"It's not a tumah!" or the IAC, or anything else I can find

[rhinodep]

Hi all,

I've become pretty adept at searching these threads and finding answers to just about anything I have going on. For my current problem though, I haven't been able to nail it down by searching.

I know there are tons of threads about rough idle, but none of them have told me exactly what I need to know to get on this.

My '97 5.0 is not only idling rough/stalling at start-up, but there is a very loud vacuum noise coming from under the upper intake manifold. My CEL is on. I would take this somewhere and have the code analyzed, but it won't stay started long enough.

The noise is coming from under the drivers side of the upper intake manifold, about half-way back. This is the opposite side of the engine from the IAC that so many people have problems with. I was chasing vacuum leaks with a can of carb cleaner (being careful!) when I finally was able to pinpoint the location of the sound. Shooting cleaner up under the manifold immediately causes RPMs to shoot up.

I suspect that either an injector o-ring has gone bad, or my upper manifold gaskets have gone seriously bad. My biggest problem is figuring out how to get the upper intake manifold off. Looks like I'd have to take half the engine out.

I've done a lot of stuff to this old rust bucket, but have I finally come ascroos a problem I better leave to the pros?

 

[yavapaires]

Do you have a Haynes repair manual? Between this site and a Haynes manual, you can find out how to do about anything. If you don't have one, they are available on Amazon for as reasonable a price as you will find anywhere. They are about 25.00 at the parts store. I think I paid 8.00 or so plus shipping for mine. For the 5.0 look at section 2c page 5 section 7.

 

[rhinodep]

Do you have a Haynes repair manual? Between this site and a Haynes manual, you can find out how to do about anything. If you don't have one, they are available on Amazon for as reasonable a price as you will find anywhere. They are about 25.00 at the parts store. I think I paid 8.00 or so plus shipping for mine. For the 5.0 look at section 2c page 5 section 7.

Thanks, Yavapaires, for taking time to reply. Posting a question and getting no replies is like being the wallflower at the high school dance!

Yes, I'm actually heading out to do that right now. I've checked-out and greased-up my local library's copy enough times; guess I'll finally buy my own.

I was hoping someone would have some pearls of wisdom about what might be going on under that manifold. I've heard others advise on here before not to remove a manifold to chase vacuum leaks, but I guess I'm out of options. If it was a weekday, I might try to limp my way to a repair shop, but instead I guess I'll spend this weekend tearing her apart. Thanks again.

 

[alohamonte]

if youre comfortable just replacing things hoping it will help the idle, go for it. thats the approach i took when i first got my ex, i just started replacing things figuring, hey this stuff is old couldnt hurt. replaced the MAF, IAC, TPS, PCV, various sensors, plugs/wires, and many of the emissions components. Finally did the upper intake gaskets and injector orings. Runs fine now, however, some of those parts were probably WAI. just nice to know theyre all new and less prone to failure now.

 

[RangerX]

I can't help with the problem, I just came in to say I love the quote in the thread title!
Don't know if anyone else gets it...

 

[Snowboi]

It couldnt hurt to replace both intake gaskets and the injector O-rings.

 

[mayhem1605]

I can't help with the problem, I just came in to say I love the quote in the thread title!
Don't know if anyone else gets it...

I have to agree. I saw it and couldn't help but chuckle.

 

[24gtmaxx]

The upper intake is held on with 8 tork t27 screws. Also the vacuum lines keep it in place (sorta) also the egr is in the front of it so it doesn't just lift strait off.

Hope this helps with the removal. When reinstalling it. Start at the center screws and work outwards alternating between front n rear till all 8 screws r tight.

The back 2 are at a difficult angle. Maybe try a 1/4 inch universal socket to get them in and out. That's what I used.

Good luck