Hey Guys,

This is a really hot topic on this forum and just wanted to make sure that most if not everyone knew that there is a really good solution to be had out there. Our Magnum engines are VERY prone to blowing the plenum gasket because they chose to bolt a steel plate to an aluminum manifold. I learned early on with my 92 Shadow that had an aluminum head and an iron block that its not a good idea to mate two metals with extremely different tempers.

Earlier this year I bought a '98 ram and could tell right away that there was definitely something bogging it down and it wasnt getting nearly as good mileage as it should. Sure enough it was a blown plenum gasket. The boys on the 2nd Gen ram side of the forum highly suggested the Hughes Engines Magnum engine Plenum kit. So I did a little research and they were right. I bought the kit and it came with a 1/4'' aluminum plate, Grade 8 bolts, what seemed to me was a metalic plenum gasket and full detailed instructions on the full installation of the plate onto the intake and the intake back on the engine. The ram runs beautifully and I couldnt be happier.

Recently while working on the dakota I noticed a burnt oil smell from the exhaust, then looked down the throat of the throttle body and saw some oil pooled up on the opposite side of the PCV. I decided it was time to Hughes it up on this problem. I went to place the order and found out that they are now putting the intake gaskets to the heads and the block in the kit!

I have had some really good experiences working with company and thought I would share it with all of you.

Here is the link to the kit that I have purchased.

http://www.hughesengines.com/Index/p...p?partid=26190

If anyone is interested, I could probably do a DIY on replacing the plenum gasket.

 

Cool! It is a great product. Lots of great reviews by others.

From factory they should of started doing that. After a few years of the problem you would think they would learn.

I wanted to order it when my gasket failed but for me I needed my truck up that same day, so I couldn't wait. But if I had the time I would of ordered it. At least one good thing the gasket I got had O-ring like seals to help.

 

Yes, the hughes plenum plate is the way to go. And so far I have taken the intakes off of 3 different V8 engines, ranging from 40,000 miles to 140,000 miles, and every one of them has had a plenum gasket that looks as though it is being pulled out of the intake. I don't think it is a matter of if the plenum will go bad, it is more like when will it go bad.

Grade 8 bolts might be overkill in this application seeing as how you are bolting into aluminum.

 

funny thing is i did myne last nite (no upgrades other than a mettalic gaskit due to lack of time and cash.) was in the shop another 4 hours and run off by the salesmen so they could lock the lot. driving home was great went sideways once by accident even. i was thrilled at how my 5.2 ran. i didn't even get to do my kegger mod (note on some 96 mag v8s the intake already has cut back ports and the divider wall sits way higher away from the plate). went and towed a small trailer today and blew it out on the way home.
pulled it down redid it set a personal record of just under 3 hrs. what i did different this time is that i used the grey axle sealer (mopar) with that belly pan gasket. some on the pan some on the intake and stuck the gasket to it. im letting it set over night. once that stuff sets up i doubt anything in there can get it loose. just think of how hard you have to pry to get your diff covers of when they are sealed with this stuff. i bend quite a few at work (and straighten leaking ones customers tried to do) thanks to this stuff.

 

Most likely if it blew that quickly it wasn't seated properly or was not torqued down in sequence. Or you have a warped plate, although I have never seen that one yet.

I wouldn't have used the axle sealer. And you would be amazed at how much more forced it put no an object when you have thermal expansion than what you can put on it mechanically at home. So really, it shouldn't matter. Think about why we heat parts to break them free? I think it is just asking for trouble to lock everything in place with axle sealer IMO.

 

I opened up the air cleaner and looked inside the throttle body and I definately have some oil residue on the right port. Thanks to this thread I would have never know I had this issue or how to find it for that matter. I was just telling my wife what crappy gas mileage I was getting. I will be ordering the Hughes kit.

I'm sure this gasket has been blown for awhile. Is this in need of an immediate fix or can I let it go for a month till I can clear some expenses and time? I only use the truck to drive to work and back (6 mile round trip).

 

i've put around a hundred on it so far today with no issues and iv'e stayed dry in the belly pan. im wondering if it's warped because i did torque it in sequence and was good for around 10 miles. at any rate the axle sealer should do fine since it does not have as high a tensel strenth as either the aluminium or the steel. if it all goes well this week then ill tend to a few other matters on it. this was a fleet truck before i had it and it sat for a few months before i got it so i have few other things that need attn from sitting. im just chipping away a bit a time.

 

You will be fine for another month. Chances are that most drive around with a blown plenum and dont realize it. Then curse Dodge for making a ****ty truck.

I like to call these "Operable problems". Meaning that you can drive with this issue but long term abuse will result in ruined O2 sensors, Catalytic converters, Not to mention all kinds of build up in the heads.

So one more month wont hurt anything.

 

I think the service manual actually says somewhere what can happen if you keep driving with a bad plenum. Of course, when I go to find it I can't, but I am pretty sure I read it at one point or another, I want to say it could lead to head gasket failure, but I could be wrong.

If you are only driving 6 miles or so, I wouldn't worry about it too much. But I would fix it when you can. It would take me about 6 hours to complete right now from start to finish.

 

I think it'll take a long time for a plenum leak to cause major problems. My 99 Dakota was burning almost a quart every 3k miles for almost a year before I got around to fixing it, I'm sure it'll shorten the life of some sensors but everything was still operating fine 2 years later when I sold the truck.