coolant loss 1997 popular problem i guess

[Smith1000]

The last time I did this in early September, I left the throttle body on the plenum until after I removed the plenum. Had to remove an angle support, or loosen the nut down below-I think to get the throttle body free it from the block. It was easier this way. I did one several years ago and had a hard time getting that nut off. Had to bend a wrench to fit in there.

[Ralph50]

yea I am also planning on replacing the UIM and noticed that bracket is going to cause a problem. Im thinking of drilling 2 holes in it and installing a small strip of steel and then cutting the bracket in two with my recrocating saw. Then use the bracket and 2 bolts to reattach. Sometimes its faster than fighting a bolt you cant reach.

R

[jbjslambert]

looks like its problem just getting to the bottom bolt on the bracket to loosen, how fif ya do this,thanks joe

[jbjslambert]

took it off, found no cracks in plenum, but found all kinds of fluid in valley area of the lower manifold, also found bolts for UIM all loose, like hand tight loose.

so water only runs through the end portion where the throttle body is, so where is all that fluid coming from

[jbjslambert]

got it off, just pryed the bracket to the left and it loosened the bolt as well, look at my other post with pics of all parts involved,thanks joe

[happydog500]

I posted a while back that some of the time the plenum is not the problem, it's the bad gasket GM used.
I was told "not true". Or was it, "I disagree"?
Chris.

[jbjslambert]

possible, if i had more time and money i would just replace the gasket on this thing. cause not seeing plenum problem

[Smith1000]

I found the same on the one I did in early September. It had been replaced before, but I believe it was overtightened. The plenum only calls for something like 9 inch pounds-don't recall for sure, but it much pressure. It would be very easy to overtighten. I do not have an inch pound torque wrench. The gasket in mine was compressed and broken. The plenum looked good even where the stovepipe goes through. I went ahead and replaced it though since I had the new one.

Several years ago, I took one off our other Lesabre and it was burned/melted by the stovepipe. I used the epoxy Kenco kit on that one. It has not leaked and now has 204,000 on it.

[Hapynzap]

I remove the ascrew and bend the bracket back just enough to clear it and pull the TB and UIM together. I clean up the throttle body on my work bench before re-installing it in on the new UIM
The wiring harness has clips (undo) by the EGR and evap solenoid that will give you enough slack to get it to slide out from underneath and to clear the stove pipe.
I re-install them together too by pushing the bracket back into position after setting the UIM/TB back on the engine and thread the bracket bolt first thing a couple turns then torque the UIM according to the pattern, then tighten the bracket
Hey that's just what works for me

[Hapynzap]

Originally Posted by jbjslambert

so water only runs through the end portion where the throttle body is, so where is all that fluid coming from

Did you drain the coolant system before you pulled it?