I live in NY. Current temperatures range from -11 to 30's. I own a 1982 300sd. I have a few questions.

Should I let my engine warm up before hitting the road?

What are the advantages/disadvantages of letting my engine warm up before driving?

There seem to be people on both sides of the fence. Some say prolonged idling in a cold climate prematurely wears out the engine.

Thought?

My opinion, a diesel is so thermally efficient that it can take forever to warm up at idle. My MO has always been to start it, wait a few seconds and then drive off at VERY restricted speeds/RPM's.

Say, for instance, keep the revs below 2000 for the first few minutes of driving, preferably around 1700 if you can get it to shift that low. My '98 will shift around that speed if I'm very gentle with it. From then on, I maintain about 30 MPH on neighborhood streets and it's usually warm by the time I have to accelerate onto the Interstate.

If you're located where you have a hard acceleration onto a highway in the first couple minutes of driving, it makes sense to let it warm up a little before getting out there. I try to make sure the needle is at least at the 40 mark before trying to get up to highway speed.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Currently I'm stationed in a rural area, so I have all the time in the world to gradual mosy up to higher speed. Problem is, my tachometer comes in and out haha, though I can still count on my speedometer.

I find that my SD has trouble shifting (slips a little) on those colder mornings. Does this correlate to cold transmission fluids?

It's a matter of preference, though I think most would agree some warmup is a good idea. Even in summer, I let my diesels run for at least 30 seconds before I drive off from a cold start.

As I have very limited opportunity to drive at slow speeds once I leave my driveway (unless I choose to go around my block for a few minutes), in winter I don't drive off until the needle is at the 40. This does not take long at all, if the car has been plugged in (block heater).

In extreme cold - as we experienced this winter for weeks, though most years that would only be maybe 5-8 days the whole winter - I let the car warm up for 10 minutes. I am old school/old lady on that and I just don't like to push my old equipment at all, in extreme cold.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

I let mine warm up while I scrape windows and/or remove snow. If I don't need to do that, then it doesn't get a warm up.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

I usually count to 60 in the winter sometimes with the throttle in a bit to give it a high idle (83 240), then go easy on it till the temp gauge starts to move. In the summer, I just start driving, take it easy for a block or two, then I drive normally.

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This could be just me, however, I believe the 2nd dash above the 40 centigrade mark on the engine temperature indicator is to let drivers know when their car is properly warmed up. This takes my car 8 minuets approximately to reach that point, and about 10 minuets outside in below 30 degrees Fahrenheit. By the time I am driving on the main road the car is at or near the 80 centigrade mark and drives excellently as well as shift as proper as can be even with vacuum leaks.

Are there ANY vacuum leaks in your system? This could be the cause of the transmission having trouble shifting. My car refuses to shift out of 2nd gear until the engine temp reaches 80 centigrade.

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Nosce Te Ipsum "Know thyself"

I find the engine warms up faster if leave the heater off till temp hit 80.
I go a few blocks easy till I see some motion on the gauge then a few good runs and the temps comes up quite fast. (with the heater off)

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1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

I haven't tested my system for vaccum leaks. Good links on vacuum leaks? She shifts perfectly once I'm up to 70-80s

I always let my old girl warm up. I also plug her in.

When it is cold out, I try to let the car warm up for a few minutes. It helps with getting heat faster and the performance is a lot better than when bone cold.

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1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

At temperatures down to 40 below I start, do up the seat belt and am on my way. Living in the second coldest capital in the world I have cold weather experience. Don't use a block heater either, I rely on synthetic oil. Only 202,000 miles and usually don't add oil between changes.

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1999 Mercedes E300TD daily driver sold at 238K miles 106K miles were mine, rust worm got it :-(
2006 Mercedes CDI new daily driver! 56,000 miles May 2016 now 85,625 Apr 2018 and Apr 2019 101,000 miles Apr 2020 109,875. March 2024 135,250, Dec 2024 145,000 miles

Even with my gasser, I let it idle for at least a few minutes (or the coolant temp hits 100*F) before I put a load on the engine. If I takeoff before then it's not happy.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

This.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Yep, just turn it on and drive....no warm up....but s-l-o-w-l-y at first.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 179k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 77k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife