2004 5.3L Silverado Losing Coolant

[Nytemare]

Heres the TSB with pics.

 

 

I found the TSB for the gradual coolant loss with no leaks on alldata....but I don't have a subscription to their site. If anybody on here does and would be so kind as to look up the info on the TSB, it would be greatly appreciated.

HERE YOU GO. GOOD LUCK

 

Document ID# 1986750

2004 Chevrolet Chevy C Silverado - 2WD

 

 

Subject:Information on Gradual Coolant Loss Over Time with No Evidence of Leak Found #06-06-01-019B - (06/12/2007)

 

 

 

 

 

 

Models:2004-2006 Buick Rainier

 

 

2001-2006 Cadillac Escalade Models

 

 

2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models

 

 

2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models

 

 

2001-2004 Oldsmobile Bravada

 

 

2005-2006 Saab 9-7X

 

 

with 4.8L or 5.3L VORTEC® GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z -- RPOs LR4, LM7, LH6, L33, L59)

 

 

 

 

This bulletin is being revised to include engine RPO L59. Please discard Corporate Bulletin Number 06-06-01-019A (Section 06 - Engine/Propulsion System).

 

Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

 

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.

 

Refer to the following illustrations on how to identify Castech casting and/or the very specific areas of the cylinder head(s) for a coolant leak from porosity.

 

 

Cylinder head(s) location of the Castech manufacturing casting logo (1).

 

 

Close up view of the cylinder head(s) showing the Castech manufacturing casting logo (1).

 

 

If the cylinder head(s) is a Castech casting (1), inspect the area around the five oil drain holes for witness marks indicating coolant seepage over time (2).

 

Important: If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

 

 

The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface (1). Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks (1), replace the entire cylinder head(s) assembly.

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© Copyright General Motors Corporation. All Rights Reserved.

 

 

Document ID# 1986750

2004 Chevrolet Chevy C Silverado - 2WD

 

[jro909]

i beleive the water pump leaking has been a problem for awhile, more commonly on the 4.8s i think

[dotsoid]

I have an 04 with these exact symptoms. Have been battling it for quite some time. Was not leaking for ever just disappearing from reservoir. This am discovered coolant in driveway. Got to doing a little more investigating and discovered coolant on the bottom side of the oil fill cap, NOT GOOD!! Oil does not look milkshakish as described in this thread. Sound like a Castech head issue??

I see the TSB posted on the thread. Does that just mean the GM is aware of the problem or do they pay to have it fixed?

 

Responses greatly appreciated!!

[minibike132]

I have an 04 with these exact symptoms. Have been battling it for quite some time. Was not leaking for ever just disappearing from reservoir. This am discovered coolant in driveway. Got to doing a little more investigating and discovered coolant on the bottom side of the oil fill cap, NOT GOOD!! Oil does not look milkshakish as described in this thread. Sound like a Castech head issue??

I see the TSB posted on the thread. Does that just mean the GM is aware of the problem or do they pay to have it fixed?

 

Responses greatly appreciated!!

 

If you see it hitting the driveway it's not the head, at least not in the area defined in the bulliten. 9X out of 10 if you are missing coolant but don't see it on these motors you just have not looked closely enough at the water pump. If you see it in the drive way now what part of the engine would be in line with the puddle on the ground?

[Nytemare]

TSB= Tech Service Bulletin...AKA...its a memo to the tech to let them know what to look for if a customer comes in complaining of this issue.

 

Generally...you have to pay.

[dotsoid]

I am by no means a mechanic. Just trying to self diagnosis. the area looks to be toward the rear of the engine. Running down oil pan on right side. Head gasket possibly?

 

What about the TSB? GM covers it or just aware?

[minibike132]

I am by no means a mechanic. Just trying to self diagnosis. the area looks to be toward the rear of the engine. Running down oil pan on right side. Head gasket possibly?

 

What about the TSB? GM covers it or just aware?

 

I can't really think of anything that is a common leaker on the back of these engines, head gasket is a possiblity but I don't remember seeing any leak at the rear of the head.

 

They will "help" on some things that are super super common but I don't think this qualifies as one of them.

[dotsoid]

So do I now have 2 problems? Mixing with oil and leaking external or would one be leading to the other.

 

I have a sneeky suspision that I have Castech heads.....

[Nytemare]

So do I now have 2 problems? Mixing with oil and leaking external or would one be leading to the other.

 

I have a sneeky suspision that I have Castech heads.....

Sounds like you may have one problem...showing itself in 2 different ways. I think you have a blown head gasket...Like Sparky said, thats the only thing to leak where your describing.

 

How long has this been happening? If you have noticed coolant in your oil for a while now...you need new main and rod bearings too...the coolant will eat them.

[txab]

I am by no means a mechanic. Just trying to self diagnosis. the area looks to be toward the rear of the engine. Running down oil pan on right side. Head gasket possibly?

 

What about the TSB? GM covers it or just aware?

 

It's going to be on your dime. TSBs are not recalls.

[PunchT37]

So do I now have 2 problems? Mixing with oil and leaking external or would one be leading to the other.

 

I have a sneeky suspision that I have Castech heads.....

 

I`m not totally 100% sure but, most Castech heads iv`e seen are the "706" castings and not the "862" cast. So, take a look see.

[SCFog]

mine is a 04 Envoy XUV. lifter noise for a month. Started after having a local Chevy dealer do an oil change... go figure!

Truck is now 77Kmiles. Dealer has no idea. My local garage guys had one truck through, therefore some experience with GM not even wanting to cover the cost of these cyl hds R&R within Warranty. who's kidding whom.

 

So, what heads does one buy, to get something of an improvement in cost and MPG? I have no compunction to purchase factory parts, that would continue the insanity.

 

And I have how much left on my loan with GMAC????????

 

How many of us is this, in just this thread?

 

Thanks, guys, for all the info.

 

Now, any ideas how to get some help from GM??

 

thx.

 

Steve

[SCFog]

dex cool and water will affect main and rod bearings?

Is this some sort of chemistry issue, or is it just lack of oiling?

How long to do this? any experience out there?

 

My truck's problem is only going on a month plus. But that noisiness can't be healthy, I know. I have opted to not run the truck for the time being; although I need to have the thing diagnosed by the local GM dealer, means that I gotta get it there....

 

Any information will be very much appreciated.

 

Best

Steve

[Z'06]

Call these guys for a free test kit and test your oil ASAP.

[lovemytruck24]

I had the SAME problems with my Trailblazer. See the latest post. (Link below)

What's happened is your Heads led to slow coolant loss, causing further damage to your engine, gaskets, and more.

I got a new engine out of the dealership, after a 5K investment. Then IT HAPPENED AGAIN.

Surprise, it was ONE castech head, and sure enough, once they replaced it (under a NEW 100,000 mile WARRANTY). The TSB's these guys posted here are your CAUSE.

These guys know what's up. You need to isolate the CAUSE, and then fix the problems, if not replace the engine.

Here's the story http://www.gm-trucks.com/forums/index.php?showtopic=107584 Copy and paste into new browser, and see what I went though.

Don't give up, call GM yourself, and ask for some answers.