Buick 3800 Series-2 Intake Manifold Questions

[Carlostrece]

I see a lot of threads about replacing the lower intake manifold's OEM gasket with a good aluminum framed gasket, such a Felpro gasket or revised GM OEM gasket part # (P/N 89017554) per GM bulletin 04-06-01-017 issued in May, 2004.

With all this talk about the lower intake manifold and its gasket, it makes me wonder: Is there an upper intake manifold too? If so, should its gasket also be replaced?

I'm sorry if these are dumb questios.

 

[FowVay]

Yes, there is an upper intake manifold and yes, it also has a gasket set that seals it to the lower intake manifold. The reason that there is not an issue with the upper intake manifold gasket is because it does not deal with engine coolant. It is the lower intake manifold that has the water inlet pipe and is filled with coolant.

It is believed that it was the advent of the long life Dex-Cool coolant that caused the problems with the gaskets. The Dex-Cool is a 2-EHA coolant which is reactive with silicone and can be detrimental to gaskets and o-rings.

 

[Trav]

I see a lot of threads about replacing the lower intake manifold's OEM gasket with a good aluminum framed gasket, such a Felpro gasket or revised GM OEM gasket part # (P/N 89017554) per GM bulletin 04-06-01-017 issued in May, 2004.

With all this talk about the lower intake manifold and its gasket, it makes me wonder: Is there an upper intake manifold too? If so, should its gasket also be replaced?

I'm sorry if these are dumb questios.

The 3800 gen 2 should have the upper plenum changed with one that uses a metal sleeve and reduced diameter egr chimney. The OE has a habit of burning through the plenum. ATP has a decent one with all the necessary pieces.
The other common point of failure on these is the plastic coolant elbows, change them for the aluminum ones from ZZP they have decent o rings on them, the Dorman o rings are not good but the elbows are good, use OE or rings with these.

Look for corrosion in the holes the elbows go into, if corroded clean it well and use a smear of RTV in there before installing. Don't forget to install a new PCV in the new plenum and a new OE thermostat (OE only from the dealer). Flush the cooling system with the lower hose removed and the hoses going to the elbows and refill with JD Coolguard 2 from any John Deere dealer, it will not harm gaskets and seals and is perfect for mixed metal engines and change the oil and filter. Just my own experience after doing many of these over the years.

https://atpautomotive.com/engine-intake-manifold

https://zzperformance.com/products/...zzkUOIIqZtj_8oX8-JxU4QocnfN1aYb3CdRNhGDBUkbrw

 

[ls1mike]

Here is my Series III. Similar to the Series II.
Upper intake/plenum installed

Upper intake/plenum removed with lower intake seen
.

Lower intake removed.

They are all really similar with and upper and lower gaskets. The Supercharged ones are similar as well. Pretty easy job.

 

[Trav]

That one looks like it uses an aluminum upper plenum ? Yes it is an easy job no need to even remove the valve covers.

 

[Dave9]

Yes, there is an upper intake manifold and yes, it also has a gasket set that seals it to the lower intake manifold. The reason that there is not an issue with the upper intake manifold gasket is because it does not deal with engine coolant. It is the lower intake manifold that has the water inlet pipe and is filled with coolant.

It's been a few years since I did one, but from what I recall this is not correct? Something about a throttle body coolant passage, results in a leak when the EGR heat makes the upper (when it's plastic) brittle and crack or melt apart. I could be wrong but do remember it was nearly hydrolocking the engine.

Mostly what I recall is the replacement Dorman upper manifold I got for it, was a very poor fit and I had to melt and reform the upper gasket's plastic frame to make it fit right, and then after getting it on, one of the plastic latch tabs for a sensor broke off while installing the sensor so I had to do it again, replace the whole upper manifold. Fortunately I'd tried to install the sensor before the rest was all back together so less work to take back apart.

On the other hand, I think the cast metal coolant elbows were made by Dorman and worked fine (no leaks), though the ZZP on Amazon are probably less expensive these days.
https://www.amazon.com/ZZPerformance-3800-Aluminum-Coolant-Elbows/dp/B06XQ7SJPQ

 

[Lawnman23]

That one looks like it uses an aluminum upper plenum ? Yes it is an easy job no need to even remove the valve covers.

Series III 3800's got a redesigned intake manifold, both upper and lower were now aluminum.

 

[Carlostrece]

The 3800 gen 2 should have the upper plenum changed with one that uses a metal sleeve and reduced diameter egr chimney. The OE has a habit of burning through the plenum. ATP has a decent one with all the necessary pieces.

https://atpautomotive.com/engine-intake-manifold

Is that ATP kit for upper intake manifold only, or both upper and lower intake manifolds?

I ask because ATP website text refers to it as intake manifold replacement kit. It doesn't mention if it's for upper, lower, or both. Obviously I'm a newbie on this topic.

I've also been eyeing a Felpro gasket kit part # MS98014T, or a revised GM part # 89017554 gasket kit (which has metal frame).

I'm concerned that the ATP kit might have signifigant overlap/redundancy of parts with the Felpro or GM kit. Is that a valid concern? Maybe all I'd need is the ATP kit? or would I still need another gasket for lower intake manifold?

Here's a link to Felpro kit https://www.oreillyauto.com/detail/.../fel-pro-intake-manifold-gasket/fel0/ms98014t

Here's a link to GM OEM kit (revised gasket with metal frame) https://www.amazon.com/ACDelco-89017554-Original-Equipment-Manifold/dp/B000EQR4PE

 

[Carlostrece]

Series III 3800's got a redesigned intake manifold, both upper and lower were now aluminum.

Are those Series-3 parts compatible with a Series-2 engine?

