Dodge 318 Magnum Intake Plenum Leak Diagnosis

[@Treyorrrr]

This is THE MOST HELPFUL thing I've found on the internet pertaining to plenum leaks. I owe you money and/or beer. Everyone either says to just look for oil in the manifold (there always is thanks to PCV) or they turn it into a science experiment using gauges and excessively long instructions. Easy and straight to the point! THANK YOU.

[@analog56x]

Cheers bud! Glad I could help you out! This is why I make these videos; to help people :)

[@trekintosh]

Thank you! Your symptoms (and sounds) are absolutely identical to my Dakota. I’m going to order an aluminum plenum plate asap.

[@analog56x]

Glad i could help :) that's why i made videos

[@karambos2]

Thanks for the idea of using a magnet to discover whether you have a stock plenum plate.

[@Habel420atgml]

Great video man! Easy to follow and comprehend. I have the same issues with my 99' and have tried everything else to remedy the constant leaking oil, AWFUL STINK, and plumes of smoke once it has idled for a lil bit.

[@CHEAPROLLIN]

Did you fix it? Mine does smoke horrible

[@dpoarch]

Good explanation, simple video, and easy to follow along. Thank you!

[@Kansas_Clairvoyant-Medium777]

Thank you, I'll be using your advice for my 99 Dakota.

[@650gringo]

On mine: Engine off, remove air cleaner, hold throttle wide open and with a flash light look straight down through the throttle body bores. I had pooled oil in the bottom of my intake manifold. Easy to see. It was fully wet with oil. Also a couple of sparkplugs were oil fouled. Lots of soot in tail pipe. After gasket replacement, engine ran way better and smoother. No soot in tail pipe. Note: Myself and other have found the bolts that hold the plenum plate on are too long and bottom out. That is why the gasket blew out. Shorten the bolts, buy shorter bolts or put washers under the bolts, and reuse the original plenum plate. No need to buy a $100 aluminum plate unless you just want to.

[@Hardcorediver44]

Yeah, I found out my plenum gasket gave out because my idle started to climb. With no leaks on the outside, I put my palm over the oil fill hole and right away I felt major suction. The crank case is not supposed to have vacuum . SO I replaced the plenum with a Hughes upgrade kit. 1/4 plate aluminum, This way there will be no variations in temperature . The old plate was a thin steel and the intake is aluminum. Now it runs cooler and I have plenty of power with no more pinging up a hill.

[@jamesmoore3346]

Just coded my truck last weak, cyl 8 had 'excessive misfire', a quick change of a set of plugs cured the 'money light' but I dug deeper and located several articles on the 'plenum' leak issue, made an adapter and hooked up my vaccumn guage to the oil cap opening, showed 8-10# vaccumn. I don't drive the truck on a daily basis so I plan to remove the plenum this weekend and pull 'forensics', depending on what I find I will decide then on either an after market gasket kit or either the aluminum plate mod kit. I like the little truck and it is currently my 'project truck'. It was a sorce of therapy for me as I was recovering from chemo and radiation treatment, after DEFEATING stage 3 lung cancer, 5-1/2 year survivor so the truck has a special value to me, even though I concider myself a chevy guy, lol.....gonna keep the lil dodge around for awhile..lol.....

[@Hardcorediver44]

@@jamesmoore3346 Once you get the plenum fixed, it will be night and day performance. Power like it left the factory. I used a Hughes kit to fix it. 1/4 inch plate.

[@charlesbunting1790]

I had one with that problem and it ran fine. You just couldn't run it over a hundred miles without putin a quart of oil in it and you could look down through th throttle body and see a lot of oil in th bottom of th intake. That kit from Hugh's engine with th aluminum plate took care of it

[@floydrulesL7]

Would you happen to have a part number for that?

[@francisbrackney2061]

We have a 5.2 in a ZJ that runs just about as rough as your Dakota there. And I am pretty sure that it may be a leaky plenum gasket. Thank you very much for your video

[@JoeHouston86]

What is the hose that is connected to the bottom left of the pcv valve? On the block itself? My block is missing that hose and just has the nipple port exposed with no hose.

[@Flores9989]

The tapping during and engine shut off is due to the plenum? I did hear right?

[@fastbusiness]

I have a '99 Ram that had a bad plenum leak like you describe. I replaced it with the Hughes kit and it worked well for about a year, then right back to the same issue. Really hate the idea of spending several more hours redoing all that hard work. Last dodge I'll own, I hope.

