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RonJudi · 02-07-2004, 06:17 PM

Moderator: Please move over to mechanics section as I have strayed too far to remain under General. Thanks Ron

I am placing this under general rather than engines because I need some good info from anyone with experience. I have bought a beautiful motor home with engine problems. Everything seemed ok and rember this thing is new to me. Normal, until I opened the airclearner up and found oil, lots of oil. Evidently the unit has a collapsed set of oil rings and is pumping to the point in 500 miles it is saturating the filter and blow by has been diagnoised as excessive. Unit has only 63000 miles. My question is if no damage is found how hard is it to do a ring and valve job while still in the coach. I have a good aquantance who does all my boat work for me including engines but he has not done a MH. His shop will accomadate the coach but little room is left. Can he get to the heads and cylinders to do a good overhau assuming he finds no cylinder damage? Is there anything special he needs to know or tricks to access. From boat engines we have seen this happen when the unit overheated and collapsed the oil rings leaving the rest of motor ok. Most of the time on a relative low mileage engine the cylinder wear is minimal. Access is our big question for this type of repair. Ron

wb13798 · 02-07-2004, 08:05 PM

not a lot of room in the unit to do an in frame repair as you describe. i don't know if it could be done. never heard of any one doing or trying to do an rebuild without pulling motor. i have a problem with my coach and i plan to pull the motor and have the motor rebuilt or replaced next month.

eubank · 02-07-2004, 09:07 PM

Woo, does anybody have any experience with this? Best I can come is to relate experience of a blown engine in a school bus. They basically pulled off the bumper and front cowling, and the engine would slide forward and out. The mechanics said that it was actually easier to pull the school bus motor than to pull the motor on some cars.

L

74Argosy24MH · 02-08-2004, 07:36 AM

If there is oil in the air cleaner compression is going past 2 sets of compression rings, I think you have more problems than oil rings.

You should be able to re-ring the engine in the frame, but it would be easier to do on a stand. The engine will have to come way up to pull the pan. Then you will have to work around the crossmember to get the rods back on the crank. You will also have to deal with the mess from rebuilding an engine in the cockpit of your motorhome, and it is a dirty job. And I still think you are going to find a ridge at the top of the cylinder because of the excessive blow by. You also need to think about what you will find on the crank journals, my thought would be low on oil with that mileage, the cylinders are pretty much splash lubed.

John

jim8860 · 02-08-2004, 05:57 PM

If you have to replace the rings on the motor,pull it it will save you time and money in the long run. What I would do first is to check the PVC system first , a cracked hose and a bad PVC could cause some problems in there. Also a stuck rings could be the problem. Try some Rislone or some Marvel Mystery oil.Good Luck

RonJudi · 02-08-2004, 07:41 PM

Just a little follow up. After I got home with the rig which is new to me we pulled the air filter and that was the first hint of a serious problem. Noticed that someone had recently changed air filter since other than being paritallyoil soaked was begining to tell on previous owner. Noticed a new pvc valve had been installed as someone before me was finding a problem and wanted to eliminate that possibility. I swear the engine sounds ok to me at idle. At a good freinds urging, he is a long time mechanic, we pulled the oil filter cover off and proceded to take the unit out for a ride with dog house open. Under load the spewing out from the pvc hose into the air filter housing began and an oil mist and smoke fill the unit and set off the smoke alarm rather quickly. At idle the pvc system absorbs all the mist and handles all it can until blow by under load exceeds the capacity of the new pvc valve and system. The amount of oil in the air canaster, maybe an ounce or so was the result of about 700 miles of travel. Except a slight smell the night I took the unit I did not have a clue as to a problem. I attributed that to a possible leaky valve cover gasket. I swear I looked in the mirrow during the trip and saw no black smoke. Amazingly other mechanics had worked on the unit installing a heater core and did not notice what ever is going on. My friend rightly predicted when the spewing would start under load even though nothing was apparent at ide. The unit has suffered some failure but I hope it is early enough that if we can get the engine out we can correct it. During the trip to get the unit I kept my eye on temp and oil and never saw anything unusual except an occasional flicker off of 40lbs of the oil pressure guage over the last 60 miles. My friend says that he may detect (hear)one cylinder low from his experiences but won't be able to really know anything until the engine is apart. There is no clicking, clanging, or any notice of oil starvation. He, thinks that the oil rings for sure are gone, possibly a cracked piston??, all the problems that were caused by something only known to the previous owner who had changed the items mentioned and possibly headed down to quickly trade it off. I sure wish my friend had a way to get that engine out of the unit as he has done some mighty find rebuilds on car engines and boats over his 50 years in the business. I will pass all your info on to him as to how to best proceed and like any good friend will try to keep my cool and stay away for a few days unitil that part is figured out. Maybe he can rent some lifts to pick up the engine but he and I are both new to the game on MHs this will be difficult learning curve. I crawled under today and see what many of you are saying about how hard that would be. I also read in the search that some have taken the front door off and removed the chair and used some kind of crane that I know nothing of to lift the engine out. Please amplify. Does that apply to this model? That must be some special cherry picker to do that. I will again pass along all comments. Ron

