Coolant leak from exhaust manifiold!

[ianmont]

Well, I finally got my newly rebuilt 383 engine started and noticed that it was blowing a lot of white smoke. After shutting it down I noticed that there was coolant coming from the passenger side exhaust manifold. I knew that it had a crack where the nut is, but I hoped it would be alright. I guessed wrong. So, I'm looking for ideas on whether to buy some headers or stick with original exhaust manifolds.
What are the pro and cons of switching over to headers?
Any help would be greatly appreciated.

Thanks, Ian

 

[HEMI-ITIS]

Ian,big block wedge engines have several exhaust bolts that are "wet".meaning they go through the cylinder head into a water jacket.You need to use sealant on the bolts or they will leak coolant.:sunny:

 

[ianmont]

Really?! Could it be that simple! I'm going to the garage right now and am going to try some sealant on the stud! Thanks!

 

[HEMI-ITIS]

Yup,it could be that easy.Don't forget to drain the radiator 1st or you will make a mess:blob1:

 

[Cranky]

Really?! Could it be that simple! I'm going to the garage right now and am going to try some sealant on the stud! Thanks!

It's just the end exhaust bolts that are wet. Dry out the threads and put sealer on the bolts.

 

[dave5237]

Yeah. I have the same thing on mine. Seems to stop after warmed up. ( # 8 stud )

 

[ianmont]

A new problem has risen!

Alright, after removing the leaky bolt, drying everthing and then applying sealant I've realized that the bolt is stripped! So, now I have to try to tap some new threads without removing the head.(yeah, like that's gonna happen)
Anyway, thanks for the replies and attached is a photo of the new engine.
View attachment DSC03422.jpg

 

[red 69 runner]

man that looks great,can you get a heli coil to fix that stripped out bolt?

 

[HEMI-ITIS]

What is stripped,the head or the bolt/stud?

 

[moparsteve636]

I'd try a new stud!tap the head and install the new stud with sealant!

 

[RustyRatRod]

Very easy fix. Get a heli coil repair kit, tap the hole in the head for the heli coil, coat it with red loctite and install it. Let it dry completely....probably 24 straight hours befoer you assemble it. Put sealant on the stud and reassemble. Problem solved.

 

[ianmont]

Sadly the bolt is fine, the hole is stripped. I'll grab a helicoil from work tomorrow and try that. Even with the car running I still can't drive it, I can't seem to find any linkage for the tranny!

 

[coloradodave]

Ian, You might try using a bolt that threads deeper into the head to see if there are some unaffected threads as a stop gap repair. The heli-coil will require you to use a 90* drill adapter to drill a 25/64" hole for the heli-coil size tap. Should be do-able in the car. After numerous coolant drips from these bolts,I use ARP thread sealant which has solved the problem.

 

[1toolguy]

Ian,big block wedge engines have several exhaust bolts that are "wet".meaning they go through the cylinder head into a water jacket.You need to use sealant on the bolts or they will leak coolant.:sunny:

It's not just big blocks my LA motor has "wet" bolts too. I used a little high temp RTV.

 

[ianmont]

The problem seems to be fixed now. I gooped up the bolt with sealant tightened it as much as I could and let it sit for 2 days before I put coolant back in, everything seems to be working fine. Thanks for all the replies!

 

[RustyRatRod]

Oh yeah, that fixed it right up.