How to replace upper intake manifold gaskets | Ford Explorer Forums - Serious Explorations

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How to replace upper intake manifold gaskets

KaiserM715

Well-Known Member
Joined
October 13, 2005
Messages
179
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City, State
Houston, Texas
Year, Model & Trim Level
'10 Ford Raptor
I had to replace my upper intake manifold gaskets to fix a vacuum leak that was giving me two engine error codes (P0171 Bank 1 lean and P0174 Bank 2 lean). I have a 2000 Ranger with a 4.0L OHV V6 with the plastic upper intake manifold. I was able to diagnose it as a vacuum leak with help from an engine computer scanner, a few other on vehicle checks and help from other forum members (of course!!). A vacuum leak in this location is a common ailment for these engines.
Here are the supplies / tools that I used:

Fel-Pro plenum gasket kit
--Part No: MS90732, $21.99 at O’Reilly Auto Parts
Blue shop towels
In-lb torque wrench
External torx socket set
Silicone grease
O-ring pick
Various wrenches sockets, extensions, etc.
Channel lock pliers
Flat blade screwdriver

Things to remember:
-Disconnect the battery. Several electrical connectors will be disconnected and reconnected throughout this procedure. In addition, your computer will need to be reset so it can recalibrate without the vacuum leak.
-Don’t force electrical connectors when you disconnect or reconnect them. Most have a catch on them that has to be depressed or slightly pried up to get the connector apart. You don’t want to have to add replacing electrical connectors on your to-do list ;)

The next three steps can be performed in any order, but this is the order I did them in.

Next, from left to right in the picture below, disconnect the vacuum line to the throttle body, the connector to the throttle position sensor (TPS), the connector to the idle air controller (IAC), the vacuum line from the PCV valve, the accessory vacuum line and then the vacuum line to the brake booster (you will have to use the pliers to squeeze the hose clamp together to remove the hose). Remove the wiring harness plug from the support attached to the intake (blue circle) and remove the wiring harness support (green circle).
disconnects.jpg


Remove the plastic cover over the throttle body connection to the throttle and cruise control cables. The throttle cable is shown with the red spring and connector. The cruise control cable is black with the red cap. Next, loosen the hose clamp from the intake air tube to the throttle body and disconnect the tube. The cables attach using a ball and socket type setup (green circle in the pic). Use a flat blade screwdriver to gently pry the cables (socket) off of the throttle body (ball). Remove the cruise control cable from the upper intake (blue circle) and then from the throttle cable. To remove it from the throttle cable, pry it up and then off of the pin on the end of the throttle cable (red circle). Remove the throttle cable from the intake. Route both cables out of the way.
throttle_cable.jpg


I removed the spark plug wires going to cylinders 4-6 (driver’s side) as the wires are threaded through the intake. I disconnected the wire at the spark plug first, then at the coil pack (circled in the photo below) and pulled the spark plug end through the manifold. Remove the four screws that attach the coil pack to the upper intake. Remove the wiring support for the coil pack from the intake (green circle). Go easy on it, I broke mine in the process :(. Lift off the coil pack and set it aside. I set mine on the passenger side valve cover (refer to the next pic).
plug_wires.jpg


Remove the six nuts that hold down the upper intake. Lift the upper intake up and off of the six studs attached to the fuel rail / lower intake. At this point any connections you forgot will become obvious J.
upper_off.jpg


I set the intake on my work bench upside down to replace the gaskets. I am pointing at one of them with my pocket screwdriver. I used a pick to pull the old ones out.
intake_out.jpg


The old gaskets had hardened considerably and were flush with the sealing surface of the upper intake. I can see how this would cause a vacuum leak.
old.jpg


The new gaskets were significantly more pliable and you can see that they protrude below the sealing surface.
new.jpg


I stuffed shop towels in the intake runners of the lower intake (to keep crud from falling in) and cleaned the sealing surface of the fuel rail / lower intake.
clean.jpg


I checked the torque on the intake studs using the Ford manual. This is where you need the external Torx sockets and the torque wrench.
intake_studs.jpg


Remove the shop towels and lower the intake down over the studs. Tighten the nuts in the order shown below. I used the e-Torx socket to hold the stud and a crow’s foot to tighten the nut.
intake_nuts.jpg


From here on reassembly is the reverse of disassembly. I used the silicone grease on the connectors for the spark plug wires as well as the socket where the throttle cable connects to the throttle body. Double check all of your wiring and vacuum hose connections, reconnect the battery and then start ‘er up!!
 



