Overheating issue with the old slant 6
- Thread starter scamp225
- Start date
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Check your transmission fluid.
kt340sport
Well-Known Member
It seems very quick for the gauge, to start moving .Did you try a hand held gauge you thread in , to see the actual temp.
nm9stheham
Well-Known Member
Take some of the reddish radiator fluid and put it in a glass jar and let it set for a while. If it is trannie fluid, it will slowly separate and rise to the top. If it is rust, it will settle to the bottom. Looks like rust but do this test to be sure.
Feling heat off of the motor does nto really tell us much anything; motors are always hot when running!
When you bypassed the heater core and then drove it, and then removed the radiato cap, was there pressure under the cap?
Also, when you said that it gets hot in about 1/4 miles and 'boils out of the radiator', where is it boiling out exactly? Into the overflow tank? Do you have a picture of the radiator cap?
Feling heat off of the motor does nto really tell us much anything; motors are always hot when running!
When you bypassed the heater core and then drove it, and then removed the radiato cap, was there pressure under the cap?
Also, when you said that it gets hot in about 1/4 miles and 'boils out of the radiator', where is it boiling out exactly? Into the overflow tank? Do you have a picture of the radiator cap?
yes there was pressure in cap.
would the top of radiator be hot enough to burn your self after 5 min drive?
doesnt seem to matter if its at idle or going 70 on the highway the gauge just keeps climbing.it there any other way to test for a blown or leaky head gasket other then a block tester or bubbles coming out radiator
would the top of radiator be hot enough to burn your self after 5 min drive?
doesnt seem to matter if its at idle or going 70 on the highway the gauge just keeps climbing.it there any other way to test for a blown or leaky head gasket other then a block tester or bubbles coming out radiator
nm9stheham
Well-Known Member
OK on the pressure. Yes, it might be that hot, but that is kinda hard to exactly say; it's too subjective and variable to be any sort of good test.
See if you can borrow a cooling system pressure tester that will fit on the radiator cap location. You can pump up the system pressure with this tester and see if the pressure holds and does not leak down; if not, then you have a leak somewhere.
Also, have you looked at the spark plugs to see if there is a fine, whitish granular deposit on any of the plug tips? That is a sign of coolant entering the combustion chamber.
Continuous bubbles out of the radiator is a common sign too. If a blown head gasket is the problem it sounds like it is pretty far gone with the apparent speed of the pressure and heat buildups.
I asked for a pix of the cap to just be sure it is a pressure type and of the right pressure rating. How did the fluid separate out? Rust (bottom sediment) or oily at the top?
I would be:
1) check the coolant coloration casue and the plugs as suggested
2) looking at the coolant in the top tank of the radiator while starting up from a cold start to see if the bubbles keep coming (sounds like the thermostat opens OK)
3) trying to verify the actual temp other than using the temp guage in the car
4) if it is really that hot, try to borrow the pressure guage; a few autoparts stores have them
See if you can borrow a cooling system pressure tester that will fit on the radiator cap location. You can pump up the system pressure with this tester and see if the pressure holds and does not leak down; if not, then you have a leak somewhere.
Also, have you looked at the spark plugs to see if there is a fine, whitish granular deposit on any of the plug tips? That is a sign of coolant entering the combustion chamber.
Continuous bubbles out of the radiator is a common sign too. If a blown head gasket is the problem it sounds like it is pretty far gone with the apparent speed of the pressure and heat buildups.
I asked for a pix of the cap to just be sure it is a pressure type and of the right pressure rating. How did the fluid separate out? Rust (bottom sediment) or oily at the top?
I would be:
1) check the coolant coloration casue and the plugs as suggested
2) looking at the coolant in the top tank of the radiator while starting up from a cold start to see if the bubbles keep coming (sounds like the thermostat opens OK)
3) trying to verify the actual temp other than using the temp guage in the car
4) if it is really that hot, try to borrow the pressure guage; a few autoparts stores have them
Throw that stupid cap as far as you can. They are total crap. Get a regular 15 or 16 pound cap with no lever.
