idle noise... i'm stumped???

bigredneck61088 · #1 (**permalink**) 08-21-2008, 09:05 PM

The truck is a 98 ranger 4.0 5 spd 4x4 with 96,000 When started and idles down to 700-800 roughtly i get a rattle/clunking noise from the passenger side of the truck, anything above that rpm the noise stops. i looked at the catalytic conver cover and seems ok, clutch has no effect on noise and truck runs great except for the noise... ford's marbling problem??? could it be this??? any info i need to know about it besides what i find when i search...any thoughts on what it could be?? im stumped and want it gone

Lead Head · #2 (**permalink**) 08-24-2008, 10:02 AM

If you have the 4.0 OHV, and if the 4.0 is anything like the 2.9, then you have a lifter that is collapsing at idle. On my 2.9 one of the lifters collapses during the exhaust stroke so the valve just snaps shut, this goes on for 10-15 seconds until it pumps back up

bigredneck61088 · #3 (**permalink**) 08-25-2008, 07:45 PM

i have a 2.9 also and have never heard that, what would it sound like and how could it be fixed?? thanks in advance

Lead Head · #4 (**permalink**) 08-25-2008, 08:27 PM

I have honestly no idea how to fix it. I'd imagine if you'd replace all the lifters it would probably go away. I've also heard of Marvel's Mystery Oil fixing it.

It sounds like this

http://www.youtube.com/watch?v=pVA4eedOYTQ

Lead Head · #5 (**permalink**) 08-25-2008, 10:47 PM

Can you get a video or a sound clip of it?