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I was looking for my intake gaskets and realized that there are two gasket sets.
96-97 have no lower gasket?

Perhaps the upper gaskets would be identical in both sets.

90733 is compatible with 96-97 4.0.
Fel-Pro ms90733 Upper Manifold Gasket Set $3.99
http://www.amazon.com/Fel-Pro-MS907...id=1165446902/ref=sr_11_1/103-3345349-4837412

90732 is compatible with 98-2000 4.0.
Fel-Pro ms90732 Upper and Lower Manifold Gasket Set $18.77
http://www.amazon.com/Fel-Pro-MS907...id=1165446929/ref=sr_11_1/103-3345349-4837412
 






Good work
 






Excellent write-up and pics to fix a very common problem.
 


















I have the same codes as yours, but its on a 2000 explorer sport with a sohc.
My question: As to the procedures described to repair the problem on your ohv... would they be the same (with standing the physical differences between the ohv verses the sohc) as to repairing my sohc?
My vehicle, when COLD won't ideal by itself (I have to keep reving it to keep it from stalling), but when it has warmed up, it runs perfect.
Any and all help and or suggestions are greatly appreciated.
TeddyB
 












Teddy-
Having never worked on the SOHC, I cannot really say what the differences would be. One thing to try is search on this site for the download site for the Ford service manual. It should cover the replacement of these gaskets. Also, you mentioned an idle problem. For my situation the leak was just enough to trip the MIL (malfunction indicator light), but not enough to affect drivability or idle. I would agree with BB's assessment to check the IAC. It may simply require cleaning (search the site for how to clean) or may need replacement.
 












Great post, but missing info for those with EGR valve(mine is a '97). - Luckily, I had my Haynes handy... A metal hose runs from the intake to the left side manfold. It is a little difficult to remove the dipstick tube to get the bolt holding the EGR hose. You have to twist the hose as you are lifting to clear the air conditioner line.
Add 13MM deep well and a 10MM sockets to the list of tools needed for this. And, watch you don't lose the EGR gasket when you remove. I found mine on the garage floor after I pulled out:eek:
 






I was looking for my intake gaskets and realized that there are two gasket sets.
96-97 have no lower gasket?
Well, my '97 has a lower gasket(under the fuel rail), and it was bad. There was a tear in the silicon ring for Cyl. #4.

attachment.php


Had to get the 90732 gasket set for the '98. The new Felpro did not have the silicon bead like the original.
After doing this for the second time due to problems not solved, you may want to go to the next step and remove the 6 studs that hold the fuel rail, replace the gasket, and the o-rings on the injectors. Haynes says to gently rock the rail back and forth... This took some hard rockin' and about 15 minutes...

attachment.php


The injectors should read around 14-19 ohms across the terminals (mine were all ~15.7 ohms). The one on the left was bad and measured 1.3ohms. Looking at the bottom, it was tan (carbon build-up). Some of the others looked like the one on the right - you can see where the dirt seeped past the o-ring and built up on the plastic flange around the tip. I also spent a lot of time cleaning carbon buildup on the fuel rail and the intake runners - upper and lower.
After installing the new lower gasket - check your book for the torque rating for these studs, as it differs depending on the year. Torque them to spec and wait a half hour or so and check it again. The gasket will settle.

cyl1leak.jpg


inj2.jpg
 






Great write-up, I'm getting ready to change the gaskets on my Ranger but this time i'm doing it myself this time. Last time it was done was about 2 yrs. ago...seems a bit soon to change them out again but it is what it is. The CEL came on yesterday and got it checked with a scanner and got lean codes on both banks. I've still got to confirm it's a vacuum leak but i'm pretty sure that's what it is.

Got a couple questions for you guys:

Kaiser (and anyone else who wants to answer)
I noticed in your pics that there was some crud on the intake plenum. Do you use stock paper air filters or an oiled type filter like K&N, KKM, etc.? Just curious to hear if the crud is a result of the oil from the filter.

