I have been helping my neighbor with a neglected 1995 Dodge Ram with the 3.9L V6. This engine is called a “Magnum” but I have to say it is pretty gutless overall. Anyway, it has the famous clatter caused by the timing chain tapping against the timing cover. Every one of these from this time period sounds like this and I understand it is a common problem. Is this a critical problem or not? I understand it can be fixed by replacing it with a newer style timing set with a tensioner. If this won’t cause damage, I say leave it alone as the noise is just a minor annoyance. I was just in as far as the water pump and was tempted to tackle it but figured it could wait.
What can happen over time is the chain will cut a hole in the cover and then the vehicle will have a massive oil leak leading to major problems if not caught in time.
Also, if the timing chain jumps time there’s a chance it could result in bent valves, push rods, and collapsed lifters. Not worth the risk if they plan on keeping the vehicle.
Tester
Ok, it sounds like this needs repair. Is this an interference engine?
I can’t tell you. I didn’t know a Ford 302 engine was an interference engine. Until a friends Ford truck jumped the timing chain and bent valves, push rods, and collapsed a few lifters.
I suppose you can let it go and see what happens when the timing chain jumps time.
Tester
I have replaced several MoPar V8 timing chains that had jumped and none had done any damage to the valve train but several had trashed the timing cover which is considerably more expensive than the one for a small block Chevy. And timing chains rarely jump as you arrive home. Murphy and Dodge were close friends.
The 3.9 L engine is listed as “Non-freewheeling” in the training manual.
If you were aware of the noise you should have replaced the chain and installed the tensioner when you had the water pump off. It would have taken an additional hour.
I’m glad you found that information, @Nevada. The 3.9 is so close in design to the V-8s but to squeeze all the performance out of the V-6 apparently meant bringing the head down or the piston up. The engine must be solid as I have never been deeper than a tune up and water pump on them and saw a few with 200,000 miles. The 318 V-8s often needed a timing set at about 200,000 miles and usually continued to give good service well beyond 300,000.
Definitely, it would be advisable to get that chain repair done soon.
I haven’t seem one break. The V-6 and V-8 use the same chain. However the V-6 has 4 fewer camshaft lobes, these voids in the camshaft will allow a closing valve/valve spring to rotate the cam forward at idle speeds, moving the slack in the chain from one side of the gear to the other causing the “slap”.
I once purchaced a 1995 Ram with 92,000 miles on it. I replaced the chain and added the tensioner soon after the purchase, I prefer not to have aluminiun shavings from the timing chain cover in the oil.
If it sounds like a problem it probably is a problem, now the only calculation left is how many miles you can go until a small problem causes a big problem.
Ok, it sounds like this needs to be done next. I regret not going for it at the same time but she said to just park the truck if it needed anything else as she didn’t have the money. Since it was immobile and sitting in my front yard, I decided to put it back together. Doh!
I know what bolts all need to come off so we can plan on this soon before I forget. It wasn’t too hard to get at the water pump and it looked like I only needed to pull a few more bolts and the timing cover would have come off.
Yes, Dodge and Murphy are good friends. Murphy and ANY MOPAR product seem to be good friends though.