Intake Manifold Gaskets - P0171-P0174

[Bigg_billy]

Felpro, but three rubber gaskets are three rubber gaskets...and they are genuine Ford parts.

 

[Bigg_billy]

Well I finally replaced the intake plenum gaskets today. It went pretty much as was laid out in this thread:

http://www.explorerforum.com/forums/showthread.php?p=1555157


except the thread was for OHC. On the push rod engine you have to disconnect the EGR, tube to plenum mount, and the dipstick support bolt in order to get it out. Not a bad job as they go, took about 4.5 hours start to finish.

Bill

 

[DonLuc]

I followed the instructions in that thread as well, then realized after I completed all the steps that the plenum still wouldn't come off due to the EGR tube and the dipstick bracket. Is there any chance of the dipstick tube coming off after removing the bracket? Everything else was straightforward, I just didn't want to pull it out and then have to start fishing around to get it back in...

I was also curious as I ordered the Intake Manifold Gasket set for my '99 ohv and included was a 1-piece paper gasket and the 3 double o-ring seals. Someone told me I could use them either/or, but I don't think he was right. The paper gasket is for the lower intake manifold, right?

 

[Bigg_billy]

Don, I don't know about the paper gasket. What I did was to loosen the EGR valve and pull it toward the fender well about a half inch so I could get a deep socket down behind to loosen the dip stick support nut. Then bend the tab up to expose the rest of the nutted stud beneath. Once you get the stud out the plenum will lift up and off. You will also have to remove the serpentine belt and the four bolts that hold the compressor on so you can lift the compressor about an inch so that the bottom of that EGR tube will clear to come out. Once out, I too wondered about getting the EGR tube out of the plenum, but it did not easily happen so I didn't bother looking deeper. I imagine it is some sort of snap fit but I didn't want to break anything. I will tell you what a difference the repair made in the running and shifting of the car. I couldn't believe it. I could see it had been leaking fuel past the gaskets for quite a while as the lower intake manifold was quite caked and stained with fuel. This EGR business made the job a lot harder than described in the thread, but now with this info you should be set.

Bill

 

[DonLuc]

Thanks for the info!

I got quite familiar with the procedure the first time. I got all the way down to the nut/bolt holding the dipstick bracket on and I was afraid I'd pull the tube out and have to put it back in and I wasn't sure how I was going to do that. Hopefully, the 2nd time around will be a breeze!

 

[Bigg_billy]

Just take off the nut, reach down with your finger or a screwdriver and bend the tab up off the stud, then you can get at the nutted stud below. Forgot to mention earlier, use antiseize when you put it all back together.

Bill

 

[masospaghetti]

If you have a plastic upper plenum, I think the paper gasket goes under the fuel rail only, and the o-rings go from the upper plenum to the fuel rail. the 94- and earlier explorers with an aluminum plenum use a paper gasket instead of the o-rings.

 

[mizestang]

Thanks for the info!

I got quite familiar with the procedure the first time. I got all the way down to the nut/bolt holding the dipstick bracket on and I was afraid I'd pull the tube out and have to put it back in and I wasn't sure how I was going to do that. Hopefully, the 2nd time around will be a breeze!

Hey Don, did changing the upper gasket take care of the p0171 & p0174 codes?

 

[maxerious]

ya I now have the same prob so i am gonna replace the uppers to as the first step as i figure ican check out all the vacum line while i am in there more closey i will let you guys know in a week or 2 if it solved th prob prob will dig into it next week sometime

 

[mizestang]

ya I now have the same prob so i am gonna replace the uppers to as the first step as i figure ican check out all the vacum line while i am in there more closey i will let you guys know in a week or 2 if it solved th prob prob will dig into it next week sometime

Changing the upper did not work for me. CEL came on after one day. Now I have to do it all over and change the lowers.

 

[maxerious]

oh god dont tell me that

 

[mizestang]

oh god dont tell me that

I changed the lowers and that took care of the problem. And it was WAY easy to do. I did the whole job in 1 hour. Only thing you need to remember is when torqing down the lower intake bolts, the torq specs are IN-LB, not FT-LBS!!! Found that out the hard way. I broke a bolt off. I didn't think 107 ft lbs was normal when I started torqing, especially on plastic, but it was one of those DOH! days. Anyways, I had the whole thing sealed already, so I just filled the hole with Hi temp RTV. CEL hasn't come on since. Now I have to figure out how to get 20 mpg. Thanks to all that helped.

 

[96XLTRanger]

how important is it to torque? i dont have a torque wrench/gauge and i usually just tighten until it gets too hard and then i use a cheater bar and do 1/4th of a turn.

 

[dogfriend]

how important is it to torque? i dont have a torque wrench/gauge and i usually just tighten until it gets too hard and then i use a cheater bar and do 1/4th of a turn.

If you don't torque enough, the bolts can loosen and eventually you will get leaks. If you torque too much, you risk snapping off the stud or bolt (see the post above yours).

The reason to torque is to try to get the same amount of clamping force (bolt stretch) at all the fasteners so that you won't get a weak area that could potentially leak later.

 

[mgreen6712]

I just finished replacing my upper and lower intake manifold gaskets. This was my first time. It wasn't that bad. I kinda knew what to look for and what to do simply by reading alot of threads here. The pics from Mikeh really helped. Thank you for posting those and your detailed instructions. Considering my working conditions it went pretty smooth. When I finished my Explorer sounds like a dream. Runs like new. It took me about 4 hours or so. If you don't count the time looking for a working flashlight. My 4 year old mechanic kept me pretty busy to. He had to come out and help me alot. I hope anyone doing this has the same results I do. Good Luck.

 

[dean1997sport]

Question

I know this thread is kinda old but I was wondering if the lower (fuel rail) is held down by the studs? I might have to do this I have the same codes and I am looking for a vacuum leak but cant seem to find one. So the whole thing is in 3 pieces? the plenum, the fuel rail and the manifold that goes between the heads? The o-rings on the plenum need to changed and the gasket under the fuel rail?

Thanks! BTW I have a 97' explorer

Dean

 

[dean1997sport]

any one?

 

[CaymanGreen]

Go here: http://www.explorerforum.com/forums/showthread.php?t=171819

 

[wow97]

Same thing happen to my i change the upper intake gasket and lower intake gasket and cnange all three oxygen senor full tune up somebody change maf sensor before i bought it and put new fuel evap with new fuel evap lines reset check engine light drove philly pa with brooklny n.y.c to see my cousin it run perfect for one week then bang the check engine light again i check fuel pressure 30 p.s.i i said what the ####

 

[I need to know]

hello

I have a 1996 ford Explorer Engine 4.0 Its given cods p0171 p0174 what do Ido to fix it.