Pulled the upper plenum on my new 1500 S engine. It was smoking black and running weak. Only 100K on the clock. Sure enough, that little EGR gasket was missing. I think the IP is new on this truck.

I found an upper plenum from an F engine and was going to use it, but can't figure a secure way to block that big EGR port in the lower intake. I worry about whatever I put in there coming out and getting sucked down the spyder.

An tried and true ideas?

Also, where do I get access to the screw that holds in the snorkle. I want to get rid of it.

Other breathing mods to come.

45 mm frost plug in EGR tower will take care of that. Upper intake will hold it in place. It won't go anywhere.

Check the kennedy diesel site for info on snorkel removal.

Dave

45 mm frost plug in EGR tower will take care of that. Upper intake will hold it in place. It won't go anywhere.

Check the kennedy diesel site for info on snorkel removal.

Dave


Do you mean a freeze plug? Did you use some kind of adhesive or epoxy to keep it secure?

I couldn't find anything on the kennedy site about the snorkel except a couple pics

Like Dave says, look on Kennedy's site under 'tech tips' and 'airbox mods'

The screw, iirc, is directly beside the passenger battery. I had to move my battery out to remove that screw on mine. Good chance to clean all the grounds and connections again.

Do you mean a freeze plug? Did you use some kind of adhesive or epoxy to keep it secure?

Nope. Just whack it into the hole, just like you would push it into the frost-plug holes in your block. You don't have to epoxy it in place there, do you?

It's a real tight fit... needs to be hammered in. Won't come out, either.

Trust me ... <grin> :muahaha:

Yep....Freeze plug - Frost plug, same thing.

Look at the DSG website. They sell one specifically for the purpose but you can get one cheaper at Napa or somewhere like that. My local Napa didn't have one in stock in that size. I found one at a local Fastener store.

Dave

Top up or top down?

Nope. Just whack it into the hole, just like you would push it into the frost-plug holes in your block. You don't have to epoxy it in place there, do you?

It's a real tight fit... needs to be hammered in. Won't come out, either.

Trust me ... <grin> :muahaha:

You want the concave part facing up. Get the deeper style, not the dish type.

Dave

Thanks

Follow this advice with caution....

If your upper intake does not have the round tower dipping down from it and is just open, that frost plug can pop out of the bottom tower quite easily...I have shot a frost plug about 5 feet in the air when I started the truck with the plug in the tower and the upper intake removed...

Follow this advice with caution....

If your upper intake does not have the round tower dipping down from it and is just open, that frost plug can pop out of the bottom tower quite easily...I have shot a frost plug about 5 feet in the air when I started the truck with the plug in the tower and the upper intake removed...

:nopics:

ROFL

Actually, Turbine Doc recommends that you shim under and block-off the EGR without using the frost plug... I still think that would gunk things up, but he knows a lot more than I do about these things.

Personally, the best move is to head for the junkyard, get an F intake (upper and lower) and replace the whole thing. Get reflashed to F specs.

But Frost plugs are easy, quick, and cheap. They also work MOST of the time just fine (what kind of nutbar flatlander starts his truck with the Upper Intake off, eanyway??)

My local Fastener store didn't have a 45mm but they gave me a couple that in imperial sizing that were very close. One slightly smaller and one slightly larger. I tried the slightly smaller one with my S upper and the EGR in place with a block off plate. This plug got spit out but it didn't have anywhere to go. I was concerned by this because when I was switching over to my Peninsular intake for my IC install if the plug got spit out there was nothing to stop it. I was going to put the project on hold until I installed my F lower intake (still have to do that) but decided to try the larger size plug. The first one kind of slid right in with little effort. The larger one required a little pounding to get it in. I also did a little test to see if it got spit out if it would get sucked down the lower intake....it will not.

The larger plug has been in there for several months now and it hasn't gone anywhere.

That's my story and I'm sticking to it. :)

Dave

Follow this advice with caution....

