Engine Issue - Towed Car Covered in ... Oil?

[jmh039447@gmail.com]

I have a 2005 Newmar Kountry Star 39-foot motorhome. We were going to Florida and on the way we stopped in Virginia at a campground.

When I arrived there we noticed the towed car was covered in (what looked like oil or fuel oil). The whole front of the car and the hood were covered with this black stuff.

I checked the engine oil and it was full.

When we arrived here in Florida I asked around and no one heard of this happening to them. An RV repair shop said they thought it might be fuel oil.

Has this happened to anyone else and, if so, what did they say it was?

John H.

[wolfe10]

I have a 2005 Newmar Kountry Star 39-foot motorhome. We were going to Florida and on the way we stopped in Virginia at a campground.

When I arrived there we noticed the towed car was covered in something that looked like oil or fuel oil. The whole front of the car and the hood were covered with this black stuff.

I checked the engine oil and it was full.

When we arrived here in Florida I asked around and no one heard of this happening to them. An RV repair shop said they thought it might be fuel oil.

Has this happened to anyone else and, if so, what did they say it was?

John H.

John,

Welcome to the FMCA Forum.

What engine and chassis do you have?

That will give us a better idea of where to start.

And, by smell you should be able to determine whether it is/was engine oil or diesel-- they are very different. Compare what is on the toad with "smelling" the dipstick and then the fuel fill for your diesel tank.

Brett Wolfe

[Chunkybeastracin@aol.com]

I have a 2005 Newmar Kountry Star 39-foot motorhome. We were going to Florida and on the way we stopped in Virginia at a campground.

When I arrived there we noticed the towed car was covered in something that looked like oil or fuel oil. The whole front of the car and the hood were covered with this black stuff.

I checked the engine oil and it was full.

When we arrived here in Florida I asked around and no one heard of this happening to them. An RV repair shop said they thought it might be fuel oil.

Has this happened to anyone else and, if so, what did they say it was?

John H.

Hello John. I am kind of new to the Diesle tech end of Motorhomes but have read that on some of the Caterpillar engines the oil vent tube needed to be extended/rerouted as it would vent on to the radiator/fan, thus spewing oil residue on tow vechilce, etc. Apparently the vent tube modification is very simple and can be done yourself if that is the cause of the problem. Good luck.

Mike

[wolfe10]

Hello, John. I am kind of new to the Diesle tech end of Motorhomes but have read that on some of the Caterpillar engines the oil vent tube needed to be extended/rerouted as it would vent on to the radiator/fan, thus spewing oil residue on tow vechilce, etc. Apparently the vent tube modification is very simple and can be done yourself if that is the cause of the problem. Good luck.

Mike

Actually, extending the crankcase vent tube is an excellent idea on ANY diesel engine built before 1/1/07-- Caterpillar, Cummins, Detroit Diesel, etc. From that date forward, all were required to have closed crankcase ventilation to meet the new stiffer EPA requirements. Prior to that, ALL diesel engines vent to atmosphere.

But, that only redirects where the blow-by goes, not how much there is.

Again, we need to wait and find out what engine/chassis he has to make specific recommendations.

[Smosher]

John H

I don't know much about the newer diesel pushers but I have one now. And had another it was a Newell. I do know after having a ford truck 6.9 with an aftermarkert turbo that when giving it a lot of throttle if would smoke really bad and unsed fuel would go out of the exhaust onto my trailer which would be real wet. I later learned to use only what throttle to maintain the speed up the incline. I believe if you were to continue this extra usage that you could possible wash the oil off of the rings in the cylinder and prematurely wear out the engine. My new diesel is a Monoco camelot 425 hp it has a extra so to call catalatic system to burn up the unsed fuel. I am not saying this is your problem but it is problem that I had. I bought the truck in 86 and still have it it is now a secondary truck but if you want to pull something it will do it.

