First post and I'm using my phone to post since my computer is RIP, and the phone won't allow me to do a search. I've read some about cracked heads on 5.3's and I think I've got them. Loosing 1/2 a gallon every other week with a dry garage floor. Looked in the oil fill cap today and found this...







Going to need recommendations on some new heads I think...Thanks from a newb.

Chip

 

I have seen some of the 5.3 heads with issues mostly the 04 and 05s for some reason. There area a few places that sell remanufactured heads for these. I think there are some on ebay. Before you swap the heads check you water pump while the engine is running. My old Yukon had a leaking water pump. It would never leave a puddle on the ground because it only leaked when it was running

 

I just replaced the pump and t-stat 1500 miles ago...I know the castech 706 are junk cause that is what I have, what are my options.

 

budget? you want small chamber truck heads to keep the CR up probably
862's would get you away from the castech problem
i seen em on ebay for $550 refurb'd
whatever you do, do it soon. we get those 706 headed motors for $100 because the bearings are dead from coolant in the oil.

 

Not all 706 are Castec, and not all the Castec 706 are junk. Castec also requires pulling the rocker stand to identify.

 

Ive personally had 3 sets of 862 castings leak. 3 different vehicles one of them being my wifes old tahoe(2002).

 

This is my wife's ride and it's going to stay stock for the most part, so I don't want to spend $1000 on performance. I did do some reading last night and see there are several different heads available; 862, 243, 799, the last two being pretty popular.

This is my bigger concern. It is very peanut buttery under the covers. I know I'll need to change the oil pretty often at first to clean out the block, but like you are saying, without tearing it apart is it a lost cause and should I be looking for a long block. I'd guess this has been going on for about 2000 miles, but the last oil change didn't look milky.

 

I checked and have the battery logo...

 

I meant to say thanks to you guys that have posted....

I found a couple different sets of heads and a 5.3 local:
or
or
I would of course check the 5.3 for head type. On the heads mentioned, can I just swap the springs from my 706 or do I need new?

 

Well crap......my wife was driving it home tonight and the check oil level message came on. I checked it and no oil on the dipstick. Is this motor going to be shot???? I guess it's going to get parked until I decide it's fate.

 

I know, another post......but

I found a new set of 862 non-castech heads. Which would be better, these 862 or the mentioned above 243's with 64K and need to visit the shop first? The 862's are $575 and the 243's are $400 plus the valve job and resurfacing.... Thanks guys.

 

How many miles does it have in it? Loosing coolant and burning oil sounds like 2 different problems! If its close to 200k I would be looking at a reman long block if you plan to keep the Tahoe for a while!

 

176,000 miles. Yea, I was hoping not to have to go that route but.......

 

Look on the bright side if it comes to that, if your doing the work yourself you can swap the Moter in less time that to r&r the heads, plus you get a warrantee! Best of luck wich ever way you go!

 

You always could clean off oil cap good, fill up on oil & coolant, TRADE it in on something else. A rebuilt motor wont bring the value up on it that much anyway when everything else has 176,000 miles.

 

Don't do this.

Someone else will invariably get fucked. It is rarely ever the dealer.

 

I learned this working at car lot. Drain antifreeze out flush with water. Moroso makes a sealer for cooling systems called ceramic sealer. You put it in drive it to operating temp let it do its thing. Flush it out fill with fresh antifreeze. It either stops coolant leak or stays same, but its relative cheap fix. How long who knows. Several dealers I know do it all the time.

 

I've done this before, I felt bad afterwards. But I ended up with another truck

If its burning oil and antifreeze then obviously something isn't right here. We've seemed to narrow the coolant issue down to the heads, which in itself isn't a terrible job to do. As for the engine burning oil it could be a few different things, but since you said it had almost no oil something bad is happening. How long has it been since its last oil change? I've seen Tahoes with 300k on them and run like new, but I've seen ones with the Castec heads take a dump at 150k so its hit or miss.

It'll probably be a lot easier to just find a complete engine and do the entire swap in one day. Since nothing is custom it should just be plug and play.

 

Relatively new Gen III owner. Just picked up a 5.3 out of a 2004 Tahoe a couple of months ago for a project I'm working on. 62K miles. After seeing this thread, I looked and saw that I had the 862 heads.

How do I tell if they are Castec or not?

 

SO........I'm going to try the inexpensive route first.

I will pull the heads and drop the oil pan. Clean everything I can in the block and underside. Washout the pan and reinstall.

I picked up some 862 heads that have been completely rebuilt. Can I swap my rocker arms or should I invest in new ones? Does anyone have part numbers and a source for head bolts, gaskets for both the heads and intake (in case the intake gasket is crap)? Any parts I'm missing?

After it's back together I'll run some engine cleaner (seafoam or other if anyone wants to give an opinion, I'm listening) drain the oil, repeat, drain and fill with synthetic.

I'm hoping bad valve seals are the cause of the oil loss....worst case I still burn oil, which means bad rings and the motor will get rebuilt.