86 Ford Ranger 2.9 AT 4x4 Coolant Puking

[kyjones]

Truck is started and runs until normal temp. will run all day sitting in the yard and not run hot, throttle blocked to about 2500 rpm, good heat with some bubbles going into overflow tank. Thermostat seems to cycle open and closed as needed, Radiator same temp top, middle and bottom. When you drive about 1 mile heater goes cold, temp rises rapidly and coolant is pushed into overflow tank till overflowing and onto ground. Temp gauge will slowly come back down and intermittent heat will return. Truck will be about 3/4 gal. low on coolant. New 195 Thermostat, New 13psi Cap Thanks for any help!

 

[low_five]

the heater core goes cold becauase of loss of coolant.

overheating while moving is usually radiator. cooling fan is irrelevant
overheating while standing still is usually fan related. the fan isnt moving air through the radiator.

Id guess its a blocked radiator thats flowing just enough to keep it cool when idling. idling even at high rpm doesnt use much gas, but once you start moving you really load up the engine and burn a lot of gas, which produces heat.

 

[pocket-rocket]

Go to Autozone (as much as I hate to suggest that store) and rent their coolant system pressure checker. The one car I ran this test on didn't drop pressure when cold. But when I warmed it up, it would start spewing coolant and when I did the pressure check with it hot, the pressure dropped like crazy. A "25 year ASE certified Master Mechanic" didn't think it was the head gasket, despite all the symptoms I gave him. Turns out, I was right and I kept the bad head gasket as a momento. I have had 2 vehicles come to me that would spew coolant when hot (leaking compression into the coolant system) and have intermittent heat, both turned out to be head gaskets. But before you go spending dough on a head gasket set, like I said, rent the pressure checker to help you try to find the cause.

 

[LearjetMinako]

Bubbles and coolant overfilling into the resevior is not a good thing. Some is normal, but not to the point of overspilling. My co-worker had this problems on a 1.9L Escort. Highly susgested that the head was cracked or blown.

 

[shadetree]

My 86 2.3 uses a 16# cap. Are you burping the radiator after filling with coolant? There has to be room for expansion as the coolant heats up. If you fill the radiator completely, it will push it out as it expands. I had a similar problem to yours on one of my Merks. It was the cap. It was a new Stant, but was the wrong part number. Mfgr screw up.

Look at the sealing valve in the center of the cap while holding the cap up in it's normal position. This valve should stay sealed to the rubber. If it hangs down, wrong cap.shady

 

[pocket-rocket]

I forgot to put something in my last post... The coolant system pressure checker kit comes with a radiator cap test adapter as well.

 

[kyjones]

Coolant puking

I made a discovery today, I exchanged caps to a pressure release type with the lever. Started the truck cold and went to high idle with throttle blocked open. Radiator hoses start building pressure immediately, when truck was luke warm i released pressure with lever on cap and top radiator hose sucked together and filled overflow to about half full. Shouldn't rad. hoses stay without pressure till thermostat open's and coolant circulates through complete system? I then closed lever and coolant was drawn back in and rad. hose expanded back out. This repeated again till truck warmed for thermostat opening, then it couldn't be duplicated while truck was at operating temp.

 

[red85]

Hoses shouldn't collapse ever. Replace that hose and check it again. Sometimes one problem will mask another.

 

[kyjones]

Coolant Puking Rephrased

Hoses shouldn't collapse ever. Replace that hose and check it again. Sometimes one problem will mask another.

I installed a slinky type spring in top Rad. hose available at Advance Auto Parts.(Didn't have hose) Drove truck while semi-cold, heat started getting warm and heat gauge started going up. Then after about a mile heat went cold and i pulled over and checked overflow tank, it was completely full and overflowing. Temp. gauge shot up and then slowly started back down, heat did not return as to much coolant was lost. Coolant was pulled back into radiator but was still about 1/2 to 3/4 gallon low. If you allow truck to warm up (idling) to operating temp. while sitting in yard i drove 2-3 mile without any problems. Excessive pressure buildup in radiator is occurring during driving when cold to the point of puking coolant, I thought Radiator was isolated from engine during warm up till thermostat opens and then circulation occurs throughout system. Where does this pressure while cold come from?