Daves97sport,
you said one of your injectors was bad because of carbon build up. Did you end up replacing it or just clean it up and all was good?
 






yeah i got this problem

Ive fixed the leak twicxe now it still keeps ####ing up. first time i just did the rubber seals on the top, second time i did the papper one under the fuel rail. after i did the lowwer one under the fuel rail all was good for a few months now its back to the same problem and i can hear the whistel when i excellerat again. so what i was gonna do is take the 1st get intake manifold and put that in along with the fuel rail that is on the 1st gen model and see what happens , i know the only differance is the its aluminum, and uses papper gaskest top and bottem of the fuel rail. but just maybe it lines up better and will not kill gaskets every two months.

I mean do you ever hear people with 1st gens complain about this?
 






Kaiser (and anyone else who wants to answer)
I noticed in your pics that there was some crud on the intake plenum. Do you use stock paper air filters or an oiled type filter like K&N, KKM, etc.? Just curious to hear if the crud is a result of the oil from the filter.

I am glad the write-up has been helpful for folks. Dave, thanks for the addition of the info on the injectors and EGR. The Fel-Pro gasket that came with the set that I bought (I did not replace the gasket in between the fuel rail and the lower intake) did come with the silicone bead on it. It is interesting that there are two different styles.

DB_1, I use a K&N style filter, but the crud is from oil vapor from the PCV valve. I actually had a small pool of motor oil settled in the upper intake.
 






Uppper and lower intake manifold gasket replacement

This is a special thanks to Kaiserm715.

My son Adam, did most ( if not all) of my job but we went by Kasiers instructions on my 1999 Ford Explorer 4L SOHC. very similar. bottom had 12 torx bolts (broke one on re-assembly) top had 8 bolt.

I took a few hours had to drive 50+ miles to get bolt replacment but well worth the trip. New plugs also, cleaned iac and MAF and used the Sea foam
treament. 188,000 mile and it purrs like a happy kitten.

Again Thanks you to Adam and KaiserM715.

Jack125
 






Kaiser,
what is the size of the external Torx socket to be used? I was going to buy a set but the smallest one in the set was an E-6. I thought that one would work but I wanted to make sure first before I bought the set.

So, I went to buy the gasket set at AutoZone and didn't realize 'til I got home that I got gaskets for a 4 cyl. motor not a 4.0L motor:rolleyes:...morons. I should've checked it before I left the store. Anyways, returned the gasket set and asked the guy for the correct set and he brought up a set that ran $94.99:eek: I then gave him the p/n Kaiser used on his Ranger since I knew our motors are the same but I had to order it as they were out of stock.
 






Daves97sport,
you said one of your injectors was bad because of carbon build up.
I stated there was carbon buildup on the injector that was bad - measured 1.3 ohms & misfire code with CEL.
You always read about how to read your plugs to diagnose problems. When I replaced the plugs, I lined them up in order to compare them. Cyl 1 plug (with above injector) was black. Cyl 4 & 6 plugs were white - injector on the right in above picture was the #4, and 6 was similar. If you look at the bottom of the injector, these 2 were not bright and shiny, as were the 3 other cylinders, which had nice tan colored plugs.
184baller:
second time i did the papper one under the fuel rail. after i did the lowwer one under the fuel rail all was good for a few months now its back to the same problem
Did you torque the studs properly - to the torque for your year? My '97 listed a range from 100something to 141 INCH/POUNDS (not ft/lbs). For the thick paper, you should step the torque - I started with 80 in/lbs, 120, then 140. After I let it settle for a half hour or so while I cleaned the runners of the upper intake, I went back over at 140 in/lbs, and each stud did turn another 1/6 to 1/4 turn. I waited more time, but this didn't make any difference.
 






manifold gasket replacement

Ranger,

I got OEM gaskets for the upper and lower intake for about $24.
at a dealer.

The broken bold cost 1.75. so about 25 buck for the job.

good luck,

Jack125
 



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Kaiser,
what is the size of the external Torx socket to be used? I was going to buy a set but the smallest one in the set was an E-6. I thought that one would work but I wanted to make sure first before I bought the set.

The size that worked on my truck was an E-7 (it sounds like you are looking at the same set I have). Sorry for the long delay, I had to actually check to see which size it was.
 






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