Coolant going somewhere

[travisc406]

So budget built a 5.7 in my 88. I ran it for 1500 miles then rechecked adjustment on my valves and when I had valve covers off there was some build up in rear of the valve covers that seemed to be coolant. Not a huge amount just minor. Wasn’t green but tasted sweet. I had also put in marvel mystery oil after 1000 miles and two oil changes at 250 and 500. I have added almost a half a gallon so far. Couple questions that I was wondering.

does marvel mystery oil taste sweet? Weird huh lol

and do you guys put anything around the coolant ports on your intake gaskets like RTV? I did not but seen in my chiltons. that on engine build they don’t say it but on remove and install they suggest rtv on gasket and the bolts????

in my head I am thinking that the rear ports on my intake are seeping into valley and causing steam in rear of valve covers. Any thoughts?

no misses runs great and no oil mixture with antifreeze that I can see on dipstick

 

[Frank Enstein]

Take the valve covers off, pull the spark plugs, and drain the oil (leave the plug out) into a clean container so you can put it back in when you are done. Put a pressure tester on at about 2lbs. higher than the radiator cap.
Go eat lunch.
See where it came out. Double check around the head bolts. All 17 head bolts go into water on a Small Block Chevy.

 

[PlayingWithTBI]

do you guys put anything around the coolant ports on your intake gaskets like RTV?

Yes, you can use "The Right Stuff" on the china rails and around the coolant ports front and rear of the heads, lay down the gasket and put a small bead on the same ports before installing the manifold. As @Frank Enstein said all of the head bolts go into the water jacket so, you need to put thread sealant on them. Plus, the center intake bolts go into the oil galley so you need to do the same to those bolts.

 

[travisc406]

Ok so I did not use thread sealant on my head bolts. My bad. Do I need to pull heads and replace gaskets or can I simply remove bolts and seal and reinstall? Thanks

 

[PlayingWithTBI]

Do I need to pull heads and replace gaskets or can I simply remove bolts and seal and reinstall? Thanks

You MAY be able to remove 1 bolt at a time and re-torque it. If it were me, I'd remove the head bolts in reverse order and start over. YMMV

 

[R422b]

What thread sealant is recommended for head bolts?
Would a person just use RTV or something more like leak lock thread sealant?

Talking about GMT400s using Tapatalk

 

[Schurkey]

Do NOT use RTV Silicone to seal threads. You can't retorque them without tearing the RTV, and when you unscrew them later, the shredded RTV is a disaster to clean-up.

There's several part numbers for Locktite/Permatex "PST" (Pipe Sealant with Teflon/PTFE)

The stuff is FABULOUS for sealing bolts and pipe thread.

I generally use 592, it's easier to get locally. 565 and 567 are also good stuff. The 592 is a high-temperature, slow-curing sealant, perfect for headbolts that get re-torqued.

https://www.amazon.com/Loctite-4836...hild=1&keywords=PST+592&qid=1618879962&sr=8-1

 

[HotWheelsBurban]

On the vortec water pump, I used Permatex Aviation, on the advice of my mechanic cousins. Been on there since February 2019 and no leaks. Could this be used on the head or intake manifold bolts?

 

[PlayingWithTBI]

What thread sealant is recommended for head bolts?

I use this stuff, PTFE, high temp, a lot cheaper, no issues.

https://www.lowes.com/pd/Oatey-Great-White-Sealant/4750813

 

[Coveman]

On a GM LS engine, the cylinder head bolts are TTY (torque-to-yield) and cannot be re-used. You might be better off getting a new set of bolts and head gaskets.

https://www.onallcylinders.com/2017/03/17/quick-tech-tty-fasteners-ls-engines-need-know/