Coolant leak

[KING BEE]

I have a 69 Coronet 440 that was turned into a Super Bee clone before I bought the car.

This last winter I pulled the motor and did a complete rebuild. Along with alot of painting and replacing of parts. The motor is back in and the car runs great. But, here is my problem. I am losing about a half a gallon of anti-freeze every time that I drive it. I will drive the car for an hour or so and after the car cools down, I'm down about half a gallon.

I did have a slight leak coming from around the headers. I installed Hedman silver ceramic coated headers on the car after the rebuild. The leak I believe was from the header bolts. I pulled each header bolt and used a high temp red silicone on the threads. I also used a container of Barrs stop leak in the radiator. This was the recommendation from a local auto shop that also builds race motors. I have personally known the owners for over 40 years and I trust them. Even though I wasn't too keen on using the Barrs stop leak on a freshly built motor. Just my opinion though. But the leak did stop.

I changed the oil today. I am using Brad Penn 10w30 and the oil looks good. This is the first oil change since I installed the engine. I am getting whisps of white smoke from the exhaust. I had the car at my buddy's house who has been a mechanic for 30 years and he thinks that the anti-freeze may be being burnt off through the exhaust. My friends at the auto shop suggested doing a leak down test on the cylinders, which is my next step. FYI the oil level has not changed with the loss of all the coolant over the last two months or so. I have also seen a small amount of coolant on the floor under the car, but we're talking ounces not cups or quarts.

I have this gut feeling that the header bolts are allowing coolant to leak past the bolts through the header gaskets into the exhaust system. I was told today that the new header bolts may not be allowing the red high temp silicone to stick allowing the leak by. It was also suggested to use teflon pipe joint compound on the threads of the header bolts to seal the leak.

I'm not sure if the teflon pipe compound is able to handle the heat of the headers and the block. So that is one of my concerns.

My question is this, can I be going through a half gallon of coolant by burning it off through the exhaust via the above mentioned possible leak. AND if that leak is the issue, what can I use on the threads of the header bolts to stop the leak.

I know someone is going to ask if the engine is building enough pressure and I'm losing the coolant through the overflow. NO. I installed a 160 degree thermostat and the engine runs consistantly around 164 or 165 degrees. I also installed an overflow container (temporarily) and it is bone dry.

Any advice or suggestions would be greatly appreciated. I will upload a photo of the engine for your viewing pleasure.

THANKS
KING

 

[HEMI-ITIS]

Do a compression test,leak down test,and then pressurize the cooling system.You should be able to diagnose with those tests:toothy5:

 

[ChargerPilot]

But, here is my problem. I am losing about a half a gallon of anti-freeze every time that I drive it. I will drive the car for an hour or so and after the car cools down, I'm down about half a gallon.
THANKS
KING

Does it keep going down every time you drive it or do you keep toping it up? If you keep toping it up...that is probably your problem. Unless you have a coolant recovery tank the fluid level should be down some from the top.

Regards,
Ken

 

[bigmanjbmopar]

Freeze plug on the head? small leak dripping down on the headers so it looks like its coming from the bolts?

 

[rrowdy]

If at all possible, you should be using studs insead of bolts. This is especially important when the hole
enters the water jacket. This is if you can move the headers back from the head far enough to get over the studs.

Hemi-itis had good advice on pressurizing the cooling sytem. You only need a few pounds then loosen
the collectors, and look for leaks.

Good luck!

 

[KING BEE]

Do a compression test,leak down test,and then pressurize the cooling system.You should be able to diagnose with those tests:toothy5:

The cooling system was pressurized yesterday at 18 lbs. And we could not find any leaks at all. The compression test, leak down test is next.

THANKS

 

[KING BEE]

Does it keep going down every time you drive it or do you keep toping it up? If you keep toping it up...that is probably your problem. Unless you have a coolant recovery tank the fluid level should be down some from the top.

Regards,
Ken

Ken

I leave the coolant down about an inch from the top due to no coolant recovery tank. I have done my homework in regards to the coolant level being kept down from the top so I don't lose a little with over pressurization. When I say that I am losing a half gallon at a time. I literally measured out with a quart jar when I refilled the radiator yesterday and it was a half gallon.

 

[KING BEE]

Freeze plug on the head? small leak dripping down on the headers so it looks like its coming from the bolts?

NOPE

Freeze plugs are new and tight. I could actually see the antifreeze weeping around the header gasket. It took a flashlight and small inspection mirror, but it was the header bolt.

 

[KING BEE]

If at all possible, you should be using studs insead of bolts. This is especially important when the hole
enters the water jacket. This is if you can move the headers back from the head far enough to get over the studs.

Hemi-itis had good advice on pressurizing the cooling sytem. You only need a few pounds then loosen
the collectors, and look for leaks.

