Hey everyone,
I have a 2001 ram 1500 Laramie with a 5.2/318 and a 5 speed. When you start it first thing in the morning, it starts right up but when it comes down to idle it sounds lopy and like it has a cam. It will do this for 45 seconds to a minute and then the idle with raise and come back down almost like the throttle what stepped on even though it wasn't, and start idling nice and smooth. Also when it is doing this loping thing it has a louder than normal hissing/suction noise coming from the intake, that's the only way I can describe it. It will get progressively louder until the idle comes up and back down and begins idling smooth. It did this before I bought the truck and the previous owner was not worried about it, but I just wanted to know your thoughts on what it could be. Not much has been done to the truck, stock everything except a flow master 40 series and it still did this before the muffler was put on.

Thanks,
Frank

 

Sounds like you might have a vacuum leak somewhere. I have seen some rubber lines and elbows that had small slits/tears in them that acted intermittently.

How's your plenum?

 

First off, thanks for replying so quickly. I did test for vacuum leaks and fixed the one that was bad. The vacuum line going down to the transmission was leaking so I fixed that and that was the only one I could find. The plenum is what I'm worried about. I don't know if the pervious owner every changed the gasket. I was doing some research online about what it could possibly be and things are pointing to the plenum. Do you know a good way to test and find out if it is the plenum leaking?

 

Pull the throttle body and have a look down there, see if you see oil pooling toward the back of the intake.

Probably would you have is a miss that sorts itself out after things warm a bit. How old are the plugs/wires/etc?

 

Ok, I'll do that as soon as I have a minute free, you guys know how that goes. Is it a big job to do the plenum? Like could I do it myself?

 

It's time consuming, but, if you have any mechanical aptitude at all, you could do it yourself. (and save yourself a ton of money.....) You should do the water pump, and timing set at the same time...... You are going to be RIGHT THERE.... no better time. You could get it all done, by yourself, over a weekend.