Gen2 3.9L V8 - Intake Manifold Gasket Index

[GreyWisent]

I think you are probably on to it, but while you are there, take a look at the big vacuum hose that goes to the check valve for the brake vacuum booster. It's right above where you were pointing the propane. Those hoses do get porous over time (unless you already replaced it).

My thoughts exactly!

That corner of the manifold is also about 1/2" away from where the aforementioned vacuum hose connects to the metal pipe going to the back of the intake manifold. The rear cover of the intake manifold (and gasket/ring) is also there. Maybe try temporarily sealing those areas better and repeat your experiment before tearing into the manifold. Even taping a plastic bag around there to redirect the air flow is worth the effort, IMO.

(REPLACE YOUR COOLING SYSTEM - 2004 Fun and Easy StepsREPLACE YOUR COOLING SYSTEM - 2004 Fun and Easy Steps)

 

[rgorke]

Red arrow: New hose, less than 1 year old.
Yellow arrow: Is there a gasket/o-ring for this piece and the black plastic part?

 

[GreyWisent]

Also, are there gaskets for the part that connects to the back of the manifold, the piece where the hose above connects? I figured I might as well change all of them while I am at it...

Yup! #5 in OP.

5) Plenum to Rear Cover gasket (1) - Jaguar AJ87992 OR the kit here: MAHLE MS19424

I've also run across FEL-PRO 61797. It's described as throttle body gasket but has the shape of the rear manifold gasket (#5). I got the Mahle kit. Sitting nicely in my living room cause I like typing here better than working on the LS...

Edit:

Yellow arrow: Is there a gasket/o-ring for this piece and the black plastic part?

Yes, this is it. Submitted this just before your post.

 

[rgorke]

Thanks!!!

I kinda stoked that I at least have some sort of idea where the problem is and bummed that I didn't replace these when I had my intake manifold off this summer when I redid my cooling system.

That being said, taking it off should be MUCH easier the second go round, no? (Yeah, I know, I just jinxed myself!!)

 

[joegr]

...Also, are there gaskets for the part that connects to the back of the manifold, the piece where the hose above connects? I figured I might as well change all of them while I am at it...

I think there's an o-ring of sorts there. See posts above...

 

[joegr]

...That being said, taking it off should be MUCH easier the second go round, no? (Yeah, I know, I just jinxed myself!!)

Yes, it does get easier with practice.

 

[DeviLSh]

Some of the jags have a different back cover on their manifold (but same gasket), with a different vac port, and an integrated/separate MAP sensor, whereas the LS has map built into EGR. Might mean there are other gaskets suppliers out there for the AJV8 family too.

I looked into swapping this over as a clean way of relocating/deleting EGR but maintaining MAP functionality. I haven't done anything yet with this, just speaking out loud!

 

[rgorke]

Thanks...

Here is my shopping list:

jaguar xj8 4.2l upper intake manifold gasket (set of 8 seals) intake gasket | eBay

Or similar vendor...this was the first that came up on my search...there are a few in TX.

And, since I am going to tear the whole manifold apart, I should change the other gaskets as well. I put in new lower manifold gaskets about 6 months ago and am assuming that I can reuse those.

I can't figure out which one of these in the attached picture is:

5) Plenum to Rear Cover gasket (1) - Jaguar AJ87992 OR the kit here: MAHLE MS19424

Is it the Fel-pro 61797?

I see they have:

3) Throttle Body to Eblow (1) (TB Gasket) - MAHLE G31842

4) Elbow to Plenum (1) (Elbow gasket) - MAHLE G31844

Finally, is there a source for the EGR tube? I have seen a few of those fail and since I have the manifold off, I was thinking of replacing that as well.

 

[rgorke]

I came across these threads on a Jag forum...

Check out my detective skills on this air leak - Jaguar Forums - Jaguar Enthusiasts Forum

xj8 intake reseal - Jaguar Forums - Jaguar Enthusiasts Forum

 

[GreyWisent]

I came across these threads on a Jag forum...

