Looked back on your first post, you have a 2.9 litre, mine is a 3, so I am going to assume they're different enough where I can't advise you accurately.

With that said, if you drained all the coolant from the rad petcock, there should be no (or very little) coolant coming from the thermostat housing.
This is going to seem silly, but is there any packing that was not removed from the water pump before you installed it that is now blocking the coolant flow ?
Check the hoses as well _ running out of ideas ???

 

You most likely had a "air dam" in the heads so coolant couldn't drain out of heads and block completely from lower radiator hose into radiator

Like if you put a straw in a glass of water and then put your finger on the top of the straw, you can lift out the straw and water stays in the straw, your finger has created an "air dam" so water can't run out of the straw

If you pull both heater hoses off at the firewall and THEN drain via radiator that will eliminate the "air dam" effect
You should also refill system from radiator with BOTH heater hoses off, that will allow the air OUT of head and block as coolant comes in
When coolant starts to come out of the heater hoses the air is gone, re-attach the hoses

 

thanks for the info , I just pulled both heater hoses off firewall and radiator will not hold hardly any coolant after drained. The spec says almost 2 gal.. could there be a blockage in the head somewhere that’s not allowing coolant in or cause if air to get stuck?

thanks

 

Could air trapped inside, not a blockage

Put heater hoses back on and start engine, rad cap off then continue to top it up, put cap back on
Let it idle until upper radiator hose at radiator end is hot, about 5min, that means thermostat opened

Shut off engine and let it cool down for 15min, should be able to take off rad cap then, be careful
Top it up if needed, you are done

Make sure over flow tank is at the COLD line
Then go for a drive, 10-20min, make sure heater is blowing hot after the 5min
Next cool down check rad level, should be at the very top, NO AIR at all

 

hi Ron thanks for the info , I did as you said.

once I started the truck my
upper radiator hose is very firm, I sat inside cab and watched temp gauge, stayed steady until about 7 min in it drastically rose up and Rpms went way up

I immediately turned off the truck

My overflow reservoir almost completely filled with coolant upon shutting off the engine.

any ideas ? Thanks for your time

ben

 

Do you have the serpentine belt routed correctly?

 

hi Grumpa, yes I have all three belts routed where they should be , 1987 2.9l

 

Thanks Jeff, yes I am pretty sure there was nothing I spent extra time cleaning out water pump mating surface before installing. I am stumped too seeing as how I passed the glove test , no coolant in oil, im unsure of what else to diagnose

 

hi ron, ive flushed out the coolant again,

when I went to refill system with heater hoses detached from firewall, the radiator fills up before any coolant comes out of end of heater hoses, should it come out before radiator is full ? thanks for your help

 

If the heater hose opening is higher than the radiator opening, you will not see anything come out of the heater hose. It helps to elevate the front of the truck or park on an incline to make radiator cap the high point.

 

+1 ^^^

Yes, put heater hose ends at same height as cap opening and you will see when its full

The coolant comes up into the engine thru the LOWER radiator hose, upper is blocked by thermostat
The heater hoses let the air out of the block and heads as the coolant flows in from lower hose

 

i kinda have the same problem and i keep getting mixed opinions so i have a 01 3.0l about 235k miles was well taken care of token to the shop but for some reason they ran straight water instead of coolant for a unknown amount of time causeing rust and build up. it ran amazing for almost 3 years with me doing all the maintence needed flushing coolant replacing oem temp sender not the receiver 2 different things lol. no problem unti about 6 months i slowly noticed the oil getting more and more polluted and a good amount of condensation coming out of exaust pipe way more than usual i did a gasket leak repair from auto zone i think. fixed the exaust condensation a little bit then i went to jail for about 2and half months before i got out my fiance told me during a visit that the truck broke down and the so called shop they took it to told them it needs all new gaskets and headers etc when i got out i got the whole story sitting at bottom of hill it started idling really bad and bunch of smoke from the exaust pipe and when i went to put coolant in almost immediately coolant starts coming out right before the catys i believeor right past the headers its been parked since if anyone can give me advice would be awesome thanks

 

Ronster, It sounds like your heads are cracked.

 

That, or one or both gaskets are gone.
It doesn't really matter, you have to remove both heads and have them pressure tested for cracks and both gaskets replaced.
Or you can simply go get new heads.

 

[QUOTE=loomdog32;2127639]The glove test pointed to a bad head gasket.

Got the heads off and, bad gasket.

Took the heads down for machine work/rebuild. Massively Cracked Heads. The Machinist was surprised the engine even ran.

The shop was able to get me a new set of heads for $550. I am now waiting for the new heads to put the engine back together.[/QUOTE


Do yourself a favor and Change the Cat Convertors. My 2005 XLT 3.0 has 3 cats, I replace the main one when I did the heads6 months ago. I'm doing the heads again because the small Cat convertors were plugged up. at least that's the only thing left to consider. I will check them after there out of the truck. Those heads are now a lot more expensive. Mine were 550.00, 6 months ago Now there 800.00 for the pair due to covid I'm told. I'm having the small cat convertors cut off and welding pipes in place of them. Your choice if you want to spend 600 bucks to replace them or 200 to bypass them. Bad Cat's can make the heads glow red even if your Gauge say's it normal operating temp. That's what happened to me so I'm changing the sending unit as well as a precaution. Originally thought it was thermostat however I boiled it to 190 degrees and It opened right up. I will replace it anyway.Seconds time a charm I hope. These heads from the factory had problems at higher millage. The Valve seats collapsed and They are famous for cracking. The Block however is a small compact warrior. Make sure the Sleeves that hold the head gasket in place are all there before reinstalling the heads. They can come out with the head if your not mindful of them and can get lost easily. I am searching for one now. I believe it was in the head and the machinist removed it to work on the head. Hopeful it's on his work bench. Anyway I'm in South Florida and The Cylinder Head Depot in Ft Lauderdale is the guy I use. 954 581 0102... I would not go anywhere else. Also make sure the Radiator did not pressurize to the point of failure, another thing I had to replace. I can not stress enough making sure the cat convertors are not plugged up. Best to you with the repair. I know a lot ab out this vehicle if anyone has an issue please ask. Crazy codes and replacing parts sucks when it may be something totally unrelated to the code presented.

 

thats what i was hoping it wasnt do u know what engines will fit in it? or know more about long block switch or something?

I really appreciate you responding