Frost Plug Pickle

[FLYER15015]

Just looking for some support here I guess, because I really know what needs to be done.

The story starts last summer, when in an effort to cure an overheating issue, I poured 3 gallons of "Evapo Rust" into the cooling system and drove the baby around for about 2 weeks.

Well that worked like crazy in that I ended up replacing all 3 frost plugs on the left side of the block as the center portion of each was "paper thin", and seeping coolant.

The inside of the block however was squeaky clean............ Even in the very back.

Now I see a tell tale trail of coolant running down the back of the block. And it can only come from one place, the frost plug at the back of the head.

SO..........

 

Plan "A" is to pull the head, which will of course include the H2O pump, for a rebuild, the radiator, for a good rodding out, and a new set of valve guides and other head maintenance operations such as a valve job.

 

Plan "B" was suggested by the guys on the chevy forum, and that was to cut a hole in the firewall and replace the frost plug from the back side. This entails cutting a hole in OR removing that beautiful brown cardboard firewall cover inside the car. Removal does not look like an easy job, and I really don't like the idea of cutting a hole in it, because it would be just above and to the right of the gas pedal, in plain sight.

 

Plan "C" which was suggested by a "friend" was to throw a can of Barr's Stop Leak in her and pray it seals up the leak.

 

I did not set this up with a poll, just looking for some knowledgeable Buick owners input.

 

PS: it is 18 degrees out today, so I won't start this project for a while.

 

Mike in Colorado

 

PPS: The track of the offending fluid !!!

Edited February 25, 2017 by FLYER15015
added picture (see edit history)

[LAS VEGAS DAVE]

Mike, you already know what to do and you just wish there was another easier way. I think the head should be pulled BUT I don't see what it could hurt to try the BARSLEAK and see if you get lucky. The inside of the block is now squeaky clean so BARSLEAK won't hurt anything. I think the BARSLEAK works by it leaking out where ever the leak is and then when it hits air the water evaporates and the BARSLEAK stuff hardens. It may be helpful to try to SLIGHTLY pressurize the system after its hot with the engine OFF to try to force a little of the BARSLEAK out the leak where it hits the air. Once it works, if it does you can drain the coolant and refill with new coolant so that the BARSLEAK is no longer in your coolant. What can it hurt? If it fixes the leak all is good. If it doesn't or if it comes back you can pull the head and do it right. I have used JB WELD on many projects that I thought it would not fix but tried anyway. It always ended up working so now I think it will work on just about anything. The BARSLEAK may fall into that same category or maybe it will fail but I still can't see a downside to trying.

Edited February 25, 2017 by LAS VEGAS DAVE (see edit history)

[pont35cpe]

Mike, you know the only way to fix it is to tear it apart and do it right. Otherwise it`ll always be on your mind, especially when you are on a road trip, wondering if it`ll make it back home. I say big "BOO" on the stop leak...  Tom

[Ben Bruce aka First Born]

Dave took the words right out of my mouth.I have used Barrs Leak with good results over the years.  That radiator will be dirtier than you expect, if it has not been rodded.       Plan B is OUT.     

 

  Ben

[Guest]

There really is only a plan A.  While the head is off you can do a valve grind or at least lap the valves in and even cut the ridge off the top of the cylinders.

Core plugs should never be messed with.  Either they are perfect or they should be changed.  They can weep on minute and dump all your coolant the nest, usually when you are half way up a hill or in the middle of a tour at the farthest point from home.

Many years ago I used your plan C on a 53 Buick.  It worked great but it certainly was not a collectable car.  Also working through the firewall is NOT an easy chore.

Bit the bullet and good luck.

[zeke01]

Is yours a pressurized system? My experience has been that stop leak doesn't work well in non pressurized systems. Zeke

[Guest]

Greetings Mike

              If you want to try a delaying tactic you might try draining the auntie-freez down below the level of the plug and see if you can use a right angle screwdriver to screw in a large sheet metal screw with silicone on it into the weak spot in the center of the plug. I decided to have .040 taken off the cylinder head while I had it off to fill my block with muriatic acid to clean my water jackets as I couldn't even pound anything in thru the hole for the petcock hole on the driver's side of the engine! Once cleaned flowed like a garden hose running and engine can idle as long as needed without heating up! Good luck!

