Expert: Rob Painter - 11/29/2010

Question
hi i may be a little long here but i have to give all facts.93 deville 136k well kept miles. car is in mint cond everything works and runs very well. no smoke no antifreeze leaks.i noticed about 6mos ago it started to get low on antifreeze in the rad now and then and lately a little more so.so i now keep the overflow filled with antifreeze so the radiator will always stay full until that runs low than i fill that again.i guess im using about a gallon and a half a month.now i know the car uses those pellets and the preivius owner did do that for reccomended maint but im always leary using any kind of radiator or block sealer for fear of clogging the heater core or something else.should i try this in your opinion or do you maybe have a brand of sealer that you like. all this is a moot point if maybe a sealer is not the ans. THANKS RON

Answer
Hello,

I think you will find my answer longer than your question-lol

Putting a bandaid on the problem doesn't fix it and just prolongs the inevitable failure of the cooling systems.

I am aware GM has the pellets they sell for coolant leaks under the ruse "maintanance.". There is also tried and true "Barsleak" and others, that all have the same result that is consistent with your concern, plugging heaters and radiators.

One must always be suspicious of a dealer selling factory-backed remedies.


The GM dealer of selling "EOS" (Engine oil supplement) meant their engine lower ends were made to fail without the coating of this product?

Addition of any "fixes" for engines as maintnance are harmful to any engine no matter who is pushing the product.



I am not an expert on metals, nor am I a chemist, but I did work on  vehicles for 30+ years.
Aluminum does not mix well with the chemicals in anti-freeze. In fact, it technically serves as a corrosive.

I will never forget all the Olds 260 CI engines that came into the dealership (all of them continuously) with leaking aluminum intakes. The great engineering at that time was to use cast iron cylinder heads and aluminum intake. The antifreeze litterally ate through the water jackets at the corners of the manifold.

Then there was the inferior design of the Chevrolet Vega engine having an aluminum block and a cast iron head. and antifreeze did not work well with the aluminum block.

Over time, anti-freeze breaks down and will form acids and this is why the system should be flushed at least every three years.




For your system, I would recomend two things. A professional back-flush which is less than $60, just about anywhere. Then a cooling system pressure test. The anti-freeze has to be going somewhere and a small leak could turn into a big leak quickly. Even in your writing, the anti-freeze adding is increasing and for what you are adding, the problem will show up with a coolant pressure test. It could be as minor as a bad radiator cap, and as major as a failed head gasket. Stop leak just compounds the problem and it is only hiding the leak temporarily.

Yes, the car is a 1993 with only 136,000 miles on it and I am sure it is very nice, but why take the chance, that one day this will turn into a major leak instantly costing you an engine? This is an engine you cannot afford to over heat because it can become junk in a matter of seconds!

All you need is one time that the temperature gauge goes over 230 degrees f. and you trying to limp this hot aluminum engine home, this engine is self destructing every second it is over-heating. There are no good used engines around and the replacement with a new engine will cost you $5,000.

In fact, Cadillac engine over-heating and destruction is one of the most common issues I deal with on this site and by then, it is too late.

This engine should be losing no anti-freeze! It isn't normal to add and at least you think of the items in the cooling system you can plug adding sealer. Some people don't.

You can't afford to play around with on this aluminum engine.

Good luck!

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