Expert: William Hawk Howes - 12/1/2005

Question
-------------------------
Followup To
Question -
Hi William, I just noticed my 2000 Durango (Just over 100,000 miles) has a, what I believe is a head-gasket failure.  I found white frothy subtance on the oil fill cap yesterday morning before going to work and the cooling fluid pretty much empty.  I had the same thing happen on an 1985 S-10 Blazer (76,000 miles or so) years ago.

My concern is that, shortly after using an oil addative to flush the system prior to having an oil change, do these addatives break down the gaskets in the engine.

I remember adding an adative to the Blazer also.  Several months afterwards I had to rebuild the upper portion of the engine, this same thing has occured again?  White froth on the oil cap and unaccounted for radiator fluid.   What do you think?

I hope I have caught it before major damage, unlike the last time when I was on a long trip.  The Blazer over heated and warped the head... Ron
Answer -
Ron,
Can you tell me what the additive was?

A Cleanor called Gum-out, this was done at an instant oil change station.  They had added this cleanor, had me run the engine for 6-8 minutes, drained and flushed system.  Then changed the filter and filled with oil.

Answer
Ron,

Regarding the Gumout Product, as far as I can find Gumout doesn't make an oil system cleaner only fuel system and external spray cleaners. I really don't know of an oil system cleaner as such. Current formulas in motor oils have a very good detergent that keeps the system pretty clear of sludge and varnish build up (except the oil pan of course) Whatever thay put in your oil is beyond me. Perhaps you could go back and offer to purchase a bottle, or at least look at it to see if its for oil system clean out. You may have some legal foundation here.
Getting back to your problem, thats a pretty good indication of a gasket problem when you see grey sludge on your oil filler cap interior and your coolant level has dropped severely. Get a pressure check done on the engine that should show you whats up.
Regarding oil additives, they usually are some form of friction modifier or a viscosity enhancer (makes the oil thicker to slow leaks and give a higher pressure reading, STP is a good example of this)
The Friction modifier is OK, but I wouldn't recommend any of the thickeners. Could cause you trouble in cold starts and may clog some oil ports. But of all of the normal additives I can't think of any that would cause a gasket to fail. As a matter of fact most will improve the elasticity of O-Rings and gaskets to help stop leakeage in older engines.
Now Radiator cleaners will play havoc with gaskets and seals and could very well result in a gasket failure, but not an oil additive.
What thay may have done was clean your fuel system with the gumout. Now from my own experience in this. WHen I had this done once (and once only) My Chrysler New Yorker backfired so badly during the cleaning that it broke one of the castings on the block, resulting in exterme valve clatter and a blown headgasket. Took it awhile to show up though. Finally the clatter got so bad I took it back to the same shop and made them pay for all the parts and labor to fix everything.
I'm not really sure what happened to yours, but I would find a good mechanic to look at it and make some recommendations.
Good Luck!