oil for worn dodge 4.7, 175k, noise @ hot idle

[ksJoe]

I bought a 02 dakota quad cab 4.7 that a dropped valve seat. While replacing the seat, I saw one of the cam bearings was badly galled. The guy at the machine shop said that's common on this engine, and recommended replacing the cam but not doing anything about the aluminum bearing in the head (its not a replaceable bearing). So that's what I did - just replaced the cam.

Current oil is 5w30. At hot idle, I hear a rocker chattering, which I've read is common on this engine.

I don't think it uses oil, but I'm not sure since I've only put 1k miles on it since fixing it. It has around 175k.

I expect to put 2k on it per year, doing stuff like: taking jet ski to the lake, hunting, driving in bad weather/snow, whenever I need a truck.

I'm thinking about 10-40 or 15-40, to see if that helps the noise. thoughts?

 

[LargeCarManX2]

Try Mobil 1 10w40 and change every two years with that amount of miles per year.

 

[Durango]

Originally Posted By: ksJoe
I bought a 02 dakota quad cab 4.7 that a dropped valve seat. While replacing the seat, I saw one of the cam bearings was badly galled. The guy at the machine shop said that's common on this engine, and recommended replacing the cam but not doing anything about the aluminum bearing in the head (its not a replaceable bearing). So that's what I did - just replaced the cam.

Current oil is 5w30. At hot idle, I hear a rocker chattering, which I've read is common on this engine.

I don't think it uses oil, but I'm not sure since I've only put 1k miles on it since fixing it. It has around 175k.

I expect to put 2k on it per year, doing stuff like: taking jet ski to the lake, hunting, driving in bad weather/snow, whenever I need a truck.

I'm thinking about 10-40 or 15-40, to see if that helps the noise. thoughts?


ksJoe,

I have an 01' Durango with the 4.7 that had bad engine troubles at 90K!!!Apparantly I had a bad valvethat had accumulated too much carbon due to using non-Top Tiered gas which was a pretty big discussion a couple yeras ago. Your lucky you got to 175K before your engine went south. If your not consuming excess oil during driving I's just stay with useing a 5W-30 synthetic oil myself instead of going to a heavier weight oil.

Durango

 

[Thax]

I would avoid a 30 weight in a 4.7 , these motors are not fond of thick oil. There are several 30 weights that are on the thick end that may help , M1 HM 10w-30 , maxlife , defy or rotella T5 are some that I would use.

 

[mechtech2]

So exactly how did you set the lifter preload?

 

[CATERHAM]

If the rocker noise when hot bothers you, you could try a heavier but high VI oil like M1 0W-40 and see if it makes a difference. If it does this oil will have the least affect on your start-up performance.

 

[ksJoe]

Originally Posted By: mechtech2
So exactly how did you set the lifter preload?


I did not. I didn't think that was possible on this one?

It has an overhead cam with hydraulic lash adjusters (which I think is the proper name for a "lifter" located in the head). The rockers are not adjustable. Post 4 of this takedown thread shows photos.

From what I've read, this engine is prone to dropping valve seats, galling passenger side cam bearings, and having rockers fall out when oil pressure dips. My rockers haven't fallen out, but I do get some clatter at warm idle.

 

[tommygunn]

I'd run 0W-40 Mobil, or even Rotella 5W-40. Just something to thicken up and basically muffle the looseness in the valvetrain. Thats all you can really do at this point. Something with a good low temp value would be beneficial if you wanna use it when its cold out though.

 

[number_41]

Is the 3.7L V-6 also prone to the same problems?

 

[ksJoe]

My hesitation for 0w40 or 5w40 is that they are only available in pricier synthetics. I wouldn't mind, except that I figured I ought to change the oil at least once a year due to moisture, and it seems like a waste to only use that kind of oil for a couple thousand miles. That's why I was thinking about 10w40 (generic dino) or 15w40 (Rotella).

When LargeCarManX2 said leave Mobile in 2 years, I thought someone would disagree with him.

If I use synthetic 0W40 Mobile or 5W50 Rotella, how long can I leave it in until moisture becomes an issue?

 

[ksJoe]

Originally Posted By: number_41
Is the 3.7L V-6 also prone to the same problems?


Not that I'm aware of. If you want to know, look at dodgeforum.com. They also have some stickies for factory service manual pdfs on some years.

I bought this truck last winter because I wanted a cheap truck as an extra vehicle. It was barely running at the time because the dropped seat was holding an intake valve open. All I know is what I learned in the last few months while I was repairing it.

 

[KCJeep]

Originally Posted By: number_41
Is the 3.7L V-6 also prone to the same problems?


I don't have one, but from spending a lot of time on Jeep forums, yes it is.