I have a '89 Ranger with the 2.9 v-6. The lifters rattle. If you drive around town through traffic lights so that the rpm is kept low, it will eventually stop rattling until you hit the highway again.

Every 2.9 i have ever seen did this, so i know that this is a common problem. What causes it to happen? The oil pressure is good ( at least by the factory gauge ). Is it possible to convert the 2.9 to solid lift ( it's 3/4 of the way there now. LOL! ).

I have been told that replacing the lifters will not help. Is this a oil starvation problem? How can it be fixed? I did a search, but found very little, which surprised me.

I also heard a rumor that the 3.1 will interchange with the 2.9 with minimum hassle. Is it true? If not, are there any motors that will?

I would like to keep the old clunker, as it runs very good when the valves get opened as they should. Get's better than 20mMPG too...

 

Have you bychance attached a mechanical guage to your engine and checked exactly how much pressure your pump is putting out? The pressure might be getting borderline at higher RPM's, but not at lower RPM's (as in too low of pressure all the time). As for the rattle, it is the lifters causing this. 2.9L do have adjustable rockers arms. A simple adjustment might get rid of some of it, but probably not all.

Probably the easiest fix for this (but not the fastest) is a new or rebuild oil pump, and set the pressure a few pounds higher than stock, or a high volume oil pump (Melling prt# M128).

 

I really don't think this is an oil pump issue. You can drive for 50 miles on the interstate at 80mph ( 3500 rpm ) in 100 degree heat and it starts to rattle pretty bad, but get in traffic and it will slowly get better until it stops. It's almost as if the oil drain-back holes in the block were clogged and it were being starved for oil. But, the pressure never drops below normal, and not all of the lifters do it.

I have heard mention of the camshaft being the cause of this, but no one has ever gotten specific as to what actually happens.

Thanks for your input, Elfatso!

 

Anytime!