Check out my detective skills on this air leak - Jaguar Forums - Jaguar Enthusiasts Forum

xj8 intake reseal - Jaguar Forums - Jaguar Enthusiasts Forum

I perused those a while ago, when trying to figure out the upper gasket p/n (glad to say they'll be the ones coming here for once for the OEM p/n ). Now I find those pictures of perfectly clean intake headers downright titillating. haha


But that reminds me... from post #11 of the first linked thread, his broke as he was removing them:

Be VERY careful when taking these off, and even more so when cleaning them!!! They are fragile by design.

One of the black tabs from one of mine came off as I was cleaning it with a rag. The grey square pads are securely bonded to the bottom of the pads, however, they are connected to the rest of the gasket by a tiny strip with a very small cross section (maybe 2mm x 1mm). The hoop loops around the tab, but is not bonded to it. As you can see from the images, the tabs are integral in sealing the two holes on each side of each port, where they're supposed to go in. And to answer an earlier question, I'm almost 100% certain now that you can't shave these tabs to fit the 2006 version.

Here are my pics. Notice how little material holds the tabs in place.

Again, if you plan on keeping these and adding RTV, be very very gentle with them!

 

[GreyWisent]

jaguar xj8 4.2l upper intake manifold gasket (set of 8 seals) intake gasket | eBay

For $10 more for the set, you could get OEM from this guy:
OEM Land Rover Range Sport Engine Upper Intake Manifold Gasket 4526549 5.0 | eBay (I mentioned him earlier)

 

[rgorke]

For $10 more for the set, you could get OEM from this guy:
OEM Land Rover Range Sport Engine Upper Intake Manifold Gasket 4526549 5.0 | eBay (I mentioned him earlier)

But he only has 7...

You think these would be better than the guy from euromarqueautoparts? They aren't degas bottles...LOL. I think I figured out the other larger gaskets from Rockauto...

 

[GreyWisent]

But he only has 7...

You think these would be better than the guy from euromarqueautoparts? They aren't degas bottles...LOL. I think I figured out the other larger gaskets from Rockauto...

Yeah, 7 and get another 1 from a dealer

The problem (for me) is that I don't know what euromarqueautoparts sells - I talked about this in my earlier post. They could be much better than OEM, or could just be stiff rubber bands. And even if everything else looks the same, the OEM ones have been tested (and hopefully improved) in cars on the road for 15 years and you know they're going to last a bit. This certainty is not something you can say for euromarque. I'm not trying to throw shade at them in any way; I would still have the same doubts if my own brother were running the shop. I just personally think that the price discount (12% in the case of this one off specific seller, as 7 of his are the same price as a set of 8 aftermarket) would have to be much much larger to cover that uncertainty. Their small "custom shop" size only serves to exacerbate this - a large aftermarket manufacturer would have more resources available for quality assurance, warranty, etc. At least they're made in the US though.

As an anecdote, I cheaped out on buying the OEM valve cover gasket kit 3 years ago and went with the (reputable!) Mahle alternative, the price difference wasn't even that much. I said the same thing ("they aren't degas bottles") and ended up with oil seeping into my spark plug wells. 4 out of the 17 items in the kit failed in a relatively short period, and arguably the most important parts.

I think I figured out the other larger gaskets from Rockauto...

I did the same. I'll post what I bought when I get home tonight.

 

[GreyWisent]

Thanks...

Here is my shopping list:

jaguar xj8 4.2l upper intake manifold gasket (set of 8 seals) intake gasket | eBay

Or similar vendor...this was the first that came up on my search...there are a few in TX.

And, since I am going to tear the whole manifold apart, I should change the other gaskets as well. I put in new lower manifold gaskets about 6 months ago and am assuming that I can reuse those.

I can't figure out which one of these in the attached picture is:

5) Plenum to Rear Cover gasket (1) - Jaguar AJ87992 OR the kit here: MAHLE MS19424

Is it the Fel-pro 61797?

I see they have:

3) Throttle Body to Eblow (1) (TB Gasket) - MAHLE G31842

4) Elbow to Plenum (1) (Elbow gasket) - MAHLE G31844

Finally, is there a source for the EGR tube? I have seen a few of those fail and since I have the manifold off, I was thinking of replacing that as well.

