Quick Help - "C" throttle body removal

[padgett]

It has been a number of years since I removed a throttle body but am having real difficulty with this one.

Remove two big nuts (Are there only two ? Can't find a third and gasket only has two holes) on TB, all wiring, hoses, cable connections to throttle plate, two small nuts on coolant pipe and should pull off right ?

Rong.

(The numbers refere to the 93 Illustrations manual (online, excerpt below) page O-12)

TB (9) is separating a little from TB/EGR adapter (14 - between it and the manifold) but something undeneath seems to be holding it on. I suspect it is the "Pipe throttle body CLNT Inlet" (81). This is a different pipe from the one with the two small nuts (18) I think is leaking.

My question is "Have I missed something or do I just keep wiggling/pulling ?"

[Guest Mc_Reatta]

Keep on wiggling. Your suspicion is correct. The other coolant pipe (81), while only held into the TB by an o-ring, after many years seals itself in place and doesn't want to budge. Keep working it and it will eventually pull free.

[padgett]

Kept on wiggling, kept on wiggling, finally came apart but now have a different dilemma: everything is nice and clean and shiny but I do not understand how the pipe that came out of the back of the throttle body seals. Curved pipe is supposed to have a gasket on one end and a O-ring on the other. Pipe that goes approximately fron the water neck to the throttle body has an O-ring on one end but just has a flare (no O-ring but pipe does not seem broken on the other (see pic).

How does it seal to the throttle body ? Is something missing. It does not want to just press back into the throttle body & must put curved piece back into water neck first ? Magic happens ? YWTK. This is part #81 in drawing above.

Should the channel through the TB be the same diameter through ? It reduces diameter part way in and that is where the pipe stops.

[Guest Mc_Reatta]

The front outlet pipe has an o-ring at the TB and the gasket at the IM. The rear inlet pipe has an o-ring on each end, TB and IM. O-ring goes inside the TB before the pipe is inserted. If your not confident on the condition of the sealing surfaces of the pipes and the TB, I'd use some silicone sealant along with the o-ring.

[padgett]

So the piece pictured is the way it is supposed to look & O-ring goes in front on the TB end? Weird. Do you then insert into TB before assembling on car ? Lever the curved end into the manifold along the way ? This is dumb.

[Guest Mc_Reatta]

I'd insert the IM end of the pipe first and then insert o-ring into the TB. Then as your placing the TB into position the pipe will be seated into the rear hole of the TB and close down on the o-ring as you tighten the outlet pipe and the two manifold studs onto the IM. I didn't want to do it twice, so I put some silicone sealant around the TB side of the inlet pipe as insurance.

[padgett]

Thank you. I have to wonder why they did not just use a conventional O-ring on the TB. This push/seal seems to rely on too many variables. It just seems dumb.

I'd go the pipe plug route except that to get to the IM side would require pulling the whole plenium.

[Guest Mc_Reatta]

I have no idea why that method was chosen either. It seems to have worked out OK as I don't know of too many leaks in that spot. Unless there is some structure inside the TB that I didn't see, a flat washer is typically used in that situation not an 0-ring.

Its only a PITA when you need to remove the TB for some reason and it did allow for the same seal to be used in three of the four spots using the compression from the outlet pipe to hold the seals in place.

They did claim that the reason that they even ran coolant thru the TB was to improve driveability. I expect it might be in an attempt to offset somewhat the consequences of running the engine so hot as well as raise the inlet temp in the winter. The only other car I've worked on that had coolant there, it was used to raise the temp so that the choke would respond to the warming engine and slow the cold idle down. No need for that in a Reatta obviously.

Given that you don't have the freezing winter cold, and have modded your engine to run much cooler, using plugs might be an acceptable option in your situation.

[Guest crazytrain2]

I'm getting ready to see if I can tackle the exact same project. Except in my case it is the throttle body coolant line (part no. 81 in your info) that has rusted thru. Naturally the rusted area runs clear down till it is flush with the I/M. Below is a link to the part I purchased which is not tapered like yours and has o-rings on both ends.

I thought the additional prints (also provided at the linked site) for various engine designs, all apparently within the "C" VIN model might be of interest, and might include your tapered model. If that makes sense. My apologies for what I know is a confusing reply. Anyways I hope its of some help. Any tips for if and when I get to try would be appreciated.

PIPE. Throttle Body Coolant Supply for Buick Lesabre (25533986)

[Guest Mc_Reatta]

Wish you luck getting the rusted pipe out of the IM and TB. Might not be exactly what I would call fun.

