A mystery ....

[UGLY OLDS]

Hey guys ....Lets start the new year off correctly .....  

You all remember my Kidd ...Lifetime Air Force guy...Yellow '37 Dodge ... Uber anal about anything he owns with wheels...( Actually wax's the inner fender panels & wheel wells on his wife's Camaro & his DD Suburban....  

 Anyhow ...The attached photos are from the camshaft from his Suburban....
It's a '08, 5.3 engine, 170K miles ,(even mix of rural/highway miles..They take LOTS of trips on the interstates )...

It has had oil changes every 5K miles at the dealer since new using Mobil One Synthetic oil..  Never late one time ...Has every service verified & logged ....Does not use any oil between changes ....Always had excellent oil pressure ..

 Here's the kicker ...This vehicle looks NEW...When the dealer opened the engine up for the camshaft repair, they were amazed at how clean it was ....NO sludge, no carbon, no residue..... The crosshatch is still visible on the cylinder walls .....

  My question ....What happened to the cam & lifters  :?:

The photos show the worst lobe & worst lifter ....There are many other lobes that are worn, ("Grooved" ?), the same way ....

Bob..

[kb426]

I don't know why but I do know that is a problem I have heard of before. Some people say it's related to the mds or whatever it's called. There is a kit that disables that and supposedly makes the valve train last longer. My thought is that it is either a lubrication problem or improper hardness of one of the materials. In other words, I don't know.

[416Ford]

I don't know anything about MDS so I am out of that discussion.
Were is it worn worse then others? Front, rear, or center of cam? I know some engine have better oiling then others. I know you know more about engine then I do so I will stop there.

[Crosley.In.AZ]

AFM  :  active fuel management system.  

I have read this system can cause lifter wear and other problems from loss of lube oil to the 4 cylinders that are deactivated via the valve train.   1, 4 , 6  , 7 are deactivated...    GM did several mods to the engine for this system.  There are AFM  delete kits

[idrivejunk]

Oh gosh... this is automotive. I was looking forward to introducing myself to a Mrs. Tree.

D'oh.

Are you guys talking about what the tuner clique calls DOD, Displacement On Demand? I have only skimmed such conversations but I may have overheard a combination of things concerning yeah a lifter roller metal or needle bearing issue and also the cylinder deactivation accelerating wear somehow. Its wierd because today I wondered what if... you could flip a switch on your rod once you got up to 70 and turn off 4? Then, if you could, would you not want it to alternate cylinder sets deactivated each time you did so? Thoughts from the commute.

Bob, rollers ain't supposed to do that    What the heck, man?  :?:  :?

[enjenjo]

From my experience with bearing wear, it looks like a lack of lubrication. Instinct tells me the roller failed and the sliding of the roller on the cam lobe caused the cam wear. We occasionally saw this on the cam rollers in Detroit diesels, and in most cases we found fuel dilution of the engine oil.

If I was making the decision, I think I would use a little heavier oil, but I am not working with the constraints factory engineers are.

[Arnold]

I don't know why but I do know that is a problem I have heard of before. Some people say it's related to the mds or whatever it's called. There is a kit that disables that and supposedly makes the valve train last longer. My thought is that it is either a lubrication problem or improper hardness of one of the materials. In other words, I don't know.

  I'm seeing  porosity in the roller. Looks pretty much identical to the "soft" cams of the mid to later 70's  305's..when you caught this at the right stage.

[chimp koose]

I believe the term was parkerizing . The coating on cam lobes that caused so many failures .

[papastoyss]

AFM  :  active fuel management system.  

I have read this system can cause lifter wear and other problems from loss of lube oil to the 4 cylinders that are deactivated via the valve train.   1, 4 , 6  , 7 are deactivated...    GM did several mods to the engine for this system.  There are AFM  delete kits

Yes, this is a "known" problem w/these engines w/AFM.The earlier models before AFM came in do not have this problem

[348tripower]

So I wonder if the reason these cams and lifters are failing is because there is not enough pressure on the lifter to keep the roller turning properly. Can that be the case when the cylinder is dropped off line?

[Arnold]

I believe the term was parkerizing . The coating on cam lobes that caused so many failures .