Steve Mosher

[garykd]

Hi John H.,

Welcome to the FMCA forum. By my signature you can tell we have the same coach. The solution is, most likely, the slobber tube (posted earlier). Tell you local Cummins shop about the problem and have them reroute the slobber tube to exit a different location. I had the problem mentioned in the OP and this fixed it. The factory allows the slobber tube to exit on the center line of the coach. This allows the wind to carry the oil into the toad. The oil could be carried directly or indirectly via the fan onto the toad.

[wolfe10]

I think there is universal agreement that ALL diesel engines built before 1/1/07 should have their blow-by hose extended to behind the intake for the cooling fan shroud (rear radiator coaches).

But, he will also need to verify that he is using the correct quantity of oil. If he had both oil blowing by in sufficient quantity to cover the front of the toad AND when he checked it at the end of the trip it showed full, it is quite possible that the crankcase was overfilled at the beginning of the trip.

An overfilled crankcase is the #1 cause of excessive oil blow-by.

Because of the wide range of installation angles, it is not unusual to have to CALIBRATE THE ENGINE OIL DIPSTICK. It can be done easily at the next oil change and obviously starts with determining the exact quantity (including filter) that you should use in your engine:

http://community.fmca.com/index.php?showtopic=388

Brett Wolfe

[mikev]

Hello all, in the interest of being thorough you may wish to check your differential as well. There can be 20 or so quarts of oil and it could be leaking as well. Low probability of getting that far back, but I would rather leave nothing to chance.

[wolfe10]

Hello all, in the interest of being thorough you may wish to check your differential as well, there can be 20 or so quarts of oil and it could be leaking as well. Low probability of getting that far back but I would rather leave nothing to chance.

And your nose would tell you INSTANTLY if it was gear oil. Really smelly stuff.

Brett

[garykd]

Hi John H.,

As a followup on Brett's previous post, my ISC is persnickety on the amount of oil in the crankcase. When the dipstick is at the bottom of the cross hatch marks, I leave it there. Consider letting the oil level settle to a reading it stabilizes at. For me, as long at the oil level is at the bottom of the cross hatch marks, the ISC runs fine. And yes I have the correct dip stick. When I change the oil, this means I add 21 qts, not the 24 qts per spec. Originally I put in 24 qts. The dip stick reading was at the full mark. The ISC would burn out the oil down to the add mark (bottom of the cross hatch marks) in 1K miles. Adding oil did no good. Now I leave it where the engine burns no oil between it's annual oil changes. I average 12K+ miles per year.

[NWJeeper]

Hi John H.,

As a followup on Brett's previous post, my ISC is persnickety on the amount of oil in the crankcase. When the dipstick is at the bottom of the cross hatch marks, I leave it there. Consider letting the oil level settle to a reading it stabilizes at. For me, as long at the oil level is at the bottom of the cross hatch marks, the ISC runs fine. And yes I have the correct dip stick. When I change the oil, this means I add 21 qts, not the 24 qts per spec. Originally I put in 24 qts. The dip stick reading was at the full mark. The ISC would burn out the oil down to the add mark (bottom of the cross hatch marks) in 1K miles. Adding oil did no good. Now I leave it where the engine burns no oil between it's annual oil changes. I average 12K+ miles per year.

Used to have the same issue on our aircraft (Piper Arrow with Lycoming engine). Manual called for 8 quarts but it would quickly burn off 2 of them so we lived with it. Never a problem, always ran great. Never heard of other engines doing this but I'm not surprised by your experience either.

[Chickadee]

I have a 2005 Newmar Kountry Star 39-foot motorhome. We were going to Florida and on the way we stopped in Virginia at a campground.

When I arrived there we noticed the towed car was covered in (what looked like oil or fuel oil). The whole front of the car and the hood were covered with this black stuff.

I checked the engine oil and it was full.

When we arrived here in Florida I asked around and no one heard of this happening to them. An RV repair shop said they thought it might be fuel oil.

Has this happened to anyone else and, if so, what did they say it was?

John H.

