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Topic: Engine Oil Temps (Read 411 times) previous topic - next topic

Engine Oil Temps

2000 U320 with M11 engine.  A week or so ago we traveled from Tonto Basin to Prescott Valley via Hwy 87 & 260.  My toad is a F150.  It was quite a climb with back to back up and down grades of +6 % grades.  I noticed on my VMSPC that my engine oil temp would rise from around 198 deg (normal) to 223 deg (max I observed).  This gave a yellow caution on the VMSPC. I have not noticed this before with my previous coach, also M11 or this coach.  Trans and engine coolant temps were normal and climbed as expected but never in the yellow caution range.  Do others have this issue?  Does the M11 have an oil cooler radiator that may need cleaning?  In the next few days will be traveling over Wolf Creek pass, La Veta and Raton.  I seem to be able to manage the oil temp by slowing the engine RPM and letting it lug a little.  That of course raises the engine temp but seems manageable for now.  I have checked the engine oil level and it is ok.  Would like to know if there is an engine oil cooler somewhere that may need servicing. 
Bill and Joyce, The House2 and Dashboard Pig III
2000 U320 4210 CAI (The House2)
Build # 5733
2019 F150 King Ranch FX4

Re: Engine Oil Temps

Reply #1 –
I experience the same thing on long grades. Roger has set the yellow at a very conservative number. Having experience with oil temps in many different engines I don't worry until it gets over 250.

What Is the Optimum Engine Oil Temperature?.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Engine Oil Temps

Reply #2 –
Thanks Craneman, appreciate the info.  Maybe I can relax and save a few drops of sweat!
Bill and Joyce, The House2 and Dashboard Pig III
2000 U320 4210 CAI (The House2)
Build # 5733
2019 F150 King Ranch FX4

Re: Engine Oil Temps

Reply #3 –
I believe we have an oil cooler and it is under the manifolds and a bitch to get at. I would have
sent it out to be serviced with the trans cooler but it was too hard to get at. I agree with chuck
I wouldn't worry about the oil temperature but I can't figure out why the oil temperature would
go down by lugging lugging the engine.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Engine Oil Temps

Reply #4 –
Quote from: oldguy –
I believe we have an oil cooler and it is under the manifolds and a bitch to get at. I would have
sent it out to be serviced with the trans cooler but it was too hard to get at. I agree with chuck
I wouldn't worry about the oil temperature but I can't figure out why the oil temperature would
go down by lugging lugging the engine.

Rpm splashes the oil creating heat. Less rpm slows the oil friction but also slows the fans and raises engine and trans temps. I have noticed the same effect on the oil temp and it takes it much longer to go back down. My race cars have always had a device called a wiper to get the oil off the crankshaft.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Engine Oil Temps

Reply #5 –
DO NOT LUG YOUR ENGINE. I have owned three semi trucks. They were equipped with pyrometers (exhaust temp) lugging even a short time on a hill would raise the exhaust temp from a normal 600-700 to over 1200. This high a temp isn't good.

M11's have three section exhaust manifolds. If you get the manifold hot from lugging, it will warp them and can pull an exhaust bolt out of the head. New manifolds are $1,000 plus labor and they will have to repair the head with a helicoil.

Don't worry about it unless your oil goes past 250 and continues climbing. 

Keep the rpms up and speed down by down shifting. but keep the turbo boost as low as possible by not mashing the go peddle to the floor.  Lower gears will multiply your torque and lower engine load.


Jerry & Nona and Kimeru the cat that thinks she's a dog
1998 36' WTFE U320  #5314 Motorcade #17711
USAF 1975-1995
2019 Subaru Crosstrek 'toad'
2003 Subaru Legacy touring car
jerry Fincher | Flickr

Re: Engine Oil Temps

Reply #6 –
Low RPM on grades raises the EGTs and is worse for mechanical engines up at altitude. I keep ours fairly high and about two hundred RPM lower than the 2130 fuel cutoff RPM on grades. Best cooling, especially up high where the air is thinner, radiator and fan are not as efficient and the injection pump may over fuel causing high EGTs.

225 degrees for oil temperature is fine. Many vehicles operate higher than that all the time. Here is a chart.  Your 198 degrees normally is perfect.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Engine Oil Temps

Reply #7 –
Us with Silver Leaf can figure out if our exhaust temperature is to hot by noticing what our intake
manifold temperature is normally and when it gets too high when climbing to back off. We can
use it like a pyrometer. Also on my coach a light came on saying the intake manifold temperature
was too high once and I backed off and it went out. At that time I didn't know anything about intake
manifold temperature, but luckily I did the right thing.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Engine Oil Temps

Reply #8 –
I'm always impressed with the collective knowledge of this group.  I love the education so thanks guys.  I have wondered about the intake manifold temp reading and what it should be.  I have never seen it get to the yellow caution, and normally runs about 190 and have never seen over 230 if memory serves.  I will pay close attention on the next grades in coming days. Will also check for an oil cooler.
Bill and Joyce, The House2 and Dashboard Pig III
2000 U320 4210 CAI (The House2)
Build # 5733
2019 F150 King Ranch FX4

Re: Engine Oil Temps

Reply #9 –
Quote from: oldguy –
Us with Silver Leaf can figure out if our exhaust temperature is to hot by noticing what our intake
manifold temperature is normally and when it gets too high when climbing to back off. We can
use it like a pyrometer. Also on my coach a light came on saying the intake manifold temperature
was too high once and I backed off and it went out. At that time I didn't know anything about intake
manifold temperature, but luckily I did the right thing.
There is nothing like having a pyrometer tapped into the exhaust manifold BEFORE the turbo. As close to an exhaust valve would be best.  If it's after the turbo, you have to add at least 2-300 degrees to the reading.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Engine Oil Temps

Reply #10 –
I agree Pierce that a pyrometer the best but if you don't have one the intake manifold will have
to do.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Engine Oil Temps

Reply #11 –
Quote from: Bill B –
I'm always impressed with the collective knowledge of this group.  I love the education so thanks guys.  I have wondered about the intake manifold temp reading and what it should be.  I have never seen it get to the yellow caution, and normally runs about 190 and have never seen over 230 if memory serves.  I will pay close attention on the next grades in coming days. Will also check for an oil cooler.
No need for an extra oil cooler and the short time in the  220 degrees range is nothing. The chart is for long term temperatures and not for slightly higher readings climbing grades.

Using lower gears climbing grades and not shutting down the engine for a few minutes after a climb helps insure a long engine life.

I put a oil temp gauge on my Austin Healey Sprite that went to 280 degrees. After driving it for a few minutes, the gauge was over the 280 mark. No wonder their engines had short lifespans.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)