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ereadingrv · 12-28-2015, 05:06 AM

Okay, turbo's been working great since before Christmas. So we FINALLY decide to return to Las Vegas...and we're not an hour outside of L.A. before we get a sudden loss of power. Turbo works, but not fully. Then...stop engine light, warning light, and even less power.

We get off the freeway and after much searching, check UNDER the coach and realize there is oil leaking. And based on the back of the mud guard, a LOT of oil has been leaking.

We add 6 quarts; the oil gauge read about 20 (lowest point, basically almost zero oil pressure) before we added the 6 quarts. After the add, it is at about 55 (60 is center of the gauge). So far, so good.

We start the coach, and the Warning light and Stop Engine Light are gone. Clearly, we have MUCH less oil than we realized. We head off tentatively down the highway, and all is well...for about 45 minutes. Then, as I'm watching the pressure drops below 40, then 20...Warning Light comes on.

We exit the freeway, and as we're doing so, the Stop Engine light comes on again. This time, we park and put it in for the night (it's now 4am; this ordeal has been going on 5 hours now) and we haven't even reached Barstow.

So, now we're waiting until the morning. In the meantime, we're hoping someone can tell us what is leaking. From inside the coach, there appears to be no serious issue on top of the engine, other than a gasket. Our mechanic is going to fix that, and he said that is definitely not the issue and is a relatively minor fix.

Any ideas?

I'd say "thanks again" to everyone who will undoubtedly chime in with far more knowledge than we have...but at this point, that hardly seems adequate.

The way things are going, you folks will have helped us "virtually" rebuild this coach by the time this is all done!

jacwjames · 12-28-2015, 08:17 AM

The turbo has a pressurized oil line feeding it from the engine, this is to lubricate the turbo. There is also a drain back line that takes the oil back to the engine.

My guess is one of these lines is loose.

It if tie pressurized line it could have starved the turbo of lubrication and potentially caused failure. If it is the drain back line you would loose oil but the turbo would be fine.

If the oil in the engine got low enough it could have starved the engine of lubrication.

ereadingrv · 12-28-2015, 12:28 PM

Once we put oil in, the turbo went back to normal. No warning lights, no stop engine, nothing...ran perfectly.

Then, 45 min. later...the same situation again. It was very, very strange. We got up this morning and checked for oil leakage, and there was a very, very small amount. When I fired up the coach, immediate warning light, but no stop engine light.

How difficult is it to adjust a high pressure line like that? And how would we tell if it's bad, as opposed to just loose? Obviously, if it's cracked, that would answer that question...but is there something internal that could be wrong with it that we can't identify visually?

rmcb · 12-28-2015, 01:08 PM

Could this be a leaky seal within the "new" turbo causing excessive oil consumption?

slowmachine · 12-28-2015, 01:36 PM

I understand that this may not have been part of your original plan, but I suspect that you would benefit greatly by learning how to access the engine and familiarize yourself with the major components. Even if you never pick up a tool, the ability to describe what you see will save a lot of frustration for you and for anyone trying to help you.

Your second photo looks a lot like the bottom end of a crankcase vent tube, sometimes referred to as a "slobber tube." If that's what it is, and that volume of oil is coming from it, I would suspect that there is too much oil in your engine. That would also be consistent with low oil pressure while driving that returns to normal after shutdown. On the other hand, the oil could be running down the outside of it from a leak anywhere above. You'd have to look at the engine to know the answer.

Mike
2000 Holiday Rambler Endeavor 40PBD
Freghtliner XC, CAT 3126B

ereadingrv · 12-28-2015, 04:37 PM

Mike...

Thank you for the advice. That is, in fact, what we're trying to do through the guidance of those on the forum. Unfortunately, we are not mechanics and we do not have a service manual for our engine. I'd love to have one, if only to learn about those issues. I can tell you for a fact that the owner's manual, which we have, offers next to no help on even basic maintenance. It covers a few things, but nowhere near enough to make us comfortable.

As for accessing the engine, we can do that, and have. But again, without clear guidelines available out there, our only real choice as far as we can see is to ask questions.

ereadingrv · 12-28-2015, 05:09 PM

Quote:

Originally Posted by rmcb

Could this be a leaky seal within the "new" turbo causing excessive oil consumption?

Hi, Roy and Debbie:

No, there are zero leaks anywhere we can see around the turbo itself or the tubes going into it. This seems to be somewhere else, and no matter how much we've looked at the engine from above, we can't seem to spot it.

One poster suggested we have too much oil, but I would say that is not the case, based upon empirical evidence. We put oil in, the oil pressure increases to a safe level and the warning light and stop engine light go away; we drive for a while and the oil pressure slowly starts dropping the longer we move.

I suspect, and hope our mechanic in L.A. will confirm it, that this is some kind of pressure hose we cannot see. The poster said it was an oil return, possibly, and I think he may be right. Until we get back, and have more info, though, I don't think we'll know for sure.

mahon1993 · 12-28-2015, 05:33 PM

Take a look at the exhaust pipe. It should only look sooty, not oily. Rub your finger in the pipe and see what you get. It should feel dry but sooty not oily. If it feels oily that's where your oil is going. Still could be the turbo with leaking oil seals. You could also check the engine coolant. If there is an oil slick on top of the coolant you have a head gasket leak.
Good luck.
Greg

Pelledan · 12-28-2015, 05:44 PM

Losing 6 quarts of oil in just 45 minuets indicates a BIG leak. I presume that the photo of the few drops of oil under the vehicle was taken with the engine not running. Otherwise there might have been a significantly larger puddle. I know that your turbo was recently replaced and I assume you had no issues with oil leaks prior to this. That said, the new turbo remains the prime suspect. The pressurized oil feed line enters the turbo from the top. It's a steel supply tube that is welded to a flange that uses an "O" ring seal to mate with the turbine bearing supply port of the turbo. That flange is located between the turbine and the compressor. The turbine is made of iron and appears in the shape of a snail shell. The compressor is aluminum and is sail shelled in appearance as well. The supply flange is between them. The oil flow over that bearing serves dual purpose. Not only does it lubricate the bearing, but it also cools the bearing as well. Typical oil flow rate to the bearing is around 5 gallons per minute. Once the oil passes through the bearing, it drains via a similar tube and flange system that converts to a drain hose that connects back into the oil sump of the engine. That drain flange is located under the bearing 180* from the supply flange. So there are 5 places to look for leaks. The pressurized oil supply line, the non-pressurized drain line, or where the drain line transitions to a rubber hose. At the transition points, that hose is connected at the steel drain tube via a small worm gear hose clamp, and again that style of clamp is use where the hose connects to the engine sump. Look at each of those suspect points. If they used the same drain hose when the turbo was replaced, the problem could be the hose itself as they do soften with age and can tear when the attaching worm clap is tightened. I doubt if the turbine bearing seal is leaking. Should that be the case, it would be leaking internally and the oil would be consumed by the engine. If that is the case, 6 quarts in 45 min would leave quite a cloud behind the coach.
Dan

mahon1993 · 12-28-2015, 05:56 PM

Quote:

Originally Posted by Pelledan

Losing 6 quarts of oil in just 45 minuets indicates a BIG leak. I presume that the photo of the few drops of oil under the vehicle was taken with the engine not running. Otherwise there might have been a significantly larger puddle. I know that your turbo was recently replaced and I assume you had no issues with oil leaks prior to this. That said, the new turbo remains the prime suspect. The pressurized oil feed line enters the turbo from the top. It's a steel supply tube that is welded to a flange that uses an "O" ring seal to mate with the turbine bearing supply port of the turbo. That flange is located between the turbine and the compressor. The turbine is made of iron and appears in the shape of a snail shell. The compressor is aluminum and is sail shelled in appearance as well. The supply flange is between them. The oil flow over that bearing serves dual purpose. Not only does it lubricate the bearing, but it also cools the bearing as well. Typical oil flow rate to the bearing is around 5 gallons per minute. Once the oil passes through the bearing, it drains via a similar tube and flange system that converts to a drain hose that connects back into the oil sump of the engine. That drain flange is located under the bearing 180* from the supply flange. So there are 5 places to look for leaks. The pressurized oil supply line, the non-pressurized drain line, or where the drain line transitions to a rubber hose. At the transition points, that hose is connected at the steel drain tube via a small worm gear hose clamp, and again that style of clamp is use where the hose connects to the engine sump. Look at each of those suspect points. If they used the same drain hose when the turbo was replaced, the problem could be the hose itself as they do soften with age and can tear when the attaching worm clap is tightened. I doubt if the turbine bearing seal is leaking. Should that be the case, it would be leaking internally and the oil would be consumed by the engine. If that is the case, 6 quarts in 45 min would leave quite a cloud behind the coach.
Dan

Dan,

If either the oil supply line to the turbo or the drain back hose were leaking the outside of the engine and that whole side of the engine compartment would be saturated with oil. When the OP stops and looks under the engine there would be oil dripping down all over the place. There has to be some type of leak happening internally.
Greg

Pelledan · 12-28-2015, 06:11 PM

I agree Greg that yes, a pressurized leak would make a mess of things in the engine compartment. However I have seek leaks that "follow the line of least resistance" and end up puddling on a frame rail or some other "plateau" and drip off from there. If the seal is indeed leaking, a quart of oil consumed every 7 minutes would leave some visual evidence in real time behind the coach. And I'd even go so far as to say that anyone following in your wake would be oil covered as well. If the leak is indeed that large and being consumed by the engine, switching the running engine off may not shut the engine down as it very well may continued to be fueled by lubricating oil when the diesel stops. A way to check the possibility of a huge internal leak would be to remove the compressor outlet hose and see if a puddle drips out when it's disconnected.

Dan

swampdog2 · 12-28-2015, 06:42 PM

Best thing for op to do short of taking m/h to a repair shop is to crawl under engine area with a flashlight and just lay there a while and see if he can figure out where most of the oil is coming from (w/o the engine running of course) he might get lucky and see where it's coming from. Taking a picture of oil on the ground just don't help much .there are so many places oil could leak, at this point it's anyone's guess .

ereadingrv · 12-28-2015, 09:33 PM

Okay, update. Our excellent mechanic, Craig, is here and there is indeed oil everywhere. When we put a bit more oil in and ran it, oil started running "like a waterfall" down the right (passenger) side of the engine block. There does not appear to be a crack in the engine block, but we CANNOT tell where it's coming from. Possible valve cover gasket? Any suggestions? Craig is here with us; if anyone wants to, or is willing to, call us, we'd be grateful! 818-900-3017.

jacwjames · 12-28-2015, 09:50 PM

The compressor is mounted on passenger side of your engine. It does rely on engine oil for lubrication and could be the source of the leak.

I would recommend you create an account on the Cummins Quickserve site.
https://quickserve.cummins.com/info/index.html

Once you create an account and register your engine (using the engine serial number) you can get lots of information on your engine including the information on the compressor or other components.