I have read several posts regarding the infamous and dreaded plenum gasket leak on the 5.2L. Does this also affect the 1988 3.9L?

 

Uhhh ... no.

The 1988 is an LA motor; that'd the Magnums that have that problem.

Now, a 1992+ Magnum 3.9, sure.

RwP

 

I've wondered myself. Looking at some 1st gen Dakotas....Only thing keeping me from pulling the trigger is the plenum thing. So, it's 92 - 96? 3.9, 5.2 & 5.9?

 

Yep; all three of the LA-derived Magnum engines; 3.9, 5.2, and 5.9 .

Dunno about the V10s.

I don't think that's a BIG reason to not buy a truck; you can eyeball down the throttle body (with the motor OFF of course!) and see how oily it is inside. If it's oily, the plenum's blown or there's really bad blow by. But even so, it's not a difficult fix for a DIY; shouldn't be but 3-4 hours at a mechanic if they know what they're doing.

And so far, just whacking the end of the nipple on the bolts and a new Fel-Pro gasket seems to fix as well as the Hughes kit.

RwP

 

REALLY??? It's like an afternoon's worth of work and not a lot of money.... chance to do some needed maintenance along the way before you're overheated on the side of road... new hoses (especially bypass hose), thermostat, and a few other things since they need pulled off to do the plenum anyways..... that would be the last thing to keep me from consider buying a truck... avoiding rust bucket would be 1st among Dakotas.... 1st among all else to prevent me from buying would be a truck that says Nissan or Toyota on the hood...… next on the list is a truck with 4 doors will keep me from buying.

 

I'm sure it is. I'm just at the age where I don't feel like fooling with it. lol