Must have redesigned the pipe based on strangeness of original design and seal.

Interesting they do not have a proper id or part number for the curved return pipe. The # in the photo crosses to the GM PN# for the o-ring seal in the accompanying list not a pipe.

[Guest Recian]

ive had mine off many times and to seal the t-body coolant tubes you put the o-ring ON the manifold 90 degree tube and spray it with silicone spray to make it slick and the t-body will slide right on and it's a guaranteed seal. Putting it in the t-body may pinch the gasket.

[padgett]

Does my picture of the tube above look right (post #3) ? There is nothing on the end that goes into the throttle body to hold the O'ring in place on the tube.

[Guest crazytrain2]

Here is a pic of the one for mine, pn GM-25533986. O-ring on IM end (short end) is black in color so might be hard to see in pic.

[padgett]

That looks like the O-ring is barely into the throttle when seated. Oh well if it works that is what is needed, just ordered it, should be here shortly.

Seems you need a complete intake manifold kit also to get the gaskets and O-rings for the throttle body.

[Guest Mc_Reatta]

Glad to see they fixed the original design snafu, but now they created the need for a different o-ring from the other two. Oh well maybe the third redesign will get it right.

If you get the IM Gasket kit from Fel-Pro, all three o-rings will be the same.

I.m sure those o-rings are a stock size, so if that's all that is needed, I would just pick them up from a hardware store, not buying a entire kit or paying over $5 each.

[Guest crazytrain2]

The two (2) O-rings in my pic came with the part.

As the movie critic said "You'll laugh, you'll cry, you'll kiss ten bucks goodbye"

Also, since my pic lacked anything to reference for size, the OD of the pipe on the throttle body end is 1/2".

[padgett]

Fel-Pro IM gasket set has six fat Orings, two small skinny Orings, one medium skinny Oring. Also have lotsa green AC Orings in many sizes.

Just pulled my original (post #3) back from the screen until the size I saw and the one (#13)on the screen matched, how I gauged how far back the Oring was.

At least rust is not something I need to be concerned about.

[Guest crazytrain2]

Padgett,

I thought you might be more concerned with what what looked like a larger outer diameter on the throttle body end of your coolant pipe. But hope it all works out for the best for you.

I am giving thought to what I'm going to do to get the old pipe out of mine (IM end) as I'm quite certain it is going to snap off. I've come up with the following idea (see Pic) and hoped you and or anyone would chime in with any thoughts.

One of my own concerns about my idea is that if the coolant pipe protrudes though the IM, I may end up flaring the pipe end in which case it will never come out (unless I drill it out, and risk creating an oblong hole)

Another thought I had was to somehow punch it down through the IM. I can access the hole in the IM if I remove the thermostat and it's cover, was yours similar?

Thanks

[padgett]

As you can see from the picture in post #3, corrosion is not an issue, the pipe is like new. Just swung back and forth with a screwdriver up the pipe until it came out of the IM.

Suspect that for any major operation the plenium will need to come off first.

I do have a new dual ring pipe waiting at the local Buick dealer, price was about the same as online plus shipping so should get back together in time for the long weekend.

[Guest crazytrain2]

Padgett,

Now I see what part you were referring to as "Front TB coolant line" Did you also order and replace that as well? As you can see by the looks of mine it is apparent I need to. If you have part number handy would save me some time as well, my computer blew up and had to get new, backup didn't include web site favorites.

Thanks

[padgett]

No, both of my lines were in "as new" condition, I only replaced the one to get the captive O'ring design (and had to shorten that to make it work).

Seems to be sealed nicely now. Did not use any sealer/silicone either, just cleaned the surfaces and lightly oiled the gaskets and O'rings.

[Guest Mc_Reatta]

The PN for the throttle body coolant return pipe (the front one with the hook) is 25533987. One higher than the inlet pipe #.

Doesn't appear to be an easy find. May have to P&P it.

Edited September 15, 2011 by Mc_Reatta (see edit history)

[Guest crazytrain2]

That 4 piece "U" shaped coolant line is about as well designed as the toys from Misfit Island on Rudolph the Rednosed Reindeer. And as I expected mine snapped off flush with the I/M. So I got the joy of tearing the ERG, the top half of the I/M & etc. Just to drill out a hole that is 3/4" away from the thermostat cover.

But on the positive end, it allowed me to put in the 2-1/2" long steel coolant line. Yup had a great time, thanks Mr Junior GM Engineer that came up with that one.