jim8860 · 02-08-2004, 07:57 PM

I hate beating a dead horse but....Take a look at the intake gaskets/the intake it self.If they are bad or cracked you can pull oil though the intake. 63000 mile is not alot on a B.B. if it was we all be in trouble.

fangthorpe · 02-08-2004, 08:23 PM

If it were me, I'd want to know for sure what was wrong before I took it out. Does your guy have a leakdown gauge? It would be worth an hour. You could even drill out the bottom of an old sparkplug and stick it on the end of your compressor line. If you hear rushing air when you open the oil filler cap, then you're right about the rings. Be a shame to rering when the problem is elsewhere. Does have all the symptoms of having been overheated, though. Does it have a new waterpump or radiator?

RonJudi · 02-08-2004, 08:46 PM

Some good detetive work going on here. Yes, the heater core had gone out and was bypassed. That is the only clue I can think off that would support the overheat theory. Overheat first kill oil rings, right???? That is my friend, mechanic's, thought. Keep up the ideas as I will give him a copy of this tomorrow.

eubank · 02-08-2004, 09:32 PM

Quote:

Originally posted by fangthorpe
If it were me, I'd want to know for sure what was wrong before I took it out. Does your guy have a leakdown gauge? It would be worth an hour.

Right! Now I remember my father -- devoted pilot and aircraft mechanic that he is -- talking about a blowdown compression test (not leakdown, if it makes a difference). Trying to figure out what was with my old VW, he hooked it up and spotted what was going on immediately.

Might want to check with a local aircraft mechanic to get the tool?

Lynn

74Argosy24MH · 02-09-2004, 06:10 AM

Overheating usually warps or cracks heads, that is where the most heat from combustion is, no coolant flow and they suffer the first damage. If your buddy does engines he must have a compression tester. I don't think you will need a leakdown test if there is oil in the air cleaner.

One other thing that can cause this is removing the baffle under the pcv. Look down through the grommet and there should be a piece of metal to keep the oil from splashing up into the pcv.

John

markdoane · 02-09-2004, 06:23 AM

I'm no mechanic. I don't have a motorhome.

But just in case its something simple, did you check the oil returns, where the oil drains back to the crankcase. If these were plugged by a piece of paper or something it could foamulate (new word) your oil and aspirate it thru the PCV valve.

Not likely, but sure would be a quick fix.

RonJudi · 02-09-2004, 06:51 AM

First, I should give my long time mechanic friend a name which is Allen. He strongly thinks we need to get into engine but I am sure he will make a few tests to confirm. I saw the blowby and unfortunately it is bad. Seeing the oil filter float around in a pool of oil gives me a sick feeling instead of the joy of a new motor home. Amazingly the engine runs as well as it does. I guess that is why no body caught it. Allen reminded me that at a car auction the first thing buyers are trained to do is open up the air filter container and check for blowby. Now he tells me. Airstream is going to check into access on this model to see the best approach and it probably will be as many of you have outlined. I will keep everyone informed. Ron

fangthorpe · 02-09-2004, 08:19 AM

The only reason I'd want to know all the secrets before pulling the motor is - what if you only have 1 bad hole? I broke a ring land on my Suburban and it blew oil under load. At idle and low speed it was fine. Compression was 120, when the others were 150. We put air in the cylinder, heard nothing out the exhaust, nothing out the intake, but it sounded like there was a snake in the valve cover when we took the filler cap off. Squirted 4-5 pumps of oil into the low cylinder and compression came up, but after 15 seconds or so, it still hissed. We replaced only that piston and all was well. That was 40K ago. Still drive it.

