Hey all,
I'm about to tackle the infamous intake manifold gasket replacement. My plan is to do both upper and lower intake gaskets. Since I haven't done this before, I was looking for some input on this project.

How long will this take? I'm fairly mechanically inclined (brake jobs, suspension swaps, etc) What do I need to remove? etc?

For reference, I've got a 2000 Explorer with the V6 OHV (pushrod?) engine.

thanks

 

I have a Gen1 Explorer and I've had the top end apart several times so I can pass on information on the Gen1 trucks. I don't know how this translates to the 2000 but I'm sure the basics are the same.

First though, why do you want to replace these gaskets?

 

I'm getting the famous p0171 and p0174 codes. I've already cleaned the MAF (twice) and replaced the O2 sensor on the passenger bank (it was shot). I've also tighten down the intake manifold bolts. Which made the codes go away for a couple months. But now their back. So, I'm fairly certain it's the o-rings.

Either way, the rtuck has 150K miles on it. It probably won't hurt to replace these anyways.

BTW, what torque do I use for the intake manifold bolts?

thanks for your help

 

I've done this a couple times now. IMHO if you have P0171 & P0174 it's one of the first places to look. Your other comment that you've tightened them down and it helped, only for the problem to return later indicates that you've got it nailed.

You can search for my earlier posts under my username to get a more complete lowdown but as somebody who is fairly adept at brakes & suspension there is nothing there that should frighten you off.

Start with the plastic engine cover, then remove the IAC and work methodically down the the engine. If you drop any bolts down into the manifolds you can retrieve them with one of those magnetic gizmos. Make sure you get to all the bolts (not as stupid as it sounds, trust me; some are well hidden under vac. pipes and plug wires etc).
Gently bump up on the upper manifold front with the *flat* of your hand to pop the EGR tube out. Don't hit it with anything whatever you do!

Assembly is the opposite of removal. My torque wrench was set to the correct figures the first time around (don't remember what they were) but it developed leaks within a year and needed re-doing. The second time I set my ordinary wrench to "a good nip" and it's been fine ever since :-)

 

Like Gil l've only done it on the early (91 and 92) Explorers. I suggest you buy a Hayne's manual as the process is a bit complicated. Judging from my new Hayne's manual (goes up to 2001) the main difference is the torque specs:

Four steps to torque the intake manifold nuts/bolts:

1999 and later:

27 in-lbs
89 in-lbs
10 ft-lbs
12 ft-lbs

the sequence is as follows:

standing in front of the Explorer with number 1 being on your right in the very front

3,5,7,2
X
1,6,8,4

The "X" would be you

That translates to: front right first, back opposite corner next, other front (left) bolt, other opposite back corner bolt, then the second front left bolt, the opposite bolt, the third from the front on the left, and the opposite.

Make sure you get some good quality gasket silicone that's made for this purpose and put an adequate amount on the corners and a thin bead on the water jackets seals.

They say to retorque the bolts after it's set up but it beats the hell out of me how you are supposed to do that after you put it all back together.

The first time I did it it took me about 4 days working a few hours a day. I have average car mechanical skills. The second time I did it it took most of one day (if I recall correctly).

Both of mine needed to be replaced with similar mileage to what you have but I thought they fixed the problem before your Explorer was made. But I suppose any gasket will fail after enough hours on the engine.

 

I saved time and money went to the dealer. $150.00 and the job was done and I picked it up the same day I dropped it off. It was worth it to me just to have a dealer that I trust do it.

 

$150 is great. I figured the Ford dealer would get $600-$800 for all the stuff they have to take off. I paid around $50 just for the new gasket.

It seems like every time I've taken it to the dealer they found more wrong with it than it is worth.

 

Well the dealer I go to is very honest with me. They have always be right upfront with what they were doing and why they were doing it. When they told me that my gaskets had to be replaced the told me that it wouldn't take that long. They were able to have my explorer back to me the same day for around $150.00 and change. You have to find that dealer near you that you can trust. My explorer after 135,000 miles at this dealer still runs great.

 

I have my manifold off right now. Last night I took about 2 hours to scrape the carbon out and soaked it in engine bright. Then took it to the car wash and blasted hot water through out. It looks nice and clean now and ready to go back on. Question: why does the back of the heads have a water outlet to go to the manifold? The manifold side is capped off. This is why I am changing gaskets due to anti freeze leak. Plus terrible pinging in warm weather.

 

Now that we know why (and it seems logical) we'll go back to your original question. Getting the manifolds off is not too difficult. You have to remove a lot of simple crap to get to the manifold. About two hours as mentioned. A/C lines are a bit of a pain. EGR can be stubborn too depending on how you seperate it (see previous post in the thread).

The upper is fairly easy and the gasket is cheap. The lower is a little more difficult as you will need to remove the valve covers. The lower gasket is relatively cheap too (more than the upper) but the valve cover gaskets are a little more expensive.

Add another hour or two for the lower.

As one of the posters suggested a Haynes Manual is the best $20.00 you can spend if your going to start doing your own work (Vol. 36024 is the 1991 - 2001 version).

Good luck!