Dye in cooling system, internal coolant leak.

[ManyCamaroz]

My extended warranty will expire in about 1800 miles. I've taken it in to the dealer several twice due to coolant loss and no visible leaks. I'm adding about 1/3 gallon of coolant every 1000 miles. The first trip they claimed to have pressure tested it (cold) and it had no pressure loss. I tested it myself last Thursday evening (hot engine) and it lost 2-4 psig in about 5-7 minutes. The next day I took it to the dealer and they let it sit the most part of the day and then tested it cold and said it did not lose any pressure over a two hour period. They said they put some dye in system and that I should bring it back in, in about 500 to 750 miles. They claimed they will pull the plugs and inspect for signs dye. I took off the radiator capafter getting it back and it appeared they added nothing more than green coolant. The overflow is still orange though.

 

Anybody know what color the dye usually is?

 

I think that they are waiting for my warranty to run out. I can't complain mcuh because my warranty actually is worthless. The warranty company went bankrupt last year. The dealer said they would stand behind the warranty since they sold it. I think that is a good gesture if you do what is right.

 

I knocked the front end off of it about 2 1/2 years ago and the body shop failed to tighten the lower raditar hose. So it blew off the next day (Christmas) on a road trip and my truck run hot. I'm wondering if some damage was caused then, it just took 2 years and 20k miles to show up. I've never had to add coolant until recently.

 

A clsoe visual inspection of the engine compartment revealed no signs of leakage whatsoever.

[100R1]

The dye is not visible to the naked eye

 

you need a ultra-violet light to see the dye

 

* compare it to how floresent colors glow under a black light

[Taki]

ive had 3 coolant leaks on my 2002 Z-71:

 

1) porosity in engine head, required new engine head (basically a factory defect)

2) leaking freeze plug

3) leaking water pump gasket

 

if the orange coolant evaporates, it sometimes looks like a white powder and becomes hard to identify...

 

if you have any skid plates, make sure they remove them when they are looking for the leaks - hard to look at the underside of the engine if a big plate is in the way...

 

otherwise, head gasket?

[mcreyaufmiller]

Is your enging a 305/350 small block or one of the newer downsized blocks? If you have one of the older designs, it may be the intakke gasket.

[tryn2lrn]

Yeah, what he said above!

[Mark_in_Tulsa]

Is your enging a 305/350 small block or one of the newer downsized blocks?  If you have one of the older designs, it may be the intakke gasket.

 

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Sorry, but is it a head gasket or intake gasket?

[budhayes3]

Is your enging a 305/350 small block or one of the newer downsized blocks?  If you have one of the older designs, it may be the intakke gasket.

 

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Sorry, but is it a head gasket or intake gasket?

 

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Intake gasket is the common failure on the 305/350.

[ManyCamaroz]

Hit the key to fast! See following post.

[ManyCamaroz]

It is a 5.7 '99 OBS. 98k miles

 

The intake gasket has been repalced twice. The second time due to shoddy installation the first time. The dealer mentioned that is it was the intake coolant would be on only several plugs but ai can't remember which ones. Seems like cyclinders 1,2,7,8. Due to the location of the water ports.

 

Anybody know?

[MrQuadrasteer]

Something I've found a few times in the past that I haven't heard mentioned, but not sure if it applies to your truck, is leaking radiator caps. I've had coolant losses that I couldn't find that ultimately turned out to be just a bad rad cap allowing evaporation.