Gathering information for replacing my intake manifold gaskets soon.
Reading through the archives, some recommend to put gaskets on dry, some recommend grease, and some recommend sealant. ROM doesn’t mention anything.
Well, which is it?
I’m using the one piece gaskets that are now sold, blue/green on one side, black on the other.
Thanks!
I think I’d use some sort of gasket dressing. The optimum stuff is apparently some black stuff sold at Toyota dealers. Seals well, but when it comes time to disassemble you can just peel it off and throw it away.
Remember that some suggest cutting those one-piece gaskets into two pieces, removing the center section between 3 and 4 for a cleaner vee.
Gasket dressing…what does that mean? Are we talking RTV silicone? And apply both sides of gasket? I think i see that Toyota stuff, may be worth a try. But i’ve never put sealant on intake manifold gaskets before, is this a Jaguar V12 thing?
Yeah, i keep reading that, about cutting gasket in half, but why? I don’t see how that makes vee cleaner. I guess when i put new gasket on head, ill see where to cut?
You also advise taking both manifolds off together, with fuel rail attached. First of all, is that a two person job? Not just the weight, but i assume lifting it wrong could put a lot of stress on fuel rail?
BTW, on my Volvos, they sell a special thick fiberglass/plastic intake manifold gasket/seal, claim it keeps the intake manifold much cooler by not transferring heat as much from head, so cooler air intake. Gimmick?!
My Mercedes 190E has a thick fibreglass intake manifold gasket installed by the factory… There must be a reason.
The intake manifold gaskets for the V12 have changed design several times. The earliest ones were metal, 12 separate pieces with a raised ridge. Replaced by 12 separate pieces that were thick cardboard. Under Ford ownership went to the 2-piece gaskets, not sure why, they’re certainly more expensive to make than the 12 identical pieces.
Remember, when it’s all together, the entire manifold, throttle body, and air filter housing is all hanging off the joint with this gasket in it. Amazes me that it seals as well as it does.
Be sure to retorque the nuts a couple of times after it’s back together and has been run a few times.
The AJ6 has a thick plastic(?) spacer on the inlet so I’d say more function that form.
Gasket dressing…what does that mean? Are we talking RTV silicone? And apply both sides of gasket? I think i see that Toyota stuff, may be worth a try. But i’ve never put sealant on intake manifold gaskets before, is this a Jaguar V12 thing?
Gasket dressing and sealants (like RTV, silicone, etc) are different. As Kirbert noted, ‘dressings’ are designed not to solidify or cure. They’re tacky, they help ensure the gasket doesn’t move while you’re lining up and assembling parts, they remain compliant which helps with the dis-similar rates of thermal expansion or relative motion across the gasketed joint. If you’ve ever worked with tappered threaded pipe, liquid pipe sealant (or “pipe dope”) is similar in that it is not mean to harden or cure.`
I don’t have any experience with the Toyota gasket product, but I’m curious about it now and may track some down. The classic “gasket dressing” is Gasgacinch 440-A. As the name implies, it ‘cinches the gasket.’ It appears that Edlebrock sells a branded version, too. This stuff has the appearance and performance of rubber cement. The odor is similar, if somewhat stronger, too. Seems like it is rubber cement that has been chemically stabilized for use with most automotive fluids.
As for using gasket dressings, I’m sure this varies by product. The Gasgacinch product is applied to both sides of the gasket and the parts that the gasket touches, and then allowed to dry for several minutes. Once it’s is dry, it becomes a sticky film that can be rubbed off the gasket or the part, if necessary. The gasket and parts are assembled as normal from there.
If the joint needs to be taken apart, the gasket should peal right off (thanks to the dressing) and any residual dressing can be removed easily, too.
Anyway, that’s what gasket dressing is and how it is supposed to work. They are certainly not ‘just a Jaguar V12 thing’ but as we all know this engines require employing all of the Dark Arts to get and keep them running.
As for intake manifold gaskets: I used the 12 individual gaskets made by Cometic. I did apply Gasgacinch to the intake ports, the manifold flange, and both sides of the gasket. Unfortunately, I haven’t run the engine yet, so I can’t tell you if this worked…but it seemed to.
Hope something here was helpful. Good luck!
