Coolant does not flow with thermostat installed

[will e]

Sorry I'm late to the party and only skimmed the last few pages. Have you checked to see if the lower hose is collapsing?

I installed a new lower hose and it doesn't appear to be collapsing. I purchased a spring to install in the hose. However, the inside diameter of the hose is smaller than the spring. Perhaps someone can offer a tip or trick to install the spring.

Coat the inside of the hose with some coolant, this reduces the friction. You spin the spring in. Try to get the hose as straight as you can while doing this.

 

[Hemikiller]

Woof! What a read....

Just to cover all the bases, get a correct stock style cap for the radiator. Stant 10229 for stock style, 10239 for release style. That may or may not solve your coolant discharge issues. Stock and most aftermarket radiators have a "FULL HOT" line stamped into the radiator tank below the filler neck. If your system purges down to around this line, stop refilling it! It's not a closed system and will find it's own level. You may also want to get an inexpensive mechanical temp gauge from the parts store to install temporarily, just to verify the running temps.

Regarding the WCCC restrictor, I have not used one but my inclination would be to drill a small bleed hole on the upper surface as well, just to put it at the highest point of the plate.

As an experiment, try using 50/50 mix of antifreeze, as it does raise the boiling point of the coolant to around 250* @ 13psi. You may be generating steam pockets with plain water and this may account for your knocking noise and 5 psi rise in pressure while it's running. The subsequent drop in pressure when you rev the motor could be the cooling of hot spots when increasing the coolant flow.

 

[klinton994]

Woof! What a read....

Just to cover all the bases, get a correct stock style cap for the radiator. Stant 10229 for stock style, 10239 for release style. That may or may not solve your coolant discharge issues. Stock and most aftermarket radiators have a "FULL HOT" line stamped into the radiator tank below the filler neck. If your system purges down to around this line, stop refilling it! It's not a closed system and will find it's own level. You may also want to get an inexpensive mechanical temp gauge from the parts store to install temporarily, just to verify the running temps.

Regarding the WCCC restrictor, I have not used one but my inclination would be to drill a small bleed hole on the upper surface as well, just to put it at the highest point of the plate.

As an experiment, try using 50/50 mix of antifreeze, as it does raise the boiling point of the coolant to around 250* @ 13psi. You may be generating steam pockets with plain water and this may account for your knocking noise and 5 psi rise in pressure while it's running. The subsequent drop in pressure when you rev the motor could be the cooling of hot spots when increasing the coolant flow.

Hemi killer,

The aftermarket restrictor has only a flat surface that rest into the block, and a slight lip around it. I have already enlarged the bleeder hole. I think the idea of trying the 50/50 coolant is worth a try.

I had only been using water after wasting a few gallons of coolant.

I'll look into the radiator cap, although mine is a pressure release type and tested fine.

Thanks

 

[klinton994]

Woof! What a read....

Just to cover all the bases, get a correct stock style cap for the radiator. Stant 10229 for stock style, 10239 for release style. That may or may not solve your coolant discharge issues. Stock and most aftermarket radiators have a "FULL HOT" line stamped into the radiator tank below the filler neck. If your system purges down to around this line, stop refilling it! It's not a closed system and will find it's own level. You may also want to get an inexpensive mechanical temp gauge from the parts store to install temporarily, just to verify the running temps.

Regarding the WCCC restrictor, I have not used one but my inclination would be to drill a small bleed hole on the upper surface as well, just to put it at the highest point of the plate.

As an experiment, try using 50/50 mix of antifreeze, as it does raise the boiling point of the coolant to around 250* @ 13psi. You may be generating steam pockets with plain water and this may account for your knocking noise and 5 psi rise in pressure while it's running. The subsequent drop in pressure when you rev the motor could be the cooling of hot spots when increasing the coolant flow.

Hemi killer,

The aftermarket restrictor has only a flat surface that rest into the block, and a slight lip around it. I have already enlarged the bleeder hole. I think the idea of trying the 50/50 coolant is worth a try.

I had only been using water after wasting a few gallons of coolant.

I'll look into the radiator cap, although mine is a pressure release type and tested fine.

Thanks

Hemi Killer,

By chance, would you have a manufacturer and part number for the correct 351C thermostat. I may look for an original restrictor plate.

 

[rocket366]

Reaching here:

You ARE NOT using an after market serpentine belt set-up that is turning the WP backwards?

You DO NOT have a Marine Reverse Rotation WP installed?

Covering all bases

Paul

 

[Hemikiller]

Hemi Killer,

By chance, would you have a manufacturer and part number for the correct 351C thermostat. I may look for an original restrictor plate.

There was a post with info, here's the pic with t-stat info.

 

[klinton994]

Reaching here:

You ARE NOT using an after market serpentine belt set-up that is turning the WP backwards?

You DO NOT have a Marine Reverse Rotation WP installed?

Covering all bases

Paul

Negative on both.

 

[klinton994]

Hemi Killer,

By chance, would you have a manufacturer and part number for the correct 351C thermostat. I may look for an original restrictor plate.

There was a post with info, here's the pic with t-stat info.

