I have a 1986/7 4x4 pickup with a 22r /weber. I believe it has been converted from efi.


my problem is:
there is lots of pressure coming out of the radiator, blowing coolant out of the overflow. I started the engine up without the cap on and it shot out like a geyser. when I rev it up with the cap off coolant blows all over the place, when the engine is warm and I floor it driving and open my hood water is everywhere out the overflow

sometimes I can go about 2 weeks with out putting any coolant in,

but I can tell when I am running low because the temp gauge will raise almost to the right before the red on warmup and usually goes back down to middle once the thermostat opens. it will get close to the red and I will shut down, wait literally 1 minute, start up, and it will immediately go back to normal.

the PO replaced the water pump and timing chain and new radiator. I've personally put a brand new thermostat 2 months ago.

ive changed the oil twice in this truck never had water in oil, i just changed my oil last week and no oil.

no water in exhuast

not sure what I'm gonna do.

 

Do a block test to test for exhaust gasses in the coolant. If there are any present (usually the blue liquid will turn yellow) then you've got a blown headgasket between a water jacket and cylinder.

Have you properly bled/"burped" the system? Park on a hill, or raise the front of the truck up high, put heat on full hot, and fan on high. Fill the expansion tank/reservoir to the hot mark, fill radiator up. Rev the motor to around 2000rpm. This will help purge all the air from the system.

The cooling system only overpressurizes for a few reasons:

1) BHG
2) air in, or getting in the system.

If you have any leaks, fix them. When coolant leaks out, it's replaced by air. Air in the system lowers the boiling point of the coolant which causes the coolant to boil. If the coolant boils, a side effect is steam, which will cause that geyser of coolant bursting from your radiator/expansion tank. (just like exhaust gasses forcing the coolant out)

Start with the easiest- a block test. If that fails, you know where the problem lies. If it passes a block test, do a cooling system pressure test/look for leaks.

Next, do a leakdown test.

 

X2

Sounds like a blown head gasket to me.

I would pressure test the cooling system to see if they are any leaks.

 

I bought head gasket and head bolts and I got the 261C and springs

gonna probably pull the head off next later this week

Im gonna put a header on it too.

 

Would a bad radiator cap cause any of this.

 

No.

Even if the RADIATOR CAP was bad, it would leak pressure out, not make it build up.

 

Head Gasket. Make sure you get your head checked and resurfaced if necessary. Don't just put on a new gasket for a band aid. Since your pulling the head off and partially apart ,if you need any valve stems seals (recommend replacing them) let me know. i have 2 packs of em i'll let go of 1 for cheap. Only need one spare pack...

 

This happened to me a few months ago... Head gasket leaked compression into coolant passages... blew all the radiator fluid out in a matter of seconds thru the over flow tank. Best of luck!!

 

Blown head gasket. Sorry dude.
My truck had the exact same symptoms.
If you wanna save your engine, pull the thermostat.
It's by no means a long term solution.

Buy a gasket kit from Engnbldr and a head gasket from Toyota (or use the one from engnbldr if you're short of cash).
Make sure you have the head decked and the block checked.
Be sure to really clean out the head bolt holes before re-installing them.

 

thanks for the replies.

22r head is coming off tomorrow.

I've got new valve oil seals, new springs, new cam, new head gasket, new head bolts and used header to instal.

I am going to do egr and air injection delete too.

And that is a good idea stuwy123, I have been just driving back and forth to work for a couple weeks with the engine doing this.

 

Just drill a hole in your radiator. It's an easy fix.

Wish it was that easy.

:wabbit2:

 

i tried that once and it didnt work so well ha ha