Fuel problems
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Fuel problems
I have a 1998 explorer 4.0 sohc 6 cycl. with 136K and two lean codes and a rough idol so I changed the plugs, cleaned the maf and iac and a week later noticed my gas mileage dropped to around 8-9mpg. I read alot of posts that talk about replaceing the intake gaskets, gut would that cause the loss of mpg? Also I can't seem to locate the PCV for sohc. Thanks Matt
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does anybody have an idea as to what would cause the mileage to go from 18-21 to 8-9 mpg. would the intake gasket have that effect also need help locating the pcv is it under the plastic housing on top. thanks matt
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The pcv valve is located on the backside of the engine sorta hard to find. My x has a hose coming from each side of the intake to a tee and thats where I found my pcv. I recently had my gasket and lower manifold replaced and i noticed a difference in mileage. Before i took it to the shop i was getting about 14-15 mpg after the repairs I am getting 20 mpg again. I assumed that with the gasket and manifold both leaking that my pcm was pouring gas into my engine to get the correct a/f mixture.
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Cargo Master
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From: BC Canada
you will need a set of valve cover gaskets, make sure you use high temp silicone (02 friendly only) gasket maker at the joints, Intake manifold/heads/block,
Take special attention to the junction at the rear passenger side, and the front between #1 and #4, a small bead around the water passages.
Take special attention to the junction at the rear passenger side, and the front between #1 and #4, a small bead around the water passages.
Elder User
Joined: Jul 2005
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Aquanut, this is SOHC.. it does not have water passages in the intake, nor is valve cover removal necessary. It has oring-type seals on both upper and lower pieces. Once you get the upper off the lower is pretty much a piece of cake.
Just be very careful with the bolt torque, as these parts are plastic and it is very easy to crack them by overtightening. They do not need to be very very tight, just tighten till you feel resistance, and then maybe 1/8 of a turn further to seat the seals.
You'll notice the new seals are much thicker and durable than the old ones, which will likely be pressed flat against the grooves in the intake assemblies. A small pick or very small flathead screwdriver will help you get them out.
Gasket sealant is not necessary, nor is it recommended.
Just be very careful with the bolt torque, as these parts are plastic and it is very easy to crack them by overtightening. They do not need to be very very tight, just tighten till you feel resistance, and then maybe 1/8 of a turn further to seat the seals.
You'll notice the new seals are much thicker and durable than the old ones, which will likely be pressed flat against the grooves in the intake assemblies. A small pick or very small flathead screwdriver will help you get them out.
Gasket sealant is not necessary, nor is it recommended.