Antifreeze Squirt from Head Gasket

[Large Arbor]

Ok, for just a little bit of time, and only on cold starts, I get a squirt of antifreeze on the drivers side headers when I start the engine. It immediately goes away and does not occur on a warm start. I talked with the engine builder and his advice was to re-torque the head. I have no antifreeze in the oil and the engine runs fine. The engine builder indicated also that stainless steel gaskets may work better as they were not available in 2006 when the engine was built. I plan to talk with the engine builder next week as I am thinking if re-torquing the head does not work, I will need to replace the head gaskets. I don't mind doing the work, I just want to make sure I do it right. It's hydraulic and has no valve lash setting, so am I wrong in thinking I just remove the rocker bar allowing access to the head bolts, torque them, and then retorque the rocker bar and see if it leaks?

Phil

[DonC]

Phil:
Had a similar episode with my big block a while back but in my case it was just a seep of coolant coming from the block/head joint. Was advised by the builder to re-torque the heads and that cured the problem. Hasn't come back in 20,000 miles since.
The explanation I got is that the difference in metals between the iron block and the aluminum heads can result in a little bit of "squirm" between the two materials that will show up over time.
If I remember correctly I just backed the head bolts off 1/4 turn reversing the tightening sequence and then re-torqued in sequence.
For the rocker shaft removal I backed off the bolts 1/4 turn at a time until they were loose and then removed the shaft. Putting it back in I ran bolts down finger tight and then did the 1/4 turn routine again until the bolts had brought the towers down into solid contact with the head then proceed with tightening to the proper torque. Because the rocker shaft is under spring pressure as you're tightening take up any slack by hand in the other bolts before doing the 1/4 turn.
DonC

[Large Arbor]

Thanks Dan. I am hoping for similar results, although my block is aluminum. So if I read your post correctly, you gradually loosened the rocker shaft until you could completely remove and then gradually hand tightened and then torqued down to spec. Was there any tolerances that you checked or anything else you looked at when you did this?

Phil

[patrickt]

Personally, I have never had any luck retorquing anything that was leaking. That said, other than your choice of gaskets and magic sealing goo, the procedure has not changed in 50 years. Here are the factory steps for replacing your head gasket, which is what I think you're going to end up doing:

[patrickt]

Originally Posted by Large Arbor

Thanks Dan. I am hoping for similar results, although my block is aluminum. So if I read your post correctly, you gradually loosened the rocker shaft until you could completely remove and then gradually hand tightened and then torqued down to spec. Was there any tolerances that you checked or anything else you looked at when you did this?

Phil

Phil, make sure you heed the warning about leak-down before cranking. (Step Six, Valve Rocker Arm Shaft Assembly - Installation) Those of us with solid lifters tend not to remember minutia like that....

[Large Arbor]

Patrick,

Can you email me the pic you posted as I cannot seem to print it or cut and paste it. Send to edward_0618@yahoo.com.

Phil

[patrickt]

Here are all those pages in a hi-res, downloadable, PDF for everyone that might want it, now and forever and ever: all_pages.pdf

[DonC]

Phil:
Didn't check anything else when I did the re-torque as it is a fairly straight forward procedure.
I have non adjustable rocker arms so there is some pressure on the push rods when loosening and re-tightening the rocker shaft.
I pulled the plugs and rotated the crankshaft two revolutions by hand and watched the rockers to make sure everything was functioning as expected before I buttoned it back up.
DonC

[patrickt]

... and you might as well toss the GM coolant leak tablets in there when you retorque it (couldn't hurt). Five bucks off Amazon.

[ame="http://www.amazon.com/General-Motors-12378255-Genuine-3634621/dp/B000QIH3C4"]Amazon.com: General Motors 12378255 Genuine GM Fluid 3634621 Cooling System Seal Tablet - 10 Grams, (Pack of 5): Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51g0Hco259L.@@AMEPARAM@@51g0Hco259L[/ame]

[DanEC]

This might be the appropriate time to review the steps for re-torqueing head bolts. I know if you just throw a torque wrench on them set for the max head bolt torque it's going to just "click" which may not actually be representative of the actual bolt tension because of the additional effort needed to break them loose from their static state.

If I remember correctly you need to actually loosen the bolts first and then bring them back to the specified torque - correct. Back them off 1/2 turn in reverse order of the pattern for torqueing them?? Does it matter how far back you go?

[Large Arbor]

Dan,

You are right on. I met with Joe Lapine of Dabury racing engines and he said loosen from 12 o'clock to 10 o'clock and then retorque. I will try that first and if it does not work I will replace the gaskets with Cometic Stainless. The guys at Danbury are really nice and know there stuff. I would recommend them to others as well.

Phil