I have a 1997 dodge ram van 2500 5.2, I did the tune-up I put bosch +2 spark plugs, standard wires, standard rotor and standard distributor cap, I used castrol oil 20w-50, and the Van seems to be shaking and feels heavy, another problem is that when I accelerate the van vibrates. I used the same spark plugs it had before, the distributor cap and rotor same standard brand, I changed the wires from bosch to standard, what do you think the problem could be? Thank you

 

One more thing, the Van has 138,000 miles on it, the prior owner didn't take care of it at all, is the oil weight fine, or shouls I use another kind of oil.

 

The van also leaks oil from the bottom, it come down to the muffler, I thought it was the oil pan gasket but i changed it my self and it still leaks, PLEASE HELP thanks to everyone........

 

One of your cylinders isn't working. Double check your firing order to make sure you didn't get two wires backwards. If that isn't the problem then you could've cracked a plug while installing them. If you want to narrow down the problem, with the engine running use a pair of insulated handle pliers to remove the plug wires from the cap one at a time. Each time one is removed and put back you should notice a change in engine RPMs. The one you remove that doesn't cause the RPMchange is the problem cylinder.

 

Leaks are a funny thing, you think you can see where it's coming from, but in reality it can travel from the actual leak to other parts of the engine. Your rear main seal could be leaking which coats the rear of the pan with oil.

20W-50 is okay in the hot weather, but not in mild or cold temperatures.