2004 Dodge Ram Repair Question
Mileage: No information provided.
Possible timing problem
Asked by Mikes mobile mechanic serviceAnswer
The quick learn procedure requires the use of a DRB(R) scan tool. This allows the system to recalibrate itself. This should be done anytime when the following are performed. 1. Transmission replacement 2. Solenoid pack replacement 3. Clutch plate and/or seal replacement. 4. Valve body replacement or recondition. Do any of these apply?
Ok then let me ask you this. The timing procedure on this truck is to set crank on TDC and the V 6 mark on both cams. Since there is no timing marks for the cam and there is some slight room for visual error shouldn't the ignition advance itself ? If a relearn isn't required?
The ignition timing is PCM controlled and would advance or retard according to conditions.
Ok so there is a mark on the block marked TDC. Does each cyilinder complete all four strokes in one crank shaft revolution or is it possible for #1 to be on the exhaust stroke at the mark? If so why would the not just put a mark like every other motor has instead of casting TDC on the block ?
Sorry if I sound rude I have been getting answers that say you have to relearn, reflash, and answers that say you don't do anything. And I'm trying to figure out how with no real timing marks on the cams how en being off a little would matter. If you were off a whole chain link it wouldn't be twelve O' clock. And TDC is supposed to mean that #1 is up on the compression stroke and I have done exactly this and cranked the truck. I didn't hit any valves with the pistons but the truck idles like its running on 4 cylinders, and not throwing a CEL or any codes and there are no misses on the missfire monitor
For every revolution of the camshaft, there must be 2 revolutions of the crankshaft therefore it is possible as you mentioned that the piston is at TDC of exhaust instead of compression but the camshafts would not lie to you. IF both camshafts are lined up correctly, it does not matter as the TDC would always be correct.
When turning the crankshaft to check the timing chain timing, did you turn the crankshaft clockwise? You cannot turn it anticlockwise as that can result in the camshaft timing going off due to slack of the tensioner.
For PCM relearns, generally you need not do anything except run the vehicles. Some highway driving then to town for a few minutes and back to the highway and the relearn should mostly complete itself.
If engine is only running on 4 cylinders, it could be otoer things that is causing it. Ensure the spark plugs are working, injectors etc. Get a compression test to determine if they are within specs.
Check for dislodged vacuum hoses and clean the throttle body if necessary.
Misfire monitor would not work if the the Adaptive Numerator has not been relearned. The Adaptive Numerator is updated by the PCM for every key-on and is relearned after battery disconnect.
I will look check if I am on exaust or compression in the morning. Is there a minimum compression reading or is it just no cylinder can be less then the greatest reading? And if everything is correct including timing and compression what can I try next?
replacing one head will most likely give you different compression on the 2 banks, that is, one head new, one with miles.
as i said before, no re learn for the timing of the motor as KHL said.
Roy
Compression pressure should be between 170 to 225 psi and as Roy mentioned, they could vary with a new head but variation should not be more than 10 percent.
The pressure might tell us something if they are out of range.