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Heater is not blowing warm air? Not sure how to fix heater, or were to buy new heater core. Does any one know if another model's heater core will work or "bolt up"?

Thanks

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1981 Chevy LUV 4x4 2.2L Diesel 4 Speed Selling out moving over to VW TDIs.

On my 79 the heater valve doesn't really open/close with the controls in the truck, so I have to basically open it for winter and close it for summer by hand. Sounds like you probably have a similar problem. The valve sits on the firewall a little to the right of the where the steering collumn comes out and has some hoses going into and out of it. First check that the cable is even hooked up to it (have someone move the control while you watch if the valve end looks fine, could be the other end is broke). As a test, move the valve by hand with the truck warmed up and see if you can get it to work that way. If everything is moving ok and you just have to move the valve by hand to get it to work, you might be able to just adjust the cable and get it all working again.

Basically, before you tear into trying to replace the heater core check everything else. The heater core being bad usually means you get a funny smelling steam bath or water/antifreeze leaking inside the cab. If just no hot air comes out, it is probably the valve. Only way the core could be bad is if it is totally plugged, but then you would have other problems like overheating because whatever plugged the core would also plug the radiator.

If the heater core had gone bad before, then someone might have bypassed it which would cause the same problem. Look for some empty hose connections on the firewall (the under the hood side) and probably some creative hose arrangement near them to check for this.

Forgot to mention, is the truck warming up properly? If the temp gauge is not coming up, the thermostat could be stuck open and the motor never gets the water hot enough to put out much heat through the heater. Usually it will get at least lukewarm though, enough to notice.

Also, the heater core is a pretty large pain to change out. Imagine everything under your dash coming out, and then having to all go back in in the right places again. There is no real quick shortcut. Its not too difficult to do, but it is a lot of work.

Also, it sounds stupid but check the water level in the radiator. If it is low the water will not flow thru the heater core.

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1980 4X4 LUV

I have a leaky heater valve on mine, just wondering if there's an easy fix for it or should i try to find one off of another luv?

i don't think that there is a way to fix these. i think your best bet would be to find one off a junkyard Luv...hmm, junkyard Luv...sounds kinda like that old song, Radar LUV

Josh

Woody is your 85 Chevy S-10 a factory 2.2 diesel or did you have to put it in as a project? I knew an S-10 came with the Isuzu diesel, but you can only find it in the early years and I know that is was rare.

The 85 Chevy S-10 is factory with 2.2 diesel . I bought it in 1996 from a used car lot with 145,000 miles. I have only had to fix the exhaust (3 times, it now supports a summit 3" dual), clutch, water pump and altenator, and i am on my third set of seats(now has buckets from a ford escort).

That is way I bought the luv, the same motor they just keep on trucking.
Plus the fuel miles are awesome.

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1981 Chevy LUV 4x4 2.2L Diesel 4 Speed Selling out moving over to VW TDIs.

Woody... If everything is hooked up and the bypass valve is open and it doesn't blow hot air, Try backflushing the heater core. You'll have to figure out which is the inlet and outlet to the core. Find the hose that goes to the water pump inlet and also disconnect the hose that connects at the thermostat housing. Take a garden hose and shoot water into the hose that connects at the water pump inlet and watch the hose that goes to the thermo, housing. If it shoots a bunch of dirt and crap out, it was plugged. Keep flushing until it's clean. If no water at all flows thru it at all, then the bypass valve is closed. I've had to do this on a number of cars to get the heat to work.

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Previous setup: 4.1 Buick V-6/TH 350
Current setup: 400 Small Block Chevy V-8/TH 350
9" ford rear end/short bed/blue
What do Water, Electricity and Humans have in common... They all travel the path of least resistance.

The thermostat housing had a blue RV type silicone gasket, so I changed the thermostat and installed a paper gasket.

I drained the radtior, and while I had the thermostat out I took a garden hose and shot water into the housing and then started the truck to let it flush. While the hose was on it all drained out the bottom of the radtior hose. (the anti freeze was a puke green color) I also took the time to take a garden hose and shoot water into the heater core hose that connects at the water pump inlet and watch the hose that goes to the thermo, how ever nothing came out so I tried it the other way and bingo, the core was plugged, guess what it was clogged with??? A blue RV type silicone.


The truck had been running hot and the gauge had fluctuated, now the heater works and reads at 3/4 of the gauge, at first I thought it was still running hot but now it seems that is where it needs to be. Drove it 1600 miles to Bristol Tenn it ran great, also getting better fuel miles.

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1981 Chevy LUV 4x4 2.2L Diesel 4 Speed Selling out moving over to VW TDIs.