Thank you to everyone on the BC who insisted I do the lower gaskets when changing
my upper plenum.
I finished the job today.
Here is what I found:
*Lower gaskets were literally falling apart.
*Oil ponding in the left rear and right front of lower.
*Upper gasket flattened on throttle body and leaking.
*Egr tube stuck and burnt to upper plenum.
The hardest part was cleaning everything and getting the fuel rail out.
It would only budge after I soaked the injector bodies with oil then continued rocking it.
Coolant elbow was a little tricky.
I will be updating this post with pics shortly.
I concluded the job with an oil and filter change and she'* ready to go.
To everyone out there that is thinking of changing their gaskets and plenum as a preventative measure "Do it". You won't be sorry you did.
I'd rather pay a little now than a lot later.







see?

Great job on getting that done! I'm glad you did the lower gaskets too. It'* a good feeling to have it all done!! One less thing to worry about....

"Ditto" Good Job. Now you can have more peace of mind, huh !

Thanks very much for letting us all know what you found. Very good "first hand" information. Many many many other forum readers should be very thankful for this good information.

The guy at Advance Auto said he handles suppyling most shops with these gaskets
and he can't keep them in stock.
Also when I picked up the coolant elbow at the dealer my service manager friend said they do not do this repair on cars over 50k without pulling the oil pan and cleaning the screen and pan.
He said coolant and sludge from cleaning gaskets and the lifter area getting down in the pan poses a problem.
When I removed my lower everything was clean and I was careful to plug the holes
and cover the lifter area with towels when cleaning the gaskets.
Oil drained showed no antifreeze or dirt so I think I'm OK.
Also notice the coffee filter in my funnel in the coolant overflow. Its a good idea when reinstalling your antifreeze to use this when you get near the bottom of the pan and there is some loose stuff in there floating around.

Also the back of the throttle plate was filthy and required a lot of cleaning.

did you get any pics of the egr stovepipe that goes from the lower to the upper?

i have another theory coming about in my mind, that'* unsupported by anything i've found out and posted in other threads...

Mine was terrible on my 99, too. It was so bad that the throttle would "stick" prior to the upper intake job. I removed all the sensors from it and soaked it in gas and scrubbed with a light duty brush to remove the grime. Not sticking any more...

No I didn't get pics of the stove pipe. Was too busy trying to clean everything when it was apart.

Dawg.... The one thing I forgot to do was drill my stat. when I had it apart.
Would have helped if I made a check list.
You get caught up in the moment when everthing is apart.

Hey Guys,
Got a welcome surprise to report.
Since doing this Plenum and gasket job my gas mileage has been steadily increasing
to where I got 29 MPG going to the beach on Tuesday.
Could this be because the PCV and MAF are now working properly since sealing everything up?