Amazing overheating problem...desperate

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ogden lafaye

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This is a jumble of answers and descriptions....

Thanks...yes, thermostat is in properly... have been working on cars since 1952 and let me tell you, THIS ONE HAS ME STUMPED...laughter, insane laughter...here is another post with the approximate story:


-Lean??? Throttle body FI here (1990 Ram D100/150 2 wheel drive automatic LWB pickup)
-Kink in bottom hose? Nahhh, all have wire coils usually, mine is new w/coil
-Air pockets, nahh, drilled 3/32" hole in new stat (Tried 4 stats by the way)
-All hoses, clamps, water pump, stat...NEW (old water pump was tight-tight and clean)
-Drilled 2nd stat since problems persisted...no such luck...problem continues...this 4th stant 195degF stat is drilled now also...no change
-Water moves in radiator at temp, but thats after it blew water to hell and back and overheated so the neighbors complained about the whistling and they live 1/2 mile away.
-I shortened and lowered discharge hose so it is below radiator fill cap...bypass hose (that little 6 inch sucker) is BRAND NEW
-Definitely good stat (Stant 195 deg F.) (drilled)
-Good pressure cap (16 lb)
-No, no bubbles...head gaskets are not leaking...once the heat is normal, this truck runs all day and night flawlessly...It is 26 years old and ran flawlessly for 25 years. I went 14 years without any major repairs.
-YES, pushes water out of overflow tank then bunches of hot hot steam
-Add 3 quarts of cold water to hot radiator and gauge goes down to normal and everything is OK for the rest of the day.
-Gets savagely hot first 3 miles, EVERY morning. EVERY SINGLE DAMN MORNING FOR 3 months...intense problem for almost a year now...I am going mad and insane. Off and on for 12 years, now it won't go away. Its a clean 2 row radiator
-It has been flushed 6 or 7 times and rinsed 30 or so times in the last month! (Maybe last 2 months) losing track of time involved on this mystery...Radiator fins blown out....nothing in them. No transmission cooler (disconnected 25 years ago) Exterior tranny cooler is free and clear of the radiator. The transmission started doing wacky things 10 years ago and it still does, with band material in the pan and hilarious shifts up and down at the strangest times...but it finally gets into 3rd gear after a few miles and works fine the rest of the day. I have hauled a big loaded trailer and truck bed many times (Like 70 full loads the past 8 years) and I have pulled stumps with the truck for years as well as pulled all the windows out of my old house for replacement. Pulled down many houses, fences, and sheds with it ever since I bought it. Did a good bit of towing other trucks years ago It has some minor dents but why would I get rid of it? This overheating is maddening and makes no sense whatsoever. I am [email protected] or 1-360-465-2809

Needless to say, I love MoPar products and have an absolutely beautiful Chrysler Sebring Convertible with low miles (140,000) I had a business and it involved Dodge Vans so I have owned about 20 different Dodge 318 powered trucks and a car or two. This pickup has outlasted them all...always my personal truck. My vans usually lasted 250,000 miles.

Desperate in WA state...thanks for any help
 
Bad thermal fan clutch is the only thing I can imagine that would cause this symptom. Or fan mounted on it backward.
 
Welcome aboard! TBI acting up part time as in messing with the timing and or the mixture (lean). I ain't up on the late stuff so I am just brainstorming (& a welcome)
 
OK, that is a bit hard to follow, what with the stumps and pulling and all.....but I'd

"suspect a combustion leak"

1...Did this "just start" on it's own?

2...Did this start happening BEFORE or AFTER you replaced a water pump?

3...Suspect a combustion leak.

4...Does the heater work at low speed? This will give you a clue if the water pump is broke.

5...Also, I'd suspect a combustion leak
 
This symptom caught my eye:
"-YES, pushes water out of overflow tank then bunches of hot hot steam"

This is quite abnormal, and indicates possibly that:
- The system is not getting anywhere near all the air out at filling (despite the hole in the t'stat). The coolant in the engine is flashing into steam in short order, and once the t-stat opens, just pressurized steam is coming out of the engine and pushes through the water in the overflow tank. The pressure would have to be somewhat high to do this, which indicates hard boiling in the block or heads. And I can't tell you how well or poorly the rad cap will seal in the presence of just steam rather than hot coolant.

