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Topic: Cat 3208 Oil temp vs coolant temp (Read 601 times) previous topic - next topic

Cat 3208 Oil temp vs coolant temp

We made the maiden voyage home with our GV today from Phoenix to Prescott. Coach ran like a champ, I think, but I have some questions about oil temp.

For most of the drive, the oil temp hovered between 205 and 225 depending on speed/incline/ambient temp (all of which varied a lot). I think this is normal, yes? The only time I got concerned was up the very steep grade from Congress to Yarnell. This is a tall mountain and even my U320 does it in 3rd gear. It's a long steep climb but not wolf creek pass long. I kept the RPMs between 2000 and 2200 for the most part but by the time we got to the top oil temps were above 275. Coolant temps never budged from ~165 and once we were safely at the top I hopped out and felt the heads and oil pan and both were warm but I could hold my bare hand to them. Oil smelled normal and was cool enough I could touch it with my finger no problem .

This thread makes me think this is to be expected and I maybe need to back off the gas on steep grades but I could use some confirmation that this isn't unexpected: 1987 Grand Villa Cat 3208 oil operating temperature

The engine dipstick says the engine oil is full and it looks to be the original dipstick so I assume it's calibrated correctly (it's yellow like the engine block).

Thanks all... more questions to come now that she's home, I'm sure.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 Oil temp vs coolant temp

Reply #1 –
I would think your engine is running too cold, it should have a 180 thermostat. If you can put
your hand on the oil pan I would say your gauge is reading high.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Cat 3208 Oil temp vs coolant temp

Reply #2 –
Just so I'm clear here you've talking about the oil temperature ? My coach doesn't have an engine oil temp gauge but it does have a transmission temperature gauge and those numbers sound like transmission temps.
88 Grand Villa 36' ORED 3208 (throwaway)Cat.
 Build # 3150
Happiness is the maximum agreement of reality and desire.

Re: Cat 3208 Oil temp vs coolant temp

Reply #3 –
Yes, too cold. Should be about 185 with transmission oil temp depending on if the transmission is in lockup. We lockup top of second, all of third and fourth and the tranny runs about the same 185.. In summer with higher ambient and engine temps, the transmission will be a little warmer.  If in a city and not in lockup, the transmission may run 200 or so. Does your tansmission lockup? If so, you should feel 4 shifts so it feels like a 5 speed.

I have to back up our steep driveway as if I use first gear, the transmission will go up to 300 degrees in 300 feet. The driveway gains 80 feet in 300.

Make sure the PO didn't remove the thermostat. Some do. Low temps mean less fuel mileage, faster engine wear and crankcase moisture may not evaporate. May see brown foam on the inside of the breather cap.

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

Re: Cat 3208 Oil temp vs coolant temp

Reply #4 –
Make sure the dipstick does or does not say check with engine running.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 Oil temp vs coolant temp

Reply #5 –
I have trans temp and engine coolant temp .
Both run best at 190 or so.
The trans reads a lot higher out of lockup . So try to maintain lock in third gear for hard pulls .

Re: Cat 3208 Oil temp vs coolant temp

Reply #6 –
So yes, I am talking oil temperature. Looking back through the maintenance log I have, an oil temp gauge was added about a year ago. I don't know where it's taking it's reading so I need to do some hunting I guess and confirm what I'm seeing on the dash.

Per the Cat 3208 maintenance manual I have, 165 is right within spec for coolant temperatures. The thermostat(s) (I assume I have two) appear to be working because the top half of the radiator was about the same temp as the heads and the bottom half was nice and cool, so it's doing it's job. The manual lists all the gauges and what they should read and an oil temp gauge is not in that list.

It seems to me that the oil temp gauge was just added for shiggles to further stress out worriers like myself.

1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 Oil temp vs coolant temp

Reply #7 –
The  OE temps are very low .  If you can get the running temp over 185  or to 195. The fuel will burn more completely. less black smoke  equals more power and MPG.   
 AS far as oil temps , it needs to get over 212  to boil the water out  .  My oil consumption went down to almost zero  after I started running the engine at 195. from the prior 180 .
  The trans will work best at 185-200. it seems  before I swapped the fans , the trans temp sat on the low peg. The shifting was harsh into 3 Lock and 4 lock.  Now that it runs warmer , it shifts much nicer without the jolt into high gear . 

