How Hot is TOO hot for oil temps

[sctrailrider]

What are your thoughts on oil temps in a turbo motor under towing conditions....... the temp probe will be in the pan....

Conventional oil -----

Synthetic oil ------

[Kennedy]

I think you'll have to wing it here and see what you get. Probe placement can make a big difference in readings.

I will say for example that my '02 Dmax runs around 180-200 with 220° being pretty warm after a hard run at a truck pull. Bear in mind that this is a liquid to liquid cooled beast.

[sctrailrider]

Yep, I kinda thought that, lots of folks don't monitor oil temp on there 6.5's..

I am thinking that with 2 coolers, I should be able to keep the temp below 230* or so, we will see....

[ronniejoe]

Chris,

Good luck with keeping it under 230F! I was shocked when I first installed an engine oil temp pickup in my truck. Towing heavy on hot days, it can reach 300F. I have the big DSG oil cooler on my truck too.

Very few people have actually measured their engine oil temps in 6.5 trucks.

[greatwhite]

300f is waaaay hot.

I do believe I've read most oil additive packages start to deteriorate at around 290f.....

[JohnC]

250 is too hot for dino oil in my book. Synthetic maybe 300, but 250 feels better.

One way to keep the temps down is to have a bigger sump...

[sctrailrider]

I found a large 30row cooler I think I will use, just need to have some lines made up for it, and I am planning to cut my pan and add 3-5" to it to give me some more capacity.

[ronniejoe]

300f is waaaay hot.

I do believe I've read most oil additive packages start to deteriorate at around 290f.....

Ya think? Yes, it's too hot. If you're running the factory oil cooler and doing any towing on a hot day, you're running a lot higher than that. As I said, most folks don't know this because most folks don't measure oil temperature. The bigger sump will help a lot.

I also run synthetic oil.

If you're gonna tow heavy on a hot day with a 6.5, you need to change your oil on a short cycle unless you've done modifications to lower temps. Every 6.5 should have an engine oil temp gage in my opinion.

By the way, what is your oil temperature when towing?

[greatwhite]

Im not trying to get into a peeing match or anything, but i was asked so ill post it up. Just my experiences with my truck;

Highest engine oil temp I've seen is 250-260 (and that made me nervous) topping Look Out pass (4700 ft) at just over 45 mph pulling my 35' TT.

Digital gauges (auber instruments syl-1813) using VDO senders for fluid temps and pressures, k type thermocouple for egts, stand alone GM 3 bar map sensor for boost.

The s-10 temp display I have in my over head console said 27 C. I think it was around 25 C when we topped the pass but done quote me on that one.

Trailer is around 8500 lb loaded and my truck usually scales 6900-7000 lbs fueled and loaded. So.....say around 15,000-16,000 CGVWR.

Could have gone faster than 45, but that was traffic speed and pushing harder would have driven egt a smidge too high for my peace of mind anyways. Traffic kind of bounced back and forth between 35-45 mph so there was some uphill acceleration in there from time to time.

Egts were tickling 1050-1100 with the WMI spraying. They'd flirt with 1100-1200 when i had to accelerate with trffic on a 35-45 mph jump.

Coolant temps hard on 210-215, no higher and no lower until the back side downhill.

Rotella T6, mainly because a pure PAO type IV is just too expensive to change as often as I do (every 3,000). Last time I talked to the shell rep he said the info he had available to him said T6 is good to 300f before the additive package begins to suffer.

Just an aftermarket (but stock sized) HD cooler for the engine oil.

The rest of the truck isn't exactly "as delivered" though...

Like I said, no peeing match intended and I've only got my word to back it up. But there's my experinces.

:)

[ronniejoe]

What was the outside air temperature? When I approached 300F, it was about 95F outside with high humidity, AC running towing my 4020 and bush hog for a GCVW of about 19,000 lb. Was running 75 mph on I-74 west of Indy.

I'm happy if it runs under 260F when towing hot and heavy.

[greatwhite]

See above, I must have editted while you were typing.

27c is around 81f.

Forgot to say the ac was blowing full cold for the....ahem....dogs comfort also.

The same setup got me around 240 in oil temps and 210 in coolant through Wyoming into SD on the rolling hills and 34c (93-ish F) indicated on the outside temp gauge. Wyoming was actually quite a butt kicker with rolling hills and high winds on my rig. Was pretty hard into the throttle most of the time. I'm not ashamed to say there was some 50-55 mph running there to keep temps in check.

Here's the whole trip:

http://i1174.photobucket.com/albums/r618/justonepict/comx-gander-1.jpg

Here's the whole rig:

http://i1174.photobucket.com/albums/r618/justonepict/1237d529-1.jpg

Lots of stories there......Lots of "humbling" experiences for my old truck, including a blown 599 block (lost a piston crown and replaced with a GEP 6500 Optimizer, but that's another story for another time).

I usually keep to around 60-65 mph when towing. Heck, Im normally around that anyways. Mostly because that's roughly around 100-110 kph, where I'm used to driving for our national average speed limit.

The truck isnt a" tow monster", but it gets the job done well enough for us.

;)

[ronniejoe]

Wow, that's quite a trip. What was your route back?

That's also a nice looking rig! ;)

[greatwhite]

Wow, that's quite a trip. What was your route back?

That's also a nice looking rig! ;)

We were moving from west coast to east so it was a one way trip.

I'd like to say it was fun, but blowing the engine on the second day in Wa, spending 10,000 to get it replaced, loosing a week of travel time and then sprinting like mad to make it in time for start of work kind of ruined it for us...

[sctrailrider]

This is the cooler I am looking at, it's about the largest I have found so far....


http://www.ebay.com/itm/Hi-Performance-Al-Transmission-Engine-Oil-Cooler-30-row-/160578859562?pt=Motors_Car_Truck_Parts_Accessories&hash=item25633ef22a&vxp=mtr

[ronniejoe]

Here's a shot of the DSG oil cooler. It has 50 rows and looks quite a bit bigger than the one on eBay. Kennedy Diesel sells these.

[greatwhite]

Here's a shot of the DSG oil cooler. It has 50 rows and looks quite a bit bigger than the one on eBay. Kennedy Diesel sells these.

Whoa momma!

That is big.

Well, compared to stock it is....

[ronniejoe]

Notice that I mounted the stock engine oil cooler for use as a transmission oil cooler. It's a lot bigger than the stock tranny cooler, too.

[greatwhite]

Notice that I mounted the stock engine oil cooler for use as a transmission oil cooler. It's a lot bigger than the stock tranny cooler, too.

Hmmm, missed that little tidbit.

And here I am sitting with a stock unused HD cooler on the shelf in the garage......

Did the transmission lines bolt right up?

Might be a good time to get my 4l80e AN case adapters out of the drawer and make up some nice new braided lines to go with 'em.

Oh Ronnie, you're a bad influence on my wallet....;)

[ronniejoe]

As I recall, I had to modify the cooler a little. I used the factory quick connect adapters that were in the original transmission oil cooler. I think I had to drill the holes oversize in the cooler and tap for NPT to make the adapters fit. It's been seven or eight years since I did it, so I don't remember exactly.