John H.:

Ya haven't replied to any of the posts and I've been waiting to hear whether that stuff on your toad did, or, did NOT, smell like diesel?? The reason I ask is that we experienced a similar issue (in our 06 Mtn. Aire) after departing a Cummins service center where we had a number of things done prior to an Alaska trip....including topping off of the engine coolant reservoir (Final Charge). After driving approx. 40 or 50 miles, I pulled into a rest area to do a walk around and found our toad covered with similar residue which did NOT smell like diesel fuel, nor engine oil, but, felt kinda slippery (like liquid soap between your fingers), and I couldn't identify any particular odor. Long story short....tech immediately drove out from the Cummins shop and we discovered that the spray back stuff was (or had been) coming from the overflow tube of the engine coolant reservoir which had been overfilled during servicing. In fact, there was still evidence of a drip or two at the open end of this black rubber overflow tube which extends down the side of your engine coolant reservoir tank about a foot. Take a look,.....that might be the only trouble.

Steve

[linda_wayne@roadrunner.com]

Have a 05 Fleetwood Expedition 38N, Cat C 7 engine & 6 sp Allison trans on Freightliner chassis, towing an 04 Jeep Unlimited. Had overheat warnings several times & mech in Tumcumcari, NM used a hot water pressure washer to clean radiator from both sides, solved problem instantly, He then installed a slobber tube extension USING AN OLD RADIATOR HOSE to within 6 inches of pavemnt, no more overheat problems in over 6000 miles. He says he has done the same thing many times on other brands of diesel pushers & has always worked well.

Wayne

[wolfe10]

Linda,

Welcome to the FMCA Forum.

This thread makes good reading: http://community.fmca.com/index.php?showtopic=288

Brett

[cmarq]

Please after 40 years with Cummins Ct. DO NOT use a piece of heater hose to extend the breather tube over time it will become soft and mushy from the oil. It will then kink from the air flow under the coach causing crankcase pressure to build up. This will cause the turbo to pass oil, low power, black smoke and poor fuel mileage. Most shop will just replace parts and not fix the cause. If you use a piece of hose be sure it is compatible with oil.

The dipstick may have been installed by the coach mfg and not calibrated. Ask your Cummins location for the proper amount for the PAN ONLY the put that amount in and remark your dipstick at that level. Overfilling will cause the rods to dip into the oil and cause many of the same problems.

[raybeard]

I had the same problem a year ago. I found that the cap or plug on the hydraulic powersteering tank had came loose, and at the same time I found out that the tank was overfilled by at least a quart. I sucked out a quart of fluid, and made sure the cap was tight. Solved my problem.

[hermanmullins]

We have a 400HP ISL. Never had the blowby as discribed here. I did have loss of power and white smoke. (another story).

It has been discussed that you need to extend the tube and put it in a better location aka outboard rather then center. My question is, could a small canister be made so as to catch the blowby and not allow it to flow into the air? Just a thought.

[wolfe10]

It has been discussed that you need to extend the tube and put it in a better location aka outboard rather then center. My question is, could a small canister be made so as to catch the blowby and not allow it to flow into the air? Just a thought.

Not sure it makes a difference whether it is extended outboard or near the center. The big issue, particularly for rear radiator configured coaches is to extended it to behind (back of coach) from the air intake for the fan shroud/cooling system. No point in putting moisture and oil vapor into the CAC and radiator where they will quickly trap dirt.

Two important MUSTS for any extension:

1. Do not restrict air flow. If the engine manufacturer designed and installed a 1" ID breather hose, do not use a smaller one or any catchment device that would have less exhaust area than that size.

2. Do not form a drip loop with the extension. Said another way, the hose must continue ONLY downhill from engine to outlet with no uphill portion. Water vapor is one of the natural components of the crankcase breather. Water could condense in the drip loop and in below freezing temperatures, freeze. Forming a solid ice plug will totally restrict air flow and can lead to blown engine gaskets or worse.

And by far the #1 cause of excessive blowby is overfilling the crankcase with oil.

