Intake Manifold gasket

dbujnak · 01-22-2008, 08:24 PM

99' Chevy Sub. going on my 5th IMG and was told that last one was Chevy's "fix all / last gasket I'll need". Is the dex-cool the reason these gaskets continue to fail? Vehicle only has 98,000 miles

fbhart@wk.net · 01-22-2008, 08:57 PM

a retired GM engineer told me it was,

after he retired he bought a new RV with GM truck running gear, said first thing he did was drain out orange coolant, flush system and replace with green coolant.

he said gm should have been made to recall the 350 engines and replace the coolant and gaskets, but it was not a safety issue, gm made millions for there service departments because normally it took about 50-60K before the leaks would show up.

he told me the orange coolant was designed for diesel engines and the gas engine gaskets would not stand up to it for the 5 year/100K before it was to be changed out.
I had to have my 350 IMG's changed at 60K but truck had been losing coolant for some time before that.

Had water pump replaced and they install some type coolant that is suspose to work with both kinds, it seams to work.

dbujnak · 01-22-2008, 09:17 PM

Thanks for the response, I'm starting to wonder why repair shops continue to use dex-cool anti-freeze when changing this gasket. I've heard this isn't that difficult of a repair so I may do it myself this time. I'll be sure to use the green coolant this time.

o3shortbed · 01-22-2008, 09:51 PM

if you do it urself(not that hard if youve turned wrenches before) the kit will come with black RTV. BUY another tube and dont be afraid to use it. any ?'s ive done this and i use green.

Diesel_Fan · 01-22-2008, 10:59 PM

is the universal coolant pretty good stuff, its green but is specified as a universal all makes/models coolant

o3shortbed · 01-22-2008, 11:08 PM

never used it i flush out the orange stuff and put in green

1979_4x4_Plow · 01-23-2008, 12:33 AM

universal is color of apple juice. the sealant that is black that works the best for all repairs needing it is called Permatex Ultra Black. dont be confused by the lower grade at wal-mart. there are 2 types, the Permatex black and Permatex ULTRA Black. reason for many of the intake manifold gasket failures is also due to the gasket material. it is plastic and aftr time it gets brittle and cracks. GM cars with the 3.1/3100, 3.4/3400, and such are real bad for it. had a customer come into the shop and wanted an oil change and coolant flush. she was an older woman and we noticed the intake leaking. when doing the oil change we saw coolant and doing the coolant flush we saw oil. we let her know and she refused any service beyond what she asked. i hate dex-cool because it gets changed into a crusty looking scale in everything. coolant in my vehicles is green stuff or universal, depending on price.

dbujnak · 01-23-2008, 09:17 AM

Thanks for all the responses, sounds like I need to get the orange stuff out and the green coolant in. Stinks, because back in the summer my water pump went out and when I changed it I filled it back up with orange dex-cool. Hopefully this will solve this ongoing problem.

98k1500 · 01-23-2008, 06:31 PM

using the green coolant wont eat the block or anything? want to make sure that when i fix the problem i fix it right the first time, 98 350 vortec. wont do any damage will it?

1979_4x4_Plow · 01-23-2008, 07:43 PM

why would the green stuff eat away at the engine? other manufacturers use green in there vehicles. not like Chevy uses a specific type of metal compared to others. they promote the dexcool because they claim it lasts 5 years or 100k or whatever. many people fail to check into there hoses and such due to this situation and argue the fact if the coolant can last that long than a tech must be lying about gaskets being bad. the green stuff is more common, cheaper, and been used for years.

01-22-2008, 08:24 PM	#1
dbujnak Junior Member Join Date: Jan 2008 Posts: 3	Intake Manifold gasket 99' Chevy Sub. going on my 5th IMG and was told that last one was Chevy's "fix all / last gasket I'll need". Is the dex-cool the reason these gaskets continue to fail? Vehicle only has 98,000 miles

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
83 gmc intake manifold gasket	joeydeherrera54	GMC Truck Forum	20	02-26-2008 05:34 AM
2003 gmc intake gasket?	2003bruce	GMC Truck Forum	3	12-15-2007 06:33 PM
Manifold and intake	Kaneskustoms	Mazda Truck Forum	0	04-02-2007 03:17 PM
question ,intake manifold gasket chevy BB, on exhaust crossover..	STRAYDOG	Chevy Truck Forum	2	02-24-2007 10:23 PM
intake manifold/TBI	scottie	Chevy Truck Forum	0	01-26-2006 01:23 PM

