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RE: Gas Pusher
Actually gas pushers have been around since the '60's. An early one was based on the Corvair platform. In the '70's the most popular one was the FMC which Tim C. and I both have. In the '80's it was the Vixen (which I had for several years as well).
Recently, it is the UFO. There have been others that started out as gassers and then the manufactures switched to diesel as the size of diesel engines got smaller and/or as the size of the motor homes got larger.
Both the FMC and the Vixen were built on custom chassis and have independent rear suspension in addition to independent front suspension. A custom chassis is much more expensive to build than just buying a van or truck chassis and putting a box on it.
I really like my rear engined unit as the sound is in the rear, no engine hump, etc., etc. I have the advanteges of a rear engine, but don't have the cost and advanteges of diesel. Some FMC's have been converted to diesel. I also like the size at 29' which is hard to find in a new rear engined anything.
On ALL rear engined coaches with rear radiators, radiator cleanliness is critical. This applies whether it is gas or diesel or new or old. Just search "slobber tube" for a lot of discussion by diesel folks.
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BigRabbitMan
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03/01/10 11:08pm |
Class A Motorhomes
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RE: diesel pusher overheating
ok, thanks for the info. My C7 is only two years old and I keep the oil level right on the mark all the time. I have not seen any evidence of oil on the slab under the MH, nor any on the fins of the intercooler....at least none that I can see from laying underneath changing the oil.
I do like the reservoir idea that Jim mentioned. Is there any "pressure" coming out of the tube or does the oil just "drain" (drip)?
Ron
Though the crankcase breather has virtually no pressure, there IS volume. So, don't restrict air flow. Said another way, make sure if you use a container, that the size of the openings exceed the ID of the hose.
And when you say you "keep the oil level right on the mark all the time", have you calibrated the dip stick to verify that the dipstick is accurate? All diesel engines are installed over enough different angles that ASSUMING the dipstick is accurate may not be true.
Yep, that was done on the very first oil change. I don't find any consumption between changes, so I don't think I have much (if any) coming out my slobber tube. During last oil change, I inspected the tube and could not find any evidence of "wet" oil around the outside edge of the tube's outlet. I'm going to crawl back under there and see if there is any space to put some sort of reservoir that will allow plenty of breathing space for the tube.
thanks for the info
Ron
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lanerd
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02/26/10 03:08pm |
Class A Motorhomes
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RE: diesel pusher overheating
The lack of a slobber tube is not the only potential problem. I had a worse situation after I installed the slobber tube and cleaned the radiator. A short time later it started to overheat again. I had a leak in one of the pressure senders that was spraying a heavy mist of oil on the inter cooler/radiator.
The problem of overheating is still the same, oily dirt that stops proper air flow.
Paul
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TEO
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02/23/10 05:41pm |
Class A Motorhomes
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RE: Slober tube on 99 cummins 5.9 ?????
On a ISB DP the slobber tube is on the passenger side near the fan behind A/C compressor & air compressor.
Add a 3/4" water hose to it and bring it to below the radiator to stop the oil from going into the CAC.
Leave the converter hole open. It is suppose to be that way.
The fluid is probably from the slobber tube.
You can clean the CAC everytime you change the top fuel filter.
Many use Simple Green. The first time with heavy crud it may take some engine degreaser to cut it.
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Triker33
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02/22/10 01:32pm |
Class A Motorhomes
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RE: diesel pusher overheating
I just zip tied a plastic jug with wide mouth to the end of my slobber tube under the engine. After 4 years it has around a quart of oil in it. Time to empty. Keeps oil from being blown back to the toad area and off the rad of course.
I like Wolfe10's extension, I'll try that with a jug on the end if I can place it in a convenient place while keeping the tube running downhill. Right now I have to crawl under the RV to empty or remove the jug.
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Jim@HiTek
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02/21/10 11:52am |
Class A Motorhomes
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RE: Oil mist on my toad
It's normal for diesels to exhaust like that, especially on the older units. That is why there is such a push for the "new cleaner diesels". The slobber tube is good advice. Are you loosing much oil between oil changes?
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brobox
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02/21/10 09:30am |
Class A Motorhomes
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RE: Oil mist on my toad
By the way what is a slobber tube?Crankcase breather tube. I added an extension so it comes out closer to the ground. The mist no longer gets on the toad. I don't now for sure, but I think it now passes under the toad.
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bsprague
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02/21/10 07:43am |
Class A Motorhomes
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RE: Oil mist on my toad
Hi thanks for the quick reply. No underbody is clean. I strongly suspect spray coming from exhaust, but it passes the emission testing we have in Ontario, so it is not effecting the smog, or it only happens under certain conditions. By the way what is a slobber tube?
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3 Hour Tour
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02/21/10 06:49am |
Class A Motorhomes
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RE: Oil mist on my toad
You may be getting some blowby from the slobber tube. or maybe some residue from over fueling out of the exhaust. I have not had that problem towing with my 5.9. Are there other indicators of residue on or under the coach.
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Dog Trainer
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02/21/10 06:46am |
Class A Motorhomes
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RE: Need Opinion from CUMMINGS EXPERT
I am not a Cummins expert, but it is common for a little oil to come out of the "slobber" tube. That is why it is there. On later engines there is a Cummins gizmo installed that traps the oil to help make the environment cleaner. You can install one as an add on but it seems pricey. There are various home crafted designs using plastic bottles too. Another solution is to extend the hose to a location that the slobber goes under or around you toad.
The main thing is to not put too much oil in it. Dip stick are famous for being wrong. Too much and it will slobber it out as it is supposed to. Next oil change, put exactly the amount of oil in it that Cummins says to. Then check the dipstick and see if it is correct.
That said, I never see why people take a perfectly adequate engine and boost the power in an attempt to blow the doors off some trucker's Kenworth. I was having this discussion with a friend whose Cat has 100 more HP than my Cummins. Our Beavers weigh close to the same. We "raced" over the three long hills from Yakima, WA to Ellensburg, WA. Exceeding the speed limit on the downhill parts was against the rules! My friend won by about a minute and 45 seconds on a 35 minute run. To me, that is not enough to justify modifying an engine.
If it were me, I would not worry about the slobber. Instead, I would watch the temperature like a hawk. Whoever put your radiator in aimed at getting rid of about 330 HP of heat, not 470! Winter days probably don't matter much, but pulling the Grapevine on 100 degree summer day with a radiator that has a little dust stuck in it may get you!
Mine is 350HP not 330HP and the reason I added the banks is because when 40ft MH is loaded and pulling a 4500 lb vehicle it does not have enough power at 350HP.I get real tired of following D/P thats going along at 50-55MPH because they are underpowered or just want to hold up traffic because they dont care about the line up behind them.With the extra power I can pass with ease and can keep up to traffic flow on hills.With 350HP i fall into the your in my way holding up traffic catagory which I detest!!!!I have pulled mamouth mountain at 80DF and never gone over normal
I will put a bottle on the tube and see what happens as I know about
the breather tube and its operational idea,s but it seemed that I was getting more than normal but thats why I was hoping to have a cummings expert come on here and tell me whats excessive and whats normal?So far no one knows anymore than I already did
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ticat900
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02/18/10 09:38am |
Class A Motorhomes
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RE: Need Opinion from CUMMINGS EXPERT
We have a cummins and had oil on our toad during a long trip. Had no idea where it came from. Learned about the slobber tube from this forum. DH located it secured a plastic bottle to put it in and no more oil on our little red jeep.
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Poodle Power
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02/18/10 08:23am |
Class A Motorhomes
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RE: Need Opinion from CUMMINGS EXPERT
If you have the Banks then your EGT will never exceed 1250 as that's when the OttoMind will turn down the boost. The system is virtually foolproof.
If you do a forum search you will find a ton of info about dipstick calibration on the ISC - they are often overfull when the dipstick reads full and will find their own level over the next 2000 miles. Mine always ended up just under the 'low' mark and stayed there till the next service.
The thing to remember is to ensure that the slobber tube is extended so any oil doesn't coat the radiator and then don't be over enthusiastic topping up the oil until you know where it's natural level is.
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stevelv
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02/18/10 07:39am |
Class A Motorhomes
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RE: Need Opinion from CUMMINGS EXPERT
I am not a Cummins expert, but it is common for a little oil to come out of the "slobber" tube. That is why it is there. On later engines there is a Cummins gizmo installed that traps the oil to help make the environment cleaner. You can install one as an add on but it seems pricey. There are various home crafted designs using plastic bottles too. Another solution is to extend the hose to a location that the slobber goes under or around you toad.
The main thing is to not put too much oil in it. Dip stick are famous for being wrong. Too much and it will slobber it out as it is supposed to. Next oil change, put exactly the amount of oil in it that Cummins says to. Then check the dipstick and see if it is correct.
