Ghost Coolant leak on my 04 Yukon XL 5.3... advice anyone?

[Mark-23]

I took it to the mechanic a few days ago, I just picked it up. It's had the leak for the past three months, I didn't find any milky color on the dipstick in the mornings, when I turn on the engine I wouldn't smell anything coming out of the exhaust.

 

He said it's either the head gaskets or it's a very small leak that's dripping into the engine and evaporates.

 

replacing both head gaskets would cost me $2000 but he suggested me to use the high-end stop leak.

 

What are you do folks suggest, should I use the stop leak?

 

Is there any other solution than replacing the head gaskets and using stop leak?

 

I don't have the budget to replace the head gasket at all, and this is my daily driver. I was planning on keeping it for a long time and fixing it up customizing it etc.

[txab]

Add dye to the coolant and maybe find the leak that way. Checked thoroughly for the Castech issue?

 

http://ww2.justanswer.com/uploads/Bluegorilla/2008-12-05_142924_Coolant_loss_5.3.pdf

 

Looked closely at the WP and gaskets for traces of dried coolant?

[Heavy 5.7]

1. How much coolant?

2. Borrow a cooling system pressure tester from autozone.

3. Find another mechanic.

[Jsdirt]

If you absolutely have to ... I've had good luck using K-Seal or Bars Leak in the past.

 

Aluma-Seal used to be great in the day - would be a permanent fix on anything smaller than a 1/4" gash in a radiator. Stuff was no joke! They changed the formulation to absolute garbage sometime after the turn of the millennium ...

 

My '86 Grand Marquis has been fed a steady diet of the stuff for the past 13 years & 170k miles to avoid replacing the heater core. Your truck isn't built like this thing was, so don't go crazy with the stuff. It can get you by until you have the funds to fix it permanently.

 

 

If you want to know for sure if that's your problem, find a garage with a 4 or 5 gas analyzer, and have them stick it in the coolant overflow bottle - if the HC starts to climb up over 200ppm, that's a confirmed head gasket leak.

 

These analyzers are STUPID expensive, so you might have tough time finding one willing to get the probe that close to coolant, but any garage worth a damn should be using it for this every day.

[txab]

You can buy test strips to dip into the coolant to check for hydrocarbon residue

[Mark-23]

1. How much coolant?

2. Borrow a cooling system pressure tester from autozone.

3. Find another mechanic.

 

1.) I used up the entire 50/50 coolant and it was close to over heating within almost 3 weeks

 

2.) the shop did the pressure tester infront of me, for 15-20 minutes nothing came out. The pressure kept itself steady. Not a single leak or drop came out.

 

3.) I left my car at this mechanics shop for 2 1/2 days, he's a distant uncle of mine. Good guy. He thinks it's small very small leak, told me to add the expensive kind of Bars Leak and that should fix it up.

 

P.S. I'm just fishing for more advice before I make a proper decision

[Mark-23]

Add dye to the coolant and maybe find the leak that way. Checked thoroughly for the Castech issue?

 

http://ww2.justanswer.com/uploads/Bluegorilla/2008-12-05_142924_Coolant_loss_5.3.pdf

 

Looked closely at the WP and gaskets for traces of dried coolant?

 

When I would turn on my car in the morning I'd take a look at the exhaust and even smell it... there is no color coming out of it, and no smell

[Mark-23]

You can buy test strips to dip into the coolant to check for hydrocarbon residue

I looked at the dipstick everyday for almost 2 months, no milky color at all... just normal darkening color of Motor oil.

 

My uncle told me just make sure I keep adding coolant when it reaches low levels and keep my motor oil clean till something weird happens. I left it at his shop for almost 2 days and they couldn't figure it out but they think it's both the headgaskets.

[Mark-23]

If you absolutely have to ... I've had good luck using K-Seal or Bars Leak in the past.

 

Aluma-Seal used to be great in the day - would be a permanent fix on anything smaller than a 1/4" gash in a radiator. Stuff was no joke! They changed the formulation to absolute garbage sometime after the turn of the millennium ...

 

My '86 Grand Marquis has been fed a steady diet of the stuff for the past 13 years & 170k miles to avoid replacing the heater core. Your truck isn't built like this thing was, so don't go crazy with the stuff. It can get you by until you have the funds to fix it permanently.

 

 

If you want to know for sure if that's your problem, find a garage with a 4 or 5 gas analyzer, and have them stick it in the coolant overflow bottle - if the HC starts to climb up over 200ppm, that's a confirmed head gasket leak.

 

These analyzers are STUPID expensive, so you might have tough time finding one willing to get the probe that close to coolant, but any garage worth a damn should be using it for this every day.

1.) Which StopLeak should I use on my 5.3? I don't even know where the leak is, it could be the radiator or water pump or head gasket which they said is most likely the head gasket. My uncle said to buy the expensive kind that's like $60...

 

2.) I don't know if they did the 5 gas analyzer on my Yukon XL. But I'm pretty sure they didn't and nor would they have one cause if they did they would've figured out what the problem was by now...

 

Does anyone have experience on this forum with Stopleak and the 2001-2006 5.3 vortecs?

[Heavy 5.7]

Have you parked the truck with some cardboard overnight under the engine compartment?

Ethylene glycol doesn't burn completely so use your finger to feel if the inside of the exhaust pipe slimy.

Have you ever changed the intake gaskets?

[Mark-23]

Have you parked the truck with some cardboard overnight under the engine compartment?

Ethylene glycol doesn't burn completely so use your finger to feel if the inside of the exhaust pipe slimy.

Have you ever changed the intake gaskets?

1.) that's the only thing I did not do is put a cardboard overnight underneath the engine compartment, but the mechanics that or find a drop. I'll try to put a cardboard piece underneath the engine compartment tonight and see how it goes

 

2.) this might sound a little stupid, by using my fingers to feel the inside of the exhaust pipe... do you mean the exhaust tip or just the bottom of the pipe running along the car?

 

3.) no I've never changed the head gaskets, but barely a year and a half ago I did replace the water pump because it had a massive leak.

[Mark-23]

1. How much coolant?

2. Borrow a cooling system pressure tester from autozone.

3. Find another mechanic.

 

I forgot to mention that they did the pressure tester on the cooling system and the pressure didn't lose a single bit of the mark, it held its pressure and it was there the entire time.

[silveradosid]

did they pressure check when the engine was hot

[newdude]

I wonder if you have Castech heads on that truck...http://ww2.justanswer.com/uploads/Bluegorilla/2008-12-05_142924_Coolant_loss_5.3.pdf

[Jsdirt]

^^^ That's a very good possibility.

 

 

If it's not that, my money is on the head gaskets.

 

In the beginning stages of failure, about the only sure-fire 100% accurate diagnosis is with the 4-5 gas analyzer. Test strips MIGHT show it ... but not always. Pump-style CO2 detectors with the blue fluid that turns green sometimes show an inconclusive result. No milky oil, no oily film in the pipe, and no white smoke will be detected in the early stages of failure.

 

If you want to know for sure what you've got going on, you need to grab list of shops within your area, and ask them to do a quick sniff of the coolant overflow bottle with the analyzer, to confirm or deny the presence of HC in the bottle. There's only 1 way HC will get in there. The analyzer will pick up residuals from a shop environment, so over 200ppm HC is the general rule of thumb to go by.

 

And if you have Castech heads that haven't been updated, then I'd put my money on that being the issue, 100%. I believe that can be ruled out by yanking the valve covers and reading the stampings in the head.