View From Under the Plenum

[Rob]

Jay,

I didn't want to continue this in the other forum because it was getting off track, but have you ever seen the view from underneath the plenum on an LT5 engine???I have the pictures on disk somewhere of the last time I took the plenum off....it "ain't" pretty!!!! I'll post them here tomorrow night. Make sure you have your service manual handy and if you need help let me know. When you're ready to get into it, let me know and I'll give you my phone number in case you need help. LOL...chances are....you'll probably be removing your's the same time I'm removing mine. LOL

 

[JT ZR-Won]

Hey Rob,
I've only seen 1 pic of under the plenum. It looks like some type of bird's nest or something:L I'd love to see the pics you have. I'll actually have the LT-5 engine manual sitting by my side as I do the deed....(God bless air tools)

I'd actually like to give ya a call before I do it because you've done this a few times.......I'm just a rookie I'll take a bunch of pics also.........I'm about 2 or 3 weeks away ( have to find some runner gaskets)

Jay

 

[Rob]

Well....looks like I'll be doing it very soon as I'm now almost positive my alternator has met God. I have to go find a new alternator....plenum gaskets, etc.....I want to lurch everytime I think about having to do this.

 

[JT ZR-Won]

Aw dude......that sucks. Let me know where you pick up the plenum gaskets. I'll be looking for those shortly. Good luck (snap a few pics too if you can)

I just put in a new battery in mine yesterday:eyerole

Jay

 

[ArtZR1991]

I got the gaskets at the local Chevy dealer. Just waited one day.

It's busy under there, no doubt about it, but mine was clean, and I especially appreciate the way they use the hard plastic line for vacuum, instead of flexable hose. Not only looks neater, but is instantly responsive because the walls don't collapse. It is available as a complete, assembled kit, but I didn't need it. Where I had my problems (if any) were the softer rubber hose sections that connected the "spider web" (part described above) to various engine parts. I used RTV gasket sealer to make them more permanent.

Had it off, clean, and on in two hours.... first time. One thing you appreciate is the machinning of the parts.

 

[JT ZR-Won]

Cool Art,
Thanks for the input

Jay

 

[ArtZR1991]

By the way, make DAMN sure you drain the coolant!

 

[Rob]

Interesting. I didn't have to drain the coolant at all when I took the plenum off. I just had to wipe up a few minor drips, but that was it. .:confused

 

[ArtZR1991]

Rob, you made my age show.

When I did mine, I remember it was a big deal to drain the coolant, and I didn't want to do it. I researched it and found out why. Now I can't remember exactly. But what it relates to is the coolant being routed through the plenum:

Page 6B-2 of the service manual:
"Coolant is drawn from the radiator by the coolant pump and is circulated thru the water jackets in the block, cylinder heads, intake housing, injector housing (LT5 only), throttle body and plenum...."

If any water is still in the passages cast into the injector housings, or worse yet, the plenum, there is considered a chance that it will get down the injector housing port to the cylinder before you can lift the plenum off, clean the top of the injector housing and tape it closed. If this happens, it is potentially very destructive.

I think that's it, but the manual makes repeated references to it throughout the throttle body (expected), plenum, and injector housing sections.

Hope this helps.

 

[Rob]

Rob, you made my age show.

If any water is still in the passages cast into the injector housings, or worse yet, the plenum, there is considered a chance that it will get down the injector housing port to the cylinder before you can lift the plenum off, clean the top of the injector housing and tape it closed. If this happens, it is potentially very destructive.

Hope this helps.

That is an excellent pointer. Be careful when you pull the plenum off because there is coolant that can leak down into the injector housings.

When I worked in Biotechnology, I collected a bunch of mats (we called them "blue diapers") that were used to ship chemicals from Sigma Diagnostics. Those little blue mats are extremely absorbent and have a plastic liner underneath so they won't leak. As soon as I lifted one end of the plenum up, I threw a diaper over the injector housings until I could get the plenum safely off, out of the way and then I could mask off the injector housings properly.

 

[David-F]

Yes have been there done that many times, after a while it doesn't look so bad.

David Fulcher