Re: Cat 3208 Oil temp vs coolant temp

Reply #8 –
Quote from: Elliott –
The only time I got concerned was up the very steep grade from Congress to Yarnell. This is a tall mountain and even my U320 does it in 3rd gear.
I don't really want to hijack this thread, but thought I'd ask here instead of via PM in case anyone else is curious.  I've been on that road many times going from Surprise to Sedona in a passenger vehicle.  It is definitely steep in places but I would have thought that some of those curves/turns would be too tight for an RV or that the ends might even be dragging :o. Do you take up both lanes sometimes?  Is the Prescott to Jerome part also doable?  Thanks.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Cat 3208 Oil temp vs coolant temp

Reply #9 –
I have been on the road to Jerome and would not drive our coach on that road!  Just saying!  Good luck Elliott and I hope you get this figured out!  Oil temps at 275 would concern me, but don't know the 3208 block!
Joe & Dottie Allen
Sold!  December 2023.      2000 U320; build # 5645
Our coach " Maxine"
Motorcade #  15922;  Escapee 150950; FMCA F330833; Boondockers Welcome;  Harvest Hosts;  Thousand Trails
'98 U320 from 2000-'06
USAF '62-'66

"Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for." ―Epicurus

Re: Cat 3208 Oil temp vs coolant temp

Reply #10 –
Quote from: Elliott –
We made the maiden voyage home with our GV today from Phoenix to Prescott. Coach ran like a champ, I think, but I have some questions about oil temp.
 I kept the RPMs between 2000 and 2200 for the most part but by the time we got to the top oil temps were above 275. Coolant temps never budged from ~165 and once we were safely at the top I hopped out and felt the heads and oil pan and both were warm but I could hold my bare hand to them. Oil smelled normal and was cool enough I could touch it with my finger no problem .

Elliott, I'm going t guess that you're talking about engine oil temperature.
When the engine oil temperature went above 275ºF did the oil pressure drop correspondingly.
You state that you kept the engine revolutions between 2,000 and 2,200 but was that with your foot to the floor?

If you have normal oil pressure all that high oil temperature will do is shorten the lifespan of you engine oil.
If you feel the need to "do something" you could pull and clean the engine oil pan as a way to check for sludge build up on the inside of the oil pan.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Cat 3208 Oil temp vs coolant temp

Reply #11 –
First thing I would do is find where the temp sensor is and make sure the gauge is working properly,if it is taking the temp where
most sensors are there is no way the oil as a whole got to 275,the coolant temp would be much hotter,try looking near the turbo
oil lines they may have put a sensor for turbo oil temp,most turbos get so hot internally they cook the oil over time and cause
the oil passage to get smaller and smaller resulting in hotter temps and turbo failure.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 Oil temp vs coolant temp

Reply #12 –
Quote from: Old Toolmaker –
Elliott, I'm going t guess that you're talking about engine oil temperature.
When the engine oil temperature went above 275ºF did the oil pressure drop correspondingly.
You state that you kept the engine revolutions between 2,000 and 2,200 but was that with your foot to the floor?

If you have normal oil pressure all that high oil temperature will do is shorten the lifespan of you engine oil.
If you feel the need to "do something" you could pull and clean the engine oil pan as a way to check for sludge build up on the inside of the oil pan.
I didn't notice the oil pressure dropping at all, it stayed pretty steady I think but I wasn't watching it as closely. I did not have my foot to the floor with the RPMs at 2200. If it hadn't been for this one gauge on the dash climbing, I'd have been super impressed by how well this little thing climbed that mountain.

@John44 I'm inclined to agree with you about checking what that gauge is actually measuring... I need to get that figured out first now that I know it's not original. Could very well be transmission temps instead.

@Dave Larsen, I'll start another thread about getting up the hill to Prescott. It could be white knuckle and dangerous if you don't know the "back way" around those switch backs you're eluding to.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 Oil temp vs coolant temp

Reply #13 –
Elliot,assume you have a heat temp gun,if not get one.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 Oil temp vs coolant temp

Reply #14 –
Elliot as I said in post #1 if you can hold your hand on the oil pan it isn't too hot infract it's probably
on the cool side. When I change oil I find everything too hot to touch. Do what John said and use a
heat gun.
 
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport
 

Re: Cat 3208 Oil temp vs coolant temp

Reply #15 –
The temperature you are saying sounds like the transmission temperature. Our 3208 84 Foretravel did the same on large grades. If I remember correctly the transmission temperature sender came off of the top of the transmission. On the 98 and 03 there is an elbow on the lower part of the transmission that has been drilled and the sender screwed into it.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins