First long high temp road trip

[Stevo]

Greetings All

Just returned from a 2200 mile road trip with the "85' 240D. Went down to northern CA and did some zig zaging back and forth from way inland to the coast thats why all the miles. Had no problems and used no oil at all. The PO was using Penzoil with some kind of "slickem additive" Arrrrgg! so I switched to Amzoil, changed it after 2500 mls then took off on the trip. Gotta admit its gona take a while longer to get used to the gyrations of the temprature gauge while driving in the mountains. With a "gasser" something would surely be amiss with such fluctuations. I had read lots of archives about the behavior of diesel cooling and I had never taken a long trip in HOT weather through the mountains. The highest it got was over the 100c mark, maybe to 105c on a LONG pull in third gear but most of the time on a pull, not over 90 or 95. Then down the other side she'd drop down below 80c. On the flat at 70-75 mph in 5th she would run at about 85.

I am wondering if you folks with oil coolers experience these sort of temps. Also it seems when I take off in the morning it really takes a couple of hours of freeway driving to get up to temp (85). Of course its nice and cool as I usually start early.

It's normal. Diesels get hot when they work hard (ie: sustained high speed and climbing a hill). Just as long as you don't get into the red while doing it, you'r e ok.

[Stevo]

turbodiesel

Thanks, Ya thats what I kept telling myself as I watched the temp climb and wondering how far to the top. Thanks to this group and all the cooling info provided in the archives I kept from freeking out. So I guess folks with oil coolers have that much flucuation also.

[vwbuge]

My baby seems to run better the hotter she gets. Turbodiesel is right, obviously, as long as it keeps out of the red, your OK.

[Nate Stanley]

---AND
the opposite happens when the engine coasts. No work=less fuel burned, so engine temp always drops when coasting downhill.

Both of my 300's and my 6.9l Ford do this, it's just a Diesel thing.

Carried to an extreme, one time when towing our trailer across the Arizona desert near Wickenburg, the fuel filter loaded up so slowly that before long I had the accelerator floored on level ground and could only do 25 MPH.

On a gasser, the lean condition and heavy load would have driven the engine temp thru the roof-- but with the Diesel, the opposite happened. No fuel= low engine temp regardless of load. The temp gage was hugging the C side of the gage, barely off the stop. A new filter did the trick.

Stevo

I took my 81 300SD up Stevens Pass and back down the North Cascades Highway this weekend. Yes, the temp gauge does climb a notch or two. Especially when I had it climbing the 6% grades at 65-70. Kind of fun with that turbo charged diesel pulling along. Never thought I would see that day when I would pass a line of Chevs and Chryslers in the old Benz, but sure enough. This one would accelerate uphill.
You must live near where I see those bumper stickers reading... 'We're all here, because we're not all there'?

[Jim Anderson]

I once came down a hill so long my diesel got so cool it stalled.

[Ridge]

Steveo,

If I recall correctly, you don't have an oil cooler. Too bad you didn't look me up while in Northern California, as I have an oil cooler that I'd have given you for free. I'm weeding out a bunch of stuff--moving.

Ben
www.reproduce100s.com

[Stevo]

Ben

Thanks for the offer. I was on a mission to see parents that are getting old so didn't have much time for planning. Actually I was thinking of getting rid of the oil cooler on the daughter's car before it dies. Seems like something that can be done away with on the 240Ds.

thanks for the interesting comments about diesels and cooling. A marine diesel comes to about 100F then you leave the dock (any sooner you get yelled at by the engineer). The engine stays at operating temp or something is wrong.