| Synthetic Oil [message #72753] |
Wed, 03 February 2010 20:03  |
psakw
Messages: 61
Registered: February 2010
Karma: 0
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This has probably been covered before so please forgive me as I am new to this.
I was wondering if it is smart to use synthetic oil in a used 455 that has 100000 miles on it?
If so what synthetic should I look for?
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| Re: Synthetic Oil [message #72761 is a reply to message #72754] |
Wed, 03 February 2010 21:04  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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My question to you is WHY change? Whatever the coach has been using got it 100,000 miles in 30 years. If you are not having oil consumption or other problems I would leave it alone.
Synthetics run OK in a tight engine. If the engine is using oil forget the synthetics. My engine has only seen Rotella Dino oil since it was new. The coach had 2 POs and both used Rotella. I use one quart in 6000 miles and the coach has just under 90,000 miles on it.
Do not worry too much about the ZDDP as that primarily affects new cams and lifters. After a few thousand miles the modern (since 2008) lower ZDDP oils do not seem to be a problem. I stocked up on Rotella before the government formulation change. Newer Rotella still has 2/3 of the ZDDP as compared to prior to 2008.
JMHO.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Synthetic Oil [message #72762 is a reply to message #72761] |
Wed, 03 February 2010 21:06 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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I run 6000 between oil changes or every fall before I park it for the winter on Rotella dino.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Synthetic Oil [message #72765 is a reply to message #72763] |
Wed, 03 February 2010 21:24 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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15W40. 230 degrees is not too bad. You want it to get that hot to boil off an accumulated moisture in the oil.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Synthetic Oil [message #72767 is a reply to message #72765] |
Wed, 03 February 2010 21:35 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Ken Burton wrote on Wed, 03 February 2010 21:24 |
15W40. 230 degrees is not too bad. You want it to get that hot to boil off an accumulated moisture in the oil.
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You can buy it most anywhere, TSC, Wally World, Any Truck Stop, AutoZone, etc.etc.etc.
I ran my oil through an oil analysis at the local truck stop last fall after 5500 miles. The analysis recommendation was do NOT change the oil for another 4500 miles. I changed it anyway because I was going to park it until spring. With an oil change and filter costing less than $20.00, I could not see any reason not to change it before winter. I only buy Wix and AC filters. I bought a case of them many years ago and I'm still trying to use them all up.
1500 miles per quart is not too bad. I would probably stay with whatever the coach has been using. I hate to recommend a change on a 100,000 mile engine when what you have been using is working OK. If you had considerably less miles then you might want to try changing to something different to see what happens.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Synthetic Oil [message #72863 is a reply to message #72782] |
Thu, 04 February 2010 22:33 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| psakw wrote on Thu, 04 February 2010 08:44 |
Good advise, thank you.
Now my next question is "What about the trans and rear" I am running standard Dextron/Mercon but some have said to change it to Valvoline Max Life which is a synthetic because of the additives. I need some advise on this and if I should change the rear end fluid to Synthetic.
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I have no issues with running synthetic lubricants anywhere it does not stand the chance of being burned like in transmissions and differentials. The higher temperature tolerance probably is a good thing.
I have synthetic in my final drive. The price difference was insignificant so why not. In my trans I have whatever Manny used. He told me it was some type of semi-synthetic that I could not find locally. I'm not sure what benefits semi-synthetics have over straight synthetics. I have never needed to add any trans fluid. If I did, I'm sure one quart of either dino or synthetic when mixed with what ever Manny used would not make much difference.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Synthetic Oil [message #72968 is a reply to message #72753] |
Fri, 05 February 2010 18:12 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| psakw wrote on Wed, 03 February 2010 21:03 |
This has probably been covered before so please forgive me as I am new to this.
I was wondering if it is smart to use synthetic oil in a used 455 that has 100000 miles on it?
If so what synthetic should I look for?
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Paul,
There are really only two reasons to go to a synthetic lube oil in an engine.
One is temperature.
The other is time.
All of the dino based oils actually disassemble (cease being lube oil) when that molecule gets to 305*F. (End of discussion, there is no time requirement for this to happen.) So, if you have a little tiny very highly loaded engine that is not happy when it has nothing left in it that is really oil, this is a reasonable answer, or maybe you have an engine that is being run harder than it was originally designed to do. The coach motor does come close to this, but with the external lube oil cooler it is pretty save under most conditions.
Dino based oil is also more much more susceptible to acidification caused by contamination by combustion by-products. This has something to do with the basic lube oil molecules used (and I could not wrap my head around the answer as to why when I heard it). This really doesn't get to be too bad in less than 9~12 months depending on the conditions.
I use synthetic in my air cooled engines because they: A - Those little suckers (30cuin) beat the snot out of the lube when they get run hard (and if I'm running one, it is usually hard) and B- Don't get run enough to merit changing the oil every 6~9 months when they haven't even be run for 10 hours.
Would I change an extended age engine (like a coach with 100K) to synthetic? Probably not. A known issue here is that the synthetics will loosen all the old deposits in the engine, and that might set loose crud that will end up places it is not wanted. I have know of engines that had sticking hydraulic lash adjusters (maybe tappets) to have the noise get cleared by changing to synthetic.
As to will it stay on the the sitting still parts better than dino oil? I have never seen evidence to that effect, and if you asked, I not sure how I might test for that quality. Since I try to remember to cold crank an engine before trying to start it, I probably never will.
My coach had about 15K on a rebuild when I got it, and I didn't want to change out oil when I hadn't driven it over the winter.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Synthetic Oil [message #72976 is a reply to message #72968] |
Fri, 05 February 2010 18:48 |
GMCNUSA
Messages: 283
Registered: August 2006
Location: Indianapolis, IN
Karma: 0
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As to will it stay on the the sitting still parts better than dino oil? I have never seen evidence to that effect, and if you asked, I not sure how I might test for that quality. Since I try to remember to cold crank an engine before trying to start it, I probably never will.
Matt
I changed to synthetic in my 18 yr old air cooled lawn tractor and when I checked the oil before staring it this past spring the dirty oil was still about 4 inches up on the oil dipstick I noticed this was the splash level when I check oil after it has just been running. It had to be wiped off to check oil level.
Just antidotal info.
Larry Dilk
Indianapolis, IN
76 Eleganza II
Patterson 455,Turbo City TBI,
Just LOVE It!
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| Re: Synthetic Oil [message #72982 is a reply to message #72753] |
Fri, 05 February 2010 19:44 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Since SYN is supposed to flow better, I would think it would flow into the pan better. I don't think it is so smart as to know where it should stay and where it should flow away. If you want some extra insurance in an extreme situation (lost coolant) it might give you the edge against temp breakdown. Longevity and anti foaming are supposedly better too with SYN.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Synthetic Oil [message #73009 is a reply to message #72982] |
Fri, 05 February 2010 23:58 |
hal kading
Messages: 642
Registered: February 2004
Location: Las Cruces NM
Karma: 4
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Senior Member |
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I would be very surprised to have either mineral or synthetic oil flow out of a bearing after shutdown. It should stay put by capillary action once the pressure has bled off. An exposed bearing surface is a different matter. Synthetic oil is supposed to be formulated to protect such surfaces for a longer time than mineral oil.
Hal Kading 78 Buskirk Stretch Las Cruces NM
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