Well ive been having some over heating issues and what not and my cars been in and out of the shop for the last 3 months and it turns out i have a blown head gasket . I just took my car to get fixed yesterday and should be back towards the end of the week. Its a little costly to fix but i refuse to let my car go espically after all the money ive put into it in the last year . Some of the things my car has been doing that helped me believe it was my head gasket was rough idling , misfiring , white smoke when i start it and on my oil cap its milkey looking . So just watch out because apparently these engines are notorious for this problem .

 

Typically the oil/coolant sludge on the cap is a symptom of failing lim gaskets.
But your symptoms do sound like head gaskets.

Make sure in the process they use Fel pro aluminum core lim gaskets for better longevity.

 

Actually...
Its not a blown head gasket...

Its the upper and lower intake gaskets..
There made of plastic from the factory...

There are now after market aluminum gaskets..
also the coolant elbows are plastic which also fail...

Since you have to disssemble them during the process of intake gaskets replacement... after that it wil be a non issue. The reason it happens was from the factory dexcool anti freeze...

Just be sure the system gets a full flushing out... to clear all the residual dexcool.

After that repair is done. You can use normal anti-freeze at the proper mix of 50/50.

 

I agree the oil cap is evidence of the lim gaskets, but other symptoms like the white smoke in the exhaust and the over heating is common when a 3100/3400 blows a head gasket.

As for dex cool destroying l gaskets, I don't buy that, especially on cars 2000 and newer. Gm did revise dex in the 90's as a result of a class action law suit. But I have had gm 3100's that blew l gaskets and always had good old green, never a drop of dex. The nylon gaskets just can't handle the hot temps and the pressure. That's the biggest issue with the lim failures in my opinion.

 

He doesn't say what model year Monte he has...

I was just speaking in general ...

Possibly thinking its a 3800.

Great Info Jason.. As always!
You Da Man when it comes to 3100/3400's etc.. Thanks!!

 

Ooh you got me David.
I honestly thought I saw a year and trim level with this message thread.

Oh well between the two of is, still good info. Beat of it, get aluminum core lim gaskets.

 

Its an 03 3.4l and yeah everythings going wrong with this car within the last year between the tranny , computer , now this but i love the car and refuse to let it go