On the other hand, a nice crate 502 would be nice.

RonJudi · 02-09-2004, 08:48 AM

First Quote folks: Manufacturer J--------, installed locally 75K and 3 years with RV cam and complete. $4800. Taking it to another place for anaylsis and all the things you guys have talked about. Let You know more soon! R&R part of that is $800. I sure hope those guys know what they are in for.

Tripp · 02-09-2004, 11:58 AM

Ditto John on the valve cover baffle. I does sound like you have ring problems though. If the baffle is in place and you are getting that much oil in the filter housing, then you probably have more than one piston with bad rings.

On the other hand, if you are missing the baffle, it is quite possible that you could have a relatively healthy engine. One of my muscle cars had a set of unbaffled valve covers on it and it would completely soak the breather in short order-the motor was fine (new), the lack of a baffle was the issue. I would still recommend your mechanic to check it out as most motor homes are abused rather than cared for. . .ie. long trips, no oil change, put up for months at a time and then expected to do it all over again.

Tripp

RonJudi · 02-09-2004, 04:37 PM

Well thats all folks! Engine has been diagnoised as terminal. And at such a young age of only 63000 miles. Even a wonderful engine needs maintenance such as regular oil changes and a owner who makes sure that overheating does not occur. Second mechanic says it is a classic case of neglect. An old probe under the cover was obviously used to check a known overheat condition which was not corrected in time. Sludge and oil marks suggest negeleted oil changes. Who would believe an owner would buy a Beautiful Airstream Motorhome keep it immaculate inside but totally ignor the engine compartment. Engine flunked all tests as suggested in all of your comments and defied all odds by only making it to 63K. Or maybe that is what one can expect without appreciable service. May that engine rest in piece and short life remind to all that engine oil changing, antifreeze change out and other normal engine service is absolutely essential.

A new RV Jasper Engine is on order and though it is a tough financial pill to swallow, it is approrpriate that the Airstream Receive her new heart in time for Valentines Day! Estimate about $5K. Ron

RonJudi · 02-09-2004, 06:16 PM

Access on these 90's models for engine change are only out the driver door per customer service at Airstream. Access is tight and may require removing items from normal long block. I will know in a week what can and cannot be passed through the little hole. Classics are out the front. I am sure a lot of you all ready know this. Airstream does not remember changing an engine at the factory on one of the 90's Land Yacht.

59toaster · 02-09-2004, 06:16 PM

Quote:

Originally posted by RonJudi
Well thats all folks! Engine has been diagnoised as terminal. And at such a young age of only 63000 miles. Even a wonderful engine needs maintenance such as regular oil changes and a owner who makes sure that overheating does not occur. Second mechanic says it is a classic case of neglect. An old probe under the cover was obviously used to check a known overheat condition which was not corrected in time. Sludge and oil marks suggest negeleted oil changes. Who would believe an owner would buy a Beautiful Airstream Motorhome keep it immaculate inside but totally ignor the engine compartment. Engine flunked all tests as suggested in all of your comments and defied all odds by only making it to 63K. Or maybe that is what one can expect without appreciable service. May that engine rest in piece and short life remind to all that engine oil changing, antifreeze change out and other normal engine service is absolutely essential.

A new RV Jasper Engine is on order and though it is a tough financial pill to swallow, it is approrpriate that the Airstream Receive her new heart in time for Valentines Day! Estimate about $5K. Ron

Cancel your Jasper engine.

If you dso some searching you can get a GM CRATE for about the same price with a 50K 36 month warranty. (about $2400)

dinoburb · 02-09-2004, 07:21 PM

... and the GM engine will be NEW. You might even look for the BB designed for towing. Tons (literary license!) of torque. Excellent warranty at any GM dealer.

Take care,