  According to the picture..what I am seeing..porosity..lol..like a lunar crater in that roller. That is just junk. bad pour/not aged properly..whatever. Crap steel that has been of course surface treated somehow. Surface treatment is pretty thin. Could be a wear issue in that once the surface treatment is worn off..the crater is exposed. I very much doubt that. Looks to me like the parent material became de-stabilized..and off came the coating. leaving that cavity
 When I worked as an automotive machinist the shop had crank,cam grinding,welding etc. Sometimes when I x-rayed/zyglo'd stuff you could "see" the crap below the surface.
 As Chimp mentioned.."parkerizing"..or other surface treatments. Once that stuff came off..depending on how trashed everything was by the time you got it apart..sometimes you could see the swiss cheese. If you got bad cams out and looked before they were trashed too bad you could see the swiss cheese.
 GM got into a mess of bad cranks too. Carbon Nitriding/Tuff Triding etc..especially in HD applications. They warped when treated.

  I dunno..that engine(cam roller) went 170k..pretty good really. Considering the application and engine..dime a dozen engine..slap another good used engine in it..go again. Probably be cheapest to do just that.

  I am curious if there is some wear issue in general related to synthetic oil? Too slippery/not "sticky" enough to stick into the grooves of the machined surfaces. I don't know if crank rms finishes etc have changed since synthetic oil? I dunno. I do know that there are quite a few..more..manufacturers that say NOT to use synthetic. I have a buddy who is all excited over synthetic oil and bought a new hemi. All set to put in in..the dealership told him if he put that in his warranty would end NOW. I dunno.
  The local small town 5 bay 5 mechanic just crazy busy garage I use now and again has seen a huge increase in synthetic oil low mileage engine failures. Quite a few Mobil 1. Just completely plugged..sludged up. Synthetic sure does sludge up. Just differently. The only thing so far that the owner has seen in common in these engines is 10/15,000km oil change intervals.

  I dunno..maybe? a dino oil might actually be better for these engines that shut down cylinders? I will pick my garage owner buddy brain when I see him next.

[Arnold]

Hey guys ....Lets start the new year off correctly .....  

You all remember my Kidd ...Lifetime Air Force guy...Yellow '37 Dodge ... Uber anal about anything he owns with wheels...( Actually wax's the inner fender panels & wheel wells on his wife's Camaro & his DD Suburban....  

 Anyhow ...The attached photos are from the camshaft from his Suburban....
It's a '08, 5.3 engine, 170K miles ,(even mix of rural/highway miles..They take LOTS of trips on the interstates )...

It has had oil changes every 5K miles at the dealer since new using Mobil One Synthetic oil..  Never late one time ...Has every service verified & logged ....Does not use any oil between changes ....Always had excellent oil pressure ..

 Here's the kicker ...This vehicle looks NEW...When the dealer opened the engine up for the camshaft repair, they were amazed at how clean it was ....NO sludge, no carbon, no residue..... The crosshatch is still visible on the cylinder walls .....

  My question ....What happened to the cam & lifters  :?:

The photos show the worst lobe & worst lifter ....There are many other lobes that are worn, ("Grooved" ?), the same way ....

Bob..

 I FINALLY :oops: remembered to ask my garage buddy about this. He has an Insanely busy 5 bay 6 mechanic garage. SOoo I dredged this thread up

  5.3 and 6.0's up here..pretty harsh climate..near one of the great lakes..a good 2 hrs north of Toronto. High humidity..winters..snowy..-20's..summer 90.

 5.3's and 6.0's..especially 6.0's from the time they came out. Not at all uncommon for well maintained 5.3's to go 4-500 thousand. 6.0s..get much more hard use..commercial..towing..run hard..poor  maintenance. They pretty much run forever.

 That my friends is all over :cry: My buddy began seeing the ODD cam issue. THEN as they got newer. MORE. Hunh?
SADLY..he says..it is just not that uncommon now for 5.3's and 6.0s to puke out cams. Does not seem to be any way to predict or prevent it. He doesn't see any other factors other than the cams can fail as early as 100 thou. Around 150-200 thou..ya..no surprise there.
  There is just no history up here of cam failures in these engines that are/were 15-20 years old. Anything after 2007 or so..just gets worse from there.

[chimp koose]

Factory probably figured out the durability problem ......they were lasting too long . Then comes the cost savings of lower quality parts to achieve the desired effect of outlasting the warranty....just. Remember that if they save a dollar in manufacturing a part , you need to multiply that savings by the number of units sold .

[37 FORDGE]

So, a year later... another 20-25K miles after new cam and lifter went in.  'burb is running great and all is good.  Only problem was I couldn't talk the mrs into putting a hotter cam in it.  She said it was fine for the first 150K miles, don't mess with it for the next 150K...

[kb426]

That's not bad news.