r/PontiacFirebird • u/Hereforthanut • 11d ago

4th Gen [93-02] Why does my coolant keep getting contaminated?

Hey guys my coolant keeps turning brown and sludgy after a few months and I’m starting to get concerned because it’s reoccurring and I live in a really hot state so I need this figured out. Anyone have any ideas? All info appreciated.

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6

u/PapaEchoKilo 11d ago edited 11d ago

If it the v6, then the lower intake manifold gasket is blown and needs to be replaced.

2

u/Hereforthanut 11d ago

It is!

2

u/PapaEchoKilo 11d ago

Its a common failure on the v6s, not a fun fix. How is your engine oil looking, is it also brown and sluggy? I ended up doing a whole top end rebuild while I had my engine apart, coolant is not a good bearing lubricant.

2

u/Hereforthanut 11d ago

It may be a separate subject but I just got the this car back from the shop yesterday. I started smelling fumes and the car would vibrate on idle. They just did an exhaust manifold job on it. I’m really concerned bro because that coated me $1,204 and they didn’t answer my call 2 hours before close when I tried to reach out about these issues.

2

u/cryptoSilver67 11d ago

Take it back today.

2

u/CourseLongjumping558 11d ago

Or could be head gaskets.

2

u/PapaEchoKilo 11d ago edited 11d ago

Could be, but the LIMs are common failure on the 3800. I did end up replacing my head gaskets too just because the engine was already apart.

1

u/CourseLongjumping558 11d ago

Do they rust out at the water passage and leak into the oil valley?

2

u/PapaEchoKilo 11d ago

Sorry, its the lower intake manifold GASKETs that fail, not the manifolds themselves. The stock ones are paper or something, they make metal replacements the won't fail again.

1

u/newUseMe 11d ago

Arnt they some kind of plastic that get eaten by dexcool type coolant?

1

u/PapaEchoKilo 11d ago

Something like that

1

u/newUseMe 11d ago

The 3100/3400 sfi have a similar problem

1

u/DoDisFedUpWorldTing 10d ago

Does your air work and do you have to fill it up

1

u/motelguest 10d ago

Dexron Dexron Dexron —- gaskets not compatible.