Lower Intake Gasket question
Thread Starter
|
New User
Joined: Aug 2019
Posts: 3
Likes: 0
Lower Intake Gasket question
Trying to find out what is the best lower intake gasket to use on my 94 Ford Explorer 4.0L ; Ford OEM F5TZ-9439-A (one-piece) , FelPro-MS-94682 (one-piece), or FelPro-MS-90728 (two-piece) ? I have both FelPro gaskets and both require RTV (included) to bridge between cylinder heads. Noticed that the Ford OEM gasket has no metal/rubber support around coolant ports; as the FelPro MS-94682 uses and Ford does not recommend the use of RTV on the OEM rubber except the step between the heads and block. The reason for leakage on most 4.0L is the manifold and block scrub the intake gasket , resulting in coolant leaks , due to the low torque specs of the intake bolts?
Posting Guru
Joined: Apr 2000
Posts: 1,746
Likes: 4
From: PNW
It's hard to say what the best is. I used the multi-piece Fel Pro 90728 (well, I bought the kit that included valve cover gaskets so it was a different part number) on two 4.0s. One was on my '95 Aerostar, which worked fine until its untimely demise just 35k miles later when it was totaled. The other application was my '98 Explorer. The Explorer has been going about 50k miles since the intake gasket was changed and all is well.
I've also used the multi-piece Fel Pro intake gasket on my 3.0 Aerostar, which worked well for about 50k miles before it, too, was totaled.
I never had any noticeable coolant leaks with the factory intake gasket and no noticeable air leaks, either. The reason for changing the 4.0 Aerostar gasket was because I installed new heads at around 90k miles. The 3.0 Aerostar and the 4.0 Explorer both leaked oil where the intake mated with the block on the back side of the engine. The 3.0 Aerostar had about 110k miles on it when I changed it and 157k on the 4.0 Explorer. I bought the Explorer with 157k so who knows how long it had been leaking before then. It wasn't terrible but enough to make me want to change the gasket (and clean the injectors while I was in there).
I've also used the multi-piece Fel Pro intake gasket on my 3.0 Aerostar, which worked well for about 50k miles before it, too, was totaled.
I never had any noticeable coolant leaks with the factory intake gasket and no noticeable air leaks, either. The reason for changing the 4.0 Aerostar gasket was because I installed new heads at around 90k miles. The 3.0 Aerostar and the 4.0 Explorer both leaked oil where the intake mated with the block on the back side of the engine. The 3.0 Aerostar had about 110k miles on it when I changed it and 157k on the 4.0 Explorer. I bought the Explorer with 157k so who knows how long it had been leaking before then. It wasn't terrible but enough to make me want to change the gasket (and clean the injectors while I was in there).
Thread Starter
|
New User
Joined: Aug 2019
Posts: 3
Likes: 0
It's hard to say what the best is. I used the multi-piece Fel Pro 90728 (well, I bought the kit that included valve cover gaskets so it was a different part number) on two 4.0s. One was on my '95 Aerostar, which worked fine until its untimely demise just 35k miles later when it was totaled. The other application was my '98 Explorer. The Explorer has been going about 50k miles since the intake gasket was changed and all is well.
I've also used the multi-piece Fel Pro intake gasket on my 3.0 Aerostar, which worked well for about 50k miles before it, too, was totaled.
I never had any noticeable coolant leaks with the factory intake gasket and no noticeable air leaks, either. The reason for changing the 4.0 Aerostar gasket was because I installed new heads at around 90k miles. The 3.0 Aerostar and the 4.0 Explorer both leaked oil where the intake mated with the block on the back side of the engine. The 3.0 Aerostar had about 110k miles on it when I changed it and 157k on the 4.0 Explorer. I bought the Explorer with 157k so who knows how long it had been leaking before then. It wasn't terrible but enough to make me want to change the gasket (and clean the injectors while I was in there).
I've also used the multi-piece Fel Pro intake gasket on my 3.0 Aerostar, which worked well for about 50k miles before it, too, was totaled.
I never had any noticeable coolant leaks with the factory intake gasket and no noticeable air leaks, either. The reason for changing the 4.0 Aerostar gasket was because I installed new heads at around 90k miles. The 3.0 Aerostar and the 4.0 Explorer both leaked oil where the intake mated with the block on the back side of the engine. The 3.0 Aerostar had about 110k miles on it when I changed it and 157k on the 4.0 Explorer. I bought the Explorer with 157k so who knows how long it had been leaking before then. It wasn't terrible but enough to make me want to change the gasket (and clean the injectors while I was in there).
Posting Guru
Joined: Apr 2000
Posts: 1,746
Likes: 4
From: PNW
If I remember correctly, I used the RTV that was included in the kit. In terms of how much, I did what the manual or included instructions recommended. I don't have the documentation in front of me, but I think it was about a pea-sized or slightly larger blob at the intake corners and where the valve cover meets the intake manifold/head joint. You'll need to tighten the intake manifold bolts in the proper sequence, too.
I also let the RTV cure for a day before firing up the engine. I have spares in my fleet so I can afford to have a car/truck down for a day. I'm a little paranoid about the goop.
I also let the RTV cure for a day before firing up the engine. I have spares in my fleet so I can afford to have a car/truck down for a day. I'm a little paranoid about the goop.
Thread
Thread Starter
Forum
Replies
Last Post
monsterbaby
1983 - 2012 Ranger & B-Series
19
Jun 6, 2012 07:55 PM
chrisPi
Explorer, Sport Trac, Mountaineer & Aviator
3
May 27, 2012 09:05 PM
