03 Trailblazer, Second Engine, Same Coolant Problem?

[lovemytruck24]

If anyone can help me I would forever be in their debt!

I have an 03 Trailblazer, 4.3 liter, V8, aluminum block. At 72K miles, dex coolant GONE, truck overheats, and it takes the dealership 4 weeks to tell me I need a new engine. Can't tell me why I lost all the coolant, after telling me it was the head gasket, and replacing that, and it happened again. Fought with GM and dealership and finally got the engine replaced for 5K. This model year did not have 100K warranty.

Now here I am over a year later. Labor day weekend, engine overheats, NO coolant, I fill it, and then it runs fine. I do have a 100K warranty on this "new" engine.

BUT since the new engine was put in, I've faithfully had oil changed less than 3K miles every time. After 200 miles after the oil change, the lifters start sticking, and then knocking is obnoxious. This should not happen with a new engine.

1-12-10 Tuesday morning, no heat, no coolant, once again. (about 3 months since they last checked it) Last check, they ran dye tests, pressure checks, and NOTHING was wrong. Dealership now says I have a cracked cylinder head.

DOES anyone have any ideas??????

[Nytemare]

Did any black cats cross in front of you...

That's some run of bad luck man....but sorry...thats just what it seems like...the 4.3 has always been an excellent engine, and this is really one of the few times I have heard of this big an issue with one. It sounds like you have taken very good care of it...so its nothing you have done, or haven't done that caused it...take advantage of the 100K warranty I would say.

 

EDIT:

 

Noticed you said...4.3 V8...Trailblazer......you either have a 4.2L inline 6 or a 5.3L V8

4.3L is a V6...it did not come in the TB....which one do you have....

[Stevens03]

No Idea, but a 2003 would be a 4.3

 

Seek the dealer for your warranty repair.

[Nytemare]

No Idea, but a 2003 would be a 4.3

 

Seek the dealer for your warranty repair.

Checked on rock auto...they list a 4.2 I6 and a 5.3 in the TB EXT...and its definitely not a 4.3L V8

 

But yes...warranty...and hope you just got two bad engines....a third and you may have grounds for lemon law

[Stevens03]

I'm tellin ya... 2003 Trail-blazer is the same thing as a s10 blazer under a new name. Like a classic verse a nbs... they made it with the 4.3.. I just can't prove it right now.. But my father-in-law had one.

[lovemytruck24]

No Idea, but a 2003 would be a 4.3

 

Seek the dealer for your warranty repair.

Checked on rock auto...they list a 4.2 I6 and a 5.3 in the TB EXT...and its definitely not a 4.3L V8

 

But yes...warranty...and hope you just got two bad engines....a third and you may have grounds for lemon law

 

 

You are right, 5.3 L, not the 4, sorry. I can't help but think there is another underlying issue causing the coolant to burn off. Bad radiator? Thermostat? or is it just the aluminum block and I really have BAD LUCK???

[Nytemare]

No Idea, but a 2003 would be a 4.3

 

Seek the dealer for your warranty repair.

Checked on rock auto...they list a 4.2 I6 and a 5.3 in the TB EXT...and its definitely not a 4.3L V8

 

But yes...warranty...and hope you just got two bad engines....a third and you may have grounds for lemon law

 

 

You are right, 5.3 L, not the 4, sorry. I can't help but think there is another underlying issue causing the coolant to burn off. Bad radiator? Thermostat? or is it just the aluminum block and I really have BAD LUCK???

 

5.3L engines some of them have Castech heads...and they crack in a specific place...If you got this engine dropped in before this problem was discovered, you probably have Castech heads...its fine. They rill replace them and you'll be fine.

 

Nothing would cause you to burn off the coolant....Its a closed pressurized system...cracks in the heads will cause coolant to leak in the oil or in the Combustion chamber and burn yes...but having a bad rad would just cause you to not have cooling at all, or it would leave a huge wet spot and lots of dead cats under your truck. Thermostat, that just keeps coolant on the engine side of the system in the engine until it warms up to operating temp, than it opens and allows all the coolant to cycle through the engine...its just a poppet and a spring. As for the aluminum block...there's literally millions of them out there...no problems at all...the biggest problem is the Castech heads...Chances are that this is your problem too.

[lovemytruck24]

Thanks Nyte, I'll call the dealer tomorrow Am, and ask what kind of heads I have on it. Is there another maunfacturer I should ask them to use?

[Stevens03]

My father-in-laws was an 02... now that I think of it...

http://upload.wikimedia.org/wikipedia/comm...TrailBlazer.jpg

 

 

Nytemare is the man..

[BKfirefighter3221]

Yeah, the castech heads crack internaly and leaks into the oil, but usualy it is a fairly minor leak. I have seen the caps leak, when they do a pressure test the cap is removed and a pressure pump installed in it's place. If they do not test the cap by itself they may not know it is leaking... I don't know about every one else but I make a habit of checking my fluids once a week, usualy when getting gas. I suggest you do the same and top off as needed, rather thatn waiting 3 months when the problem comes back. If I were you I would just put a new cap on any way if it has never been replaced. They should maintane 15 or 16 psi, for every 1 psi the system raises the boiling point, or overheating temp., goes up 4 degrees. So if the cap is say holding half of the pressure the temp that the coolant boils would be lower. Good luck

[gmtech4]

is it an SS or not?????????

[Nytemare]

is it an SS or not?????????

SS comes with the 6.0L

 

EXT comes with the 4.2L I6 and a 5.3L and the Trailblazer just comes with a 4.2L

and yeah the 02 was an s-10 Blazer Trailblazer...it was a package....the next year the trailblazer became its own vehicle..and 2 model years later the s-10 Blazer was no more.

 

The dealership will catch it if its Castech heads...don't "TELL" them to do anything...they will probably not be very receptive to your suggestions. Its why you pay them...or your warranty pays them to fix stuff...they don't need our help man...

[lovemytruck24]

is it an SS or not?????????

 

 

It is Not an SS. Thanks tho....

 

I called the Dealership, Service Manager assures me they must have tested the radiator cap, not just the radiator and coolant system. I asked him to check the records anyway. He can't tell me the manufacturer of the heads. I told him to go find out.

 

Will update all later. Thanks Everyone!

[Nytemare]

is it an SS or not?????????

 

 

It is Not an SS. Thanks tho....

 

I called the Dealership, Service Manager assures me they must have tested the radiator cap, not just the radiator and coolant system. I asked him to check the records anyway. He can't tell me the manufacturer of the heads. I told him to go find out.

 

Will update all later. Thanks Everyone!

 

If you want the TSB about the Castech heads....do a search for Castech here and a whole bunch of posts will show up.

 

Here I did it for you...post #38 thats the TSB

http://www.gm-trucks.com/forums/index.php?...stech&st=30

[BKfirefighter3221]

Castech was not the only supplier for those heads. Running the vin # will not tell you which ones the truck has. As in the tsb, the valve cover has to be removed and checked for the casting logo on the top of the head. I have done one Avalanche with this problem, but his only complaint was loosing coolant. We left it under pressure over night and no external leaks, thats when we removed the valve cover and found the Castech logo.