Engine/Transmission (1998.5 - 2002) '02 scuffed #6

[dmckemy]

It happened really quick. I passed a large truck, pulled back into my lane and noticed a tick (like a loose rocker). Drove on a few miles it got a little louder, turned and headed for home.

Has this happened to any of you and do you know for sure what causes it?

In my case (when i passed the truck) the egt did not go above 1200, boost was 34 lbs.

The machine shop folks rebuilding my engine say they're convinced it's lack of fuel to #6, they have seen a bunch of them.

I did have to replace the injection pump about 2 thousand miles ago. Lift pump pressure is 14 lbs all the time at the pump.

 

[Mikey-KE7LBB]

Kind of amazes me that one can suffer this amount of damage from passing a truck with EGT and boost far less than someone on the extreme side with a pulling truck producing 90+psi boost and who knows what kind of EGT.



Have you looked at the cooling on #6??? Maybe a bad cast on block/head that wouldn't allow sufficient cooling to the rear cylinders???

 

[PVanderlugt]

Kind of amazes me that one can suffer this amount of damage from passing a truck with EGT and boost far less than someone on the extreme side with a pulling truck producing 90+psi boost and who knows what kind of EGT.





It is not strictly boost or pyro that matters, timing is far more important than either one of those. You can roast an engine real quick with timing and never see boost or pyro go outside of accepted limits.

Pete

 

[WestTN]

You haven't been running Fram oil filters have you?

 

[cerberusiam]

The machine shop folks rebuilding my engine say they're convinced it's lack of fuel to #6, they have seen a bunch of them.

I hate to say it but I think you had better find a shop that knows diesels a little better. These guys sound like gasser jockeys and thats all. Diesels don't melt pistons from a lean fuel condition, they just loose power.



Too much fuel, too much timing, or plugged piston cooling jets is the likely cause. Number 6 is problematic because of its location and the restriction in air so a little too much fuel plus timing on a hot cylinder and stuff happens.

 

[ata]

For the amount of damage on that piston I don't think it all happened in one quick pass. I don't think EGT's had a lot to do with it either. That cylinder has been run hot (water temp) or there is a lack of oiling and oil cooling from the bottom end. (oiling jets) Make sure your machine shop checks and makes sure all the oil passages on the crank and block are clear. If it was EGT's the top of the piston would show something. But what little of the top and rings of piston I can see it looks good. Like said lack of fuel on a diesel is lost of power not heat.

 

[CAPTPHIL]

Welcome to the club, My dues were 10,500 dollars. The same deal, at 535000 mi. The Tick turned into a knock. The problem was narrowed to a bad injector or a clogged piston oiler. We bored and sleeved #6 and rebuilt with six new standard pistons. All six injectors were bad. That was not a result of getting on the loud pedal one tlme. This is normally caused by lack of lube to the piston or washing of the cylinder by a injector.
Good Luck Capt Phil

 

[Vaughn MacKenzie]

How about a pic of the top of the piston?

There have been two other guys I've read about on TDR over the years melting a piston at about 1200F, both times a 24-valve. Gauge accuracy can also contribute to such a problem as there isn't much safety margin at 1200 if sustained very long.

 

[Sticks]

Agreed, your mechanic has no clue.

I am in the middle of replacing an engine (5. 9 12v) in a piece of equipment at work. Only symptoms prior were a miss, and excessive blowby.

Cracked injector lines and #6 had very little fuel. Bad delivery valve. Swapped out delivery valves and #6 still missing. Compression test was 30psi.

Upon engine removal and dis-assembly, #6 was melted and only 1 piston ring left. Cylinder wall was done, valves dinged up from debris, and #5 evidently swallowed some debris (minor scratching). Rolled the engine over and #6 cooling jet was MIA as well.

Cheaper to replace engine than rebuild.

Lesson to everyone. You get a miss, find it and fix it ASAP.

Other than installing an EGT probe on all 6 cylinders, I have no idea how one would catch a missing cooling jet.

 

[aharman]

When did they start putting piston cooling nozzles in the Dodge 6B's? I thought they didn't have them until 2003, when they went to the common-rail version.

 

[CAPTPHIL]

Started with the 01. 5 HO engines, most people don`t know that these engines are different
inside when compared to the standard ISB`s for these model years. They could only be purchased with the NV 5600.
Good Luck Capt Phil

 

[cerberusiam]

Started with the 01. 5 HO engines,

Ahh, no.



