Near overheat and no hot air -Troubleshooting

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Oct 4, 2005
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On my morning commute I my 96 80 started heating up for the 2nd time in the past 2 weeks. Mostly, i do short trips (less than 10 miles) and have never experienced this before. Also the heat has been working intermittently for the past 2 weeks. Sometimes it blows hot - then just mild air.

I made it to the office - after letting everything cool down I noticed that I have oil leaking att he engine side of the radiator - no tools but I've been able to :

top off coolant
check water valve
add oil
check fan

Engine sounds good and is not overheating at idle. No hot air blowing.

Ideas and thoughts on what I can do/check before my 9 miles home?
 

inkpot

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How much coolant was missing? Is the fan belt tight? Is the control cable still connected to the heater valve?
 
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Not much coolant was missing/if any...I just wanted to make sure it was at the line in the res. Hot from instrument panel and smoke some white smoke from drivers side hood.

Oil was low. Fan belt feels good, cable is connected to the valve and the valve is moving with the change from cool to hot.
 

inkpot

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White smoke may of been steam from leaky radiator. I would run it up to full temperature and look under the hood for signs of coolant leak.
 
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Forgot to mention - no noticeable smoke at tailpipe...

Wouldn't I be able to identify a leaking radiator by the presence of coolant leaking? How about the oil under near the radiator?

Thanks!!!
 
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The smell is sweet, but the small puddle under the rad is definitely oil. I am not sure if there is a change in the radiator - garage is too dark.
 
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The smell is sweet, but the small puddle under the rad is definitely oil. I am not sure if there is a change in the radiator - garage is too dark.
The radiator doesn't take "oil", only coolant. The coolant would be red or green (sometimes brown when bad...)

The puddle underneath could be red. But that could mean coolant or power steering fluid, depending on the location of the leak and what the substance on the ground is like. oil is slick when rubbed between your fingers. Coolant is "less slick" than oil, but "more slick" than water........

Smell, feel, and look for the leak. That will determine its origin.

Just because there is steam or smoke from under the hood could be anything. You must accurately describe what it is, with correct terminology for us to be any REAL help to you. Not trying to be snarky, just advising how to sort out what you are really seeing.

Pics help too.

The location under the truck helps with diagnosis as well. lay a piece of clean cardboard under the truck and determine the source of the leak.
 
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Appreciate it - and I'll do this. Just to clarify I am just trying to identify and cross out all I can from my office garage (no tools, cardboard, or lighting) before determining whether I should try to make the commute home.

Thanks!
 
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If it’s a red oil up near the radiator, it could be your trans cooler lines leaking.

To keep the coolant system from pressurizing and forcing a “hot” leak, you can loosen the radiator cap one click. I had leak once that only occurred when radiator got up to temp and pressure, by keeping it unpressurised I was able to make it home (100 plus miles) with only the occasional stop to add coolant directly to the radiator. CAUTION: if you go this route, keep the truck running and add a little at a time, you don’t want to shock the hot engine with cold coolant.

Watch your temp gage like it was a gremlin that was going to chew your knee caps off on the way home.
 
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OK, before you go:

While cold:

1) Remove the radiator cap and check coolant level. It SHOULD be right at the top of the neck. If not, you have a coolant leak. Add distilled or bottled water to fill it up enough to get home. Also fill the overflow tank to the full cold line as well.
2) Check engine oil with the dipstick. It should be at the full mark and the color should be a honey color or a dirty oil look, but NOT chocolate milk colored.
3) Pull the transmission dipstick with the engine OFF. The level should appear grossly over-full (like 3" above the full mark) but the oil should be clean and red to dark red.
4) Check the Power Steering fluid level by unscrewing the cap and checking the dipstick level. It should be at the "full cold" mark. If lower, you may have a PS leak.

This should be the major fluid checks required.

Check to make sure you have all belts installed and none are missing, rolled over, or wadded up on the water pump.

Good Luck!
 

ppc

M Go Blue
 
 
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On my morning commute I my 96 80 started heating up for the 2nd time in the past 2 weeks. Mostly, i do short trips (less than 10 miles) and have never experienced this before. Also the heat has been working intermittently for the past 2 weeks. Sometimes it blows hot - then just mild air.
That description leads me in the direction of a malfunctioning thermostat.
 
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Oct 4, 2005
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I’m worried it’s the head. Overheated on the way home again after topping off the fluids. After letting it cool, there is still coolant in the rad and in the reserve.

It drives fine - no sign of power loss but is heating up at a quickening pace and the blower still pushing cold. I did get it home though - so I’ll get to really look it over on the weekend.

Thanks all!
 
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I’m worried it’s the head
Look at it this way, if it turns out to be the head gasket going bad you'll know what to ask your wife for Christmas. If you're real good, maybe she'll even ask Santa to being you a Turbo Charger to install when you replace the head gasket!!!
 
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LINUS

Waiting for the Great Pumpkin
 
 
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Thermostats tend to “fail open” when worn out, so the lack of heat in the cabin might be from that.

But a failed thermostat just stays failed/neither the motor oe heater get to any great temp after one fails.

Unless your fan clutch is toast at the same time you failed the t-stat, IDK what else to guess at for worn parts.

Does your fan clutch have any maint in your ownership? -Does it resist movement to any degree when you try to spin a fan blade, or is it sloppy loose & never been changed?
 
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