M923a2--8.3 has alot of blow by at oil dip stick

[gem1410]

I have an 8.3 in a m923a2--I took it out today for the first time since I got it--oil level was good with clean oil--had to add 1 gallon antifreeze--everything looked good--after 2 hour 45mph ride there was alot of blow-by at the slobber tube and the oil dip stick--also had a nice oil drip out of the hole in the housing behind the engine--engine ran well and sounded normal--oil and antifreeze levels are good--Is this blow-by a normal condition--Thanks george ----video shots http://youtu.be/nObwREObk-Q ---------------http://youtu.be/tWTpbg1K7-8

 

[gem1410]

other video of slobber tube---http://youtu.be/tWTpbg1K7-8

 

[Suprman]

Seen that before it was bad rings on one piston. Is the same thing coming out of the drip tube?

 

[R Racing]

If it were a Cummins 250 I would be concerned.

 

[gem1410]

yes it is--did not have either until after the run--

 

[Suprman]

Hard to tell from the vid. It is possible there was some water in there that's burning off. It's possible you are loosing coolant and it's boiling off. Does the oil show any foam? That blowby is not right either way it looks like combustion going into the crankcase. How was the temp?

 

[gem1410]

The temp stayed steady normal-- center of gauge--coolant level remained steady--old coolant smelled burnt and looked dark--no extra pressure under rad cap--truck may have sat for years at the base--first hot run--no oil in coolant/no foam on oil stick--oil still clean--what could i video to give you a better look--thanks

 

[Rmtaunton]

For best hopes I would change oil , and start again a little and I mean little bit of water will do that , I am just hoping for the best , good luck

 

[patracy]

That's excessive in my view. I'd be concerned with a ring issue.

 

[Suprman]

You shouldn't be over 205. Was your fan coming on?

 

[gem1410]

I bought it at a location last winter when it was very cold and starting fluid was not spared by the crew at the lot --I agree it looks excessive

 

[Suprman]

Starting fluid is a known culprit of ring damage. Do you hear a pulse or popping coming from the intake stack? If so then it's def combustion and you will need to pull the head and take a look. You will probably see ring pieces melted onto the piston top. A cylinder and sleeve kit with am upper and lower gasket set should cure it. Probably only one bad out of 6. Been there done that it's not too bad. A local machine shop will be able to clean up the head if needed.

 

[gem1410]

I did not hear the fan engage --on returning the engine idled for 5 minuets--then I removed the coolant cap and there was no excessive pressure and the coolant was the same level as before the run---no popping or pulse from the exhaust--I will get up a video with sound of the exhaust tomorrow

 

[Rmtaunton]

You have two of the best helping you now , listen to them !!! Oh and I am not one one them

 

[Suprman]

If you have valve damage on that cylinder you may hear a pulse from backpressure coming up the intake stack. A diesel shop has test equipment that will give you an exact diagnosis pretty quick. It may be worth the few bucks taking it to your local Cummins dealer and get their opinion prior to tearing it all apart.

 

[patracy]

I did not hear the fan engage --on returning the engine idled for 5 minuets--then I removed the coolant cap and there was no excessive pressure and the coolant was the same level as before the run---no popping or pulse from the exhaust--I will get up a video with sound of the exhaust tomorrow

The fan is temp controlled. But there's a chance the pneumatic switch never engaged it. I'm just a little confused about the coolant being low. So coolant has remained at level after that first fill? There's only a hand full of ways what we see can happen. Ring/piston/cyl wall damage, headgasket damage, or a crack/leak from the coolant system. Since we're not certain what this is exactly, take a mirror and place it over the oil cap. Water vapor will fog up the mirror. Blowby will not.

 

[gem1410]

I listened and there was no pulsing from the intake stack--there was not fogging on a mirror placed over the oil cap hole or at the blow-by tube --I know you guys are correct--ring or cylinder damage--I ran another 8.3 today and had no blow-by at the oil dip stick and very little smoke at the blow-by tube--Thanks very much for your time and helping me with very specific tests--George

 

[Suprman]

Don't let the repair scare you it's not that bad especially if you can do it yourself. I have the sleeve tool kit here in CT you can borrow it as long as you bring it back. It's 200 bucks for the cylinder and sleeve maybe another 300 bucks for gaskets. 200 for new fluids and whatever you pay to have the head cleaned up if it needs it. If you don't have back pressure in the intake then the head may be fine. I took pics of everything as it was taken apart. It was summer when mine was done but you can probably tent over the front of the truck to do it.

 

[74M35A2]

Cummins typically will not specify cranking compression specs, but they do for leak down I believe. Regardless, you could measure the specs of all 6 cylinders against each other, and see if one is weak. Then you would know what to ask for Christmas. There should be tools, or one could simply convert an injector to do so.

What at does the vapor smell like? When I was shopping for my 925A2, the first one I looked at had blow-by like that, and it smelled like burned oil.

 

[plode]

My truck occasionally has "blowby" like that out of the slobber tube, and sometimes a decent amount of smoke..., sometimes it doesn't. It's weird. Sometimes it's zilch, sometimes it's the same as the video.
Truck runs great however. I've never done a rebuild as in depth as replacing pistons and sleeves...but considering the price I think it'll cost to have it done...I think I should at least try.