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Topic: Oil Build Up - Need help to identify part (Read 844 times) previous topic - next topic

Oil Build Up - Need help to identify part

I have a considerable oil build up occurring that has translated into a few drops that are getting blown around the engine bay while driving. I have attached a few pictures for reference.

The coach is a 2002 with the 8.9 400 ISL engine. The leak appears to be coming from the part in the picture which is located on the drivers side rear of the engine near the giant oil filter.

I am guessing I need to replace the gasket but am fearful it might be more. I have not cleaned the engine and taken another picture. I wanted to clean and replace at the same time if possible. I also noticed a good bit of oil buildup by the (blow by tube??). I try to not let the engine idle more than a couple minutes.

As always I appreciate any help you can provide.
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX

Re: Oil Build Up - Need help to identify part

Reply #1 –
Best advice is to completely clean that area of all oil deposits and determine the SOURCE of the leak.

Wouldn't hurt to put a 4" extension on the crankcase breather, as it is normal for oil vapor to vent.  And, if the crankcase is overfilled with oil, it can vent a LOT of oil.
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: Oil Build Up - Need help to identify part

Reply #2 –
Bret your suggestion makes sense. It is hard to tell from the crappy picture but there is not a trace of oil anywhere above it next to that component. It looks like the oil has been seeping out of the edges of that piece.  I have no ideas what that piece is called or what it does.

Great idea to extend the crankcase tube past the engine.  I will double check the oil level but it was fine last time I checked not terribly long ago.
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX

Re: Oil Build Up - Need help to identify part

Reply #3 –
Quote from: Eric & Alena + 3 –
I have no ideas what that piece is called or what it does.
That may be the engine oil cooler.

I found the parts diagram below for the engine oil cooler on my C8.3 engine.  It sure looks similar to the part shown in your photo.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Oil Build Up - Need help to identify part

Reply #4 –
Will be a whole lot easier to find a leak on a clean engine and easier to repair when you find it,looks like it's been seeping for years.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Oil Build Up - Need help to identify part

Reply #5 –
And it wouldn't hurt after identifying the source to retorque bolts holding the offending item.  I have seen where bolts loosened over time (or gasket shrunk a little)and retorquing fixed the leak.
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: Oil Build Up - Need help to identify part

Reply #6 –
The part you are looking at is the oil cooler.  As other have suggested clean it up in order to know for sure where the oil is coming from, but it looks like it is coming from the oil cooler.  The early 400 isl has lots of oil blowby due to the low exit for the blowby tube which allows the blowby to go out before the oil droplets fall out.  Put a longer hose on the pipe so the oil doesn't get all over everything.  Don't try to catch it with bottle as I did at first, or you will eventually end up with a big mess.
2002 36' U270 Foretravel

Re: Oil Build Up - Need help to identify part

Reply #7 –
Quote from: jbeem –
Put a longer hose on the pipe so the oil doesn't get all over everything.  Don't try to catch it with bottle as I did at first, or you will eventually end up with a big mess.

Have to ask what kind of a mess was made by putting a "properly designed" catch bottle (area of holes for exhaust from the bottle greater than ID of the hose)?

I did this on my 2003 ISL with no issues.
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: Oil Build Up - Need help to identify part

Reply #8 –
I found a page that has two photos of the oil cooler cover (front and back).

https://www.agkits.com/cummins-8-3l-lube-oil-filter-adapter-head-housing-3974325-3934159.aspx#.XhSRHmaZOuU

The "part numbers" in the comments below refer to the diagram in Reply #3 (above).

I think the way it works is engine oil circulates through the aluminum casting.  A thermostat (#19) and a pressure regulator (#12) control the flow of oil.  Depending on thermostat position, oil may be routed through the "cooler core" (#10).  The cooler core sticks through the side of the engine block into the water jacket.  This, then, is a Liquid to Liquid heat exchanger.

Why is this important?  In order to replace the gasket (#11) under the aluminum casting you must remove all the retaining bolts.  When you pull the aluminum casting off, the cooler core will most likely also come loose, which opens a big hole in the water jacket.

So, if you do decide to try to install new gaskets you should have both new gaskets on hand (#11 and #9).  Unless you drain the engine coolant from the block ahead of time, you should also plan ahead for the possibility of loosing some coolant out the hole in the side of the block.

I would try Brett's idea:  clean up all the old oil mess so everything is dry, then try torquing down the bolts on the casting.  See what happens.  If that doesn't fix the leak, go to Plan B (replace the gaskets).
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Oil Build Up - Need help to identify part

Reply #9 –
Page A-82 of manual linked below gives R & R instructions for oil cooler assembly on C8.3L engine.  Most likely also applies to your ISL.

