01 4.0 SOHV upper intake manifold removal
 

It doesn't look anything like the illistration in my Haynes book.Where are the bolts located and how many?

4 on each side, 2 on the front port and 2 on the rear port. They are either allen head or torqx head.

They're torqx.I saw them and thought maybe they were for the lower intake.Thanks for clearing that up.I.m getting a PO300 random misfire code along with PO174B and a PO171 system lean on banks 1&2.Do I need to replace the seals on both upper and lower intakes or just the upper?
This is my 1st thread on here.I've found most of the other information I've needed searching the archives.Some good stuff thanks to people like you.Thanks again!

First, welcome to FTE!!!

Before removing your upper and/or lower intake, there is a simple test you can do to find a vacuum leak. While the engine is at an idle, spray the upper to lower intake interface with carb cleaner (or other combustable) and look for a RPM change (either increase, or decrease). Repeat this procedure with the lower intake to heads interface.....

Good luck!!

Fast answers.Love it!I'll try the carb cleaner.I've read of using propane,but that made me a bit nervous.Thanks.

Be careful with the carb cleaner also!!!!

There was no noticeable change in RPM's.Where else should I check?

That's good news, I think you verified that you don't have a vacuum leak at the manifolds, or heads!!

The next thing that will throw lean codes (on both banks) is a dirty MAF sensor. Are you running a K&N air filter by any chance? They are known to contaminate MAF sensors, and IAC valves with the dirt and oil that they pass.
Try cleaning your MAF sensor (be very careful), and reset your PCM by disconnecting the negative battery cable, and touch it to the positive cable.

Good luck!!

Thanks again and again.No K&N.Cleaned the sensor as best I could.It didn't appear too dirty but I live and work in very dusty conditions.I'll have to get the codes scanned again.Watching the grandkid while I'm trying to do this so I apologize for the spotty replies.Is there anything else I might check in the meantime?

Nothing until we hear the results of cleaning the MAF, and resetting the PCM.
Did you have a CEL (Check Engine Light) with the codes?

Yes there was a light.I don't have a scanner and won't be able to check until later in the week(Can't get out,got the grandkid still).I'll again post as soon as I get a scanner.

Check all the rubber vacuum lines - they are known to get hard and crack, which allows in unmetered air and results in lean issues.

Haven't reread the codes yet, but after cleaning the MAF ,clearing the computer, and roughly 10 starts and over 600 miles the CEL hasn't stayed on at any time.I take it this is a good sign?:)If so I bow down to you guys,if not I still appreciate everything and will let you know when rechecked.

It's the intake.. I've run into many of these that I was only able to verify by replacing the gaskets.

They tend to leak when the engine is cold, you might try the same check on a cold engine on a cold morning.

If your engine is SOHC (Single OverHead CAM) then replace both upper and lowers. There are no coolant passages in this design and once you have the upper off, the lower is a piece of cake.

If your engine is OHV/EFI (Traditional Push-rod style) then you only usually need to replace the upper.

Good luck.

I just took off my upper intake manifold this weekend (to put on the supercharger!) and I discovered that it was just starting to leak at the #1 cylinder. The upper intakes have O-rings to seal them, so I'm guessing that just re-torquing the bolts would have solved the problem. I'd definitely try that before I took the whole thing apart...