If the transmission fluid looks ok, then you need to flush everlovin HELL out of that coolin system.
If the transmission fluid looks ok, then you need to flush everlovin HELL out of that coolin system.
nm9stheham
Well-Known Member
Uh-oh....Is that red oily stuff floating on top of the water in that bucket? Is that from the engine? Looks like trannie fluid......not good. Rad cap at least looks OK for pressure rating'; I kinda feel the same way about the lever types; I don't use them at all anymore.
Time to stop driving the car; looks like the trannie cooler tube in the bottom of the radiator has sprung a leak. You can use a hose to bypass the cooler lines back to themselves (I would do that like TONIGHT to try to limit water into the trannie), but hopefully there is not much water in the trannie. I would be pulling the trannie pan numero uno job to see if there is any water in the bottom, and any indication in the trannie fluid, like discolored foaming or gunky stuff.
(Rad obviously need to be rebuilt/replaced.)
If the trannie is clean (may or may not be), then a full cooling flush is needed first to get all the oil out of the engine block and cooling system. Use a real flush product and do it 2-3 times. You gotta get all that oil out before you can start re-testing the engine cooling system. After flush, I'd pull all of the hoses off and rub them clean inside, and do a seaprate, soapy clean in the radiator, water pump, themo housing, everything I could get off.
Once there, if the trannie has just a little water in it, I would do multiple flushes with cheap trannie fluid and cheap filters driven for just 1-2 miles between flushes, checking for more water after sitting overnight in the pan each time. Only after I found the pan free of water after sitting overnight, would I put more cheap fluid in it and drive for 10-20 miles, check again to see if there was no water in the pan after sitting overnight, and do it again if I found any. Once clean of water after a longer drive and an overnight sit, then I'd put in good stuff and filter. There may be a better way, but you gotta get the water out; it's cheaper than a rebuild. (Then I would cross my fingers!)
Time to stop driving the car; looks like the trannie cooler tube in the bottom of the radiator has sprung a leak. You can use a hose to bypass the cooler lines back to themselves (I would do that like TONIGHT to try to limit water into the trannie), but hopefully there is not much water in the trannie. I would be pulling the trannie pan numero uno job to see if there is any water in the bottom, and any indication in the trannie fluid, like discolored foaming or gunky stuff.
(Rad obviously need to be rebuilt/replaced.)
If the trannie is clean (may or may not be), then a full cooling flush is needed first to get all the oil out of the engine block and cooling system. Use a real flush product and do it 2-3 times. You gotta get all that oil out before you can start re-testing the engine cooling system. After flush, I'd pull all of the hoses off and rub them clean inside, and do a seaprate, soapy clean in the radiator, water pump, themo housing, everything I could get off.
Once there, if the trannie has just a little water in it, I would do multiple flushes with cheap trannie fluid and cheap filters driven for just 1-2 miles between flushes, checking for more water after sitting overnight in the pan each time. Only after I found the pan free of water after sitting overnight, would I put more cheap fluid in it and drive for 10-20 miles, check again to see if there was no water in the pan after sitting overnight, and do it again if I found any. Once clean of water after a longer drive and an overnight sit, then I'd put in good stuff and filter. There may be a better way, but you gotta get the water out; it's cheaper than a rebuild. (Then I would cross my fingers!)
That is a great idea and you have alot of good suggestions, how long would it take to separate like you say it will?
Dont have this problem but I am curious.
nm9stheham
Well-Known Member
Unfortunately, if that is the pix of your coolant in the bucket, the trannie cooler loop in the new rad is apparently defective; I would venture to guees it has a small pinhole in the loop. Hard to say exactly why until it is pulled out and taken apart. Do you have a local rad shop there? Or is this under warranty?
The trannie fluid is pumped under higher pressure than the coolant pressure so it is entering the coolant when running. But, once the car is not running and that trannie pump pressure is gone, there is nothing saying that some rad fluid won't seep back into the trannie cooling line and get carried into the trannie when it gets started again. You'll only know by puling the trannie pan and looking carefully. Once the rad is pulled and fixed for sure, then the flushing of the trannie ought to carry any coolant out of the lines. I would not put in any stop leak; it is not designed to fix a leak like you have in the trannie cooling loop in the radiator.
