CM 870 Smoking white

[tree98]

Looks pretty normal to me

[Ken Worth]

(01-26-2025 )tree98 Wrote:  Looks pretty normal to me

Also discovered injector 1 and 2 leaking and this is number 4 injector rocker. Would this be my smoking issues? The rocker arm? Is this a case to change cam and rocker asap or can I get away with just changing the rocker arm/ roller. For a while before having to replace the cam? All the other lobes, rollers, are clean no scratches

[Ken Worth]

Pictures of cam lobe.

[tree98]

No that wouldn't be the cause of the smoke but your cam and rockers are going to need replacing soon. Do the rest of the cam lobes look grooved or scarred as well? What about all the other rockers?

[Rawze]

(01-26-2025 )Ken Worth Wrote:  Pictures of cam lobe.

its right on the edge of failure.

make sure your crank case breather tube and the screen mesh behind the top gear cover are not clogging up. Poor crank case ventilation is the number one cause of cam failures due to oil starvation of the top end when the engine cannot breathe well enough.

The number 2 cause is not adjusting the overhead valves every 2 years / 250k miles.

[Ken Worth]

(01-26-2025 )tree98 Wrote:  No that wouldn't be the cause of the smoke but your cam and rockers are going to need replacing soon. Do the rest of the cam lobes look grooved or scarred as well? What about all the other rockers?

No all the others look good maybe some discoloration but no visible marks or dents. Only this one.

Do you think they both can keep going or should I look into changing at least the rocker arm+ roller for now? Or is that pointless with out changing both to be nice and smooth?

[Ken Worth]

(01-26-2025 )Rawze Wrote:  

(01-26-2025 )Ken Worth Wrote:  Pictures of cam lobe.

its right on the edge of failure.

make sure your crank case breather tube and the screen mesh behind the top gear cover are not clogging up. That is the number one cause of cam failures due to oil starvation on the top end when the engine cannot breathe well enough.


number 2 is not adjusting the overhead valves every 2 years / 250k miles.

Is this mesh screen behind the cover where the breather tube comes out of? Front of the engine? Top right.

And do you think I should bother trying to change the rocker arm+ roller now or is that pointless and just send it untill cam shaft gets eaten up more?

[tree98]

(01-26-2025 )Ken Worth Wrote:  Is this mesh screen behind the cover where the breather tube comes out of? Front of the engine? Top right.

Yes

(01-27-2025 )Ken Worth Wrote:  And do you think I should bother trying to change the rocker arm+ roller now or is that pointless and just send it untill cam shaft gets eaten up more?

To do it right you need to change that cam and all the rockers that ride on it. I would do it within the next few thousand miles at the most. If you wait to long it's going to start flaking metal off into the oil and causing more damage to other components.

Be glad you caught it when you did. And honestly if the injector cam is in this condition then the valve cam is probably right behind it, rocker shafts are probably wore out, it's likely time for everything up top to be replaced.

[Rawze]

(01-27-2025 )Ken Worth Wrote:  ...
Is this mesh screen behind the cover where the breather tube comes out of? Front of the engine? Top right.

And do you think I should bother trying to change the rocker arm+ roller now or is that pointless and just send it untill cam shaft gets eaten up more?

Newer model ISX's have a crank case filter, which many people end up bypassing or using a maint.-free version at some point after having issues like this.
ref: http://rawze.com/forums/showthread.php?t...376#pid376

Those filters are the premature death of overhead cams and having turbo problems ... but your model engine does not have this. It has that mesh (looks like a big brillo-pad) on the back side of the top gear cover instead.

---------------------------------------------
I would say that its already on its way out ... but has not failed yet.

If it were mine, I would just keep an eye on it for now ... its not an emergency at this point ...

== Do a full overhead valve adjustment.

== DO the next 3 oil changes at about 5,000 mile intervals to get rid of all the soot-packing that has built up in the block/engine over the years.

== And also run a gallon (12% mix) of decent modern brand of gear lube, 80/90 or 85/140 to raise oil viscosity and allow that cam to live a bit longer.

==============

Since you say your turbo is bleeding oil too...

Turbo will often bleed oil if the crank case pressure builds up in the engine as well, so ...

I would, yes, ... remove that top cover and clean out the Brillo-pad mesh on its back side, or replace the top cover all together. Also ensure the breather tube is not clogged anywhere along its length. One never knows if there is an insect nest up in it, dirt, or whatever.

last but not least, after getting the block free of excess soot/carbon buildup .. change oil based on fuel mileage instead of some arbitrary number, so that all the internals live their longest life possible.
here is a chart to go by...

Rawze Wrote:If your average fuel mileage every 10,000 miles is ...

less than 5 MG -- Change your oil every 8,000 miles or so.

5 - 6 MPG -- Change your oil every 10,000 - 12,000 miles or so.

6 - 7 MPG -- Change your oil every 12,000 - 15,000 miles or so.

7 - 8 MPG -- Change your oil every 15,000 - 18,000 miles or so.

8 - 9 MPG -- Change your oil every 18,000 - 22,000 miles or so.

above 9 MPG -- Change your oil every 22,000 - 28,000 miles or so.

ref: http://rawze.com/forums/showthread.php?t...617#pid617

-- Then, I would check it again in 6 months, and take more pics ... compare them to the pics you already have, monitor wear rate, and ensure it is not getting chewed up by then. Save up moneys in the mean time by slowing down, conserving fuel, etc.. to get ready for that kind of a medium-big repair job.


and here is more info on the excess can wear issue that ISX's will suffer ...
http://rawze.com/forums/showthread.php?t...783#pid783

just my thoughts on it any ways.