I pulled over opened engine bay and both doors to let cool. After about 45 minutes I turned on van and drove about a half mile to a safer location where I called AAA and had the van towed to my house.

I have since: replaced thermostat with OEM, did radiator flush and added new fluid, replaced a few hoses that looked suspect.

The heater blows, the spark plugs look good. However, the van will not turn over. It sounds like it is going to and then fails. I was able to get it to run shortly but it sputtered off.

I now believe there is some sort of head gasket leak? What are the next steps I can take to get the van diagnosed?

Really don't want to have to get rid of this... Thanks in advance

[Gingervan19]

HI TV Family,

Recently my van overheated for the first time while chasing powder. After realizing the van was running extremely hot, I pulled over opened engine bay and both doors to let cool. After about 45 minutes I turned on van and drove about a half mile to a safer location where I called AAA and had the van towed to my house.

I have since: replaced thermostat with OEM, did radiator flush and added new fluid, replaced a few hoses that looked suspect.

The heater blows, the spark plugs look good. However, the van will not turn over. It sounds like it is going to and then fails. I was able to get it to run shortly but it sputtered off.

I now believe there is some sort of head gasket leak? What are the next steps I can take to get the van diagnosed?

Really don't want to have to get rid of this... Thanks in advance

Do a leak down test. https://www.amazon.com/Stant-12270-C...5318080&sr=8-1

[Burntboot]

"However, the van will not turn over. It sounds like it is going to and then fails. I was able to get it to run shortly but it sputtered off."

If the engine isn't cranking (turning over) then it could be seized, but I suspect you mean to say that it is cranking but failing to start/run?

Regardless of the overheat condition, standard rules apply - verify spark and fuel and move on from there.
You need to take the time to diagnose the no start before jumping into any other repairs.
Once you get it running you can better evaluate the engine's integrity.

[oli larsen]

leak down tests are great for checking the state of your rings or valve seats and valves.
I'd start by pulling the plugs and cranking it over with them out. sounds like you may have popped the head gasket and have coolant in a cylinder or two,causing hydro lock.
pull the plugs, crank it over and see if it blows water out of the plug holes. a very quick and easy way of discovering what you have done to it.
if there is water in the cylinders don't be tempted to try and start it up after its been pushed out.it will only make matters worse!
good luck and I hope its ok.

[Gingervan19]

leak down tests are great for checking the state of your rings or valve seats and valves.
I'd start by pulling the plugs and cranking it over with them out. sounds like you may have popped the head gasket and have coolant in a cylinder or two,causing hydro lock.
pull the plugs, crank it over and see if it blows water out of the plug holes. a very quick and easy way of discovering what you have done to it.
if there is water in the cylinders don't be tempted to try and start it up after its been pushed out.it will only make matters worse!
good luck and I hope its ok.

http://www.toyotavantech.com/forum/s...Coolant+losing

[oli larsen]

If the car has overheated and won't turn over why splash out on a pressure tester when pulling a plug could reveal water in the bore. solving the mystery very quickly and for no out lay.
a leak down test is mainly for testing the rings and valve seats etc.... but yes it can also be a test for the head gasket. if you bear in mind the cooling system holds about 1-1.1 bar anyway even if the head gasket is gone id expect to see pressure loss through old rings and valves before it overcomes a leaking head gasket and then pressurises the cooling system. especially on a 25 year old engine thats either done many miles or has had a lot of short trips in its life.

[momentum]

Well, I finally got around to working on the van again. I pulled the spark plugs and tried to start vehicle. Of course engine did not fire., there did not appear to be radiator fluid present. Plugs all look good accept the one furthest back from front of vehicle, which is covered in oil. I replaced spark plugs, vehicle will not turn on.

-Not sure what to do as my next step? get van towed to mechanic? I am intimidated by the task of taking the engine apart, especially since the van is parked in-front of the house...

[VanCo]

How hot did it get? How far into the red was the gauge? Steaming, gurgling from the overflow, etc? When you opened the seat was the wave of heat intense? I ask, because for an engine to not run after an overheat is rare and can mean the rings have collapsed and the compression is too low to combust the fuel. It could also mean the head is warped or cracked. Keep in mind these are worst cases based on the engine temperature going nuclear.

[Burntboot]

Momentum - I think we are having issues with terminology.
I cannot tell if your engine is seized or you have a no start condition

As far as "turning over" goes, most people use that turn to describe the engine spinning by way of the starter (Rrrrr Rrrrr Rrrrr)
Failure to fire would be, it makes that previous noise but the mixture won't ignite and the engine doesn't actually start running (fire)

When an engine is severely overheated, it is possible to seize the engine (things melt together and no longer move)
Said another way, you can not turn the crankshaft, no way, no how.
Is that the situation we are in?

I suspect that your engine turns when the starter is engaged but that the engine is not firing?
Is this the situation you are in?

They are 2 totally different situations and we really need to be clear which it is.

[momentum]

I love you all! Firstly, I apologize on terminology.

-Vanco: Yes it got VERY HOT. The gauge was in the top of red. It was about freezing outside and at elevation above 4000', I immediately pulled over and cooled van on the way to the local ski resort. Van was towed home.

-Burntboot: "I suspect that your engine turns when the starter is engaged but that the engine is not firing?
Is this the situation you are in?"

Yes, I would suggest the van does not "turn over" i.e does not run. I checked the voltage and battery is good, has gas, alternator is good.

[Burntboot]

Okay so just so we are TOTALLY CLEAR:
If the crankshaft is turning while you're holding the key in start position, then the engine IS turning over! (good news, by the way)
The fact that it fails to start is a different matter.

First order of business is to verify compression and spark, come on back with those answers and we'll head to the next step.
BB

[ZillerGrizz]

Momentum-

"Turning over"= turning the key and hearing: cranking, trying to start, getting some noise indicating that there is mechanical movement.

A seize of the engine would indicate that nothing is turning or moving or making any noise when you turn the key.

So, is there any movement/noise/Rrrr, rrr, rrr when you turn the key?

[momentum]

The van does turn over. Getting a bit ahead of myself stressing

[VanCo]

A gas engine needs spark, fuel, and compression to run. Since overheating can impact compression in a couple of ways (and not really impact spark or fuel directly), and the van ran fine prior to overheating I would start with a compression test. I hope it's not a compression issue but, deep into the red on these vans is probably around 250+ degrees. That is enough heat to do some damage to rings, valves, head, and head gasket.