Skip to main content ↑ ↓
Topic: smoke coming from the engine near the fuel filter area (Read 551 times) previous topic - next topic

smoke coming from the engine near the fuel filter area

I was pulling into a campsite yesterday and I noticed smoke coming down from the engine in the area of the fuel filter.  I didn't get a good look at exactly where it was coming from.  I could barely see it but it was there.
It wasn't steam.  It almost looked like exhaust smoke.  The engine runs fine.  I have an appointment to have the oil changed next week. and I am going to have them check it out.  But I was wondering if anyone had experienced this before. 
It is a Cummins M11 450 HP. 

Thanks
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #1 –
Before moving it, you need to determine exactly what it is. Hate to see a coach go up in flames!

If posting a picture of the area would help, please do that.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: smoke coming from the engine near the fuel filter area

Reply #2 –
Do what Brett said,try and find a leak,the shop will be looking for a leak at $200 an hour,you can look for less.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: smoke coming from the engine near the fuel filter area

Reply #3 –
Fuel filter as in along the passenger side frame rail?  A bad battery cable (or a bad battery) could smoke.
Matt B
1998 u-320

Re: smoke coming from the engine near the fuel filter area

Reply #4 –
It's on the passenger side.  It's the one they fill up with diesel after they change the filter.
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #5 –
Does the '98 U320 have a "slobber tube" ?
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: smoke coming from the engine near the fuel filter area

Reply #6 –
I've never heard of that before.  I'm not sure.  I was reading about it. 

It does seem like the kind of vapor that you see when you open the valve cover where you put oil in on a car engine.

Is it just a hose that allows excess oil to escape?
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #7 –
Quote from: 18360 –
I've never heard of that before.  I'm not sure.  I was reading about it. 

It does seem like the kind of vapor that you see when you open the valve cover where you put oil in on a car engine.

Is it just a hose that allows excess oil to escape?

In my 1997 u295  different engine, it was on the passenger side. It is a vent for the crankcase. It's a hose that ends about the bottom of the engine..
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: smoke coming from the engine near the fuel filter area

Reply #8 –
Here are the pictures.  The slobber tube is right next to the fuel filter.  I can see now this is where the "smoke", bad choice of words, is coming from. 
Is this normal.  Do I need to clean it or change it or what? 
Can I drive an hour to home.
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #9 –
Try taking the oil fill cover off when running the engine and see what happens,it is on the valve cover,do that and let us know what happens.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: smoke coming from the engine near the fuel filter area

Reply #10 –
It's normal to see some oily smoke from here when the engine is hot, or at operating temp. As long as it's not excessive which could indicate other issues. Someone more familiar with the M11 ( assuming that's what you have) may chime in on this topic.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: smoke coming from the engine near the fuel filter area

Reply #11 –
Check oil level.  If overfilled, the slobber tube gets a lot more oil/vapor. When you do check the oil with the dipstick, look and smell it.  Any sign of diesel fuel in it?  Let us know oil level and your assessment of its condition.

By chance has the engine been started and just idled for "exercise"?  That will help explain the excessive moisture coming out.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: smoke coming from the engine near the fuel filter area

Reply #12 –
Any chance you could make a video of the "smoke" could always send it to one of our phones,you said you were getting a oilchange,how many miles and time on the oil and what brand and weight?
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: smoke coming from the engine near the fuel filter area

Reply #13 –
Before you have an oil change on that engine call Cummins with your engine number to confirm how many quarts that engine/oil pan combination needs. On some engines they don't need what the FT book calls for.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: smoke coming from the engine near the fuel filter area

Reply #14 –
I checked the oil.  It is pure black and smells only like oil.  The level is exactly where it should be.  Someone at some time wrote on the block 35 qts. 
Now whether the last guy who changed the oil only put in 35 qts in or used the dipstick to determine the level, I don't know.
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #15 –
I usually start it and go.  However, a few weeks ago I had the AC worked on. I left it there. I know it was in and out of their shop several times.
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #16 –
I have a video, but I can't send it on this platform.  If I can have someone's phone number i can send it that way.

Thanks
Rick & MJ Berry
1998 U320 40'
Ohio

Re: smoke coming from the engine near the fuel filter area

Reply #17 –
Quote from: 18360 –
    Someone at some time wrote on the block 35 qts. 

That leads me to believe that you have the short oil pan like ours as that is what ours takes not 42 qts. like our FT book calls for.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: smoke coming from the engine near the fuel filter area

Reply #18 –
Got the video from Rick,at idle it looks like the puffs from an old steam engine ,the puffs sort of correspond with the rpm,he's
not sure what brand or weight oil but is has been a year and has about 7K miles,my advice was to have Cummins check it and
get a oil sample and maybe a compression check,also not using oil and no leaks,what do our M11 gurus think?
96 U270 BUILD 4810
85 380SL
Drummonds TN.