2004 5.3L Silverado Losing Coolant

[citrustools]

also get a block tester. will show any exaust gasses in the cooling system

 

oil loss/coolent loss.....i would start looking at a possable head gasket or cracked head.

and i know you did not want to hear that.....

 

good luck

 

 

<{POST_SNAPBACK}>

 

 

 

But with a cracked head, or a blown/leaking head gasket, that should make the oil look like a chocolate milkshake, and it looks just fine and it showing no signs of mixing with coolant.

 

To update, the valve tapping has gone away for a bit (as far as I know...now that i'm back at school, there's no telling what it does during the week when i'm not home).

 

Coolant loss continues. But I just ran across another thread where somebody had the same problem on a 2004 Sierra with the 5.3, and it was the water pump gaskets. I'm definitely going to look into that this weekend....maybe see if I can't dig up a FSM, as I REALLY hate the Haynes and Chilton's manuals.

 

Oil smoke show has stopped, but it still uses oil....still not sure on that one.

 

Thanks all for the suggestions, and I welcome any more. I'll definitely keep yall updated.

 

I forgot to add that Oil pressure stays with in what appears to be a normal level based on a hot or a cold engine...IF ANYTHING maybe a tad on the high side when driven cold, but it may still be with in factory spec for this engine.....I have not looked up what the pressure is supposed to be.

 

[citrustools]

 

 

But with a cracked head, or a blown/leaking head gasket, that should make the oil look like a chocolate milkshake, and it looks just fine and it showing no signs of mixing with coolant.

 

To update, the valve tapping has gone away for a bit (as far as I know...now that i'm back at school, there's no telling what it does during the week when i'm not home).

 



Blown head gaskets do not necessarily mean coolant will go into the oil, it may just be leaking coolant into a cylinder or 2 which may also be your morning piston slap as you are referring to a lifter that may not be the case. It may be a small hydro lock from coolant being in said cylinder. And that will give you white smoke until the cylinder clears. Pull the spark plugs and see if one of them is real clean vs. the other ones that will show carbon trace. That will prove out a bad head gasket out the cheap and simple way. Better yet, park said vehicle after it is fully warmed up and let it sit overnight. Pull the plugs in the morning and crank the engine and see if coolant shoots out a hole or 2. Obviously customers do not want to hear that. I was a GM master tech with Cadillac for 30 years and a shop foreman.

 

 

[parris001]

So, I've been observing and wondering, "what is the fix?" Is it possible to get a good set of 706 casting Castech heads? Are they all junk? Will another casting number promise a better cylinder head? What does the dealership do to fix this problem? More of the 706 castings?

 

I find this to all be totally ridiculous! Lot's of antifreeze in the oil, lifters rattling, oil consumption........ but no answers

[kgrigsby]

So, I've been observing and wondering, "what is the fix?" Is it possible to get a good set of 706 casting Castech heads? Are they all junk? Will another casting number promise a better cylinder head? What does the dealership do to fix this problem? More of the 706 castings?

 

I find this to all be totally ridiculous! Lot's of antifreeze in the oil, lifters rattling, oil consumption........ but no answers

 

bl

 

Last year my 1999 gmc 4.8l 250,000 km had all the issues with the valve noisy lifters, loss of coolant with no visible sign of leaks on outside of engine.

I checked to see if i had the castec heads and did not.

Another thing I found in regards determining if you have antifreeze in you oil is your oil will not always be ' milky' on the oil dipstick to confirm that antifreeze has mixed with the oil, antifreeze does not like to mix with oil. You have to drop your oil and if it comes out kind of chunky or blobs, you have antifreeze in the oil, it will end up on the bottom of your drain pan.

I found the problem when I pulled the intake manifold off, THE TOP ROW OF BOLTS ABOVE PUSHROD GALLERIES, (11mm, not the main head bolts) ON THE LEFT HEAD HAD LOST TORQUE and subseqently antifreeze was able enter the oil pan via the valve pushrod galleries, there was evidence of corrosion, etc on the pushrods, aft lifter area.

At this point I was 90% sure I found the leak but decided to change the head gaskets, when they were pulled I found no evidence of leakage around the head gaskets gaskets.

So what I suggest, pull your intake manifold off, (only way to get at the smaller 11mm? bolts) check torque, if loose retorque, put intake back on (new gasket), if not and no sign of corrosion etc in pushrod galleries continue on with changing out head gaskets. If you do this it should take, 2-3 hrs versus 4-8 hr for a head gasket change depending on your experience.

If you are looking for a complicated explanation for this problem there is not one, that was all it is. Let us know what you find, Good luck and pm me if you need.

[gmc2004Z71]

I,m going threw this problem now I have a 2004 GMC sierra 5.3 Z71 in great conditon & well maintaind with 163,000 most high way miles . Here are some resent pictures tooken from repair shop.It started a couple of months ago started noticeing anti frezz disappering no leaks ever found & would talk to several shops about problem & every one had differnt ansewers & price quotes from $100 to $1200.00. I took it for regular oil chang & when they showed me my oil filer & all of this thick sludge clumps of oil would drain out & inside oil filter and from there i new it was going to get expensive. I took it to local mechanic and was told that engine needs to be replaced . If any one can help with information on what would be best option to do with a New ,remanufactured a or rebuild I want to keep truck payed way to much to get rid of it what to[email="[email protected]

[maxf]

I'm on my second day of research about this matter, and I have an '03 Gmc Yukon w/ 79k miles, thats currently in my local dealership with a cracked Castech head, sludge everywhere and basically staring at a $4,000 bill that they want to charge me, just to replace the heads and clean out the oil pan. So, naturally I opted to call a local respectible Engine rebuiler, a complete new longblock, with install was $4,600. Whats the deal with that?