Don't forget #6) ! It's a tiny, but very pricey metal gasket.

Wanted to make a new thread, as I cannot locate a comprehensive thread on LVC that lists all gaskets associated with the V8's intake manifold.

There are a total of 6 Gasket locations that attach to the manifold assembly.

1) Lower Manifold Gasket (2) (From spacers to head) - MotorCraft 2W9Z-9439-AA OR FelPro MS69293

2) Upper Manifold Gasket (8) (From Spacer to Plenum)

a. EBAY Seller
b. TBD for other style seal (See picture below)
​

3) Throttle Body to Eblow (1) (TB Gasket) - MAHLE G31842

4) Elbow to Plenum (1) (Elbow gasket) - MAHLE G31844

5) Plenum to Rear Cover gasket (1) - Jaguar AJ87992 OR the kit here: MAHLE MS19424

6) EGR to Elbow (1) (EGR Intake side gasket) - Motorcraft 2W7Z-9D476-AA​

Here's what I got:
1) x2 + 5) MAHLE MS19424
2) Rover 4526549 (from dealer)
3) FEL-PRO 61510 (bought it some time ago when it was on sale and had free shipping - only reason I chose this)
4) MAHLE G31844
6) MOTORCRAFT CG740 - same price as any other aftermarket brand, so might as well

(However)
#3 MAHLE G31842 is $1.50 now at RockAuto! https://www.rockauto.com/en/parts/mahle,G31842
#6 MAHLE G31851 is $8 now at RockAuto https://www.rockauto.com/en/parts/mahle,G31851



Pictures of the above:

1) x2 + 5) MAHLE MS19424

2) Rover 4526549 (from dealer)

3) MAHLE MS19424

4) MAHLE G31844

6) MOTORCRAFT CG740

(Forgot to take pic of - will update)

 

[rgorke]

Ugh, anyone see a potential issue with these...other than “Made in China”

It says “V6”. I have a V8. They were listed under V8 on Rockauto.

 

[GreyWisent]

Fel-Pro 61798 looks to be the V8 version according to both RockAuto and the Fel-Pro website (see attached).

V6 is *9E936* - FelPro 61356
Gasket | FordUS
V8 is *6C653B* - FelPro 61798
Seal | FordUS
(Looks like you have to select a vehicle to see the diagram. Not sure what's up with their site tonight.)

The whole thing is a mess to me though. Ford parts website has different fitment notes on the results summary and product page (note that this supposedly only fits up to 2004: Seal | FordUS but shows up with an application year covering 2006 in the results page for 2004+ LS).
Note though that Mahle G31844 is listed as a replacement for 4H2Z-6C653-AA (which should not cover 6C653B above, and 6C653A is the rear one as per ford diagram).

None of these helps you with your problem though - why is V6 printed on what you got? Short of calling Fel-Pro, not sure what you can do. Do you want me to measure anything on mine? Hard to take an accurate diameter of these when not installed. I would just assume it's good and see if it fits when you install it - downside is that you might have to wait for a new part, but this is what's exciting about our cars, right?!

 

[rgorke]

Thanks, I am planning to compare the gasket I take off with this one. If it matches, I put it in, if not, I’ll clean up the old one and put some RTV on it.

 

[rgorke]

Upper intake gaskets came today. I got the 7 OEM off eBay and one from our local Jag/Range Rover dealership.

Got the manifold out...the small torx screws holding the aluminum part to the plenum we not very tight at all. That being said, once the screws were out, it took some encouragement to separate them.

The gaskets are a mess. Really disintegrating and stuck to the aluminum part. I will do some careful cleaning of the surfaces. Seeing the condition of the gaskets makes me even more confident that these contributed or are the culprit to my lean codes.

Also, the rear Fel-pro gasket IS the correct one.

Here’s a picture...

 

[GreyWisent]

Thanks for sharing. Looks like you (or a predecessor) already went at them with RTV before?
I think once the tabs start going (looks to be the case in most of them), that option goes out the window with them. (Warning to anyone venturing to pull these apart.)

