GM drive train engineer makes following recomendations
for the pre-N* engines ...

if you know who the gent is, PLEASE KEEP IT TO yourself.
he has requested that nothing is posted with his name and
jeopardize his job.

this thread covers coolant, transmissions, plugs, belts and ... well, read on.

Quote:

name-withheld by request

Personally, I think the idea of a thorough servicing is a good idea but I do not condone the idea of transmission flushes or radiator flushes.

It is entirely adequate to drain the trans fluid from the bottom pan and refill with fresh Dex3. Replace the filter when the bottom pan is off for the fluid drain. Forget about the idea of a flush. You don't need junk flushed into your transmission from the flushing equipment that is misplumbed/misrouted/not cleaned/full of old oil/etc.

The radiator service does not require a flush or cleaners either. Just drain the radiator at the petcock at the bottom of the rad tank, refill with fresh 50/50 green coolant (conventional, silicated coolant - Prestone or Texaco ) and distilled water. You are just trying to get a fresh charge of coolant in the system to replenish the corrosion inhibitors in the coolant. No need to introduce tap water for flushing or any sort of caustic cleaners that cannot be thoroughly removed. Just drain and fill with fresh 50/50 premix. You should have been doing this every 2-3 years or 30K miles anyway. The coolant's corrosion inhibitors deplete this frequently and need replacement. If not replaced frequently internal engine corrosion can/will result including head gasket and intake gasket failure. The steel core of the gaskets can rot out from the inside out in the presence of corrosion-inhibitor-depleted coolant. Don't forget to add the GM coolant supplement pellets (sealant) when the coolant is replaced. The engine got 6 of the large pellets from the factory which by now (if never replaced) are rather depleted. I would put 6 more in with a fresh charge of coolant. Do the radiator drain and refill every year from now on to ensure a corrosion inhibited system. It is quick and easy and can be done with an oil change.


Otherwise , if the engine is running fine, I would leave it alone. The plugs installed should now be dual platinum and should never really need replacement. If the wires, etc. are not disturbed then they should be fine , too. There is really nothing else on the engine to service or "tune-up"

It would probably be a wise thing to replace the accessory drive belt at 100K/10years....it really doesn't owe you a dime past that point if you catch my drift.

 

tap water ?


read the following:
From http://www.nichols.nu/tip514.htm

"From the ASA Shop tech tips.
If you use hard water in these systems, you are asking for mineral buildup problems. Softened water, on the other hand, contains dissolved salts that act as an electrolyte, encouraging galvanic action between the dissimilar metals. That's why distilled water is quickly becoming the water of choice!

From an article by Gregory T. Fieldson B.S., PhD in Chemistry:
Should I use tap water or distilled water?
I recommend distilled water. If you have exceptionally soft water it would be acceptable, as well. Basically, the engine metals are going to corrode to some extent no matter what water you use, and hard water will encourage the resulting metal salts to precipitate.

From the Rover Tech Tips site:
Other contaminants can come from the water that you use with your antifreeze. Most tap water has a trace mineral content. Depending on the source of your water, you may or may not have minerals that will become sediment and block your system. The safest way to refill your system is to use distilled water. This should be a 50/50 mixture with coolant for the best heat transfer.

From the Red Line site:
The anti-scaling ingredients in Red Line WaterWetter allow its use with ordinary tap water. However, using with distilled or deionized water will accomplish some scale removal in the cylinder head area.

From a Saturn GM Tech site:
A 50/50 mixture of this product and distilled water is required.

From Aftermarket World tech site:
Antifreeze is mixed with water (preferably clean distilled water since hard water can introduce unwanted minerals into the system) , usually at a 50/50...

From the General Motors EMD (diesel locomotive) engine handbook:
Distilled water should be used in the cooling system to offset the ac***ulation of scale and foreign matter, which contribute to overheating the engine.

From MotorTrend online:
In addition, the use of hard tap water in the system leaves mineral deposits that can build up and restrict the flow of coolant; this is why it's recommended you only use distilled or soft water in the system.

From Texaco's Product Bulletin on DexCool:
However, to maintain the integrity of a cooling system and to help assure long life, deionized or distilled water is preferred over tap water."

 

Stomper

If you re-read the post I believe it says 50/50 mix green coolant and DISTILLED water. It goes on to say , do not use tap water for flushing purposes. However you have provided good info, thanks.

 

G.A.R.Y.

I did see that. My intent was merely to provide backup for the "do not use tap water" for those that have doubts.
There are those that will not accept anything unless the facts are backed by at least 1/2 dozen sources.

 

Agreed

 

My local service department does not use the pellets. I also read that Gm no longer recommends pellet use. Anyone have comments?

 

i believe that to be correct on newer models where the aluminum casting process was perfected to reduce porosity.

as to the older models, they still have the porous engine blocks and one needs to follow the GM instructions as posted on top of your radiator.



.

 

My deville was assembled October 2003. Does this qualify for no pellets?

 

every Allante ever made rolled out of the factory with the GM Supplement, the pellets.

the GM coolant supplement pellets are made by the same company that markets BarsLeak gold, its the same as the GM supplement.
The BarsLeak in the jar with the brown liquid has the same material for sealant as the GM supplement but includes the soluable oil (brown liquid) to make it easier to pour in.

I only recommend the conventional BarsLeak, BarsLeak Gold or the GM coolant supplement.

The ingredient in the coolant supplement is ground up ginger root and walnut shells. The fibers in the ginger root mat in a leak and swell when exposed to the air on the other side of the leak to seal it. The other sealers that use metallic components (such as BarsLeak Liquid Aluminum or the Solder Seal sealant) are definitely NOT recommended. The GM sealant and/or the BarsLeak brand is better because of the ability of the sealant to seal any coolant seepages without doing any other harm to the system. The main focus of the recommendation to use the supplement is to
protect against any internal seepages that would put coolant into the oil and be invisible otherwise. The ground up ginger root has proven to be one of the best imaginable cooling system sealers. It just works better than anything else currently known and is basically harmless to the cooling system.

If your car (not a Allante) needs the gm supplement, there WILL BE A STICKER atop the radiator calling for them.



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