Hemi Killer,

thank you. To make me even more crazy, I did a re-test for combustion gases in the radiator. I could not get the test fluid to change color to save my life. I verified the fluid was good by testing at the tail pipe. The fluid turned yellow immediately.

I purchased an infra red temperature gun. With the engine at operating temperature, based on the dash gauge, the thermostat housing is between 190 and 200 degrees.

The water in the radiator was around 125 degrees.

Today, for the first time, I did see slight movement of water flowing through the slots in the upper portion of the radiator. When I increased the rpms to see if flow would increase, the radiator belched water out of the filler neck.

I had originally taken the water pump of and inspected it. The impeller was fine. There was slight resistance when turning the shaft. When I held the impeller and attempted to turn the shaft there was no slippage. Even after doing these inspections, could it be possible the pump is week and not pushing enough water? I'm reaching here.

 

[justford]

I don't think so but since you have it off I would go ahead and replace it.

 

[Stanglover]

Klinton 994, I've been away for 2 weeks and am surprised to say the least that this issue is still ongoing. You mast have dropped a small fortune trying to get to the bottom of this........... and likely turned (more ) grey haired doing it!!

While I'm definitely NO expert, I too would be frustrated beyond belief. Everything I can think of and more has been done. So what's left?

The use of plain water could be part of the problem for sure. You now know that water is coming out of the rad overflow, so I would go to 50/50 Prestone and a catch can while sorting the issue out.

If it were me, I would now go back to an original set-up with he restrictor and a correct Cleveland t-stat. Install a new w/pump and make sure the direction of the belt/pump rotation is correct. Can belts be put on wrong to change direction, I'm not sure, but may be worth checking.

Soooo, hope you get to the bottom of this soon. It's getting to be a long read to keep all the suggestions in mind.

Geoff.

Edit: No way to change pulley/pump direction. It will always be clockwise. Had to go check my engine and check direction of the PS pump and alternator. The old mind was playing tricks on me!

 

[klinton994]

I'd like to thank everyone for their input and ideas with my overheating issue. This weekend, I believe I've narrowed it down to be a head gasket or cracked head.

I drained the water and added a 50/50 coolant, water, mixture.

I left the water level about two inches below the filler neck.

The outside temperature was in the mid nineties.

I took the car for a thirty minute ride through the back roads, ending at a friends house, who is very knowledgeable about cars.

After arriving at his house, I checked the temporary coolant overflow tank that I installed. I was surprised to see only a tablespoon or so, of coolant.

Using the infra-red temperature gun, he found that the intake manifold feed to the number five cylinder was considerably warmer than the others. It was in this area that I was hearing what I described as a knocking sound.

The car sat for a few minutes while we discussed what the problem could be. During this time, with the motor off, surging could be heard in the upper radiator hose.

We decided to do another test to see if any combustion gases were in the radiator. I had done two previous test on different days. One test the fluid turned green, on the second test the fluid remained blue.

When he released the pressure on the radiator cap, he was surprised at how little pressure was in the system.

I started the engine, and the test for combustion gases in the radiator turned positive immediately. Also, the water was flowing freely through the radiator.

I conclude that in my previous efforts to locate the overheating problem, the cars engine was not truly up to operating temperature, although the gauge on the dashboard indicated otherwise.

 

[Stanglover]

I'd like to thank everyone for their input and ideas with my overheating issue. This weekend, I believe I've narrowed it down to be a head gasket or cracked head.

I drained the water and added a 50/50 coolant, water, mixture.

I left the water level about two inches below the filler neck.

The outside temperature was in the mid nineties.

I took the car for a thirty minute ride through the back roads, ending at a friends house, who is very knowledgeable about cars.

After arriving at his house, I checked the temporary coolant overflow tank that I installed. I was surprised to see only a tablespoon or so, of coolant.

Using the infra-red temperature gun, he found that the intake manifold feed to the number five cylinder was considerably warmer than the others. It was in this area that I was hearing what I described as a knocking sound.

The car sat for a few minutes while we discussed what the problem could be. During this time, with the motor off, surging could be heard in the upper radiator hose.

We decided to do another test to see if any combustion gases were in the radiator. I had done two previous test on different days. One test the fluid turned green, on the second test the fluid remained blue.

When he released the pressure on the radiator cap, he was surprised at how little pressure was in the system.

I started the engine, and the test for combustion gases in the radiator turned positive immediately. Also, the water was flowing freely through the radiator.

I conclude that in my previous efforts to locate the overheating problem, the cars engine was not truly up to operating temperature, although the gauge on the dashboard indicated otherwise.

Eureka!! So now I guess you're going to pull the left bank cylinder head. Perhaps not necessary, but if you have the intake off and the left head, perhaps it might be prudent to replace both head gaskets. That way you will, have even thicknesses of gasket.... and peace of mind!!

Comments have been made before about suspecting the head gaskets, but pulling heads is not a fun job until all other possibilities have been exhausted, which looks like has been done.

Reading other posts on the replacement of intake manifolds and the valley pan and gaskets, you will have noted that it is not a good idea to use the rubber end seals, but to use a good bead of "The Right Stuff" as well as around the ports as described in the instructions (Fel-Pro). Others prefer NOT to use silicone based sealants around ports as it does not tolerate gasoline. Aircraft grade Permatex (or Permatex 2) worked for me.