Got the manifold out...the small torx screws holding the aluminum part to the plenum we not very tight at all.

Yeah, they're pretty much hand tight. I have yet to look at mine very close, but I think I was already seeing some cracking, so I wouldn't give 'er. I imagine gradual uniform torque in a pattern (middle, 2 outer, 2 in between) is the answer - wish there was spec for it.

 

[rgorke]

Thanks for sharing. Looks like you (or a predecessor) already went at them with RTV before?

Not sure about that...parents had the car since mile 89 and every repair was done at the dealership.

Regardless, I’ll get that all cleaned up with a seemed...lol just kidding.

Any suggestions on getting the gunk off? Brake clean? Plastic scraper?

 

[GreyWisent]

every repair was done at the dealership.

Never heard of a dealership that's resourceful enough to try to repair something; surprised they didn't try to drop a $1500 new intake on your lap. Anyway, that RTV gasket patch is not a factory option AFAIK.

Any suggestions on getting the gunk off? Brake clean? Plastic scraper?

I would plug the holes first, take off the RTV and clean the mating surface. After that, clean the insides and injectors.

For the RTV, I've had some success wiht leaving it sit in "gasket remover". I have a spray from Permatex. To me, it seems like it's acetone with a thickening agent - it congeals into a bubbling gel the moment it come out of the can and doesn't run (fast). I like this "feature" because it won't drip down anywhere you don't want it to. I would keep it away from the injectors, thus my suggestion to plug the ports up. You have to let it sit for a good 5 minutes though. If you trust your dexterity, I would go ahead and cut the excess RTV gasket off first, but make sure you don't touch any of the metal with the knife (i.e. don't scratch it).
I would then attack the ports with carb cleaner.

Other than that, to quote Joegr, there are various opinions around here as to what works best at removing RTV gaskets. Unfortunately I don't think brake clean will do anything to that. Try and see - and let me know please, because I have to catch up with this work by the end of the week. I suspect you'll eventually get bored and savage it with a plastic scraper; that's always been my experience.

 

[GreyWisent]

On an re-installation note, I have a wild idea that you can probably start the nut on the engine rear wiring harness retainer before putting the manifold on. Then slide the harness on, since it's a groove, not a hole. A lot of people seem to struggle getting that bolt on and locating it by hand, with tape attached to their fingers and other tricks. I wonder if what I'm suggesting would work.

 

[rgorke]

Ha!!! I didn’t even put the bolts back on the wiring harness last time!!! I had a hard enough time getting the manifold out...that harness doesn’t like to cooperate!!!!

And nothing metal is going anywhere near the mating surfaces!!! Just gonna use an old credit card or plastic square scraper thing that I got from The Pampered Chef. It’s for getting stuck on gunk off expensive pans w/o scratching them!

 

[rgorke]

Got it pretty clean pretty easily. There was also RTV around the TB to plenum in addition to the gasket.

One thought is that with all this RTV, does it wear out? Seems like as it ages, it’s ability to seal with temperature changes diminishes.

Wondering/thinking that just the gaskets with NO RTV is the way to go...

 

[GreyWisent]

Nice and clean! I like it. How happy is your better half that you're using her fancy pan scraper on your car though? Haha

And nothing metal is going anywhere near the mating surfaces!!!

I didn't think you'd make that mistake... just wanted to make sure that you didn't think I was suggesting that.
The credit card is a good trick; nice soft plastic.

Wondering/thinking that just the gaskets with NO RTV is the way to go...

Yes, most definitely!
Even the RTV manufactures (who have a vested interest for you to use their product as much as possible) blatantly state that you shouldn't use it everywhere and that more is not always better. You have new gaskets, so you don't need RTV. It might actually interfere with the gasket performance (if you look at your pictures, it looks like it got underneath some of the gaskets). And from the looks of it, RTV will help in ripping your gaskets if you ever take them apart again - by the added mechanical stress of separating the RTV from the gasket. And if you don't take it apart again, these new gaskets should last you until way after the RTV cracks.