Good luck!

DAMN

My buddy Rich (the mechanic) told me to use studs instead of the header bolts but at the time, I was watching the funds rather close and in my mind, I couldn't justify an extra $100 or so on studs. Hell, I had new header bolts in my hands that came with the headers. :angry9:

I like the idea of loosening the collectors when pressurizing the coolant system. We did not do that yesterday. We just pressurized the system.

If I bite the bullet and have to go with the studs, what would be your suggestion on what to use as a sealant on the threads of the studs ????

Cause if I have to take this damn thing apart again, I want to do it right !!

 

[KING BEE]

Just for your viewing pleasure another photo of the engine

 

[rrowdy]

I'd want to find the exact cause of the leak before going to the work and expense of changing over to studs.

Loosing Two quarts in an hour or so of driving is a lot of fluid to lose and you might want to get the engine

up to temperature and duplicate the conditions of the coolant loss close as possible before pressurizing..

If in fact the loss is due to leaking past the header bolts and you choose studs, I've sealed the threads with

Red loctite and also JB weld. Both work well as long as you don't have to take them back out.
(Don't ask me how I know this).

Try http://www.allensfasteners.com/search_results.asp?txtsearchParamCat=115 for the studs

Good Luck!

 

[rrowdy]

I almost forgot,

Wow, Thats a beautiful build!

 

[KING BEE]

I almost forgot,

Wow, Thats a beautiful build!

THANKS

My buddy Rich just left and we discussed your thoughts. We talked about putting the car back on my lift and loosening the collectors, running the car to get it up to temp and see if we are getting the coolant leak out of the collectors.

I don't have a problem switching over to the studs on the headers. My only problem is the passengers side front tube is just touching the inner fender well and I really need to make an adjustment to keep it from touching. With the torque of that 440 when the car idles you hear and feel a definite thud every time the header bounces on the inner fender well. So replacing the bolts with studs and making that adustment might be a blessing in disguise.

 

[KING BEE]

I'd want to find the exact cause of the leak before going to the work and expense of changing over to studs.

Loosing Two quarts in an hour or so of driving is a lot of fluid to lose and you might want to get the engine

up to temperature and duplicate the conditions of the coolant loss close as possible before pressurizing..

If in fact the loss is due to leaking past the header bolts and you choose studs, I've sealed the threads with

Red loctite and also JB weld. Both work well as long as you don't have to take them back out.
(Don't ask me how I know this).

Try http://www.allensfasteners.com/search_results.asp?txtsearchParamCat=115 for the studs

Good Luck!

I tried the Red Loctite originally and the bolts leaked to beat the band. That's why I switched to the Red High temp Silicone. I actually remember when I origianlly took the engine apart and removed the old headers, they had the Red High temp silicone on the threads of the header bolts.

 

[rrowdy]

I tried the Red Loctite originally and the bolts leaked to beat the band. That's why I switched to the Red High temp Silicone. I actually remember when I origianlly took the engine apart and removed the old headers, they had the Red High temp silicone on the threads of the header bolts.

I wonder if at sometime in the past, someone broke some studs and did a crappy job of drilling them out.
It has to be frustrating to finish such an awesome build and have to deal with this.

Keep us updated on what you find.


Good luck

 

[KING BEE]

I wonder if at sometime in the past, someone broke some studs and did a crappy job of drilling them out.
It has to be frustrating to finish such an awesome build and have to deal with this.

Keep us updated on what you find.


Good luck

Not sure, but the holes did not look like they were drilled. They looked untouched and original. Frustrating to say the least.

I will be doing a compression test on the cylinders hopefully later this week or early next week. Plus, we are going to put a dye in the radiator and use a black light to see if we are losing the coolant through the headers.

The plan is to unbolt the headers at the collectors and run the car up to temp and try to simulate the leak under normal driving conditons.

If my gut is right and it is being lost through the headers, the FIX, is going to be, PULL the headers, put in studs with a good thread sealant, new header gaskets and last resort is to put the ceramic sealer in the radiator.

I do not want to have this problem again.

Plus I want to say thanks for your help. I will post what the outcome is and what I have to do to fix any problems I find.

 

[KING BEE]

Finally found the problem. I know it has been a while since I first wrote this post, but I have been fairly busy. First off I would like to thank those that responded with their help and suggestions with this. Now I will let you know what I found and where I am at.

We did the leak down test. The most forward cylinder on the passenger side was the obvious problem as we pulled the spark plugs and that particular cylinder had the cleanest spark plug and it TASTED like anti-freeze. We put 100 psi. on that cylinder. You could actually hear the anti-freeze bubbling and the top radiator hose just vibrated in my hand.

