2004 5.3L Silverado Losing Coolant

Wicked6 · April 7, 2009

2002 Tahoe, 5.3l.. We're losing about a quart every 2 months or so - primarily city driving with the occasional road trip.. I noticed a small pool of coolant yesterday on the garage floor, appears to be front left..!? I thought the waterpump leaked on the right side..?? Anyway, it looks like we'll be tearing into it sometime in the very near future. I am getting nickel and dimed to death on coolant..!

MikeInCtown · April 8, 2009

2002 Tahoe, 5.3l.. We're losing about a quart every 2 months or so - primarily city driving with the occasional road trip.. I noticed a small pool of coolant yesterday on the garage floor, appears to be front left..!? I thought the waterpump leaked on the right side..?? Anyway, it looks like we'll be tearing into it sometime in the very near future. I am getting nickel and dimed to death on coolant..!

I would love to find coolant in a puddle somewhere if I knew my truck was leaking because you have a pretty easy job of locating the problem then. Probably have a radiator leak or a leak at a hose.

My truck is leaking antifreeze from somewhere as I can smell it and see it slowly dissappear. Oil is good and never goes low and I can always smell the antifreeze at the front of the truck after I've been driving a while. I think the radiator may be bad because it smells from the radiator after I turn the truck off and I get a strong smell when I pop the plastic cover off that protects the front of the radiator/trans cooler/condenser. Until I do a UV light test I won't know for sure. I had a pressure test done and the guys at the shop had no clue. I certainly don't want to go looking for a cracked head.

neonhomer · April 15, 2009

I am wondering if I am having the same issue. I am slowly loosing coolant somewhere. Cannot find an external leak. There is no coolant in the oil, but I haven't pulled the valve covers. (Going to do that this weekend)

An unexplained item is also that I am having a random misfire issue on ALL cylinders.

Bad thing is, I don't have upwards of $3000 to change heads.

Do they make an aftermarket head for the 5.3???

MikeInCtown · April 16, 2009

I am wondering if I am having the same issue. I am slowly loosing coolant somewhere. Cannot find an external leak. There is no coolant in the oil, but I haven't pulled the valve covers. (Going to do that this weekend)

An unexplained item is also that I am having a random misfire issue on ALL cylinders.

Bad thing is, I don't have upwards of $3000 to change heads.

Do they make an aftermarket head for the 5.3???

$3 grans would be if GM put new heads on your truck. if you bought a set at a boneyard and did the job yourself I would bet you would be in at less than $400. if you had a machine shop check everything out it would still be probably less than $500 total.

Oh, and I believe that Trick Flow makes a head for the 5.3 now. IIRC Summit has advertised them for ~$1,800 or somewhere in that range.

pdtech · April 22, 2009

Howdy fellas.

First off let me say ya'll got a nice forum here. I've recently found a problem with my step dad's 2004 Silverado, with the 5.3L, right at 83,000 miles....bought brand new. While going to dinner two weeks ago, it began to over heat. The temp. guage would get to about 230-240, hang there for a minute or so, and then settle right back down to 210. It would then stay at 210 for a while, and slowly begin to creep back up to 230-240....it never got to the red zone, which is a good thing. All this was happening while driving down the road. Sitting at a light or in traffic, it would creep up a little bit, but only to about 220 or so.

Once we got out of the restaurant and the engine had about 3 hours to cool back down (as it was a chilly night), I checked the level, and sure enough it was low...practically empty. About one month prior to this when I changed the oil on his truck, I noticed the coolant level was low, but not this low. I topped it off and didn't think much of it....figured all the miles on it, maybe it just got low over time.....until that night at the restaurant.

We managed to get it back home (about 20 miles away) that night with it still doing the same thing. First thing the next morning, I once again filled it back up (taking an entire gallon to bring it back up to full), and the overheating has stopped. Problem is, the level is significantly lower than it was 2 weeks (will be 3 weeks this weekend) ago. It is not leaking on the outside, so it's definitely something internal.

First thing I checked was the oil, and it looks fine and does not smell of coolant, although I'm not totally ruling out the possibility that there is a small amount getting inside the crank case. He told me that one day last week he fired it up in the garage to leave for work in the morning and he said it blew out a pig puff of white smoke, but ran just fine (which is making me lean away from a Head Gasket problem) and cleared up pretty quickly. Then, this past Friday morning, he went to run some errands and noticed the valve's tapping very loudly when he first fired it up, but that also cleared up pretty quickly.

My question to you all is, does this sound like an intake gasket issue? From talking with my dad who has been mechanic for almost 40 years, he's had to put a lot of intake gaskets on GM vehicles (just did one last week on a mommy van as a matter of fact) and says they're pretty common to go out.

Again this truck has almost 83,000 miles on it, and they're pretty much all highway miles (he does at least 70 miles a day round trip for work). He bought it brand new and takes pretty good care of it.

I've got zero experience with Chevy trucks....I'm a Jeep guy and my knowledge is mainly in Cherokee's and Liberty's, as well as somewhat on Wranglers, so I turn to you all for advice. I'm no stranger to forums, and I did use that handy dandy search feature, but did not really come up with much of what I was looking for.