-Drew
Thanks, it does help. I’ve now read about the Edlebrock Gasgacinch, and it says designed for intake manifolds (can’t handle oil or gasoline). It also says to apply to gasket surface and metal only on head side. Nothing about intake manifold side. So it sounds more like something that will keep the gasket from moving when installing, and to make sure the gasket doesn’t get cooked onto the head (thus hard to remove). I guess the intake manifold side doesn’t see such high temperatures, so i may just do what they say and apply it on head side. It doesn’t seem like a sealant of any kind.
Greg
As Kirby suggested taking out both manifolds at once is my recommendation as well. There is some flexibility of the fuel injector hoses So I would not worry too much about some slight flexing of the manifold assembly. ( have the wife help you ) You can see a picture of me removing and holding both intake manifolds joined by the fuel rail. I was a lot younger and stronger. Note that the fuel rail is my custom design, but you get the Point.
I don’t understand the reasoning of this. Berny, your link suggests using your method, you don’t have to replace the injector seals. Those seals must be the least expensive part on a V12 engine to replace. And I would suggest the seals be replaced anyway to avoid vacuum leaks. Help me out here ?
SD Faircloth www.jaguarfuelinjectorservice.com
Regarding intake manifold nuts/studs, i’ll be redoing my half-ass job when I first got the car and plugged up the air pump holes. I’m going with the 1/4" x 3/4" pin anchors as described in Kirby’s book.
Since I won’t need the two hole braces/washers anymore, I was going to buy stainless steel washers and new stainless steel nuts while at it. Because some say one washer may not be thick enough to provide enough ‘bite’, I’ll double up on the washers and also put a stainless steel locknut.
The originals were those grooved kind of lock washers. Will a standard lockwasher be fine?
Kirby,
I think this may be the Toyota product you mentioned. It came highly recommended by a local mechanic. I used it on a few of my recent Jaguar projects but it is too early for me to judge its performance. I purchased it at a local Toyota dealetship parts department.
Paul
Looks like the perfect seal to use on my oil pan gasket this fall? Will be nice knowing my Jaguar has a little bit of Toyota technology in it! 
Get the ‘cometic’ intake manifold gaskets. They are thicker and are designed to compress with minimum pressure creating a better seal vs a paper gasket. They work extremely well and I have used them a few times now without any liquid sealant.
The Toyota stuff looks very interesting if you google for it. I can’t link to it directly, but I came up with this post from forum.ih8mud.com
FIPG stands for Form In Place Gasket, and it works well. Another name in Toyota literature is Seal Packing, and the manufacturer is Three Bond. There are actually 4 common types, with some variances in availability.
The most common is black in color, and is used for sealing against oil (oil pans, timing covers, etc.) Its counterpart is gray in color, and until recently, was usually only found on factory assembled engines. With the advent of our Subaru engine in the FR-S, we’ve had to find a source for it, since these engines won’t seal with the commonly available black FIPG.
There is another black FIPG, but this one is supposed to work with Long Life & Super Long Life Coolant. A lot of techs I know don’t differentiate between the two, but use the one intended for oil on everything. Knowing the difference, there are certain portions of some timing covers, and few of our water pumps, that require this seal packing.
The fourth type should be familiar to MUD users as the orange one. It is designed to be used with transmission fluid & gear oil, so manual transmissions, transfer cases, & differentials are all places you will find this FIPG.
For me they only reason to take the manifolds off as a unit was less work. ( smile)
Greg,
I first used the Toyota FIPG sealant on the camshaft cover gaskets of the 4.2L XK engine in my 1984 XJ6 Vanden Plas about a year ago after I did an engine swap in that car. It seemed to work well (no leaks) over a few months of driving, but I sold that car and I won’t be able to see how it performs over time. I used the FIPG last week on the camshaft cover gaskets of the freshly rebuilt 3.4L XK engine from my 1957 MK VIII. I am building up that engine on my engine test stand for some live running outside the car before I install it sometinw in the fall. So although the FIPG looks good, I have no idea if it is any good in these applications yet.
Paul
I clearly misremembered that cutting up the gaskets idea. Looking at the photos of the manifolds Bernard provided, it would evidently make more sense to cut each gasket into five pieces, leaving 3 and 4 together as one piece.
You are talking preHE, correct? Bernards was a 70s XJS.