If your upper intake does not have the round tower dipping down from it and is just open, that frost plug can pop out of the bottom tower quite easily...I have shot a frost plug about 5 feet in the air when I started the truck with the plug in the tower and the upper intake removed...

Okay , where's the advice? I got the warning. What did you do to secure yours?

I just did this last weekend and the 45 MM plug dropped right in with no resistance without the metal EGR Gasket. With the gasket in there it was snug but not what I would call tight. I left my EGR in place with the vac hooked up to it and now I get code 32 and 33. I thought I wouldn't get these since the EGR was there and operational just without the passage. guess I'll be doing a reflash sometime in the future.

Another member gave me a GM part number for an F code EPROM and said it could be had for $45, I called two different dealers today and they both quoted me $109. At that point I would rather go with an aftermarket reflash in the $300 range and get the other goodies that come with it.

Okay , where's the advice? I got the warning. What did you do to secure yours?

I think his advice was not to follow mine...

... which means he knows me better than you do <grin>

He was telling you to make sure your upper intake has a 'tower' going down to hold the frost plug from popping up.

I just did this last weekend and the 45 MM plug dropped right in with no resistance without the metal EGR Gasket.

Bob, you need to make sure the frost plug is TIGHT... not snug, but 'hammered-in' tight.

And you have an OBD-I ... you shouldn't code with the vacuum still hooked up. Hmmm...

I agree with your thoughts on getting a new chip, to F specs. Fixes your EGR issue and gets all the other benefits at the same time... if you're already gonna be paying 1/3 of the price just to get to F specs, that's money thrown away if you decide to go for some power later.

I think his advice was not to follow mine...

... which means he knows me better than you do <grin>

He was telling you to make sure your upper intake has a 'tower' going down to hold the frost plug from popping up.


And you know me better than he does :D

:nopics:

ROFL

Actually, Turbine Doc recommends that you shim under and block-off the EGR without using the frost plug... I still think that would gunk things up, but he knows a lot more than I do about these things.

Personally, the best move is to head for the junkyard, get an F intake (upper and lower) and replace the whole thing. Get reflashed to F specs.

But Frost plugs are easy, quick, and cheap. They also work MOST of the time just fine (what kind of nutbar flatlander starts his truck with the Upper Intake off, eanyway??)

I've actually done it twice - once it shot up about 5 feet in the air (hood was off - we had just installed the wrecker engine if you recall that episode). You should have been there - KAPOP! LOL

The second time is just kind of popped out and landed in the lower intake - lucky it didn't get sucked in farther - shut the truck off in time...

Jif, it's probably more than snug since I had to use a hammer to seat it but without the gasket it would fall through. I wasn't expecting to get those codes either.

Jif, it's probably more than snug since I had to use a hammer to seat it but without the gasket it would fall through. I wasn't expecting to get those codes either.

I was under the impression that you were supposed to seat the frostplug without the gasket in place. Maybe I'm wrong... I thought the whole idea was to seal-off the 'S' lower so that it was (effectively) an 'F'.

Sigh. One would think I'd get tired of being wrong...

It would still be sealed. That mystery gasket is really more of a shim. Without it you'd need a slightly larger plug.

Dave

So now we're talking 46 or 47 mm? What about red locktite?
BYW, I've never seen an "f" upper intake with a tower extending down. Is there really such a thing?
It would still be sealed. That mystery gasket is really more of a shim. Without it you'd need a slightly larger plug.

Dave

That is going to depend if you have the mystery gasket or not.

Yes some F uppers came with the webbing and EGR tower. msuman who posted about screwing up his plenum has one.

You shouldn't need the locktite but it might not hurt.

Dave

without that gasket it would have taken more than locktite to make up the difference. I'm on board with trying a larger frost plug. if the shop had one I would pick up a 45, 46, and a 47 if it was available. I would rather have put the plug in without the gasket.

Can I just close the upper intake, where the EGR sits by making a blind gasket, or do I have too absolutely to close the port with a frost plug?

