HELP! Overheating Problem.Head gasket??

[TimS]

Hello. Been working on an issue with my 72 Barracuda original 318 car with 130,000 miles on it. Driving down the highway temp gets up to about 240. This isuue just started last week. In the last year and a half the car has had new water pump, Radiator recore, new rad cap and thermostat. These are all still good. I have good radiator flow.

Other symptoms.
Very little to no pressure at the rad when cap is pulled after long drive.
Milky substance on the inside of my fairly new recore rad.
Dry compression check at cylinders 1 and 3 are 135. Rest of cylinders 150 to 155.

LH head gasket bad?

Would like some views before I dig into this if possible. THANKS!!

[Plumcrazy]

Sounds like it's time for new head gaskets.  And maybe a valve job while you have them off.

[TimS]

Thanks for the info. I'm pulling them off now.

[TylerCharger69]

The milky substance you describe tells me  head gasket troubles.   Pull the cap off the radiator  and start it.....look and see if you see it bubbling in there.   A leakdown test when the car off can narrow it down too.

[mikepmcs]

i would cease driving until you get it fixed.  could cause catastrophic problems.
v/r
Mike

[dodge freak]

Check to make sure the head is not crack, might just be the gasket but then again heads do crack sometimes.

[TimS]

I got the LH head off, the side I suspected based on the lower compression #'s I saw at #1 and #3 cylinders. Don't see any cracks. Should I see some signs of something? The leak though was small enough that I suspect I may not. Especially head gasket wise.

[dodge freak]

I would pull the other head, you should notice something , a ring, gasket wet, crack , ripped . Take the other side off. You might have just had coolant leaking and the compression would be fine. Maybe Barrs leak would have stop it, but you are doing the right thing, keep up the good-and hard work.

[TylerCharger69]

I agree...have both heads done, checked for cracks  and new gaskets.   If one went out..well....odds are the other will follow suit and crap out on you as well.

[TimS]

I did expect too see something on the one side I took off. Thinking lower compression at 1 and 3 was a sign. Though I did squirt some oil in those cylinders and got the compression to come up about 12 lbs which could signal rings but I wondered with the piston pushing that oil up some if that would seal that small gasket seep.

[mopar_madman]

drain the bad stuff out and fill with oil until you get it fixed the mix of that is bad I heard.

[TimS]

Thanks for all the suggestions. Having both heads checked ,new gaskets and boiling the radiator out sounds like a good plan. I was trying to do the minimal if I saw an Issue with the LH head when I got it off but since nothing stands out I better pull the other. I planned to do a rebuild on the motor in a couple of years and was hoping I could get by but ,Oh well. Thanks again! I guess my 69 Charger work with have to wait a bit.

[TimS]

Just getting around to updating everyone on the overheating issue with my 72 Barracuda. Its all back together and running great. A list of what I did includes:

1. Remove radiator and take to shop for clean out and pressure test.

2. Remove heads and check for cracks, warpage, regrind valves and replace seals.

3. Replace Timing chain and sprockets.

4. While working on all this I went ahead and replaced the ole point distributor with new Mopar Peformance electronic ignition.

5. Keeping in mind in the last year and a half I have had the radiator recored, replaced the thermostat, water pump and temperature sending unit.

6. One last check for any leakage around anything. Rad tranny cooler, block and heater core.

Now after I got all this back togther I ran the car down the road. Car ran super with no leaks. It was about 95 degrees and humid outside so this was going to be a real good test. Believe it or not after all this the temperature at the stock gage will reach 230-240 degrees running down the highway. Same as before. Symptoms were still when the car first warmed up and got to temp it will sit at around 160 degrees, which is what I have in it for a thermostat. In about 5minutes running down the road after warmup the gage would go to about 230 indicating gradual overheat.

Because there was nothing left to try I dug into the cluster. I had a spare gage cluster voltage regulator so I replaced that. That ended up being the issue. As soon as I did that my gage now stays at 160 during highway driving and runs about 180-190 during hot idle sitting still, which is what I see on my other cars.

Woulda/shoulda but I obviously wish I would have put another aftermarket gage or something on the car to verify.

The white subtance in the radiator was because of the use of cheap antifreeze. I am guilty of using Walmart super tech in that car and my radiator shop guy tells me that some cheap fluids will foam after a while causing this stuff to stick to the core. Thats what I was seeing there. No more of that. And the fact that I had little to no pressure when I pop the cap on the radiator after pulling in from a hot run, I still have that.

So alot of work, learned some leasons that I thought would be good to pass on. Don't forget about that cluster volatge regulator.

[mopar_madman]

My 71 demon I had did the same,factory guage said ran hot put aftermarket on and it was fine. Do you have any pics of the cuda, would love to see it?

[TimS]

A friend of mine has a 72 Demon that may have the same problem. His meter pegs though, which is a little more obvious. Mine would just go up gradually then stop at a point. Attached is a shot of the car in my garage.

I can get back to my 69 Charger project now.

[TylerCharger69]

That's a 72 Demon???    Looks like a 'Cuda to me

[mopar_madman]

A friend of mine has a 72 Demon that may have the same problem. His meter pegs though, which is a little more obvious. Mine would just go up gradually then stop at a point. Attached is a shot of the car in my garage.

I can get back to my 69 Charger project now.

beautiful car!, what else you got hiding in there?? 

[TimS]

In there with the 72 Barracuda is a 71 Cuda 340 4spd, a 69 Dodge Super Bee 383 console 4spd. I also have a 70 Roadrunner B5 blue 440+6 AT with 4.10 dana and 69 Charger 383 console AT That resides in my garage. All original #'s matching cars.

[Reidar]

Im no expert, but i had a overheating problem with my 360 engine. It was boiling over and i also had what looked like milk inside my valvecovers.

For a while i was afraid i had a crack in on of the heads or the engineblock itselve, but turned out to be a leak between the intake and the head.
New gaskets and some sealer solved the problem.

Just my 

Reidar

[TimS]

Mine ended up being that Voltage limiter in the gage cluster.