Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

External coolant leak at head?

Thread Tools
 
Search this Thread
 
Old 07-17-2014, 08:32 PM
  #1  
Teching In
Thread Starter
 
95BRMW's Avatar
 
Join Date: Nov 2013
Location: CT
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default External coolant leak at head?

while working on my 5.3 swap project the other day, I noticed coolant had been dripping off my cross member. I looked up the passenger side of the engine and found it's leaking coolant from what looks like the corner of the head by the casting number where it meets the block. When I picked up this engine I noticed traces of coolant in the same spot but thought nothing of it. I put in new head gaskets and bolts and dropped it in the car.
Being this is happening again, is it safe to assume I have a bad head? These are the famous 706 Castech heads, but don't show cracks internally, and my motor oil is free of coolant. Anyone ever hear of these failing externally?
Old 07-17-2014, 11:36 PM
  #2  
TECH Senior Member
iTrader: (39)
 
LilJayV10's Avatar
 
Join Date: Apr 2007
Location: Evansville,IN
Posts: 9,309
Received 857 Likes on 610 Posts

Default

Could it be coming from the freeze plug on the end of the head?
Old 07-18-2014, 11:15 AM
  #3  
TECH Apprentice
iTrader: (1)
 
Exeodus's Avatar
 
Join Date: May 2008
Posts: 328
Received 7 Likes on 4 Posts

Default

Could it be from the coolant crossover tube?
Old 07-18-2014, 11:45 AM
  #4  
Staging Lane
iTrader: (3)
 
Nwayne's Avatar
 
Join Date: Oct 2010
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default

I had this isuue and it turned out to be the crossover tube. Replaced the gasket, leak gone.
Old 07-18-2014, 10:36 PM
  #5  
Teching In
Thread Starter
 
95BRMW's Avatar
 
Join Date: Nov 2013
Location: CT
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default

Took a closer look today and it's not coming from the head, its coming from the head bolt on that corner. These aren't w
Old 08-11-2014, 09:12 AM
  #6  
Teching In
Thread Starter
 
95BRMW's Avatar
 
Join Date: Nov 2013
Location: CT
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default

I added some of those GM coolant tabs to it, seems to have slowed the leak down a lot, but it's still there. Now I can see where it's coming from and it's not good. There's a 1" crack in the head right above one of the bolts. I don't see any coolant in the oil, so it's just a nuisance (for now).
I found a couple pairs of heads in the yard, both are 5.3s, one has 706s without the castech logo and the others are 862s. Any difference or advantage of one over the other?
Old 08-11-2014, 09:18 AM
  #7  
Moderator
iTrader: (4)
 
Darth_V8r's Avatar
 
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,446
Received 1,836 Likes on 1,145 Posts
Default

I got bit by that on my 04 suburban, except it was going out the exhaust. I grabbed used 706 heads from a 07, and havent' had issue since. Verify the year is not 04-06 before putting them on. FWIW, I don't think thers is much diference between 862 and 706.



Quick Reply: External coolant leak at head?



All times are GMT -5. The time now is 02:26 PM.