Oil in the coolant?

[EastCoastCB]

Originally Posted by Drew Bru

A friend who bought a bus from the same school district lot that I did had failing liner seals. He had a bit of sludge on the dipstick, took it to the IH dealer and they diagnosed the problem. Said the liner seals usually fail catastrophically instead of weeping like his were. He had the engine rebuilt to the tune of 9K or so.

Yep sounds about right. Although from about 98 or 99 to 2004 the coolant had a way of eating DT's apart inside. Pinhole leaks in the liners, failed timing cover sets, etc.

[AaronTSchultz]

Originally Posted by jazty

What you are describing sounds like normal blow-by for an older diesel engine.
Best to rule out any possible faults of course, but if everything comes back clean on an oil analysis then it might not be anything to worry about.

If it turns out nothing's wrong, that's going to be amaizing. Just as a weird possibility, is there a way to check the fill cap to the coolant, to make sure it's at 10psi?

I suppose I could also just buy the pressure tester/vac fill and pressure test the system again. It was solid 4 months ago when I filled it.

[EastCoastCB]

Originally Posted by jazty

What you are describing sounds like normal blow-by for an older diesel engine.
Best to rule out any possible faults of course, but if everything comes back clean on an oil analysis then it might not be anything to worry about.

This is a strong possibility as well. Older navistars seem to always have a bit of smoky/steamy stuff coming out of the blowby tubes.

OP- can you post pics or a vid of what's going on?

[AaronTSchultz]

I have a video on my phone, but I think it's too large to upload. Any pointers on that?

[EastCoastCB]

Originally Posted by AaronTSchultz

I have a video on my phone, but I think it's too large to upload. Any pointers on that?

upload to youtube then embed it or link it here.

[AaronTSchultz]

https://youtu.be/1hQP-iGH9CA

https://youtu.be/qXJL3ip0Ztg

[AaronTSchultz]

I think I got it. Let me know if that works

[EastCoastCB]

does the vapor smell sweet and sickly?

[jazty]

I would do a compression test pronto.


That "chugging" that is coming out of the dipstick indicates the likelihood of a bad cylinder. Maybe broken piston rings, worn cylinder walls, or maybe a cracked piston.

[jazty]

Being that you are working with a DT466e (note the 'e' part) you could also get a tech with a scanner to run a contribution test, which gives similar information to a compression test. It should tell you if you have a dead cylinder.

[AaronTSchultz]

Why am I not seeing any of that coming out the exhaust? I'm not questioning you, but trying to understand for future diagnostics

[AaronTSchultz]

Originally Posted by jazty

Being that you are working with a DT466e (note the 'e' part) you could also get a tech with a scanner to run a contribution test, which gives similar information to a compression test. It should tell you if you have a dead cylinder.

Thanks, I'm going to try that. I have a diesel mechanic that lives in the neighborhood, but more of an auto diesel mechanic, not Bus diesel Mechanic. I'll see if he has any ability to do it.

[jazty]

You're best to watch a youtube video or two on blow-by to understand it best (check out some of Adept-Ape's videos). I'll give a brief intro to it, though.


All engines have blow-by, for one. All engines pressurize air and fuel for combustion. That pressure is mostly contained, but some of it will inevitably leak past the piston rings. Either through the piston ring gaps or between the cylinder wall and piston rings. There is no such thing as a perfect seal.


As an engine runs over time the clearances will increase due to wear. Thus more and more unburnt air-fuel/exhaust mix will make it's way past the rings. That's likely the white smoke you are seeing.


If one cylinder has a significantly worse seal (bad rings, worn cylinder wall, cracked piston) than the others you will see a puff of smoke as all of it's contents push past the piston rings during the compression and exhaust strokes, into the crank case.


Diesel engines have more obvious blow-by than in gasoline engines because they are operating at much higher compression ratios.

[EastCoastCB]

Originally Posted by AaronTSchultz

Why am I not seeing any of that coming out the exhaust? I'm not questioning you, but trying to understand for future diagnostics

cause what comes out of the exhaust isn't the same as what's in the crankcase perhaps.

[jazty]

Originally Posted by EastCoastCB

cause what comes out of the exhaust isn't the same as what's in the crankcase perhaps.

To add to that, stuff that stays within the cylinder during the intake, compression and combustion strokes gets pushed out during the exhaust stroke into the exhaust system. Stuff that escapes from the cylinder during those strokes and leaks into the crankcase and needs to be vented somewhere.

[EastCoastCB]

Originally Posted by jazty

To add to that, stuff that stays within the cylinder during the intake, compression and combustion strokes gets pushed out during the exhaust stroke into the exhaust system. Stuff that escapes from the cylinder during those strokes and leaks into the crankcase and needs to be vented somewhere.

yeah this ^^^

[AaronTSchultz]

Originally Posted by jazty

To add to that, stuff that stays within the cylinder during the intake, compression and combustion strokes gets pushed out during the exhaust stroke into the exhaust system. Stuff that escapes from the cylinder during those strokes and leaks into the crankcase and needs to be vented somewhere.

Oh duh.... Sorry it's 101 here today in Denver, and I'm working on a/c here in the bus, and one of the units showed up with a cracked fan.

I really learn a lot from adept ape. Kinda embarrassed I didn't quite think through the exhaust stroke having no white smoke to push out because no compression left possibly... And all of its in the crankcase.

If it's a bad cylinder, would I notice a massive decrease In Power? Because I have not noticed that. ... Although, I am new to diesels.

I think I'm going to get the prognosis from the international dealer, and go from there.