01-22-2008, 08:57 PM	#2
fbhart@wk.net Senior Member Join Date: Mar 2007 Posts: 115	a retired GM engineer told me it was, after he retired he bought a new RV with GM truck running gear, said first thing he did was drain out orange coolant, flush system and replace with green coolant. he said gm should have been made to recall the 350 engines and replace the coolant and gaskets, but it was not a safety issue, gm made millions for there service departments because normally it took about 50-60K before the leaks would show up. he told me the orange coolant was designed for diesel engines and the gas engine gaskets would not stand up to it for the 5 year/100K before it was to be changed out. I had to have my 350 IMG's changed at 60K but truck had been losing coolant for some time before that. Had water pump replaced and they install some type coolant that is suspose to work with both kinds, it seams to work.

01-22-2008, 09:17 PM	#3
dbujnak Junior Member Join Date: Jan 2008 Posts: 3	Thanks for the response, I'm starting to wonder why repair shops continue to use dex-cool anti-freeze when changing this gasket. I've heard this isn't that difficult of a repair so I may do it myself this time. I'll be sure to use the green coolant this time.

01-22-2008, 09:51 PM	#4
o3shortbed Senior Member Join Date: Jan 2008 Location: L-burg KY Posts: 334	if you do it urself(not that hard if youve turned wrenches before) the kit will come with black RTV. BUY another tube and dont be afraid to use it. any ?'s ive done this and i use green.

01-22-2008, 10:59 PM	#5
Diesel_Fan Senior Member Join Date: Jun 2007 Location: West Texas Posts: 97	is the universal coolant pretty good stuff, its green but is specified as a universal all makes/models coolant

01-22-2008, 11:08 PM	#6
o3shortbed Senior Member Join Date: Jan 2008 Location: L-burg KY Posts: 334	never used it i flush out the orange stuff and put in green

01-23-2008, 12:33 AM	#7
1979_4x4_Plow Senior Member Join Date: Dec 2007 Posts: 98	universal is color of apple juice. the sealant that is black that works the best for all repairs needing it is called Permatex Ultra Black. dont be confused by the lower grade at wal-mart. there are 2 types, the Permatex black and Permatex ULTRA Black. reason for many of the intake manifold gasket failures is also due to the gasket material. it is plastic and aftr time it gets brittle and cracks. GM cars with the 3.1/3100, 3.4/3400, and such are real bad for it. had a customer come into the shop and wanted an oil change and coolant flush. she was an older woman and we noticed the intake leaking. when doing the oil change we saw coolant and doing the coolant flush we saw oil. we let her know and she refused any service beyond what she asked. i hate dex-cool because it gets changed into a crusty looking scale in everything. coolant in my vehicles is green stuff or universal, depending on price.

01-23-2008, 09:17 AM	#8
dbujnak Junior Member Join Date: Jan 2008 Posts: 3	Thanks for all the responses, sounds like I need to get the orange stuff out and the green coolant in. Stinks, because back in the summer my water pump went out and when I changed it I filled it back up with orange dex-cool. Hopefully this will solve this ongoing problem.

01-23-2008, 06:31 PM	#9
98k1500 Senior Member Join Date: Jan 2008 Location: Manhattan,Kansas Posts: 320	using the green coolant wont eat the block or anything? want to make sure that when i fix the problem i fix it right the first time, 98 350 vortec. wont do any damage will it?

01-23-2008, 07:43 PM	#10
1979_4x4_Plow Senior Member Join Date: Dec 2007 Posts: 98	why would the green stuff eat away at the engine? other manufacturers use green in there vehicles. not like Chevy uses a specific type of metal compared to others. they promote the dexcool because they claim it lasts 5 years or 100k or whatever. many people fail to check into there hoses and such due to this situation and argue the fact if the coolant can last that long than a tech must be lying about gaskets being bad. the green stuff is more common, cheaper, and been used for years.