Irregular RPM's?
 

Hey guys, sorry to make another new thread but I am deciding if i need to get rid of my Dakota because of too many repairs that need to be done(and i have out about 1200 bucks into it over the last 7 months). I believe the clutch is going, and it has a hard time starting up when its cold. My question this time is, when im driving and i push the clutch in, the rev's go down but not all the way. It seems to jump around quite a lot until i make a complete stop and are there for a couple seconds...is this something with the clutch needing to be replaced? I wouldnt mind it as much, but it really makes my truck sound horrible. Its a 99 Sport 4x4 5sp. with a flowmaster 40 on it and a suspension lift. Also, while im idling my exhaust kinda buzz's or resonates at a very inconsistant rate(my idle is a little rough right now as well, but its too cold out to try to clean the tb or check the 02 sensor(if i could figure out how.) Any ideas or adivce would be very helpful.

RE: Irregular RPM's?
 

Sell it and get a v8. Oh wait! Sorry, I just get used to saying that lately. When was the last time you did a regular tune-up on your truck? I assume it has been in the last 7 months according to the amount of money you have spent, but might as well ask. When was the last time you cleaned you intake manifold? I have never used the Sea Foam that I have heard about, but I have used other intake manifold cleaners on a regular basis to keep everything moving smoothly. Cleaning the TB, as you originally stated, would also do nothing but help your situation. You say it's very cold out, what kind of oil are you using? There are many different variables here that might be contributing to your rough idle/irregular RPM's. Most of the simple solutions are both easy on the money and DIY jobs.

RE: Irregular RPM's?
 

I have not done a full tune up on it since i have had it, since i have been putting so much money into it. I really just want to sell it and get somethign else, but probably cant get anything for it, maybe 5500 and considering i have put so much into it and paid 7200 for it, that would be a horrible idea. Anyone have any ideas on the best way to sell or trade this truck? It simply has too many problems that i dont have money for.

RE: Irregular RPM's?
 

It is very unfortunate that this situation has come about with your truck. It seems someone has sold you a lemon. [:@] Fortunately, I would do a tune-up on it, which is a relatively inexpensive DIY project that can not only improve preformance but reliability and gas milage.

RE: Irregular RPM's?
 

might be a leaking pletum. (intake manifold.)

RE: Irregular RPM's?
 

I have a 99 Durango and a 2000 Dakota, a lot of the general things went wrong on both vehicles around 80000 miles. And to be honest they weren't too pricey becuase I changed the parts myself. Things I have done that made huge difference in how both vehilces ran: replaced oxygen sensors (both up and down stream) ABS sensor, water pumps, (I would recommend when you change the water pump you replace all radiator hoses and thermostat), rear U-joints, Serpentene belt and tension pully. Sparkplugs, wires, cap and rotor get changed every two years. Should clean throttle body at roughly the same interval. Threre have been a lot of people here talking about weird clicking and whistling noises..... I wonder if they have checked their rear Ujoints..... they start out by making a clicking noise from the needle bears going bad. But when the needle bearings are completely shot you get a hi pitched whistle from metal spinning on metal. Dakota's are great trucks, but there are new truck people, who always buy new vehicles and run the crap out of them without doing any maintenance and then sell them the first time it makes a noise. Then people like me buy them and a have to do all they maintenance the previous owner was too lazy to do. I am not a mechanic by any definition.... I am a parts changer. I consult with my mechanic friends for diagnostics, and they explain to me what parts I need to change. I plan to put a million miles on my truck, but I understand its going to take some matainance.

RE: Irregular RPM's?
 

Start first with the obvious: when was the last time a major tuneup was done? Perhaps never. Pull the spark plugs and see how they look. If they look old at all, replace them with good copper plugs, shouldn't be more than $15 for the set. Cap and rotor - are the contacts good, clean, and brass? If they're worn, crapped up, or aluminum/tin, replace them. That'll run you another $15-25. Plug wires - if they're old, cracked, gummed up a lot, or worn, replace them too. Those will be $30-60 or so.

I highly recommend going online and printing out prices of items, then going into the local store and asking them to match the price. I know Schuck's and NAPA will do this. It can save you almost 50% or more on some things versus just going to the counter.

The upstream O2 sensor is the one that controls the mixture, so if that's original it might be time to replace it as well. Unfortunately that's going to be $120 or so for one with a plug on it, or about $60 for one that you splice wires on.

The downstream O2 just tells the ECU if the cat is doing its job, and doesn't control mixture at all. I wouldn't waste money replacing this one unless you're throwing CELs due to cat problems and you know for sure that the cat is fine (new and working properly).


I would, however, pull the plastic air hat off the throttle body and open the throttle blades to look down into the intake manifold. The 5.9/5.2 have a known problem of blowing out the gasket in the intake plenum which will cause several problems. It'll be a major vacuum leak, your engine will ping under load, you'll consume oil, be down on power, and if the leak is bad enough it'll idle funny. Look down into the plenum with a flashlight and check to see if you've got standing puddles of oil in there. A light coating of oil is fine and normal (PCV will suck some in there), but if there's enough to form a puddle, you've got a problem. If that's the case, it might be time to consider upgrading the manifold a bit - either shortening the runners or swapping out an M1 intake depending on your wants.

RE: Irregular RPM's?
 

Thanks for all the advice guys! Really sorry for all these questions, but I am really new to working on cars and trucks myself. I understand how most things work and have a chiltons manual, but am afraid to do any of that stuff myself being that i have never done it before. Also, I am up north for school with no driveway or place to work on it and we already have snow...makes it pretty tough for me to do it myself. I called a couple places to see how much for them to put in new plugs, cap and wires, they said about 220-250...which seems insane to me considering i can get the parts around 100 bucks if i have looked correctly. Would this be worth it? According to a record left in the truck when I bought it, new spark plugs were put in a little under 20,000 miles ago. Also i really wanna clean out my throttle body but again have no way of really doing it, is this something i could/should pay for? and if so how much? Thanks a lot, all responses are greatly appreciated.

Also, im thinking about a new clutch...dodge told me about 900 bucks, anyone know where i can get it cheaper? its a 99 sport 3.9 v6 5sp. 4x4