 

[Carlostrece]

Dorman makes good parts for Jeep Cherokee XJ in my experience. I successfully used lots of Dorman parts on my Jeep. A lot of other guys at Jeep forums also use and recommend Dorman for replacement parts. For Jeeps (Cherokee at least) Dorman is a goto brand for stock equivalent replacement parts.

So when I got a 97 Buick Park Ave I assumed Dorman would be good for Buick too. I bought some Dorman headlight housings for Park Ave. Total junk. I had to throw them away.

I then bought another aftermarket brand of headlight housings (recommended by Daniel Stern) and they're adequate (best currently available). OEM headlight housings are not available anymore.

I don't understand why Dorman makes good products for Jeeps, but some Dorman parts are inadequate for Buicks.

 

[ls1mike]

Are those Series-3 parts compatible with a Series-2 engine?

I don't think so because of the EGR stuff. My kids current Buick Series III is running around with Dorman upper intake/plenum. 25,000 miles now.

 

[Trav]

Is that ATP kit for upper intake manifold only, or both upper and lower intake manifolds?

I ask because ATP website text refers to it as intake manifold replacement kit. It doesn't mention if it's for upper, lower, or both. Obviously I'm a newbie on this topic.

I've also been eyeing a Felpro gasket kit part # MS98014T, or a revised GM part # 89017554 gasket kit (which has metal frame).

I'm concerned that the ATP kit might have signifigant overlap/redundancy of parts with the Felpro or GM kit. Is that a valid concern? Maybe all I'd need is the ATP kit? or would I still need another gasket for lower intake manifold?

Here's a link to Felpro kit https://www.oreillyauto.com/detail/.../fel-pro-intake-manifold-gasket/fel0/ms98014t

Here's a link to GM OEM kit (revised gasket with metal frame) https://www.amazon.com/ACDelco-89017554-Original-Equipment-Manifold/dp/B000EQR4PE

The ATP kit they call an upper manifold is also referred to as a plenum, it is the upper only. The kit has everything you need but no gaskets for the lower manifold or thermostat and thermostat housing seal. I would use OE parts for those. It is common to have some overlap unless you cherry pick ever single o ring, gasket and seal from OE, just keep or toss whatever is not used.

 

[Dave9]

Here's a link to Felpro kit https://www.oreillyauto.com/detail/.../fel-pro-intake-manifold-gasket/fel0/ms98014t

I just remembered something. I used that Felpro kit, and the RTV sealant tube was old and set up in the tube. So was another tube I'd already opened and used previously. Check whether your RTV is usable before starting the job. The Felpro kit worked fine, besides that.

That price at OReilly's seems high at $98. It's $60 on Amazon.
https://www.amazon.com/Felpro-MS-98014-Intake-Manifold/dp/B002LWL3XI

 

[Carlostrece]

I just remembered something. I used that Felpro kit, and the RTV sealant tube was old and set up in the tube. So was another tube I'd already opened and used previously. Check whether your RTV is usable before starting the job. The Felpro kit worked fine, besides that.

That price at OReilly's seems high at $98. It's $60 on Amazon.
https://www.amazon.com/Felpro-MS-98014-Intake-Manifold/dp/B002LWL3XI

I've already have plenty of fresh RTV. So no worries there.

Normal prices I've seen at autostores are around $100. The $60 Amazon price is exceptionally low. I'll buy it from Amazon if Amazon is the seller (as well as order processor). 3rd party sellers on Amazon are sometimes sketchy, IME.

 

[Carlostrece]

Would the items in my parts list below be everything I need to address common 3800 weaknesses?

• ATP part # 106001
• Felpro part # MS98014T
• ZZP Aluminum Elbows for 3800 Series 2
• Stant 195F thermostat for Buick Park Ave
• 50/50 premixed Prestone Green or John Deere JD Coolguard #2

I also want to replace valve cover gaskets and oil pan gasket. Should I use Felpro or OEM gaskets for those things?

Should I replace the OEM plastic valve cover?

I want to replace dipstick orings or maybe entire dipstick (to prevent oil leaks). Suggestions?

Am I missing something?

P.S. - I'm aware the transmission has weaknesses, but that will be another topic for another thread.

 

[ls1mike]

How bad does the pan leak. It sucks replacing that gasket

 

[Carlostrece]

How bad does the pan leak. It sucks replacing that gasket

Oil pan gasket replacement is difficult?

 

[ls1mike]

Oil pan gasket replacement is difficult?

I have some photos I have to find, It is involved.

 

[ls1mike]

I had to drop the subframe a bit and lift the engine to get the pan out. This was my Series II supercharged car.

You can see how high I had to get it.

Worst bolt I have ever had to remove or reinstall.

all these have to come out to lift the engine so you can get the oil pan out.

I can remember if this driver's side or passenger side subframe to engine mount

If is just seeping and not leaving a puddle or has no oil loss, it is not worth it on a high mileage car. The last time I had one with a leak
I went around and tightened up the oil pan fasteners and it stopped.
There are for sure worse jobs, but I did not like this one at all.

 

[Carlostrece]

I had to drop the subframe a bit and lift the engine to get the pan out. This was my Series II supercharged car.
View attachment 256213
You can see how high I had to get it.
View attachment 256214
Worst bolt I have ever had to remove or reinstall.
View attachment 256215
all these have to come out to lift the engine so you can get the oil pan out.
View attachment 256216
View attachment 256217
I can remember if this driver's side or passenger side subframe to engine mount
View attachment 256218

If is just seeping and not leaving a puddle or has no oil loss, it is not worth it on a high mileage car. The last time I had one with a leak
I went around and tightened up the oil pan fasteners and it stopped.
There are for sure worse jobs, but I did not like this one at all.

It's surprises me that it's difficult to replace an oil pan gasket. Mine is either not leaking, or only a minor drip at most. I'll just check bolts tightness. How tight is proper?