Help With '97 Dodge Ram W/ 5.9 (360)Magnum

[mpace6a]

Sunday night, drivin my dd 97 Dodge Ram home, on the highway when it wouldnt shift. KInda normal since it needs the speed sensors replaced, backed off the gas, then accelerated again which usually makes it shift, only instead it bogged down and started clunking, like if you run out of gas. Got it pulled over, tried starting it again, and it sounds like the intake and tailpipe are clogged. pulled the airbox, looked in the throttle body and it looks like its full of oil. Ran diagnostics to see what codes it threw.

P0300-Random Misfire

P0302- Cylinder 2 misfire

P0303- Cylinder 3 misfire

P0304- Cylinder 4 misfire

P0307- Cylinder 7 misfire.

As far as i can tell, all this happened at the same time at 58mph,

Anyone have any idea what happened? My best guess is the plenum disintegrated but i don't know.

[terrawombat]

The ignition coil died.

[mpace6a]

but it still starts fine?

[terrawombat]

You failed to mention that it still starts.

[mpace6a]

Yea, still starts no problem, but when its running it fights to stay running. Sounds plugged up, plus a rattle, sounds lower end/tranny area. Throttle body is full of oil which is why i think the plenum finally went?

Also if it helps any i can look at my obd2 scanner and find out all the specifics of when it through the codes

 

[shelbyluvv]

I'd look into the plenum. Sounds like the issue.

[mpace6a]

yea thats what I'm afraid of. hopefully i didnt fry any cylinders or the heads...5 misfires at once scares me. this projects going to the back burner though, mj is closer to being driveable. any thoughts on anything i can check before pulling the intake?

[shelbyluvv]

The oil in the air box is a big indicator. Shine a light down the throttle body and see if oil is in there. There was a TSB out to help diagnose the pinging magnum.

 

Did it ping under throttle?

 

TSB

http://dodgeram.info/tsb/2000/09-05-00.htm

 

 

The sell a trick replacement plenum.

http://www.hughesengines.com/Index/products.php?partid=27091

[mpace6a]

No oil in the airbox, but the throttle body was full of oil.

Also, what does pinging mean?

And does anyone have any experience with the plenum replacement?

[terrawombat]

I have this guy's kit: http://thespeedfreaks.net/showthread.php?5666-My-New-Plenum-kits-65-bucks!!!

 

It worked well on my 5.9. I think I paid about $100 after buying all of the required gaskets (which he doesn't supply).

[Comanche County]

Here's what I did to my 5.9 plenum, basically the same thing as Terra but its tig welded to the intake.

 

But even a severe plenum leak usually won't cause all that at one time. The excess oil being sucked into the intake could foul plugs but its unlikely they'd all crap out at once.

 

If there's oil visable through your TB, then you need to replace the plenum gasket, but while you've got the intake off you might as well replace the steel plate with aluminum that's either bolted or welded on. It will last much longer than a new gasket with a steel plate on the aluminum intake. The problem is the two metals expand and contract at different temperatures that's why people go with aluminum plates. But check all the normal stuff, plugs, wires, coil, cap, rotor first.

 

[Lemmon714]

I had a similar issue with my 96 dakota and a 3.9 with random misfires.  I changed the cap, rotor, ignition module, plugs and nothing helped.  I did a fuel pump check and found the regulator at the fuel pump was bad.  Fuel pump would make pressure and when the truck was turned off the pressure went to 0 psi.  I replaced the fuel pump and rebuilt the fuel injectiors- I think the regulator clogged the filter screens in the injectors.  The injector kit has a set of filter screens and o-rings.  After the rebuild of the injectors it runs better than when I bought it new.  I also find that the oem mpoar pcv works much better than aftermarket pcv's- maybe my opinion but I have fixed many problems by changing the pcv to oem for friends.