[27donb]

Do it right, do them all.  If one is leaking, if one is paper thin, there might be more.

 

Different animal, but on my 27 Master I removed the front push rod cover to change the gasket, and discovered the freeze plug under there had a green drop on it.  I went through the same ideas in my head.  How can I make this an easier, quicker job.  On my car there is a plug in the back of the head, and below it in the back of the cylinder block, that face the firewall.  After much floorboard disassembly, I could probably have replaced the cylinder block one, but the head was inaccessible.  There was no way I was going to cut a hole to replace it.

 

I pulled the engine.  It gave me a chance to remove them all, put the engine outside and flush a lot of sediment and rust from the water jacket.  I spent a lot of time afterward with a magnet, pulling out rust that couldn't be washed out.  I blew it all dry.  Reinstalled all new plugs, and painted the engine.

 

 

Edited February 26, 2017 by 27donb (see edit history)

[Daves1940Buick56S]

Plan A! Last Feb, just a year ago, I pulled the head (again!) to replace the valve springs and to thoroughly clean out the block. I used a chain hoist on the head/manifold assy since I wasn't pulling the manifolds this time and that saved a lot of work. My at that time brand new to the work 10 yr old assistant did 90% of the work and we had it off in less than 4 hrs including a lunch break.

 

Cheers, Dave

[37_Roadmaster_C]

Ok I will jump in and strongly encourage you to pull the head and do it once and do it right.  You will be happier and will not have to worry about it failing down the road.  Punching the firewall is just wrong IMHO and stopleak is a bigger risk to the radiator and heater than I would take.  My thoughts, your car and peace of mind.

[DonMicheletti]

37  Roadmasterds advise is right on!  You will never regret doing it right. You wont have the anxiety of having a failure, using Bars Leak, at a bad time

[Marty Roth]

Mike - sorry to have to agree, but doing it right you won't regret it later.

 

Did you get to try the saloon in Clayton?

[1967 - 1997 Riviera]

Just my two cents, but I'd advise you to opt for plan A and do it right.

 

I once had a slowly leaking freeze plug on a 1977 Chevrolet Impala with the 305 c.i. small block V-8 that I did not want to $repair$ and I could not afford another car at the time. So I used the Barr's Stop Leak and crossed my fingers. Sure enough, it did work on sealing the leak. But, the first winter after that, I noticed the heater did not produce as much toasty heat as before. I had done nothing else to the cooling system, so I could only conclude that the Stop Leak, while doing a great job on the engine coolant leak, must have also clogged my heater core to some degree.

[ILIKECARS53]

I agree with plan A, pull the head.  But you may want to rethink doing all the other work.  I agree with the radiator flushing and water pump rebuild, but if the engine is running fine and  not blowing any smoke I would refrain from the other fixes you want to do.  Others may disagree but i am a strong advocate of.... if its not broken don't fix it.  Unless you do a total engine rebuild just replace the leaking plug and move on or before you know it you will have the whole car apart due to the.......might as wells.   But it is your car  and  you have to make the call that is right for you.

[DonMicheletti]

An "old time" theory is that if you ground the valves on an older, worn engine you might well create an oil burner.  Better vacuum?

[Brian_Heil]

Back in the day, I had a leaking freeze plug on a beater Nova.  Could not get to it and did not have the money to fix correctly as a broke college student.

 

Found a freeze plug block heater that bolted in the correct size freeze plug hole.

 

Knocked the freeze plug into the block (could not pull) and bolted in the block heater freeze plug and went years that way until I sold it to the next kid.

[FLYER15015]

Brian,

I wish I could do what you suggest, however on mine, you can't get 2 fingers between the head and the firewall, let alone any tools.

Mike