Hey guys I have a 98 ram 1500 4x4 5.2. I've had it for almost two years an still haven't been able to figure out my rough idle. When idleing either after being started and sitting in park or when I'm almost to a stop the rpm needle will bounce back and forth about 100rpm or so and give a mild shaking.

It also has a long cranking on some starts, usually hot starts and it seems to crank faster than normal those times.

I've changed the plugs, wires, rerouted the wires according to the tsb, ignition coil, rotor and cap, idle air control.

Never had a check engine light or any pending codes but it's always done this. Also sometimes it has more take off than others. I was thinking either tps or a fuel pump issue, the battery is 6 years old but it never has any slow cranking issues and it read 12.something volts after sitting overnight and over 14 with the motor running, I replaced the terminals as one was a little corroded but as with everything else, to no avail. Just wondering if you guys had any input.

Thanks guys.

 

Probably vacuum leak. Have you fixed the plenum yet?

 

I took out the throttle body to clean it out but there wasn't any tell tale pool of oil in the intake. That was last year but I'll take the tb off after work today when I do the oil change and see if there's any oil in there.

 

I do know one of the wheel cylinders is leaking a little brake fluid into one of the drums, would that count as a vacuum leak?

 

No, but that's one more thing you need to fix.

 

Okay I was just wondering. It's been leaking about as long as I've had the truck I just hadn't realized what it was until recently. After winter I'm going to get new shoes drums hardware and cylinders for both sides, since I wasn't able to tell which one is leaking. I'm got a new throttle body gasket so I'm going to take off the throttle body while I do my oil change after the girl goes to work in a few mins and I'll let you guys know what I find.

 

If you need to change wheel cylinders, change them both. Look forward to having to replace the lines as well.

 

Yeah you guys were right, I was able to use a flashlight to see the pool of oil at the back of the intake. Time to visit Hughes engines. I noticed their kit comes with a 190 degree thermostat but I'm pretty sure mine is a 180 degree thermostat. Is it recommended to change it to 190 or should I get another 180 degree one elsewhere?

And yeah when I do the wheel cylinders I may as well do the shoes and drums etc at the same time since I don't even know if they were ever done.

 

Correction. It used to come with one. Now they suggest either a 180 or 195 as an add on. It says the stock is the 195 but I thought mine was 180 by stock. Definitely doesn't run at 195. Also it recommends a coolant bypass pipe. Is that different than the bypass hose the kit already comes with? Just want to get it all ordered at once.

 

Bypass hose goes from water pump, to intake manifold. That should be all you need. They MIGHT be talking about the little pipe that the heater hose hooks to on the drivers side..... but, you can get those from the Help section at the parts store for pretty cheap.