Brett

[deenad]

Hi John H.,

As a followup on Brett's previous post, my ISC is persnickety on the amount of oil in the crankcase. When the dipstick is at the bottom of the cross hatch marks, I leave it there. Consider letting the oil level settle to a reading it stabilizes at. For me, as long at the oil level is at the bottom of the cross hatch marks, the ISC runs fine. And yes I have the correct dip stick. When I change the oil, this means I add 21 qts, not the 24 qts per spec. Originally I put in 24 qts. The dip stick reading was at the full mark. The ISC would burn out the oil down to the add mark (bottom of the cross hatch marks) in 1K miles. Adding oil did no good. Now I leave it where the engine burns no oil between it's annual oil changes. I average 12K+ miles per year.

That's almost the exact same thing I do with our ISC in a Dutch Star. If I leave the oil any higher than about half way between the low and high marks it'll blow oil out. Leave it slightly low and no problem.

[Spike45]

I have a 2005 Newmar Kountry Star 39-foot motorhome. We were going to Florida and on the way we stopped in Virginia at a campground.

When I arrived there we noticed the towed car was covered in (what looked like oil or fuel oil). The whole front of the car and the hood were covered with this black stuff.

I checked the engine oil and it was full.

When we arrived here in Florida I asked around and no one heard of this happening to them. An RV repair shop said they thought it might be fuel oil.

Has this happened to anyone else and, if so, what did they say it was?

John H.

What you are experiencing is crankcase oil droplets coming from the breather tube. It is an unfortunate but common occurrence for RV engines. It is more of an issue on the smaller displacement but high horsepower diesel engines from Cummins and Caterpillar but no engine is exempt if it does not have a better means to trap the liquid oil carryover.

On the Cummins ISB, ISC, ISL this can be quite pronounced. Engines before 2010 had open crank case vent tubes, now they must use closed crankcase ventilation systems that trap the oil and return it to the engine while venting the fumes into the air intake.

On other forums like iRV2 in the Cummins Power Train section you can find a lot of posting on this topic. The simple homemade fix is to attach a catch bottle to the vent tube. You may need to extend the vent tube to an easily accessible location as you will need to dump the catch bottle periodically. That catch bottle must have vent holes in it to allow the blow-by gas volume to escape. Some have added 'brillo pads' and similar to act as a medium to hold the liquid oil. An early version of the Cummins ISB used just such a crankcase breather catch device. It was mounted on the front gear cover.

On the Cummins ISC and ISL, the breather assembly is mounted behind the oil filter. It looks to be like a small flat box with rounded corners. It has a clear plastic tube that extends below that about 10 inches or less. With the High HP ratings of these engines, especially the ISL 400 and ISL 450, there is considerable blow by gas volume although normal. The low mount location of the breather is not good as there is considerable airborne oil droplets inside the engine at that point. Earlier C8.3 Cummins engines had the breather mounted on a valve cover with much less airborne oil droplets thus lower amount of liquid oil going overboard.

[BMB2311]

The same thing happened to me on a recent trip. When I opened the engine compartment on the coach it was pretty obvious what had happened. My oil dip stick has a rubber plug around it that expands to plug the tube by turning a handle on the end of it. When I checked the oil before departing on this particular trip I had over tightened the seal which forced the plug out of the tube. Put the dip stick back in, tightened it properly and no problem since or before for that matter. The oil level was still full. It doesn't take much oil to make a big mess.

[johnctysonfmca]

Your problem can be differential oil. I had this problem with my 99 Windsor. Made six trips to Monaco and Cummins and they always worked on engine blow by tube. Since no one could correct problem it became necessary that I would have to find problem myself. I crawled under coach and determined that oil was comming from the differential vent tube. Upon my inspection of the vent tube I determined that the vent tube was improperly installed. The vent tube was installed in such a manner that a drip loop was formed (similar to plumbing p-trap). This allowed oil to collect in the trap and when pressure built up in the differential this trapped oil would burp out and blow under motor home and then deposited onto dingy. My proper positing of the vent tube corrected this problem.

After correcting the problem, this also solved the problem of having to top off differential each time coach was serviced. I have now owned this coach for 13 years and have never had to top off differential since correcting problem and dingy has not been oiled since. Coach has 80K miles.