So if anybody has got any advice to throw my way, by all means throw it. And I apologize if this is in the wrong thread, so feel free to move it if need be.

Oh and once again the specs: 04 Silverado, 5.3L, Automatic, 4x4 (not that it matters), 83K.

And yes, I did make sure to put the orange Dex Cool coolant in it. I've converted my Cherokee over to the orange stuff and the Liberty being a newer vehicle came with it from the factory, so I've got plenty of it in my garage.

Thanks for your help guys. This is the first issue he's had with this truck.

Check the water pump gaskets-very common for 5.3's around that year-buy the updated gm gasket-not one of the after markets

pdtech · April 22, 2009

Check the water pump gaskets-5.3's around that year are common to leak-buy the updated gm gasket-not one of the aftermarkets and it wont happen again!

tmicklet · May 23, 2009

Hello,

Just an update to my previous posts. In my case it was a cracked head (castech heads). To all out there, if you are losing coolant with no evidence of where it is going, getting ticking lifters on a cold start that goes away, blowing blue smoke on a cold start, chances are that YOU HAVE A CRACKED HEAD. I went through the hole thing last fall.

The dex-cool leaks into the oil but turns to jelly under the valve covers (looks like butterscotch) and also thins out the oil causing the ticking lifters. The blue smoke is some of the butterscotch looking stuff getting sucked through the pcv and burning, once the path is clear no more smoking.

I hope this helps you guys out there. I went through it too.

Any questions email me at [email protected]

Cheers

Jansen · May 27, 2009

I too am loosing coolant but not very bad. Mine tends to use it until the coolant is 1" below the cold line then not use any more. I plan to investigate as soon as I can. Is it possible to see the Castech logo with only pulling the valve cover or does other hardware need to be removed?

drew2150 · June 4, 2009

I have a 2004 Sierra, 120,000 miles, replaced water pump just over a year ago, could smell coolant, finally found moisture behind water pump, lower pass. side there is a space about 3/8"wide. You will need a good light to see in this area.

Now, using coolant had to add 1 qt of oil between changes, and a sticky shellac like substance on dipstick. Sound familliar?

My question. Heading to Florida next week for vacation, I'm thinking the crack head thing here, am I gonna be ok to drive down and back just keep an eye on things?

Any thoughts from you all would be good. Thanks in advance.

Drew

7WTGLX · September 23, 2009

Hello,

Just an update to my previous posts. In my case it was a cracked head (castech heads). To all out there, if you are losing coolant with no evidence of where it is going, getting ticking lifters on a cold start that goes away, blowing blue smoke on a cold start, chances are that YOU HAVE A CRACKED HEAD. I went through the hole thing last fall.

The dex-cool leaks into the oil but turns to jelly under the valve covers (looks like butterscotch) and also thins out the oil causing the ticking lifters. The blue smoke is some of the butterscotch looking stuff getting sucked through the pcv and burning, once the path is clear no more smoking.

I hope this helps you guys out there. I went through it too.

Any questions email me at [email protected]

Cheers

I have had the same problem going on with my 04 1500 Silverado 5.3L. This spring I read all the service bulletins pertaining to the bad heads and everything, did a compression test and it led to a bad head gasket. So I had a mechanic freind of mine replace the heads and gaskets for me since I didn't have the time. But the problem is still going on and now I'm getting a little pissed 'cause I'm $2800 into it with nothing fixed. I'm trying to find a test kit to pressurise the cooling system and see if anything shows up, but now I'm thinking that it's either worn piston rings or a cracked block. I live in Alaska and last winter we had a cold spell that dropped down to about -35F for a couple of weeks and it was after that when I first started to notice this problem. Due to the fact I live here I test my coolant regularly during cold months and it was supposedly good down to -45. I know that replacing the piston rings is a pretty involved procedure and spendy, and a cracked block means a new engine. If I do have to replace the engine I would like to drop a 6.oL in for the extra power for towing. But would it match up? I've tried looking for resolutions to this problem that people are having with the 5.3s but havn't seen any yet that say they have actually fixed this problem. Does anybody know for sure what is causing this?

I'm using about a gallon of coolant every 3-4 weeks, oil looks good, no vissible leaks, smell coolant after driving, I can smell coolant in the exhaust, and I use about 1/2-1 quart of oil every 3000 miles, and it blows whitish-blue smoke on start-up (not every time). I drive 100 miles round trip for work and I don't want to get stranded on the side of the highway with winter coming fast.

7wtglx1 · September 24, 2009

Could this problem be caused by a faulty pcv?

Stoned_Elvis · October 25, 2009

could the cracks in the head be welded?

Nytemare · October 25, 2009

could the cracks in the head be welded?

NOPE!!!

If they could GM would do it rather than giving you new heads...you know that.

Edit;

Well I shouldn't say they "can't" be welded....it can....but the head wouldn't be the same...you may warp it with the heat, stress the material somewhere else, it just wouldn't ever be a sound repair.

dallupgrad · October 28, 2009

Is there a recall on this?

Nytemare · October 28, 2009

There is a TSB if your truck has Castech heads. if not you are SOL.

Use the Sites Search function and look up CASTECH. there are quite a few postes about it with the TSB in there also, and what to look for on your heads to know if they are Castech.