Is this a problem prior to 1994 on the 5.2's?
I notice the TSB is for 1994-1999.
Has anyone had this plenum gasket failure in a 1993 or 1992 Dakota?
Or does anyone know why the TSB did not include model years prior to 1994?
Thanks for any enlightenment you would care to share.
John

 

All '92-'03 Magnum engines 3.9, 5.2, and the 5.9 are subject to the plenum gasket failure issue. Just the nature of the beast.

 

Ok, thanks for the reply. I've also searched and read a lot on the subject of this plenum gasket failure and have read where people with 1993 models have infact replaced theirs too. I'm not sure why the TSB did not include 1992 & 1993????
Mine is a 1993 model and while looking down through the throttle body, I do see oil residue mainly on the divider wall and the other visible surfaces, but do not see a puddle in the bottom. I have been getting spark knock for years on anything other than 93 octane gas. I do have to add oil between changes but I have not actually kept tract of it to say how much. It is not near as bad as a friend of mines..... Mine only has 107,000 miles on it now and is driven by my daughter. I'm wondering if their would be any problems using a kegger intake from a 1998-1999 model from a junkyard in order to be able to have it ready to install not long after removal of the original one. I'm thinking if the price is not too bad on a junkyard unit, I might as well get one that does not need the divider wall removed. What would be the dealbreaker in using a 1998-1999 in place of the 1993? And would their be any gas milage benifit of using one without the divider wall. My daghter is not interested in any other aspect of this other than gas milage.
Thanks for any help on this subject: John

 

Personally, I would save the money on buying a new intake manifold and spend it on an aluminum plenum plate instead and a high quality gasket. I almost look at the plenum gasket as a one time maintenance item on these trucks as opposed to a repair. I've just had too many trucks with the plenums go out. Actually every truck. Some worse than others, but all were bulging when I pulled them. All in all, after doing it, it is only a 4 hour job now, I'd say 8 hour my first time.

As for time, I don't think it is more than 20 minutes to actually swap the old plenum on the intake you have in there, so I wouldn't have one waiting and ready with a new plenum if it were me.

hughes engineering has the plenum plates and kits for sale.

 

I am seriously considering the Hughes kit or one of the other brands. I have not researched the different offerings to determine which one is the best for the job.
But the only reason for considering the 1998-1999 was to get one without the divider wall in it. I don't want to spend the time it takes removing the one that is in my original.
Thanks: John

 

97-up intakes don't have the EGR port. So you will be LOOSING MPG. If your doing it just to delete the divider it is not worth it, the divider is not restricting anything. There is plenty of space for air to flow through.

 

Ok, thanks for the info. I'll most likely just do the plenum fix and forget about the kegger mod and all......

 

have you confirmed that the plenum gasket is the problem?
there is a simpe test to determine for sure....

 

No, I'm not 100% sure. I don't have a vacuum/pressure gauge to follow the TSB instructions. I think I may have an old vacuum gauge laying around that use to be mounted in one of my street rods from yesteryear. Please do tell or provide a link.
Thanks: John

 

remove pcv valve from valve cover, let it dangle on it hose...
remove crankcase breather cap from other valve cover, let it dangle on its hose.
Start the engine and let it idle, works best when engine is warm...

put one hand over the pcv side valve cover hole, other hand likewise on breather cap hole.
after about 5 seconds, lift one hand slowly and see which way the air flows.There is usually enough oil vapor present to see the air flow.
the crankcase SHOULD be under a slight pressure....if the air flows IN instead of OUT, the plenum gasket is bad..

(if you have a vacuum gage, plug one hole with your hand and the other hole with vacuum gage)

this should be a sticky....