Understand.

I suppose I won't know until I get the o-rings replaced and check for a vacuum leak, both of which still make me scratch my head as to why it would cause a rough running (almost like out of balance compression / misfire / timing / air fuel mix) symptoms.

I'm thinking I'll also clean the throttle body while I've got the fuel rails off.

Thanks for the help.

 

Friend of mine repalced the plenum gasket on his truck. To do that, the intake must come out. After everything was installed back, his truck ran rough. Had power, but ran rough. Turned out, the #1 injector O-ring tore as the injector was being put back in. He replaced the O-ring and his truck runs like brand new now.

 

"Like brand new"?

I can only hope. As described it fits my run condition so I'm hoping this weekend I can wrench on my whip a bit and see if this really solves my problem. I'll keep you posted.

 

Shoot, I just did the plenum gasket last week and let me tell ya....DAMN! One forgets just how powerful these Magnum engines really are when their not sucking in oil. LOL.

Keep us updated, mang.

 

Well the easy fix, replacing the injector o-rings wasn't the culprit. I went ahead and purchased the lower and upper (plenum) intake gaskets and I'll pull it apart tomorrow. Here's hoping 'cause my poor 'ole girl is running like Roseanne Barr to a vegetarian buffet.

 

Check to make sure your plenum is actually blown before you pull it all apart. If you look down into the intake manifold while holding the TB open, do you see oil at the bottom? Another way to test is to start the truck and disconnect the hose on the driver's side valve cover (towards the back) that goes to the air box. Once disconnected, check if there's suction from that fitting on the valve cover. There should NOT be any suction. If there is, your plenum gasket is toast.

.....and I lol'd at the Roseanne Barr comment.

 

Audiomechanic, I have a '95 with same prob, is there supposed to be oil? And do I need to check the fitting in the valve cover, or going to the airbox?

Thanks for all your help

Joe

 

There is supposed to be a very light film of oil on the bottom of the intake, but nothing more. If your intake is dark brown or you see pooling of oil down there, your gasket is blown.

You want to check the fitting on the valve cover for suction, not the hose.

 

I think a better way is to cap that one off also and check at the oil dipstick tube. It's also smaller and easier to put a fitting in it.

 

So after inspecting the following this is what I'm finding:

1. The plenum inspection through the throttle body with a flashlight reveals the following:2. Removal of and plugging the valve cover breather cap:I'm literally fishing with no hook here.

Thoughts and ideas?