4.3 Engine help

bigytwotone

Original poster
Member
Dec 7, 2011
489
Dawson creek BC Canada
Hello guys i am helping off road bella with her truck and we just got it diagnosed buy Big O and found out that the valve cover gasket is leaking the intake gasket is toast and the oil cooler lines are shot so my main ? is how hard and long dose it take to do a intake gasket on the 4.3 V6?? here in take gasket is so bad the truck smokes whit all the time so we have parked the truck now is there any thing else we should look for??
 

Brian@work

Member
Dec 5, 2011
14
When I replaced mine it took me the better part of the day to pull everything off and clean it, then a couple of hours the next day to put it back together. You could possibly do it in a day but I was doing it by myself for the first time so I took my time and made sure I did it right. I bought the upper gasket kit that has every gasket in it for the upper half of the motor and pretty much replaced everything. The only thing I didn't replace was the fuel injector spider, but I wasn't having any problems with it so no since in changing it. It's not a hard job just a time consuming job getting everything apart and back together. On mine I had to pull the AC compressor, alternator, and power steering pump to get the brackets out of the way in order to get the intake manifold bolts out. The ONLY thing that gave me any trouble was the hard fuel lines because you have to kinda bend them out of the way without kinking them and then bend them back into place when your done. It's fun holding both lines in place and putting the cover back on with the other hand, a helper would have been nice.
 

RayVoy

Member
Nov 20, 2011
939
bigytwotone said:
yeah Off Road Bella will be helping she wants to learn how to do the mechanical work on the truck.
If your asking the "how do I do it" question, obviously, you have not done it before, and now you have the blind leading the blind.

I would suggest, a trip to the library and a copy of the engine tear down book might be a good idea.

Take the hours from the post above, and double it:twocents:
 

bigytwotone

Original poster
Member
Dec 7, 2011
489
Dawson creek BC Canada
Well not completely blind leading the blind i have a lot of mechanical experience just not intake manifold on this motor i have do this on lots of 4 bangers and V8's but not this one just wanted to know if there was any thing hat was special about this one.
 

RayVoy

Member
Nov 20, 2011
939
bigytwotone said:
Well not completely blind leading the blind i have a lot of mechanical experience just not intake manifold on this motor i have do this on lots of 4 bangers and V8's but not this one just wanted to know if there was any thing hat was special about this one.
Ok, that's fair.......... these engines (and a number of other GM engines) are prone to leaking coolant through the intake manifold gasket.
The white smoke you are seeing, is water vapour.

You should not drive it.
 

bigytwotone

Original poster
Member
Dec 7, 2011
489
Dawson creek BC Canada
No. this is not water vapor it is always there and it shouldn't be the exhaust smells like burning antifreeze i know that automobile's have water vapor for a little at start-up but that goes away as the motor worms up then there should be nothing coming out the tail pipe this is white smoke not water vapor
 

MAY03LT

Member
Nov 18, 2011
3,422
Delmarva
bigytwotone said:
how hard and long dose it take to do a intake gasket on the 4.3 V6??

bigytwotone said:
i have do this on lots of 4 bangers and V8's but not this one just wanted to know if there was any thing hat was special about this one.

If you've done the 5.7, this will be cake.

As far as time, it's a two day job when I do them. Day one is removing/cleaning the intake, dropping in the new gaskets, running the rtv beads, and bolting the intake on. That's where I stop. I let the rtv cure overnight before doing anything else. On day two I button everything back up. I'd say the time is 6-7 hours between the two days. edit - then again I do this crap everyday so my time might be faster then the actual time it might take someone else.
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
RayVoy said:
Ok, that's fair.......... these engines (and a number of other GM engines) are prone to leaking coolant through the intake manifold gasket.
The white smoke you are seeing, is water vapour.

You should not drive it.

bigytwotone said:
No. this is not water vapor it is always there and it shouldn't be the exhaust smells like burning antifreeze i know that automobile's have water vapor for a little at start-up but that goes away as the motor worms up then there should be nothing coming out the tail pipe this is white smoke not water vapor

Maybe, to be clearer, the white smoke is coolant vapor. (And coolant is 50% water)
 

tricguy007

Member
Dec 7, 2011
131
If u r burning antifreeze I'm going to bet u have a head gasket out, smell the coolant if it smell like exhaust u my friend have a head gasket failure.
 

Bartonmd

Member
Nov 20, 2011
545
tricguy007 said:
If u r burning antifreeze I'm going to bet u have a head gasket out, smell the coolant if it smell like exhaust u my friend have a head gasket failure.

What they're saying is that the intake manifold has coolant in it, which leaks into an intake port, causing the water to go through the combusion cycle... These engines commonly pop intake gaskets, and it's extremely uncommon for them to blow a head gasket... Both will cause a burnt coolant smell...

Mike
 

RayVoy

Member
Nov 20, 2011
939
Wooluf1952 said:
Maybe, to be clearer, the white smoke is coolant vapor. (And coolant is 50% water)
Thanks Wooluf, that is what I was saying, by the time the coolant gets to the tailpipe, it is vapour

tricguy007 said:
If u r burning antifreeze I'm going to bet u have a head gasket out, smell the coolant if it smell like exhaust u my friend have a head gasket failure.
The 4.3 engine, and a lot of other GM engines, have coolant passages in the dome.

Bartonmd said:
What they're saying is that the intake manifold has coolant in it, which leaks into an intake port, causing the water to go through the combusion cycle... These engines commonly pop intake gaskets, and it's extremely uncommon for them to blow a head gasket... Both will cause a burnt coolant smell...

Mike
Thanks Mike, the combienation of iron block, aluminum dome, GM Dexcool and subsequently changing to the old "green" antifreeze causes the leak.
 

Bartonmd

Member
Nov 20, 2011
545
Plus, that's a really thin gasket web/surface, there, and the flowing coolant with the 2 different metals causing dielectric corrosion, which eats the gasket...

Mike
 

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