| Oil burning [message #201054] |
Fri, 08 March 2013 19:26  |
Denny
Messages: 1
Registered: July 2012
Location: Ohio
Karma: 0
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Just returned from a 3000 trip (first one since purchase). And used a qt of oil every 200 miles. No blue smoke out tail pipe that I can see.. Also, oil pressure is 50lbs cold and 20lbs hot at speed. 5 lbs at hot idle. Engine runs and sounds good. Time for a rebuild?
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| Re: Oil burning [message #201057 is a reply to message #201054] |
Fri, 08 March 2013 19:57  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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| Denny wrote on Fri, 08 March 2013 19:26 |
Just returned from a 3000 trip (first one since purchase). And used a qt of oil every 200 miles. No blue smoke out tail pipe that I can see.. Also, oil pressure is 50lbs cold and 20lbs hot at speed. 5 lbs at hot idle. Engine runs and sounds good. Time for a rebuild?
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Might want to consider a new PCV valve and new filter on the other valve cover.
Or you may be overfilling and therefore loosing the first quart fast. See the archives for calibrating the dipstick.
Back when these were new -- a quart every 500-700 miles was not uncommon. We just have different expectaions these days.
Dennis
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: Oil burning [message #201058 is a reply to message #201054] |
Fri, 08 March 2013 19:57 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Sir, what part of the world are you in and what year and model of your coach?
First thing I would do is an oil analysis. It will tell all. Check locally with bigtruck repair shops and see if there is a lab close to you. We have one in Knoxville that charges $12 and has results in an hour. Since all the materials that touch the oil is made of different metals they can tell you xactly what is bad. Find a lab and see how they want the sample taken. Some can pull the oil out of the dipstick hole. Get the engine warm first.
Let us know.
| Denny wrote on Fri, 08 March 2013 20:26 |
Just returned from a 3000 trip (first one since purchase). And used a qt of oil every 200 miles. No blue smoke out tail pipe that I can see.. Also, oil pressure is 50lbs cold and 20lbs hot at speed. 5 lbs at hot idle. Engine runs and sounds good. Time for a rebuild?
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C. Boyd
76 Crestmont
East Tennessee
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| Re: Oil burning [message #201061 is a reply to message #201054] |
Fri, 08 March 2013 20:20 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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How are you getting your PSI readings? A lot of gauges are not accurate. If you go to the outdoor thermometer aisle at the hardware you will notice all the thermometers read different. I have 4 dial tire pressure gauges that vary by 5 PSi min. What oil is in there? and did you change it so you know what it is. I run Rotella 5w40 full synthetic and WIX or AC filter. Follow the dipstick cal suggestions as noted. There is that "first quart burn off" syndrome when stick is out of cal and unit is overfull. The engine becomes a Vitamix and whips up the high oil and sucks it thru the PCV. After it is at correct level, the level sits there for 1000 miles or better. Welcome.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Oil burning [message #201064 is a reply to message #201055] |
Fri, 08 March 2013 20:25 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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As Dan says, Not necessarily.
Many things can cause oil burning. One common thing on our coaches is a crack in the intake manifold. Other things like PCV, or a few stuck rings are also a possibility. If the intake was off recently, it could be a leaking intake manifold gasket.
I would remove the air cleaner cover and look for any evidence of oil. Oil here would indicate a defective PCV valve or excessive crankcase pressure (ring blow by). Replace the PCV. They are cheap and a 5 minute job to replace.
I would next pull the plugs and see what they look like. If they are uniform in color between cylinders that would say one thing, If there is only one or a few cylinders different we are looking at other problems. You probably ought to do a compression test while you have the plugs out.
The second thing I would do is to pull the carb and look at the bottom of the the manifold below the carb. Look for any oil residue or evidence of burn oil (carbon).
What weight oil are you using? I would suggest 15W40 Rotella which is available at Walmart, TSC, AutoZone and any truckstop. If you are using synthetic oil stop now. That stuff for some reason does not smoke and sets up deposits hard like glass that has to be chiseled out later.
That is where I would start Before condemning the engine to a rebuild.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Oil burning [message #201076 is a reply to message #201054] |
Fri, 08 March 2013 21:44 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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If you pull the Quadrajet, don't tighten the 4 mounting bolts more than just snug or you can warp and ruin the carb. Use flare nut wrenches on the fuel inlet and start by hand and again don't over crank . If the engine isn't ticking or knocking it may be ok and just problems as already noted not needing tear down
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] Oil burning [message #201079 is a reply to message #201061] |
Fri, 08 March 2013 22:21 |
Ronald Pottol
Messages: 505
Registered: September 2012
Location: Redwood City, California
Karma: -2
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Senior Member |
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Dial tire gauges were tested by Consumer Reports years ago and found to be
essentially useless after being dropped (as you may have noticed). Stick
with stick or digital (perhaps those suck too, not seen a test), but the
stick kind are accurate and durable.
Ron
On Fri, Mar 8, 2013 at 6:20 PM, John R. Lebetski <gransport@aol.com> wrote:
>
>
> How are you getting your PSI readings? A lot of gauges are not accurate.
> If you go to the outdoor thermometer aisle at the hardware you will notice
> all the thermometers read different. I have 4 dial tire pressure gauges
> that vary by 5 PSi min. What oil is in there? and did you change it so you
> know what it is. I run Rotella 5w40 full synthetic and WIX or AC filter.
> Follow the dipstick cal suggestions as noted. There is that "first quart
> burn off" syndrome when stick is out of cal and unit is overfull. The
> engine becomes a Vitamix and whips up the high oil and sucks it thru the
> PCV. After it is at correct level, the level sits there for 1000 miles or
> better. Welcome.
> --
> John Lebetski
> Chicago, IL
> 77 Eleganza II
> Source America First
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Plato seems wrong to me today.
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1973 26' GM outfitted
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| Re: [GMCnet] Oil burning [message #201094 is a reply to message #201079] |
Sat, 09 March 2013 07:27 |
tphipps
Messages: 3005
Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
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Senior Member |
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Look at the valve cover gaskets. They may have been over tightened some time during its life. They will leak if over tightened, due to crushing of the OEM gasket. I suggest replacing with the valve cover gaskets designed for the Chevy Truck 350 Diesel (not GAS) They are identical, but a better material and available in 2 thickness. The driver side is easy, the passenger side is a PITA.
Another place to look is at the valve covers. if they have been replaced by non stock motorhome valve covers, i.e. aftermarket chrome covers, they are not correct for the engine and reports are of oil losses. These covers are seldom changed, but P.O. have been known to do things to their hearts desire.
Lots of things to check, start with PVC and filters. Easy and fast. Many good suggestions here.
Tom, MS II
2012 Phoenix Cruiser model 2552
KA4CSG
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