Dodge 1500

My 2005 Ram 1500 makes a knocking noise (like a diesel) when i first start it up. The colder it is the louder it is. Once warm it is quite and i have no performance issues.

Your bearings are shot, your looking at a lower end rebuild at a minimum. You maybe able to get it to lessen by putting in a lighter weight oil such as a 5w/30 as opposed to a 10w/30, but its not going to fix it. The problem will get worse, and the more you drive it the more you risk damaging the block and the crankshaft.

Well, I get in trouble every time I comment on Car Talk, but It might just be a valve lifter a little faulty, and could last another 100K miles. It could be a lot of thinags that don’t require a lower end rebuild.

“Once warm it is quite”

Of course, I assume that’s just a typo and he means quiet, but I agree with Elly - I refuse to say whether it’s the first time or not :). This could be fiarly minor and last years with this knock. Don’t forget that most people can’t tell the difference between a lifter rattle (?) and a bottom end knock.

Deer1224, what weight oil are you running in your Ram 1500/2500 (you said one, selected the other), what engine do you have, and what’s the mileage on it? Have you been performing regular oil changes, and at what mileage interval do you do them?


I have a 2002 Chrysler minivan with a 3.3 V-6. My lifters would rattle on cold start up. On a Chrysler forum I read that the Mopar and Fram filters that I was using had anti-drainback valves that didn’t work very well. They suggested Motorcraft FL-1 filters for my van. Problem solved. I don’t know if the FL-1 would fit your truck, the threads and gasket fit my van but the filter is much longer than the one I was using. I would try getting the right Motorcraft filter for your truck if it is the lifters. Any mechanic should be able to listen and tell you if it is lifters or bearings.

You may have a piston slap problem with your Ram 1500. Piston slap occurs when the piston skirt hits the cylinder wall. The noise lessens or disappears as the engine warms up. The old straight 8 Pontiac engines were notorious for this, but the engines seemed to run forever If this is the problem, it isn’t a big concern.

If the bearings were shot, the noise would start out quieter and get louder as the engine warmed up and the oil thinned with heat. I think piston slap is likely the problem, though these engines aren’t really known for it. It could also be valve lifters.

Noisy lifters are common on the 5.7L (Hemi) on a cold start, even when new. A noisy timing chain/guides is a possibility on the 3.7/4.7L. We can only guess, you should have someone listen to it.

Oblivion you have it backwards oil thickens as it heats, well it’s viscosity goes up I should say. I understand what you mean which is why I sugested a lower viscosity oil for start up.

I thought about lifters but I have found that lifters usually stop tapping as soon as oil pressure builds. The op said it does not stop untill the motor warms up

Gsragtop, all you need to do is look at your oil pressure gauge as your car warms up or pour some oil from a container on a cold day vs. a warm day to confirm what I said. While oil ‘protects’ at its rating once it warms up, the base stock does thin. And I have personally observed many vehicles with rod knock getting louder as the oil warms up.

Sorry for the second comment… my web browser decided to be flaky and apparently not post this the first time…

“Oil thickens as it warms up” ???

Yeah, “Oil thickens as it warms up” ??? This is why I like Car Talk!!