Flushing GM 3.1L coolant

[FL-400S]

2003 Buick Century
2002 Chevy Malibu x2
2001 Chevy Malibu
2005 Cavalier x2 (2.2L ecotec)


So we have 4 GM 3.1L V6's in the family and the first one is probably having the intake gasket problems. Ive read that its due to dexcool eating the nylon or silicone gasket, and that a new metal gasket will hold up better. I am thinking that I need to flush out the other three and probably our cavaliers to prevent this from happening (refill with G-05?). How do I go about doing this on the 3.1L's? Is there a good tutorial online?

 

[wapacz]

From my understanding it is from a mix of problems. One being the dexcool. The next being bad gasket design. Then the third being bolts loosening up. By themselves there may be small problems. But mix them all togther and you have the perfect storm.

The engines in the cavaliers aren't know for bad gasket design or bolts loosening and such they don't have a problem with dexcool.

 

[dwendt44]

Those that I've worked on, it was easier to just loosen the lower radiator hose and drain the system that way.
It comes out fast at first.
Wapacz is correct. The factory dexcool is only part of the problem. Plastic gaskets and low torque specs are also major causes of manifold problems.
9 ft lbs. is ridiculously low.

 

[mstrjon32]

Open the lower radiator hose, turn on the heater, and stick a garden hose into the radiator, run it that way for a while, then drain all the water out and fill it with distilled water and a coolant mix.

 

[Jim Spahr]

If you have Dexcool , you need to change it out to the new Prestone 'either-or' coolant. It you are determined to use the Dexcool, be sure to change out and flush every year. The big selling point on Dexcool was that it was Long Life. Not so. I have a 1994 Chev Impala SS V8 that came with the green coolant. I was convinced to 'upgrade' to the new long life Dexcool that came in the 1996 Impala's. Big mistake. The two interacted and turned into a brownish slush in the rad, the block, the heater core, and the reservoir. I drained and flushed the heater, the engine block, and the radiator three times and still had brown sludge in the coolant. I drained and flushed it again and drove it with straight water for a day and drained and flushed it one last time. It still showed some sludge, but I went ahead and put in 50/50 coolant and distilled water. BTW my car with an LT1 V8 has drain plugs on either side of the engine to allow you to drain the block. the first time I tried to open these two drains, they were so clogged, they wouldn't drain. I am saying -don't just drain the radiator. GM still won't admit the mistake of using dexcool in the 1996+ cars.

 

[wapacz]

I wont say dex is the best stuff ever but it really isn't as bad as some people make it out to be. It has two large problems which only come about if the system wasn't design right for it. One is that the gasket material needs to be the right kind or it is weakened by dex. The other is that if a good amount of air gets into the system, it sludges up.

If I remember right in 2004-2005 the finally fixed the gasket issue. I forget when they went to a seal cooling system. Pretty sure you can tell if you look at the over flow and see if it has a screw on top.

 

[wapacz]

Originally Posted By: FL-400S
2003 Buick Century
2002 Chevy Malibu x2
2001 Chevy Malibu
2005 Cavalier x2 (2.2L ecotec)


So we have 4 GM 3.1L V6's in the family and the first one is probably having the intake gasket problems. Ive read that its due to dexcool eating the nylon or silicone gasket, and that a new metal gasket will hold up better. I am thinking that I need to flush out the other three and probably our cavaliers to prevent this from happening (refill with G-05?). How do I go about doing this on the 3.1L's? Is there a good tutorial online?


Also now that I think about it the the interval for dexcool is 5 years. So all of them except for the cavaliers need it if it hasn't been done yet.

 

[onion]

IMO, you'd be crazy to refill with Dexcool. I prefer G05 as a replacement.

 

[TomdieselS]

I've done 2 LIM repairs, 97Malibu & 98 Lumina, 3.1's, both had block drains on both sides. Front easy to access, couple inches away from oil filter, rear is *&%$%; requires removal of RF wheel, then you can alternately see/manipulate. Be forewarned, if you allow the problem to fester and experience any overheating or other problem that might require removal of heads; the 'improved' LIM gasket is NOT included in most headsets because GM didn't recall it. So if you (or your mechanic) needs a headset, ask many questions first. I recommend the Felpro LIM gasket, it's got the best chance of stoping the problem.

 

[onion]

+1 on everything Tom said.

And put locktite on the bolts.