I bought the tahoe with a blown head gasket, took it to the shop and had them rebuild the engine, once I started driving it I noticed it was using alot of antifreeze, so I researched it and came up with CASTECH heads. I drove it over 2k miles with nothing mixing in the oil just a leak of antifreeze I could not find. I checked he oil once a week to make sure water wasn't getting into the oil, last time I checked it I found the signs of water getting into the oil. Took it to a friends shop, he pulled the valve cover, we could not find the CASTECH symbol anywhere on the passenger side head (706 head). We did a pressure test, it was holding at at 12psi. I don't know what else to check or what else to do, and ideas??
It may have been covered up by all the sludge. My 04 silverado had the 706 castech heads and I started noticing lower than normal oil pressure. I pulled the valve covers and had the same thing. I replaced the heads myself with used 862 heads. I also dropped the oil pan and cleaned it out along with replacing the oil pickup tube and oil pump o ring. My truck only had 70000 miles on it too.
has to be a cracked head...no coolant passing thru these intake manifolds. Youre gonna need a new/used set of head(s)....if the gasket had blown again, you wouldn't have that milkshake under the covers. Take it back to the shop, imo.
Problem with taking it back I already got a refund for the engine build because of problems, already had to replace a push rod because it broke and the timing set because it was sagging.I drove over 2000 miles with no water getting into the oil, not it has water in the oil. The mechanic is pulling the heads, he said it could be a bad spot on the block itself were the head mated to the block.
This. The rebuild had to have come with some sort of warranty more than 2000 miles. You should have taken it back as soon as you noticed it losing antifreeze. Take it back now for sure.
head could've cracked after they installed...maybe they didn't torque them down correctly...maybe they didn't clean the head/block surfaces...removing heads, cleaning and inspecting them would be a good start to all this. good luck...sounds like a nightmare
you almost have to take the rocker stand off and look right under it....kinda hard to see the lil battery looking logo if you don't remove the rockers and stand
you almost have to take the rocker stand off and look right under it....kinda hard to see the lil battery looking logo if you don't remove the rockers and stand
He called me about an hour ago he was in the middle of taking the heads off, maybe with them off he can get a better look at them, if it does turn out to be the heads i'm going to replace them with a set of 862 heads...
I found a set of 862's for 400.00 shipped already rebuilt, I'm a little strapped for cash so these will have to do, not a bad price I have bought heads from the shop before and he offers a 3 year warranty.
You guys were right! Got a call from the shop and was told he found the castech mark! I went up there to bring him some cleaner so he can clean the heads up so we can look for the crack, first time looking for it we didn't see anything. I came back about an hour later to pick up a sand blasting cabinet and brought my oldman with me to show him th mess, when i looked at the head it stuck out like thongs on a fat chick, a CRACK! It was an inch long, since the heads were cold it ws closed up, you had to look close to see it, at the end of the crack was burnt oil were the steam had cooked it to the head, and the pushrod was caked also with black crud. This has been going on for 6 months, I am so happy I finally get to finish her up this summer!
are they using new bolts every time they remove the heads? these bolts are a one time use kinda deal. Id get a set of ARP bolts (reusable) if I was you...with your luck, u might need them :insane2:
Just ordered the new heads, felpro gasket kit and felpro head bolts.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
GMC Truck Forum
5.8M posts
82.8K members
Since 2004
A forum community dedicated to GMC and Chevy full size owners and enthusiasts. Come join the discussion about Silverados, Sierras, and other full size trucks performance, modifications, suspension, lift kits, tires, maintenance, and more!