We pulled the head on the passenger side but nothing jumped out at us. The gasket was just fine with no tears, cracks or obvious problems. I took the head to the shop that rebuilt it and showed it to them. Chuck, one of the owners looked at the head and in a split second spotted where the leak was at. Now in my mind, I was hoping for the best and expecting the worst. I figured cracked head or a cracked block and expected big $ to fix it. To say the least I was happy with what Chuck found. When the shop machined the heads to clean up the valve seats, THEY machined just a hair too much and got into the water jacket. Actually there were two valves showing signs of leakage.

The shop sent the head out, had a pressure test done and found 3 leaks in that particular head. The fix is to put some type of silicone in the head, let it dry for 24 hours and then bake it at 350 degrees. It is not actully a silicone but whatever it is, I found out that this will fix the problem and is a very good method for fixing the problem. After finding the leaks in the first head, the machine shop wanted the drivers side head also. The second head was fine with no leaks and they decided to run the same process on that head to ensure no future problems after I put this thing back together again.

As far as expecting the best. Well let's just say the shop is paying for everything as it is their screw up and not mine. I should be getting the head back this week and will start putting everything back together because I would like to get the car back on the road before winter sets in.

Just before I took the engine apart, I was driving it and it ran great. Even running on only 7 cylinders. I can't wait to get it on the road and see how it runs on all 8.

Again, thanks guys for your input. I will be replacing the header bolts with studs. I am fixing the clearance problem with the passenger side header and the inner fender well. And I am purchasing all new head and intake bolts to ensure that when I put this back together, everything will be tight and there will be NO LEAKS WHAT SO EVER.

Thanks again, KING BEE

 

[KING BEE]

Finally got everything put back together yesterday. Long day but glad it's done. Unfortuantely the old shoulders, back, and arms aren't as happy as I am.

Anyway, just fired the car up and at first I got just a little nervous. There was a lot of steam coming out of the exhaust on both sides. After the car warmed up, that went away and I felt a whole lot better.

The passenger side header issue I had with it's clearance (or lack of as it was touching) to the inner fender, well was fixed while the engine was torn down. What I can tell you that a 1/4" clearance makes a world of difference. The car ran absolutely GREAT !!

OK, now is where I get just a little pissed. I originally had an issue with the header bolts leaking and this goes back to last winter when I rebuilt the engine. Low and behold, the front and back header bolt holes go into the water jacket. I pulled the bolts and sealed them up with Red High Temp silicone. That actually fixed the problem. Then I found out that I was losing a half gallon of anti-freeze every time I drove it and now that problem is fixed.

Just shut the car off and I hear PSSSS !! Naturally, I get the flashlight and mirror and go looking. I have anti-freeze leaking from both headers. :angryfire:

Don't know if I'm more pissed at myself or the shop that worked on the heads. The guys at the shop are brothers and have been friends of mine since high school. They build race motors and are very good at what they do. In talking with them, we discussed the exhaust manifold bolts and how they go into the water jacket. They told me to use pipe dope, or as some may call it, TFE pipe thread compound. Both brothers said that they use it, it stops any leaks and is great for this application. Well, I did use it and let me just say, IT SUCKS. All four holes are dripping as if nothing was on the threads of the studs at all.

Now, I have to wait for the car to cool down, drain the radiator, pull the front and back header studs, clean them and I'm going back to the Red High Temp silicone.

FYI, for those that ever have an issue with a 440 leaking coolant from your exhaust manifold bolt holes, the best thing I have found to use is the Red High Temp silicone. DO NOT use Red Loctite, DO NOT use pipe thread compound, USE Red High Temp Silicone. It really does work.

KING

 

[KING BEE]

FINAL UPDATE

I got a little anxious last night so I drained the radiator, pulled the 4 header studs. Cleaned them, and used the Red High Temp Silicone. Let the car sit over night. Just filled the radiator with coolant, took the car for a ride and there are NO LEAKS anywhere.

Actually, the car runs and idles great. The temp gets to 160, thermostat opens and the car runs on an average at 158 degrees.

Now, I'm having a nice cold Summer Shandy just celebrating.

Thanks again to those that gave me some positive input and information

KING BEE

 

[coloradodave]

Whoops!!!!

After using many different thread sealers, the one that SOLVED the leaking problem was ARP thread sealant. Ones that didn't work? Permatex 3-H, teflon paste and several others. Use studs or bolts with plenty of purchase in the heads. Don't believe the coolant could find its way from the coolant passages through the header bolts to the interior of your exhaust. Any of the plugs look super clean? How many times have you added coolant?

Whoops. Should have read further before posting this. Glad you found the problem. BTW, water in the cylinder does a great job of 'steam' cleaning the plugs and piston crowns. All is right with the world....