Can I just close the upper intake, where the EGR sits by making a blind gasket, or do I have too absolutely to close the port with a frost plug?

By blind gasket, I guess you are talking about a solid gasket that will sandwich between the upper and lower intake, blocking off the passage into the upper egr area. If so, it would have to be some pretty heat resistance stuff to withstand 1000 degreeF exhausr. Maybe the freeze plug AND the solid gasket would be the ticket. You know, the ole' belt and suspenders approach

Yes, I meant a solid gasket wich will be placed as a sandwich. I will try to find some stainless stuff to make it. Unfortunately, no frost plug available here...

matuva, are you talking about a gasket between the upper and lower intake or between the egr valve and upper intake. Not that there is that much of difference, but anytime you can keep exhaust away from the intake metal, the cooler your intake charge will be.

Can one "hog" out the S engine intake upper and not upset the codes on the engine? I'd like to get rid of the excess casing material.

matuva, are you talking about a gasket between the upper and lower intake or between the egr valve and upper intake. Not that there is that much of difference, but anytime you can keep exhaust away from the intake metal, the cooler your intake charge will be.

Yes, I'm talking about a gasket between the EGR valve itself and top of upper intake.
Should this mod work ? I've been told that this mod will not throw any code.

I haven't got time yet to do the mod but I'm almost intersted in as it is said to help lowering intake temp.

Those of you going freeze plug route ever thought of chilling the plug literally freezing it so it will be smaller than the hole & once it comes back to normal temp it will be mechanically held in place.

For me I ran 6 years with shim under the EGR valve between it & top of the upper plenum, the plenum never gunked up, only time I had excessive EGR leakage is when I tried to reuse egr "tower gasket" that goes between upper & lower plenums.


Shim material under the EGR needs to be of sufficient thickness to where it won't blow out over time, 1st shim I used was maybe .030" thick it blew out after about 4 years in place, needs to be at least .060".

Matuva on my 95 I plugged it with the freeze plug and left everything else in place and I'm getting code 32 and 33. haven't checked the vacuum yet but the pump is only about 2 months old.

For me I ran 6 years with shim under the EGR valve
But only did this while off roading.....:D

Which is why it was shimmed under EGR so I could be be street legal by just removing 2 bolts then the shim & reinstall the EGR with no shim/blankoff plate in there ;) freeze plug would not allow me to be legal nor in a warrantable modification free configuration

fonecop1, thanks for sharing.
TD, it looks like you are not encountering troubles with your mod. Is it because of your reflash PCM or because your truck is an 1998?

I was running that way before the reflash, S system does not monitor EGR flow, it monitors for changes to vacuum at prescribed times as solenoids open & EGR valve opens/closes, my "off road" method lets PCM think it's doing work it is supposed to ber doing even though no EGR gasses are mixed.

When all warranties expired I had this reflashed to full F so now it doesn't look for excess hardware I don't need for off road operation

Those of you going freeze plug route ever thought of chilling the plug literally freezing it so it will be smaller than the hole & once it comes back to normal temp it will be mechanically held in place.

For me I ran 6 years with shim under the EGR valve between it & top of the upper plenum, the plenum never gunked up, only time I had excessive EGR leakage is when I tried to reuse egr "tower gasket" that goes between upper & lower plenums.


Shim material under the EGR needs to be of sufficient thickness to where it won't blow out over time, 1st shim I used was maybe .030" thick it blew out after about 4 years in place, needs to be at least .060".

How did you get that shim to remain in place? Were you still using the " S" upper manifold with the webbing removed?

Yes stocl intake, removed webbing is inside the upper, shim goes on outside of the upper sandwiched between upper intake & the bottom of the EGR valve, traced the outline of EGR valve onto metal sheet stock, cut it and drilled hole in each end to match holes in blank off plate, easy on easy off when "off-road" journeys completed

EGR blocked this week-end.:D
I put a piece of stainless stell as a sandwich between EGR and intake, and voila! Runs fine and throws no code :D

Thanks TD :thumb: