4.7L cold start noise / lifter noise / slapping
I have a '03 Ram 1500 with a 4.7L, VIN N and it has been at the dealership for almost 4 months now. I purchased the truck used with 63,000 miles on it. The truck runs great but has a cold engine start up noise that was not there when I first got it. A few days later it started the lifter type noise. The noise is coming from the right side of the engine. Very prominent from the passenger fender well. If you walk around the truck it actually sounds like it is coming from under it, even with the hood open. If laying under the truck it sounds as if it is coming from just below the right head. Used a stethoscope and listened to it and everything is quiet except from the right head. Sounds like a loose rocker arm or a bad lifter. No where else in the engine do you hear anything with the scope. When laying under the truck listening and after the sound starts to soften it sounds like something is slapping around in the lower end instead of up by the right head, then the noise fades away. The sound use to only last for about 30-45 seconds and ocassionally up to 2 minutes. The sound is loud then softens and then goes away. Was worse in the mornings and slight noise if truck sat for 3-4 hours.
The truck had a fresh oil change with conventional oil when I first bought it. Thought it might have been cheap oil in it so I changed it and put in Mobil 1 synthetic 5w30 and the noise got worse. I had the lifters on the passenger side changed by an independent mechanic. The noise never went away and didn't change. Found out it was still under the Powertrain Warranty so I took it to the dealership that this independent mechanic had called for help. They replaced just the timing chain tensioners and the noise went away for a few days (charged me under the powertrain warranty for timing chain, guides and tensioners but did not replace the chains...this is another story in itself). When the noise came back I had the oil changed again with a different brand filter. It has now had 5 different brand filters on it all with anti-drainback valve including Mopars oil and filter. NO change.
After the dealership accepted blame for not putting the parts on they have been diligent up 'till now with trying to fix it. They then replaced the chains and guides plus changing the lifters in both heads (right head has had two sets of lifters/lash adjusters at this point). The noise changed to only in the morning but stayed the same lasting for about 30-45 seconds. It was loud for the first 20 seconds then softening and then finally going away.
They then replaced the injectors on the right side and cleaned the fuel rail but that didn't help either.
So the independent mechanic gave me a TSB from IdentiFix that showed a 2001 Dodge with a 4.7L VIN N making a lifter type noise that turned out to be a bad rod bearing. The excessive bearing clearance was allowing the piston to tap the bottom of the head. However the TSB did not state if it was only during cold engine start up. Having shown this to the dealership they decided to replace 4 pistons and rod bearings on the right side on the engine, re-used the rods and pins. At the same time they installed a new cam, new rocker arms and new head on the right side...re-using the old valves and springs. The noise never went away but the consistancy of it had changed the length of time shortened. Sometimes it would be quiet when I started it then 15 seconds later the noise would start and last 20-40 seconds.
So the dealership tried running 10w30 in it instead of 5w30. The 10w30 made the noise about four times as loud and make the noise every time I started it reguardless of how long it sat but the longer it sat the worse the noise was and the length of time would increase. I drove it for about 4 hours to go see my brother and got in it 4 hours later and it tapped for almost 3 minutes.
Dealership then changed the oil pump. No change in the symptoms from when they put the thicker oil in. Also the longer the distance that I drive the truck and then let it sit, the louder and longer it is. Now it even makes noise after only sitting for 30 minutes. But if I start it cold and don't let it warm up, just run it till the noise fades away then turn it off, the next time I start it it is virtually quiet.
Now the problem is worse and I can tell the Service Manager is getting "burnt-out" on it. I can't take it to another Service Department because now it has 70,600 miles on it (out of warranty). The dealership I have working on it is keeping an open ticket on it until the problem is fixed. I have alread paid the deductable and the problem is not fixed. Paid that when they first worked on it. I contacted the Daimler/Chrysler customer service department and filed a complaint about the engine noise and all they tell me is to continue working with the Service Department until it is resolved.
I did take it to another dealership and they charged me to tell me that I have a "sludged-up" engine and carbon on my valves and pistons....This is not true because I have seen the inside of the engine, the independent mechanic, the dealership I am working with and a mechanic friend who works for GM have all told be that the other Dodge Service Department mis-diagnosed the problem....they tried to charge me $250.00 to "flush the engine" and if that didn't fix it then they wanted to charge me $110.00 an hour to find the problem because it would not be covered under the Powertrain Warranty because the engine was "sludged-up" from poor maintanance. I told them they were wrong and at this point the Service Rep said "You owe us $48.00 and you can take your truck back to ******* Service Department and let them figure out what the problem is" Found out later all they did was removed my oil fill cap and looked at it but claimed they used a vidio device to look inside the engine including the combustion chamber....hard to do that if you don't remove a spark plug.....still had road dust on all eight of the coils and if this was done at least one would of had some sort of smudge marks on it. I left and took it to my mechanic friend and we took the valve cover off on the right side and saw that it still had the old chain and guide on it. When we looked down inside further, we saw a nice shiny new secondary tensioner pushing against and old tensioner arm. Put the valve cover back on and took it back up the the dealership and chewed butt and almost got escorted off by the police. The Service Manager didn't beleive me that his Tech didn't put the parts on. I had taken pictures and he didn't even want see them. I told him I wasn't leaving till they made it right and I stood my ground and many parts later I am here.