Coolant Mixing with oil 73K miles

[parkavenuechrome]

Hi, I bought a 96 lumina in very good shape for 400 bucks today, I knew it had coolant in the oil, the motor is smooth no knocks or loss of power at all.. The motor only has 73K on it and I would think that is low miles for the head gaskets to fail on the 3400 motor... Doesnt over heat at all either... Coolant looks brand new, and it has green stuff not dexcool in it which i know someone screwed up which isnt helping the motor at all.. Any thoughts on maybe just intake gaskets? The car has been sitting for the past 2 years undriven... Thanks!

[rhandwor]

I would use a pressure tester the link is a picture of one.
http://www.autopart.com/tools/toolsmain/tool/T_7060.htm Use the link and search adapter for your vehicle. If the gage pulses with appx. 10 psi on it a head gasket is bad. A radiator shop will do an analysis for dissolved gas in the coolant. Also if it smokes or misses I would suspect a blown gasket.
Otherwise replace the intake gaskets. A web site lists where to send bills for intake gaskets for some refund from GM I'm still waiting for my check.
Any independant garage will do a pressure tester for a fee.

[plambeth]

+1

If head compression checks out - seems that this problem is commonly the lower intake manifold gaskets. Do a search - see the TSB on it. There are newer torque specs, etc.

And do not forget to get new bolts, with the proper sealant on the tips if you do it yourself.

[paulbungard]

I had a very similar problem. Cause was the hard plastic gasket between the
PLASTIC intake manifold and the block cracking and generally falling apart.

(Why not silicone or cork or some other fiber is known only to GM. Hard
plastic sounds like a very poor choice to me for parts that get very hot)

According to conversations with several mechanics and other web site posts,
this is a common, well known problem with certain GM cars ESPECIALLY if the
engine has had DexCool anti-freeze in the engine since it was new. Do a
GOOGLE search on DexCool and read the posts for yourself.

There is a class action lawsuit going on (closed to new applicants now)
charging GM knew this DexCool turned acidic and jelly like, damaging the
aluminum parts of the engine, plugging the radiator, water pump, thermostat,
and other places where it could get a grip.

You can purchase a new intake manifold for $100.00 and new gaskets for
$50 to $100 and replace them yourself. You MUST use a chemical flush to
clean out the sludge from your engine and radiator before you pour in new
anti-freeze. I have been told to use the GREEN aluminum friendly anti-freeze
instead of DexCool, and that is what I am doing.

If you are VERY lucky, you can drain your oil, install new filter and oil after
fixing the leaky gasket and MAYBE get a few thousand miles more out of your
engine. If you are not lucky, you may as well look around for a replacement
engine.

paul

[evo-00]

Why would you need a new intake?

[Jrs3800]

Originally Posted by paulbungard

I had a very similar problem. Cause was the hard plastic gasket between the
PLASTIC intake manifold and the block cracking and generally falling apart.

(Why not silicone or cork or some other fiber is known only to GM. Hard
plastic sounds like a very poor choice to me for parts that get very hot)

According to conversations with several mechanics and other web site posts,
this is a common, well known problem with certain GM cars ESPECIALLY if the
engine has had DexCool anti-freeze in the engine since it was new. Do a
GOOGLE search on DexCool and read the posts for yourself.

There is a class action lawsuit going on (closed to new applicants now)
charging GM knew this DexCool turned acidic and jelly like, damaging the
aluminum parts of the engine, plugging the radiator, water pump, thermostat,
and other places where it could get a grip.

You can purchase a new intake manifold for $100.00 and new gaskets for
$50 to $100 and replace them yourself. You MUST use a chemical flush to
clean out the sludge from your engine and radiator before you pour in new
anti-freeze. I have been told to use the GREEN aluminum friendly anti-freeze
instead of DexCool, and that is what I am doing.

If you are VERY lucky, you can drain your oil, install new filter and oil after
fixing the leaky gasket and MAYBE get a few thousand miles more out of your
engine. If you are not lucky, you may as well look around for a replacement
engine.

paul

First the gaskets are made of Nylon 66... Problem is when the coolant becomes acidic... I am not siding with GM as I feel they could have done a lot better in terms of gasket design for certain..

Also for thew 3100-3400 Fel Pro does have a set of aluminum gaskets for these engines.. So when any of you go to replace your gaskets, make sure you get the aluminum ones..

[evo-00]

My intakes lasted to 121K miles. I replaced with plastic and if I get another 100k out of them I'll be happy and the car will prob. be in the junk yard with good intakes. I just think replacing actual intake and using alum. gaskets is a waste of money. Now a neon headgasket is another story.