The B series has had piston cooling of some type since it rolled off the production line in the 80's. Integral piece to their longevity.



There have been a couple revisions to the jets, placement, and pistons over the years but the big change is the gallery cooling that started in the late 03 HO's handle the much higher sustained temps of an emissions engine.

 

[CAPTPHIL]

Ahh, no.



The B series has had piston cooling of some type since it rolled off the production line in the 80's. Integral piece to their longevity.



There have been a couple revisions to the jets, placement, and pistons over the years but the big change is the gallery cooling that started in the late 03 HO's handle the much higher sustained temps of an emissions engine.

Thats why TDR is so great. I can continue to learn. My personal knowledge is limited to 98. 5 to 02 ISB engines. As you can see by my sig. over a million miles on them and I will ride. the 01. 5 to my funeral.

Thanks for the correction, Capt Phil

 

[EDankievitch]

Piston Cooling or rather lack there of that's the only way you'd do that much damage.

 

[Sticks]

Piston Cooling or rather lack there of that's the only way you'd do that much damage.

Cylinder wash from dribbling injector or low compression would do it too.

 

[aharman]

Ahh, no.



The B series has had piston cooling of some type since it rolled off the production line in the 80's. Integral piece to their longevity.



There have been a couple revisions to the jets, placement, and pistons over the years but the big change is the gallery cooling that started in the late 03 HO's handle the much higher sustained temps of an emissions engine.

This is a reason I have not been getting more aggressive in fueling up my '01 SO.

Maybe I was thinking of the change in piston design, from standard to gallery-cooled. I did not realize the change was in '03. I thought it was with the HO engine in '01. 5.



(Note to self: If you want to build a stronger engine for your truck, get '03 pistons, and the cooling nozzles to go with them. )

 

[cerberusiam]

Maybe I was thinking of the change in piston design, from standard to gallery-cooled. Could that be the difference between SO and HO engines at the '01. 5 model year? This is a reason I have not been getting more aggressive in fueling up my '01 SO.

I think they changed the nozzles some for better cooling but not positive on exactly what it was. The gallery cooling was only on the CR HO engines, not on the SO's or 24V's, those are still the splash cooling.

 

[Midnite]

I've been wondering for some time about the benefits of an additional oil cooler, and this thread brought it to mind again. I guess if the oil isn't actually getting to the bottom of the piston then it doesn't really matter though.

I was thinking more in line with having a greater margin of safety at higher EGT though.

 

[DIESELWRKS]

I learned a lesson with my latest rebuild. #5 intake valve was broke and then chomped in to piston. Rip at sourceautomotive did rebuild he said it got really hot the color and look of under the head he said it had some heat to it. I had a 62/14 HTT at the time it wasn't that I didnt have enought air to cool, but thought I was. the only thing was found out later the pyro was not accurate on upper temps around 1200 deg, it would not read right. after 2 1/2 years the pyro was not registering. I saw it do this slowly over time . should of replaced it then. but I didn't and over time of towing, Daily driving and driving like a idiot. well it caught up to me. all new pistons. head work, cam, springs. some people have great knowledge and ears listening to these engines. I cant hear in stereo anymore the Marine Corps around to much explosive and big guns to long. but bottom line if you think something is sounding wrong etc. get it checked out.



2002 HO 6-SPD LB 4X4 QC BD 64/71/14 SB-DD3600 TST PM3/SMARTY MACH 4'S, RINGS/STUDS, BIG STICK,SPRINGS,HTT 3 PIECE,AFE/2 " 5" EXH GAUGES, FASS 150,DRAW-STRAW, DSS-BOX DT PRO-FAB TRAC BAR, CONV-T STEERING,BORGENSON BOX AND SHAFT,DUNKS TRACTION BARS, AIR BAGS,37" TOYO MT'S 6" RCD LONG ARM LIFT. . . THANKS RIP www.sourceautomotive.biz

 

[Vaughn MacKenzie]

Pre gallery-cooled 24-valves can take a heck of a beating provided you keep the EGT in check. No need to switch to gallery-cooled pistons IMO.



I am thinking dkemy's #6 somehow got a chunk of debris thrown up that got wedged between the piston and cylinder wall that chewed it up? I have never seen a scuffed piston where the crown shows no sign of overheating. Also notice it seems to just be on one side but can't tell for sure without more pictures.