Note:  Recommended torque for cooler cover bolts is:  18 ft-lb

http://truckroadservice.com/barth_attachments/Cummins_8.3_Manual.pdf
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Oil Build Up - Need help to identify part

Reply #10 –
Thanks for all the great advise and information. I really appreciate the knowledge and assistance. You are part of what makes owning a Foretravel special!

I will start with a real good cleaning and check the torque on the bolts. Hopefully it just needs a little tightening. As pointed out this issue has  very likely been in place for quite some time. The issue has just recently elevated in severity to catch my attention.
2002 U270 34' Build 5953
Cummings ISL400HP
3410 Floor Plan
Longview, TX

Re: Oil Build Up - Need help to identify part

Reply #11 –
Use a good degreaser, Oil Eater, Industrial Purple etc then rinse.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Oil Build Up - Need help to identify part

Reply #12 –
Quote from: Chuck & Jeannie –

Why is this important?  In order to replace the gasket (#11) under the aluminum casting you must remove all the retaining bolts.  When you pull the aluminum casting off, the cooler core will most likely also come loose, which opens a big hole in the water jacket.

So, if you do decide to try to install new gaskets you should have both new gaskets on hand (#11 and #9).  Unless you drain the engine coolant from the block ahead of time, you should also plan ahead for the possibility of loosing some coolant out the hole in the side of the block.

I would try Brett's idea:  clean up all the old oil mess so everything is dry, then try torquing down the bolts on the casting.  See what happens.  If that doesn't fix the leak, go to Plan B (replace the gaskets).

I am sticking my nose in here to point out that anti freeze and oil are a bad combination.  You really don't want to take a chance on your lubricating oil becoming contaminated with anti freeze.

And in a cleaner gentler world I've learned to use odorless mineral spirits, catch pans and the appropriate brushes for my initial cleaning.  Then gunk engine degreaser and the garden hose when no one is looking for a squeaky clean surface.  I buy the Gunk concentrate and dilute it according to directions with odorless mineral spirits.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Oil Build Up - Need help to identify part

Reply #13 –
Have used a siphon gun/sprayer with the mineral spirits,works good but wear a good mask, even if you don't end up doing the
job yourself get the engine clean,the shop can work better and faster at $120 plus per hour on a clean unit.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Oil Build Up - Need help to identify part

Reply #14 –
Quote from: wolfe10 –
Have to ask what kind of a mess was made by putting a "properly designed" catch bottle (area of holes for exhaust from the bottle greater than ID of the hose)?

I did this on my 2003 ISL with no issues.

Wolfe, I drove to Alaska this summer and had the oil changed in route.  When they changed the oil they filled it to the full mark instead of the file mark that shows the true full, and I didn't realize how much oil would blow out if it is filled past the file mark.  So I was driving long miles each day and going up large mountains and didn't check the oil bottle everyday.  Well, it got so full that the blowby blew the oil out of the bottle and all over the back of the rv and toad.  The bottle was also partially melted by being near a hot fluid line that ran next to where the bottle was, so I got rid of it and just put on a much longer hose than what was there originally.  No more oil on the back of RV or toad and no crawling under the RV to check and empty bottle.
2002 36' U270 Foretravel

Re: Oil Build Up - Need help to identify part

Reply #15 –
With the proper oil level, I emptied it every oil change and never had over 1-2 ounces in it.

Completely understand if overfilled, it will blow out a LOT of oil.
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: Oil Build Up - Need help to identify part

Reply #16 –
Beem,not knocking your oil change but unless you told them to fill it to a "file mark"most shops would have done the same thing,that would have been the first thing I told them to do.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Oil Build Up - Need help to identify part

Reply #17 –
Quote from: John44 –
Beem,not knocking your oil change but unless you told them to fill it to a "file mark"most shops would have done the same thing,that would have been the first thing I told them to do.
I won't have to worry about that again because I bought a 26 quart oil pan and will be doing the oil change myself from now on.
2002 36' U270 Foretravel
 

Re: Oil Build Up - Need help to identify part

Reply #18 –
I usually identify where the thickest oil deposits are and then drive to a car wash and remove as much as possible. After driving home, I check to see what is remaining and use Craneman's Purple cleaner (cheap at Walmart) along with a brush and air siphon to get the last deposits off. Never spray the engine when it's running. Install a drain valve so you can stop and start the flow during oil changes. Especially important if you engine has an aluminum oil sump.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)