Can I suggest that you go through the burping process slowly and repeatedly and with just 1-2 minutes of run time at any time, then allow a cooldown and repeat? Also, make sure the truck is pointed up hill; put it on a jack if you need to.

Another suggestion- Put a pressure gauge cap on the rad and stop every minute to see what is going on.

Questions:
- Does it do this if you start cold and idle, and not drive?
- What radiator? Does the cap actually match the rad opening for 100%
- What coolant is being used?
- Heater core hooked up? Do you open that when you burp the air out?
- Engine mounting normal? Not sloped 'downhill'?
- Any pix of the installation that you can share?
- Cooling fan(s) set up?
- Any excess water in the exhaust? Indicating that coolant is leaking out an exhaust port overnight?
 
Reminds me of the 455 in my old Toronado that had cracked heads....
 
My thoughts on the combustion chamber leaks are that it ought to run hot or too warm all the time; the OP says it is fine after the initial daily episode. Unless it is a water jacket leak that occurs when cold.....??
 
RedFish said:
Or fan mounted on it backward.
Click to expand...

A fan mounted "backwards" on the shaft, still blows the same way,, perhaps not as effectively, depending on fan shape, .. hence some fans have a "front"

You have to change rotation to get it to reverse flow...

hope it helps
 
nm9stheham said:
This symptom caught my eye:
"-YES, pushes water out of overflow tank then bunches of hot hot steam"

This is quite abnormal, and indicates possibly that:
- The system is not getting anywhere near all the air out at filling
Click to expand...

I don't know. Mopars are not known to be difficult to bleed. The only thing I've ever done, over the years, is to leave the heater hose off which connects to the Tstat, fill until coolant comes out there, then attach the hose and finish. Check heater when warming up. Heater should of course be set for full heat, and as engine warms, the heater should obviously warm at both heater hoses. This indicates flow.

When you can check / adjust water level. There is nothing changed in the magnums which complicates this.

Only other thing I could suggest is maybe Stant has finally become fully chineseoattianated. Maybe buy an OEM dealer supplied stat?
 
ogden lafaye said:
This is a jumble of answers and descriptions....


-No, no bubbles...head gaskets are not leaking...once the heat is normal, this truck runs all day and night flawlessly...It is 26 years old and ran flawlessly for 25 years. I went 14 years without any major repairs.
-YES, pushes water out of overflow tank then bunches of hot hot steam
-Add 3 quarts of cold water to hot radiator and gauge goes down to normal and everything is OK for the rest of the day.
-Gets savagely hot first 3 miles, EVERY morning. EVERY SINGLE DAMN MORNING FOR 3 months...intense problem for almost a year now...I am going mad and insane. Off and on for 12 years, now it won't go away.
Click to expand...
Well, you got the "jumble" part right. That was very hard to read, bordering on incomprehensible.

Instead of jumping around randomly, think about what is different between engine cold and engine warmed up. For one thing, when the engine is cold the coolant path is through the by-pass hose and the heater core. If the coolant can not circulate enough to warm the thermostat the thermostat will not open and the engine overheats. You need to be absolutely certain coolant is circulating when the engine is cold. That means test, not guess. By-pass the heater core if you have to to see if the symptom changes. Normally the hose nipples on the water pump from the by-pass hose and the heater hose should warm gradually as the engine warms up before the thermostat opens. If not, there is no or not enough coolant circulating.

I watched a tech got nuts trying to diagnose the exact same problem on a Fiero. (Yes, I know.) On that car the engine would get hot on a cold start. If you shut it off, waited, then restarted and repeated that three times enough heat would soak into the thermostat to open it and it would be fine the rest of the day. If the thermostat was removed the problem would not occur. The only by-pass path was through the heater core and it was mostly blocked. It would put out warm heat but not circulate enough coolant in a cold engine to avoid a overheat condition. See? The cause may not be obvious.

If the head gaskets were leaking cold you should get misfires and steam out the exhaust on start-up, one would think. Or you should see coolant in a cylinder when pulling the spark plugs on a cold engine and pressure testing the cooling system. I don't see how a fan or fan clutch causes a overheat on a cold engine when no coolant should be circulating through the radiator. If the water pump impeller was slipping when cold the problem would have been corrected by the replacement of the water pump.

