2007, Part 1a: 5.7L V8 Engine Sludge and Gasket Change
by John R. Hess with
additions from Mole Snoopster
To appear in March 2007
© 2007 All Rights Reserved
all aware of the problems with the 3.1, 3.4 and 4.3L IMGs (Intake
Manifold Gaskets), what about with the less noticed 5.7L Vortec V8? Did it suffer when GM
switched over to DEX? California's John B believes that it
did. He became a believer while performing a gasket changeover. Below
are the photos. At 100,000 miles, clearly
something was not working well inside the engine of his 1999 Chevrolet Suburban K1500.
Below: While the photos are a little out of focus, the
contaminant-sludge in the coolant channels is still recognizable. Plus, it looks like the gaskets had indeed been leaking
coolant at certain points around the port.
lay the groundwork, John stated: "I'm the original owner and did all cooling maintenance myself. I flushed and replaced the
DEX-COOL twice since new (about 3 year intervals). I mixed 50/50 with distilled water and never added any other product except Bars Leaks factory sealer (gold powder). The orange sludge is about 1/4 inch thick."
believes the sludge above came either from the DEX-COOL itself or from
other components that were broken down by the antifreeze. He's convinced
that this sludge interfered with the cooling of the cylinder heads, causing excessive heat and leading to detonation. The detonation problems occurred mostly in hot weather.
John says: "It's also possible the cheesy plastic intake
manifold gasket developed slight air leaks over the years causing the fuel/air mixture to run too lean."
He adds, "now when I periodically check under the radiator cap, the coolant level
is never low. Fel-Pro actually told me about the special gasket they make called the Problem
What caused John to finally undertake the arduous repair is when the IMG
eventually failed to the point where "coolant
was shooting out of top of the engine like a geyser."
Above: Some type of sludge has coated the radiator hoses. If
anyone has analyzed this contamination and KNOWS exactly what it is,
please call us at 800-883-8929. Or use this email link: Click to email imcool.com.
Above: The "Problem Solver" Fel-Pro PermaDryPlus® gasket
that John Bell chose to replace his original part. As seen, this gasket
is built around a metal carrier versus nylon used in the original model.
concerned about the future of his "Burb," and wanting it fixed
right, John had called me last summer looking for a true expert to guide
him through a quality repair. I pointed out several DEX experienced
shops who I knew would lead him correctly. John chose to work with Bruce
Balfour, owner of Mac's Radiator and Air Conditioning (562-920-1871),
Bellflower, California. Bruce provided the Fel-Pro gaskets.
you have similar stories but maybe with differing details and outcomes,
and would like to share them with Cool Profit$ Magazine's readers,
please call me at 800-883-8929. Click
here to email your story.
to DEX-COOL 2007, Part 1
to DEX-COOL 2007, Part 2
to DEX-COOL 2007, Part 3
© 2007 All Rights Reserved