Dexcool sludge

[dlundblad]

I noticed this in my brothers 1998 Blazer last weekend. I'd give it a 2/10.. The reservoir has a thin film and when the radiator cap is removed, it has a bit sitting at the base of the fill hole. I replaced the t stat last February which didn't have a thing on it.

Should we just perform several (perhaps 3-4) drain and fills with distilled water or should some sort or flush be used as well.

Also, has anyone had any luck with the lovely radiator drain petcock? When I did the radiator, I couldn't figure it out and just used the lower hose. I don't like antifreeze baths.

Thanks in advance folks and Merry Christmas.

 

[barkingspider]

I recommend replacing the upper manifold gaskets first, then go ahead and flush the cooling system. I used the prestone flush. I didnt have any issues with the petcock on my old s10 radiator. Then fill with whatever cooling you like

 

[dlundblad]

Originally Posted By: barkingspider
I recommend replacing the upper manifold gaskets first,


What good would this do? The truck has 81k on the OD if that matters. Should have mentioned this in my first post.

 

[Chris142]

Originally Posted By: dlundblad
Originally Posted By: barkingspider
I recommend replacing the upper manifold gaskets first,


What good would this do? The truck has 81k on the OD if that matters. Should have mentioned this in my first post.
Because it will most likely leak with new coolant

 

[ls1mike]

Because it is a 17 year old 4.3 with a histoiry of faulty intake manifold gaskets and you are seeing sludge. Time to do the intake gasket.

 

[dlundblad]

Didn't know they had a reputation for faulty intake gaskets. Thanks for the heads up.

 

[buck91]

How old is the coolant- have you been maintaining it?

 

[dlundblad]

Couldn't tell you. Only had it since February.

 

[Donald]

Originally Posted By: dlundblad
Didn't know they had a reputation for faulty intake gaskets. Thanks for the heads up.


The original DexCool issue was an intake manifold gasket that had a plastic section. The DexCool damaged the plastic causing it to leak air into cooling system which caused the sludge. DexCool is fine as long as no air gets in.

The FelPro gasket is the one to get.

 

[BigD1]

My 1998 Malibu that I bought new went through this twice. Change the manifold gaskets to Felpro before coolant starts getting into the oil. If you are lucky, the leak would start out as an external weep.

Has the manifold gasket already been changed, and the sludge you are seeing just did not get removed proper?

 

[Chris142]

Originally Posted By: dlundblad
Didn't know they had a reputation for faulty intake gaskets. Thanks for the heads up.
the 4.3 is probly the leader. Im suprized you didnt know

 

[BigD1]

I had manifold on the brain for some reason, but I meant intake manifold. My brain tries to block out the nightmare I went through with the Malibu.

 

[cronk]

Its the lower intake manifold gaskets that fail on these. Use the Felpro "Ultraseal" kit and you won't have any more problems. (Felpro sells both a stock type and their upgraded "ultraseal" line)
You'll probably want to use a chemical flush to get all that greasy slime out of the system.

 

[FastLane]

My 4.3 did the same. It's the intake gasket.

 

[I_4]

If left uncorrected the dex cool will mix with the oil and wipe out the bearings, resulting in a rod thru the block. Happened to my brothers 96 Blazer years ago. Do the Fel Pro kit now. Do not delay this repair, unless you are looking to replace the engine.

 

[Blinker]

You have an intake gasket problem not a coolant problem. I have dealt with so many 1996 and newer GM vehicles with this problem and its always a faulty gasket. Change it, change the coolant and install a new thermostat because yours is probably gunked up with sludge. Change the oil if contaminated. Fel pro has a full line of gaskets that elimnate the problem, the "Updated GM" gaskets arent perfect and ive seen them leak again with update GM gaskets. Buy fel pro and it should be the last time you replace it unless tearing the motor apart for something else.

 

[Gasbuggy]

Also, if it hasn't been done by someone else, replace the lines to the remote oil filter. They get brittle and break randomly. Happened to my moms 98 years ago and I just saw a Blazer dump a ton of oil out in a parking lot the other day when one broke on a poor person. A neighbor of mine lost the engine in S10 Super Sport when one of his broke while he was driving.

 

[Blinker]

Originally Posted By: Gasbuggy
Also, if it hasn't been done by someone else, replace the lines to the remote oil filter. They get brittle and break randomly. Happened to my moms 98 years ago and I just saw a Blazer dump a ton of oil out in a parking lot the other day when one broke on a poor person. A neighbor of mine lost the engine in S10 Super Sport when one of his broke while he was driving.


Where is the remote oil filter location?

 

[Blinker]

Oh i remember now after seeing it online, I always thought it was weird how a filter was mounted by the headlight assembly.

 

[Gasbuggy]

Originally Posted By: stower17
Oh i remember now after seeing it online, I always thought it was weird how a filter was mounted by the headlight assembly.



Not there. Under the bumper there is a plastic access door.