[@francisbrackney2061]

Yep,,, I'm going to coat the gasket with permatex aviation form a gasket on both sides before I install mine. Makes it oil proof. That is what we did for the crank case on my brothers shovel head Harley Davidson engine block, and after 15 years it still works great without any oil leaks.

[@fastbusiness]

@@francisbrackney2061 That sounds like a great idea. I wish I had done that to mine. Also, I should have put some blue loctite on the bolt threads. They come with some on them, but I think more would help. The suggested torque is in the inch-lb. range, so there is not much force holding that plate down. I followed the instructions in the kit from Hughes and as I said, it worked until it didn't. I haven't taken it apart to see what failed, but I expect that some of the bolts worked loose and let the gasket fail.

[@Thundarr995]

@@francisbrackney2061 That's exactly what I used on my brother's 5.9L Magnum plenum gasket. I cleaned up the factory bolts and cleaned out the threads on the intake manifold with brake cleaner. I used blue lock tight on the plenum bolts and followed the tightening sequence and torqued it down exactly. It's been about 1.5yrs since I replaced that gasket and he hasn't bugged me to fix it again. Hopefully it's fixed for good,cuz I don't wanna do it again. 😆 But I think I may have to replace it on my 5.2L ZJ soon because it seems to be using a little oil. I looked down inside the intake manifold and it looks like there's a little oil in it. I figure that the plenum gasket is probably bad,just not bad enough yet to make the engine run bad.

[@GarageBuildzz]

Basically the same issue. I tried this method and too me it felt like it was blowing air and not sucking in. I’ve replaced a bunch of sensors and still the same issue

[@CHEAPROLLIN]

Will it blow a ton of smoke if plenum is bad

[@turbofiat]

I got a 2001 van 3.9 liter. The front two cylinders are misfiring. OBD II reader is throwing a code saying two much oxygen in the exhaust and its blowing oil out the top of the engine. But its not sucking oil into the intake. Could tye plenum gasket still be blown? Seems like excess air is entering the front two cylinders .

[@chvydrptop]

Thanks for sharing this video. So the blow from the cylinder comes from the opposite side of the crank case (driver side) in this case? If the plenum has a leak then this side will have a suction on it as opposed to a air shooting out that you should feel on your thumb? I thought the pvc side (passenger in this case) was the side that had positive pressure. The PVC function is to go up and down and stop that positive pressure at certain thresholds.

[@analog56x]

chvydrptop the blowby doesn't come out of just one side. It pressurizes the entire crankcase, including up in the valve area. The PCV valve is to allow some blowby to recirculate into the intake and be burned. Inside your combustion area (after the throttle body) is all vacuum. When the plenum starts leaking, it creates a vacuum inside the crankcase, and starts sucking in oil, which destroys your catalytic converter, fouls your plugs, and can cause a horrible running condition if it gets bad enough.

[@davejames2015]

Wonder if they make a solid intake

[@analog56x]

Id imagine an aftermarket intake would offer that option...

[@thomaslockley945]

That is a electrictronic controlled transmission from the factory of that yr model

[@josephteichroeb1042]

What if when u plug the pcv end on the intake the truck dies

[@oldcroneysgarage9739]

My 99 dodge ram has a 360. It idles rough,and if you let off the gas to fast it stalls out and doesn't like to start again,in burns oil, and it's putting gas in the oil. Could that be a bad plentum?

[@kingtwiztid3704]

I had the same idle issue, it ended up being my iac (idle air control)

[@Toothless69420]

did it smoke at start and whenever you drove it smoked even more?

[@marcovalle9410]

@@Toothless69420 mine does

[@Toothless69420]

@@marcovalle9410 same here still i think its the headgaskets

[@francisbrackney2061]

Our don't smoke. But has a rpm surge, and it misfires below about 2500 rpm, , just basically runs like a engine with a vacuum leak. Only I could never find any external leaks. The exhaust also has a strong odor of nitrogen like it is running too lean.

[@javier1975ify]

Good morning analog., I have a RAM 5.2 1999 in the morning it turns on well but sometimes during the day while I use it if I turn it off and then I will turn it on it takes time to turn on and it turns on failing but it is still normal then what could be

[@analog56x]

Id start with basic maintenance. Change the fuel filter first. I had an issue with starting my 3.4L swapped 4runner after it was up to temp, ended up being fuel related. Fired up perfect when cold, but it struggled after id run it then try to start it again. I ended up changing the fuel pump, and it was fine

[@Skyler1640]

Hey I have a 1997 Dodge Ram it has a misfire on cylinder 2 I think it’s a bad intake manifold it burns so much oil when I give it 3000 RPMs Blue smoke goes out the exhaust shakes really bad any suggestions ? Thanks

[@analog56x]

using a magnet on a stick, put it down your throttle body and see if it sticks. if it does, you've got a steel plenum base, and the gasket is probably breached. if your problem is only at 3k ripums or higher, it could be rings. check for vacuum in the crankcase like i show in this video, and go from there :) if you dont have vacuum, id suspect bad rings or something else.

