Gray green substance under oil cap - Cummins ISX15

[SupVit]

Unfortunately this is not moisture. Something else.
Cap just after 1500 miles through NC and TN, sunny days. Excessive blowby (at least I'v never seen it before).
With old oil this substance was dark gray green, now much lighter.

[Rawze]

Looks like coolant in oil. Even if you have red coolant, it usually makes for green-ish tinted slime.

Any coolant seeping into the oil system will eat the engine up alive real fast. - Pull the oil pan off it, pressurize the coolant system to 20-PSI and let it sit over night. Take no chances with it...

(04-06-2018 )Rawze Wrote:  ...
- We let it sit over night with 22-PSI pressure on it until next morning. Low and behold, we searched and searched and there was zero signs of coolant getting into the oil at first. Sometimes it is obvious, but sometimes it is hard to find. We wiped everything down and spun the engine a few times over by hand and could not immediately find any kind of coolant intrusion problem even though it is clear that there is a problem with the head, a gasket, liner... something. After looking and wiping things down under the engine, we decided turned it by hand some more ... slowly to see if we could get a better view at each cylinder. While turning the engine over by hand very slowly, when piston number 5 came up on a compression stroke, it started to gurgle and tiny droplets of water/coolant started to pour down the inside of the liner wall. Number 5 piston was leaking coolant out of the bottom of the piston. So far this tells us that there is a problem in the head or the head gasket.
...

ref: http://rawze.com/forums/showthread.php?t...6#pid25356

[SupVit]

Yes, this will be right way to save engine. I saw on the forums, you told people many times to use this method.
What does this substance smell like? There is no smell of coolant. Smells like diesel engine exhaust + hot oil.
Asking because I don't see change of coolant level, color of coolant, oil level. Nothing. But substance appears fast.

[SupVit]

Also there is another change of engine work.
Engine knocks when I push throttle pedal.
The heavier the moment on the engine, the louder the knock. Quieter at 1100, increases significantly after 1500-1700 rpm (when heavy truck climbs the hill). Almost every day when I pull a heavy load in the mountains, at the end of my shift I hear the engine works louder. Something deteriorates faster under heavy load. Knock is almost absent at idle.
Absent during engine braking going downhill. So the problem somehow intersects with the operation of the fuel system
The knock frequency is 2 times less than the engine speed (I recorded the sound of the engine, slowed it down 4 times and counted the knock frequency). The knock goes, it seems to me, just above the compressor. Maybe the head gasket near 1, 2 cylinders ... And now I think maybe, because of the gasket, there is a mixing of fluids. And knocking is combustion high pressure. It's time to take the head off and look for the problem.
The knock began to appear in the summer of 2019. I already went to the Cummins dealer to test the fuel system, they did not find anything. Went to Rush Center - same result. Went to experienced mechanic -same. Few thousand dollars wasted but nobody knows. It looks like it's time to just open the engine. Probably it's the same problem...
There is about half an inch of foam in the coolant tank. I thought before it's okay, because liquid flows into the tank and foams. But now I think foam is here because of gases going into cooling system through the gasket.
Somehow everything goes in logical chain too easy :-))

[Rawze]

is this truck deleted? ... or all the emissions still intact?

[Rawze]

(03-05-2021 )SupVit Wrote:  ... went to the Cummins dealer to test the fuel system, they did not find anything.
...Went to Rush Center - same result.
...
Went to experienced mechanic -same. Few thousand dollars wasted
...

sounds to me like you've been taking it to the wrong places.

Most OE cerrtified places are nothing but gaggle of clueless idiots who r trained to do thing but put a computer on it, sell you the most expensive solution to put out the fire while solving little to no problems, and take your money!

[SupVit]

yes, the emission system is working, not deleted. I take good care of the system, do not allow idling for a long time, DEF is always almost a full tank. Truck never asked for regeneration, always does it on the road.
Summer 2019 Volvo+Cummins dealer tested the fuel system on the road and in the bay, changed the operation of the injectors, the amount of fuel. Said the computer shows no problem.
Nov 2019. A private shop can fix everything, smart experienced mechanic. But, unfortunately, a new employee worked with my problem. Decided to change the compressor, I immediately agreed (I was a very young owner :))). Ride around the area, no knocks. But nothing has changed when you pull the trailer and the load.
Jan 2020 Rush center, useless guys. They found driveshaft timing, windshield brades worn out (I bought them 2 weeks before :))), bad buttons on the steering wheel and bad a/c dryer.
And my friends said me at that moment to wait little bit because problem has just begun to appear and I will spend a lot of money looking for it.

[Waterloo]

Personally, I would get a load to Atlanta and go see Mr Hagg... Haggai Automotive and Diesel repair, Griffin GA. 678-688-8107

[SupVit]

Done on the truck since summer 2019:
Overhead adjustment (work surfaces look new)
Checked for metal plungers and surfaces in the fuel pump. Practically new.
New compressor.
New crankcase filter, imap sensor, air dryer+governor, coolant oil fuel filters.
Checked for rail pressure few days ago (I have small code+main parameters reader). 7800-8000psi on idle. After stop the engine - 7900-7800 for 40 minutes.
All, except compressor, done by me on my truck parking lot. All done step by step according to pdf documents on Quickserve site.