Thinking more about it, I would be doing the engine flushes and the trannie change/flush at the same time: i.e., put in the engine flush and fresh trannie fluid/filter and run for a bit at the same time. BTW the hose in the thremostat might help some to initially flush the engine, but that won't necessarily get into all the nooks and crannies. Like RRR said, your engine needs to have the he** cleaned out of it; any of that oil will block heat flow from the engine surfaces into the coolant and from the coolant into the radiator.
nm9stheham
Well-Known Member
I don't rightly know; probably not long for oil to start separating, unless there is some additive to make it break up. Looks like the OP's bucket test did not take long.
And if anyone knows what else this orange oily stuff could be that is floating on the water in the bucket picture, now is the time to speak up!
valiant1966
Well-Known Member
I tend to agree with nm9stheham. The fluid in the bucket looks like trans fluid not rust. I would focus on getting that "new" radiator checked out.
You won't need trans sealer after getting things fixed. That's not the issue. The leaky trans cooler in the radiator is the issue.
One option is to get a separate trans cooler and then plug the bungs where the trans lines go into the radiator. You're still gonna have to get all the remnants of water out of the trans and all the remnants of trans fluid out of the radiator. Dennis
You won't need trans sealer after getting things fixed. That's not the issue. The leaky trans cooler in the radiator is the issue.
One option is to get a separate trans cooler and then plug the bungs where the trans lines go into the radiator. You're still gonna have to get all the remnants of water out of the trans and all the remnants of trans fluid out of the radiator. Dennis
TylerW
Well-Known Member
These old engines have a very simple cooling system. The thermostat goes spring side toward the engine, not the radiator.
I don't recall if I saw the water pump mentioned. Sometimes the impeller can come apart without showing outward signs other than the engine not cooling well.
Either way, with a new radiator, new thermostat and coolant circulating there is almost no way it can overheat unless something worse is going on like a blown head gasket. It should run about 180 degrees all day long.
I absolutely would get that radiator out of there and exchanged. Tell them it split the trans cooler and you need another one, no discussion. Be glad it didn't pump coolant into the trans because that is BAD news.
Get the new rad in, new thermostat, fill it, run it and let it burp a couple times as you fill the coolant and see what's going on. If it's still going up/boiling you have something worse going on.
I don't recall if I saw the water pump mentioned. Sometimes the impeller can come apart without showing outward signs other than the engine not cooling well.
Either way, with a new radiator, new thermostat and coolant circulating there is almost no way it can overheat unless something worse is going on like a blown head gasket. It should run about 180 degrees all day long.
I absolutely would get that radiator out of there and exchanged. Tell them it split the trans cooler and you need another one, no discussion. Be glad it didn't pump coolant into the trans because that is BAD news.
Get the new rad in, new thermostat, fill it, run it and let it burp a couple times as you fill the coolant and see what's going on. If it's still going up/boiling you have something worse going on.
I found that my radiator was catching debris from the block since the car had sat for many years by previous owner. I changed the thermostat and flushed the radiator several times. But what worked best was to connect a hose to my shop vac and vacuum out the radiator to clear the fins. Flushing helped but I could see gunk sitting in the fins. It was sold material and came out nicely that way. Mine runs cool now and I do not have a fan shroud on my 64 valiant. Though I would if I could fine one local and cheap enough.
trapster
Well-Known Member
check your plugs to make sure you are not running too lean in the carb.
nm9stheham
Well-Known Member
That is a pretty interesting way to do it; I would go slow on that to be sure I did not collapse anything with strong suction from the vacuum, but it sounds like a solid idea. I assume you vacuumed from the top of the rad (which is the reverse of the normal flow)?
trapster
Well-Known Member
Grey as in powdery , could mean you are running lean and that could cause it to overheat.
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