That said, I never see why people take a perfectly adequate engine and boost the power in an attempt to blow the doors off some trucker's Kenworth. I was having this discussion with a friend whose Cat has 100 more HP than my Cummins. Our Beavers weigh close to the same. We "raced" over the three long hills from Yakima, WA to Ellensburg, WA. Exceeding the speed limit on the downhill parts was against the rules! My friend won by about a minute and 45 seconds on a 35 minute run. To me, that is not enough to justify modifying an engine.
If it were me, I would not worry about the slobber. Instead, I would watch the temperature like a hawk. Whoever put your radiator in aimed at getting rid of about 330 HP of heat, not 470! Winter days probably don't matter much, but pulling the Grapevine on 100 degree summer day with a radiator that has a little dust stuck in it may get you!
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bsprague
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02/18/10 07:25am |
Class A Motorhomes
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RE: Need Opinion from CUMMINGS EXPERT
I'm not a Cummins expert, but there are some things you can check and I have a few questions.
What do you mean by 'blow by'? Are you losing oil? More than a quart per 1000miles? Or are you seeing black particle residue in your exhaust or on your tow? Is there oil on the inside of your rear engine access (as if it was being blown out of the slobber tube)?
Has this recently started? Have you had your oil changed lately?
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ua40j
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02/17/10 03:53pm |
Class A Motorhomes
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RE: diesel pusher overheating
Been there too with the dirty radiator, cleaned it myself with two cans of engine cleaner/degrease. Use a liquid engine cleaner rather than a foaming type as the liquid penetrates the fins better. Follow the product directions. Apply from both sides of the radiator/turbo inter-cooler and yes it can get messy. As noted above do not pressure wash. I added an extension to my crankcase vent to reduce the chance of clogging the radiator again. Good Luck, FBL
Good info fatboy. A couple of questions, when you entended your slobber tube, what did you use and where did you relocate the end of it?
Most people recommend something like "Simple Green", but I've often wondered about brake cleaner or engine degreaser.
Ron
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lanerd
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02/14/10 04:00pm |
Class A Motorhomes
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RE: diesel pusher overheating
The clogged radiator is the most common reason for the kid of overheating you describe. Our 2000 Safari had a 300 Cat 3126B, rear radiator, and cronically heated up. Safari installed, under warranty, a "heat kit" that consisted of new rear doors with bigger air slots, an additional grill in the rear cap below the doors, a 9 blade fan, a reduced pully size to increase fan rotation speed, an extended slobber tube and in some cases a new shroud around the radiator.
The mechanic who did the work also warned me that the thermostats, plural, there are two, fail eventually and cause overheating as well. Cat recommended that they be changed on maintenance intervals but I forget what the interval is.
Ron
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pusherpilot
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02/13/10 06:49pm |
Class A Motorhomes
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RE: diesel pusher overheating
No it is not normal I'll bet you have a rear radiator. Sounds like you need to add a slobber tube (a rubber hose added to the engine breather) and clean the radiator. The engine breather is not long enough (most engines are behind the radiator except in MHs) to stop oil particles from the engine getting on the radiator making it easier for it to hold any dirt/dust which reduces air flow. Steam cleaning is better than pressure washing as it's easy to damage the radiator fins with a pressure washer. This cleaning is something you can do yourself, especially if lifting the beds gets you to the engine. Otherwise you have to do it from underneath the MH as it needs to be done from the front of the radiator and will require several times using a good degreaser and lots of water.
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Ivylog
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02/13/10 05:02pm |
Class A Motorhomes
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RE: diesel pusher overheating
Griffins,
This sounds like a typical partially clogged radiator fin situation. Engine oil from the breather or slobber tube collects on the engine side of the radiator, collects dust and dirt and then blocks good cooling airflow. Do a search on the board for radiator cleaning, the subject has been covered a lot on this site. Good luck.,
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overlanders
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02/13/10 04:52pm |
Class A Motorhomes
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RE: Some power steering fluid on the back of the DP-EDIT
Don't think its trans fluid. Look at the slobber tube hanging from the motor to be the oil droplet culprit. This is quite normal and I have the same problem. I am looking for the kit to put on the end of the tube to catch the oil or to make one if I can't find one.
>>Here's one. >>>http://i53.photobucket.com/albums/g71/scomp225/MVC-002S.jpg?t=1264683275
LEN
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SCOMP225
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01/28/10 05:55am |
Class A Motorhomes
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RE: Some power steering fluid on the back of the DP-EDIT
Don't think its trans fluid. Look at the slobber tube hanging from the motor to be the oil droplet culprit. This is quite normal and I have the same problem. I am looking for the kit to put on the end of the tube to catch the oil or to make one if I can't find one.
LEN
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OLYLEN
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01/27/10 10:35am |
Class A Motorhomes
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