I have read many of these type of threads, and Google searched anything and everything regrarding Castech cylinder heads.

My findings are that GM is wiping they're hands clean of this issue, it's the fault of Castech apparently, and we (the consumer) get ****ed.

My motor is junk because GM opted w/ the lowest cylinder manufacturer..Bid. Cheap parts = more money, and lucky for them they only seem to bust AFTER the warranty expires = more money.

 

Guys, remember when Firestone had a bad batch of tires that came equipped on Ford trucks and such about 10 years ago...

Yeah, Ford replaced my tires with brand new ones, no questions asked. WTF, why can't GM stand behind they're product and fix a problem that thousands of loyal GM customers are experiencing due to they're negligence.

[Yamaheart]

I also have a antifreeze smell when exiting the truck . I have looked all around the engine and cant see any visible leaks . There appears to be seepage around the intake at the top.The water pump looks dry. I bought the truck Oct 2009 74 000 kilm I have added about 1 gal since then . This problem seems very common on these trucks you would think GM would stand behind this problem and resolve It . I would hate to think I have to spend 3000 bucks to repair some crapy heads that should have never been used In the first place

 

[Z'06]

If you think the Castech problem is bad, just wait for the GMT900 trucks with AFM to eventually fall out of warranty. Those weak lifters are a problem that will only get worse.

[ezdropper]

Seems like GM needs to pay for the repairs or recall the vehicles with the defect, but I guess since it is not a safety issue, they won't do either.

[mcvoss]

Ok, I am victim of the bad head(s), Slow coolant loss, drained oil today and full of sludge. I need some assistance here. I am going to pull the valve covers to see which head is bad,

 

I have never replaced a cylinder head. I am good at working on cars, any advice.

 

Do I need just the rebuilt head, any suggestions where to get them, head and valve gaskets?

 

 

 

 

Thanks everyone. This really sucks.

[kgrigsby]

Ok, I am victim of the bad head(s), Slow coolant loss, drained oil today and full of sludge. I need some assistance here. I am going to pull the valve covers to see which head is bad,

 

I have never replaced a cylinder head. I am good at working on cars, any advice.

 

Do I need just the rebuilt head, any suggestions where to get them, head and valve gaskets?

 

 

 

 

Thanks everyone. This really sucks.

bl

 

Seriously look into this, read it carefully It may save you a lot off bucks.

 

Last year my 1999 gmc 4.8l 250,000 km had all the issues with the valve noisy lifters, loss of coolant with no visible sign of leaks on outside of engine.

I checked to see if i had the castec heads and did not.

Another thing I found in regards determining if you have antifreeze in you oil is your oil will not always be ' milky' on the oil dipstick to confirm that antifreeze has mixed with the oil, antifreeze does not like to mix with oil. You have to drop your oil and if it comes out kind of chunky or blobs, you have antifreeze in the oil, it will end up on the bottom of your drain pan.

I found the problem when I pulled the intake manifold off, THE TOP ROW OF BOLTS ABOVE PUSHROD GALLERIES, (11mm, not the main head bolts) ON THE LEFT HEAD HAD LOST TORQUE and subseqently antifreeze was able enter the oil pan via the valve pushrod galleries, there was evidence of corrosion, etc on the pushrods, aft lifter area.

At this point I was 90% sure I found the leak but decided to change the head gaskets, when they were pulled I found no evidence of leakage around the head gaskets gaskets.

So what I suggest, pull your intake manifold off, (only way to get at the smaller 11mm? bolts) check torque, if loose retorque, put intake back on (new gasket), if not and no sign of corrosion etc in pushrod galleries continue on with changing out head gaskets. If you do this it should take, 2-3 hrs versus 4-8 hr for a head gasket change depending on your experience.

If you are looking for a complicated explanation for this problem there is not one, that was all it is. Let us know what you find, Good luck and pm me if you need.

[mcvoss]

Did a pressure test today, guess what, left head was has a hairline crack where the TSB says. Thanks GM. I'm going to go ahead and replace both. Man this ticks me off, I have babied this truck.

 

 

 

 

Thanks guys for the advice I really appreciate it.

[jro909]

i wish new GM would step up and right the wrongs of the old gm....repay the people that pay out of pocket for stupid crap like castec heads,dead clusters,steering clunk....some stuff on a vehicle should never die or have problems...

[Dxray]

Hi, i have been experiencing the what seems to be a common problem with missing coolant and valve chatter on start up on my 05 silverado 4.8l. I can't see any sign of water in the oil from the dip stick but pulled the valve covers to see. There was some butterscotch pudding all underneith the covers on the drivers side. I looked for the castech mark but there was an X where the mark should be, good right? Then i pulled the cover on the passenger side, there was not as much pudding on this side. Then i spotted the castech mark on this head. Looked for a shiny spot in the oil weep holed but the whole head itself is not very dirty so i see nothing out of place. Going to do the intake gaskets this weekend and hope thats what the problem is.

 

 

Castech mark right?

 

[txab]

Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

 

Important: If the cylinder head(s) are Not a Castech casting, follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

 

 

 

Castech head images