1346 Excessive Crankcase Pressure Code

Michael Diagnostician Champaign, Illinois Posted   Latest  

Greetings, today I have a case study on a 40ft. New Flyer Transit Bus with a Cummins Isl 9 Engine that has a 0555 code for Crankcase Pressure above normal. This case study I will admit is not super complicated but I thought this has some good info for you HD Techs using Insite and also Techs on here that use the Texa unit. Here are the first two screen shots I did on the codes showing the Code on the Texa Unit and then Cummins Insite. Unfortunately Texa is still not providing Freeze Frame for the Midrange Engines on Cummins. Hopefully they will get this issue resolved soon. So if you look at the freeze frame for the crankcase pressure it is excessive. I have 20.5 inches of water. So we have an issue. I then double checked the engine protection settings in Advanced Ecm Data and found that it only shows the Crankcase Pressure Code for Derate which is 0556, it goes into Derate at 25 inches of water.

So after seeing this I hooked up Texa and went for a Test Drive to confirm the complaint. As you can see in the graph data the Crankcase pressure went to 3.25 psi and registered 4 Volts. I have also included a chart that I got off of google showing the conversion of Inches of Water to Psi. As you can see the Pressure is through the roof on this one. So of course the next logical step is to take off the crankcase filter cover and inspect the crankcase filter. Ok so the filter was plugged, I know not rocket science here but I thought this is good info to share. So I replaced the filter and did another Test Drive with Texa and everything is now peachy. Also I would like to add Texa fixed the glitch in the graphing with the latest update. You can scroll through the graph again and read exact values again. Thank you Texa. Well that is it. Short and sweet. I promise I will have more interesting ones up soon. I have quite a back log now. Just need time to do them.

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Edwin Mobile Technician
Charleston, South Carolina
Edwin Default
 

Thanks Michael for the great info. I actually have a 6.7 qsb that is throwing a p0556 code that I am going to try and get to tomorrow. I will see if I can get a screen shot of the crankcase pressure from insite to put up. Have you ever thought about using a pressure transducer to see if you can get a more accurate measurement? I thought about it but will have to find a good spot to install it…

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

Had Cummins Isx in March. That had Cylinder balance issues and alot more. Crankcase pressure was hitting above 25inH2O. We ended up doing a full rebuild along with a new camshaft(bad lobes). Engine had over 800k on it. I don't scan data on hand. But, pics show how bad Crankcase filter housing was plugged. This also had upgraded filterless cartridge.

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Michael Diagnostician
Champaign, Illinois
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It looks like coolant got in the oil. Did the Egr Cooler go bad and cause that? That looks very similar to what I see when a Egr Cooler goes bad.

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

That engine had egr deleted. Had cylinder liner issue. On Cylinder 5. Had to recut block due to liner seats being worn uneven. On this engine due to amount of contamination. I don't think my wps would have shown back pressure on road draft tube. Would have to use dipstick or oil fill. Since breather was blocked off by debris. It was hitting high back pressure at idle even. On Insite. Easily…

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Ouch, that's pretty cool you guys do rebuilding. So are you guys a full fledged machine shop as well? Every now and then at the bus garage if we can not get an engine we will do in chassis but it is few and far between. We will do Heads, cams, lifters, Pumps. But if the engine goes poof we send out for a reman, lol.

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

We send out heads and blocks. But fuel system and many other components. We rebuild or sell new. We have dedicated departments for that. With distribution across US. Alliant Power and some brands are us.

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

I saw that you said you have a wps, so you guys are using scopes that's great! Do all of you use scopes at the shop or just some of you? Sorry it is just nice to see that this type of testing is starting to catch on. I've been busting my but trying to get more Techs interested in this using this equipment.

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

I have personally bought a Pico and several accessories. Have about 4 scopes myself. The shop has a older 2 channel Pico. That I convinced then to buy. We had a problem Duramax medium duty that had issues affecting trans and engine. At the time since I did not have a scope yet I built one. Using a oscilloscope program on android market and making my own harness. Using mic input for headset and…

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

I have made adapters for trucks that have road draft tubes with filters. The manufacturer will give you an orifice spec, or you can find it on the special tool site. On these systems you need the orifice to build pressure in the system, otherwise it has open venting. Good to help find engines that need an in-frame rebuild. I use the WPS on range 3. International wanted $220 for what I can make…

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Thanks Matt I have seen this specified in the service manual as well. Guess I need to break out some fittings and try this out. Thanks Matt. I prefer the Wps 500 myself for this type of testing. I like the wps better than the first look. First reason is because you get a actual pressure reading and it is not as busy as a firstlook. Firstlook on a running Diesel Engine is a pain to decipher. Wps…

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

Here is a post from a truck: diag​.​net/msg/m2r7j23n2e…

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Hi Edwin, no I have not tried it that way. But it is a good idea. I have had good luck using the crankcase pressure sensor, has not lied to me yet.

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Edwin Mobile Technician
Charleston, South Carolina
Edwin Default
 

Hi Michael do you have a link to that sensor?

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Hi Edwin I use the crankcase pressure sensor on the engine that is already installed. It does however make a good sensor though to look at exhaust and intake waveforms. I have made a few. I have not calibrated them yet though on the Pico Software. It's on the to do list though. Just have to figure out the minimum and maximum code set criteria and then scale it. Did you get a Pico yet? Sorry…

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Edwin Mobile Technician
Charleston, South Carolina
Edwin Default
 

Michael..i have not. I got the snapon and the escope. Now if somebody from Pico wants to send me one to play with......😉

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

Snap-on is good for blow-by testing too, I use it all the time in GMM mode for this :-) Sometimes it is a pain in the butt to drag out the computer and cables lol. I just upgraded to a Triton, perfect scope for me. If I need more than 2 channels it is Pico time.

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

The Triton is a 2 channel? Got a pic to share? I would like to learn how to use multiple types of scopes.

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

Yes, 2-channel. Exact same hardware as Modis Edge.

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