Hello -

This is my first post here, although I have enjoyed reading all the various posts in the different forums.

I am having a BIG issue with my 92 Ranger 4x4, 2.9L V6. I bought the truck a few months ago with 127K on the clock, now up to 129K. The truck ran great when I bought it with the exception of a clogged heater core. The temp gauge rarely got above the "C", just wrote it off as a faulty temp gauge. I replaced the thermostat and replaced the heater core, would work for a week or two and then require a blow out with compressed air. Has been this way up until about a week ago.

A week ago I was driving down the freeway at about 60 MPH. The truck began to hesitate but nothing abnormal was indicated on the gauges and no check engine light came on. I nursed it home and parked it. I noticed that the coolant reservoir was bubbling and that you could hear and fell the coolant rushing through the radiator. This past weekend I rebuilt the cooling system. Another new thermostat, new hoses, new water pump and new coolant. I removed the radiator (was told it was new when I bought it) and flushed it with clean water, flow was fine, not clogged.

The issue I am having now is the truck starts and runs great, temp gauge gets up to the middle of the normal range and holds consistent for the most part, however, there is no heat. I removed the hoses from the heater core as the truck was running, and no coolant is reaching them. The truck would emit steam from the heater core hose coming off the water pump, then every once in a while, a little coolant would could pumping through.

The top return hose on the radiator is firm, there is a lot of pressure being built up and the truck is not overheating. No milky oil or anything like that. I am lost for why I am still not pumping coolant into the heater core and what the problem could be. ANY help or advice you can give me would be great. We "burped" the system of air the best would could, is it possible that I am still getting an air lock somewhere?

Please help and thank you in advance!

Johnny B

 

Change the lower radiator hose. Sometimes the inner liner will peel away and a "flap" will come loose and clog the water inlet to the pump. You may get just enough flow to keep the engine around op temperature but that's all.

 

Thanks for the reply OTR, I put a new lower on this weekend, as well as new heater core hoses. The upper seemed fine so I did not replace it.

Any other ideas?

 

You could still have an air bubble.
Park the truck facing uphill , as steep as you can get.A 50-60 percent grade will work. Remove the rad cap and top it off again.

 

Thanks, I will give that a try after work and will report back with what I get. I am really hoping that it's not a head gasket!

 

Just for the fun of it, with the engine cold, pull the end of the heater hose off the pump and the one by the thermostat and do the following:

1. If your system has a hot water valve, ensure its functional.
2. Try blowing through one of the heater hoses and see if you can push coolant or blow air through the core.
3. Using a piece of stiff wire such as a coat hanger, try pushing it down the tube at the water pump and the one by the thermostat ensuring their open.

I had a water pump once for an S-10 that the factory forgot to remove the casting flashing from this tube and it wouldn’t let water flow through to the heater core. Dangest thing I ever saw. Also, you may have enough rust built up at the one by the thermostat to plug it as well.

 

I used low pressure from my air compressor to blow the crud out of the heater circuit.

It blue muddy water all over ne and the truck, but it worked great.

Made the wifey mad too, but, I am u8sed to that.