Anyway, you'll be back on the road soon with the overheating issues gone.

All the best,

Geoff.

 

[klinton994]

I'd like to thank everyone for their input and ideas with my overheating issue. This weekend, I believe I've narrowed it down to be a head gasket or cracked head.

I drained the water and added a 50/50 coolant, water, mixture.

I left the water level about two inches below the filler neck.

The outside temperature was in the mid nineties.

I took the car for a thirty minute ride through the back roads, ending at a friends house, who is very knowledgeable about cars.

After arriving at his house, I checked the temporary coolant overflow tank that I installed. I was surprised to see only a tablespoon or so, of coolant.

Using the infra-red temperature gun, he found that the intake manifold feed to the number five cylinder was considerably warmer than the others. It was in this area that I was hearing what I described as a knocking sound.

The car sat for a few minutes while we discussed what the problem could be. During this time, with the motor off, surging could be heard in the upper radiator hose.

We decided to do another test to see if any combustion gases were in the radiator. I had done two previous test on different days. One test the fluid turned green, on the second test the fluid remained blue.

When he released the pressure on the radiator cap, he was surprised at how little pressure was in the system.

I started the engine, and the test for combustion gases in the radiator turned positive immediately. Also, the water was flowing freely through the radiator.

I conclude that in my previous efforts to locate the overheating problem, the cars engine was not truly up to operating temperature, although the gauge on the dashboard indicated otherwise.

Eureka!! So now I guess you're going to pull the left bank cylinder head. Perhaps not necessary, but if you have the intake off and the left head, perhaps it might be prudent to replace both head gaskets. That way you will, have even thicknesses of gasket.... and peace of mind!!

Comments have been made before about suspecting the head gaskets, but pulling heads is not a fun job until all other possibilities have been exhausted, which looks like has been done.

Reading other posts on the replacement of intake manifolds and the valley pan and gaskets, you will have noted that it is not a good idea to use the rubber end seals, but to use a good bead of "The Right Stuff" as well as around the ports as described in the instructions (Fel-Pro). Others prefer NOT to use silicone based sealants around ports as it does not tolerate gasoline. Aircraft grade Permatex (or Permatex 2) worked for me.

Anyway, you'll be back on the road soon with the overheating issues gone.

All the best,

Geoff.

I'm probably a few months from attacking the heads. It will be a winter project when I relocate the bikes to the shed and the mustang indoors for a period of time.

I will certainly be removing both heads. I'll probably have the local machine shop check them out and go through them.

Although I certainly don't want to pull the heads, I'm relieved to finally know where the problem lays.

Thanks again.

 

[Stanglover]

I'm probably a few months from attacking the heads. It will be a winter project when I relocate the bikes to the shed and the mustang indoors for a period of time.

I will certainly be removing both heads. I'll probably have the local machine shop check them out and go through them.

Although I certainly don't want to pull the heads, I'm relieved to finally know where the problem lays.

Thanks again.

Sounds like a plan. You have to go so far anyway, so do it all and be done with it. You'll have to let us know how it all works out when completed. Hope you don't find any other 'gremlins' in there.

Geoff.

 

[klinton994]

Greetings,

I wanted to get back to everyone who offered their help to me, and to let you know my findings.

I have pulled off both heads and believe that the driver side gasket may be installed incorrectly.

The passenger side gasket has a small tab with the word FRONT marked on it. The word FRONT is on the right side of the gasket closest to the front of the engine.

The driver side gasket has the same tab and the word FRONT marked on it. However, the word FRONT is on the right side of the head near the firewall.

Both gaskets are still in place on the block. I have a couple of questions.

1. Is the word FRONT printed on both sides of the gasket, as in top and bottom of the gasket, at the same end of the gasket?

2. Is there a left and right gasket?

Thanks to everyone for their help

 

[Mikes73]

There is no left and right head gaskets. During installation one gasket must be flipped over to get the "front" of the gasket facing the radiator.

 

[Bill73Ragtop]

Yup, 351 Cleveland head gaskets must be installed with 'front' being at the front no matter which side faces up. One tell-tale of incorrectly installed head gaskets is the sound of coolant thumping when the engine is shut down after it reaches operating temp.

 

[basstrix]

Great! At least now you know the root cause. Was there any sign of leakage from the head gasket? If it's not crystal clear the HG was leaking, I would continue to look for where the exhaust was entering the coolant.

Thanks for following up, I learned something from this one.

Bill, thanks for that input regarding the coolant thumping....I suspected the sounds klinton994 was hearing was due to backward head gasket but I have no personal experience with it and couldn't offer much more than my suspicion.

 

[klinton994]

Yup, 351 Cleveland head gaskets must be installed with 'front' being at the front no matter which side faces up. One tell-tale of incorrectly installed head gaskets is the sound of coolant thumping when the engine is shut down after it reaches operating temp.

Exactly. It sounded like it was percolating. You could hear the thumping and see the upper radiator hose vibrate.