Use a logical process. Test, don't guess. You will get it sorted. That's all I have for now. My brain is overheated.
 
Step 1 = They sell a kit that tests for combustion gases in the coolant system.
Step 2 = If radiator is original, replace it, and if newer, have it flow checked.
Step 3 = Check the condition of the water pump impeller.
Step 4 = Your done, assuming the water pump drive set-up is correct and the fan is pulling air thru the rad.
 
Put the water in before you leave home.( hilarious laughter)

Sounds like the initial surge of hot water cannot get through to the bottom of the rad,fast enough. Maybe a water flow-thru test will see it. Next time out, before you pop the top, grab the lower hose and see if it's still cold. Then work your way up the rad. Or bring an IR gun.
 
friends 383 would blow water out the rad and overheat, was 2 bad head gaskets. he ran it like that for a few weeks, just used a radaitor cap with no spring and a huge puke tank (it was in a 63 300 so had loads of room) it would blow water out the rad into the tank and eventually suck it back up, fine for short runs. Jsut leave cap off and start it, if it bubbles in the rad, you got air ingress from somewhere. His water pump was little more than a disk, as the fins had rotted off! PO had ran alot of straight water in there in its past life.
 
AJ/FormS said:
Put the water in before you leave home.( hilarious laughter)
Click to expand...

^^^^ Yeah,, I was gonna ask if it could be leaking coolant overnite,, no/low on coolant to start with,, the coolant would be too low to heat the thermostat,, till it was steaming.. thennn you fill the system...
 
To check if the impeller is slipping,, fab up a tool as in pix,, you can take the by-pass hose off,,,, send the tool down the inlet and snag the impeller,, then turning the fan.. it saves removing the pump..

Being a new pump,, you can be fairly confident the vanes aren't rotted off..

hope it helps
 

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Do a coolant pressure test when cold and also a compustion chamber/cylinder leak down test when cold while looking in the rad for bubbles. Something is causing the block to cavitate when its cold.
I have seen a slipping fan act this way once in my lifetime so its possible.
 
ogden lafaye said:
Gets savagely hot first 3 miles, EVERY morning.
Click to expand...

Cracked heads? Could be a hairline crack that allows enough coolant to leak into the the chamber until it gets warm enough to close up the crack then it's OK. Hence the steam (excessive pressure) Have you looked down into the cylinder with a light to see if there is excessive carbon or is it super clean like it's been washed? If it's super clean, it's getting water washed. Is this a 360? If it is, it probably has '308' heads? I believe they are known to crack between the valves. Could be a dropped valve seat?

Other thing I can think of is something happening during the warmup cycle, like detonation or an overly lean condition until the coolant temp gets to a certain point then the a/f mixture stabilizes until the next cold start. I know nothing about early computer controls but perhaps you have an electrical/computer issue?

Have you checked your coolant temp sensor for proper operation? Done a leak down test? Checked for a vacuum leak that closes up after it gets warm? All kinds of stuff to do before you start replacing parts.
 
Lots of good suggestions here. You will have to go through each step in some sort of order. I will throw my two cents in. Is there anything that could be putting a load on the engine causing it to do too much work? Something that maybe would ease after a few miles. The trans problem seems closely related, maybe a converter problem. Maybe the parking brakes take a little time to release. Check the rear end after driving for a while. I've seen some that glow red they drag so bad.
 
999yards said:
Very fine fracture in exhaust valve seat?
Click to expand...

Thats a clever thought and THAT is the best clue so far...it could certainly close up after it warmed up, couldn't it?
]
There is a Tom McCahill type in my circle of friends that speculated on a fine crack in one of the heads. Yours makes a little better fit to the symptoms.

Sooooooooooooooo. As of last week:

In the extreme: I changed the stat to a drilled 180 degF. I changed the pressure cap to 13 lbs. It has passed the morning test 3 times in a row now...crossed fingers. I'll keep you posted.

Transmission:

Old time transmission guys working out of their garages just don't seem to exist anymore. All of mine but one have passed on. The last standing is 78 and he just won't tear into mine...too much work.

I know someone but they are 750 miles away and probably $1500 to $1800...and thats R&R myself.
 
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