[@stunnasam21]

I would do a leak down test on your cylinder heads, you could have multiple things going on.

[@This0is0pointless]

Have a 98 doing the same, cloud of blue smoke when revved so high, you ever figure it out?

[@abelcerrillo2162]

change out the guts on the distributor...camshaft sensor rotor an cap..

[@shugatoast7844]

as of yesterday I am the proud owner of a 1996 Ram 3500 dully V8 Magnum 147k mikes

[@mopars23]

my crankcase tube don't have any vaccum doin this any ideas?97 dodge 1500 5.9 mag,runs put it in gear and stalls

[@analog56x]

mopars23 any transmission issues? Your lockup solenoid might be acting up? Does it just sputter and die, or bang and die?

[@mopars23]

bang and die,i can move it but it bucks.

[@analog56x]

mopars23 sounds like a transmission problem. Id guess theres an issue with your lockup solenoid. You have the 46re in your truck? I cant remember which wire it is, but you can cut it and it will disable your lockup. If that is not the issue, then its a simple case of reconnecting the wire. Ill see if i can find out which wire the lockup is.

[@mopars23]

i meant 98 but i do have a 97 parts truck.how would i know if its 46re? it has 2 driveshafts.thanks so much replyin back

[@analog56x]

mopars23 the lockup solenoid is the orange and black wire going into the connector on the driver's side of the transmission. If its 98 it will definitely have the 're' transmission. That would be the electric controlled trans. The 'rh' is hydraulically controlled.

[@ClaytonBoyle]

Thank you!!!!!

[@bryanwelton1442]

hell ya buddy cant wait to see the ol dodge smoke some rubber!

[@jorgebustillos4354]

Can anyone help me I have the same engine on my 98 Jeep Cherokee and it starts like for 5 seconds then cuts off can anyone help me that be very helpful thank you.

[@nicklewound71]

Jorge Bustillos security needs to be reset. The security systems on The 1st gen grand cherokees (ZJ) have a fuel system cut off for security. It’ll let it run for a second and then kill itt self. If you have the factory key or a key that works with the driver door and rear hatch, instead key into the hatch and cycle lock to unlock 3 full times and that should reset you’re security. If that doesn’t work, do it with the drivers door/ passenger door if it has a lock cylinder. I have a 96 with a 318 I fought those problem for a long time before I figured this out! Hope it helps!

[@weber247]

I hear a whistle like a jet engine when truck is warm. Is that not sign along with the loping idle.? I could look in and see the curves and the bottom edge of the steel pan from throttle body. There is an oily buildup in there too, what about o rings? is that stain by injectors at bottom side of kegger from oil or fuel? Vacuum test seems easy enough, yours is real bad...

[@analog56x]

if you have the steel pan, and you see oil or oily residue on it from the inside, id be willing to bet that the gasket is breached. when that gasket fails, it creates a vacuum inside the block and sucks oil into the intake.

[@scraplifetrashtocash4551]

@@analog56x Oil inside the Pentium, can also be a result of a bad Pcv too.

[@dirtykingsgaming]

Is that a Laramie? Tho

[@dirtykingsgaming]

Yo

[@smokingwithslim5118]

U never showed the rpm

[@MEMPHISBOI_901]

I miss my ram

[@GRIZZLYGRIZZGG]

Dodge magnum wtf is that😂

[@DarkeeseLatfiah6]

a line of engines produced for a decade.

[@ledgercook5761]

Magnums are what terrorized you grandpa back in the day

[@BlackCatFever2011]

Im not listening to a guy that rigs up fuel line with hose clamps in between factory hose and fuel rail.. Sorry.

[@analog56x]

Rofl, you obviously didnt watch the part where i said it was temporary to aid in diagnosis :P oh well, your loss.

[@BlackCatFever2011]

@@analog56x not losing much. Your truck is an abortion

[@analog56x]

@@BlackCatFever2011 haha, i know, thats why i got rid of it.

[@analog56x]

@@BlackCatFever2011 but while you're out here taking shots at people, post up your truck bud. Easy to rip on someone when you're hiding your pos.