How for diesel engine to warm up?

[oparrott]

Hey Friends! I searched the posts and too my surprise didn't find the answer to my question.

I recently replaced the thermostat on my 82 300SD. The coolant temp runs about 85 C once completely warmed up. I live in Massachusetts where the outside temp is 30-50F right now. The "problem" is that it seems to take a full ten (10!) minutes for the engine to warm up all the way. It climbs slow and steady up to 85. I do mostly about town driving so most of the time the car isn't completely warm. It definitely performs with more pep and better shifting once up to 85. Should I have to wait so long? Seems like my wife's Honda is up to temp within two blocks. What do you think?

[Veloce300DT]

10 minutes to warm up to normal operating temperature seems normal to me for a 617 engine.

[Brian Carlton]

The 617 seems to take forever to warm up.

The 603 warms in 1/2 the time. Probably makes it to 80° C. in seven minutes or so, driven very easily.

[vwbuge]

I noticed that if I let mine sit in the driveway and idle it will never get to proper temp. Only after driving will it climb to normal operating temp.

[Ali Al-Chalabi]

The Honda also does not have a real coolant temp gauge. It is programmed to simply stay in the middle regardless of temp unless it gets way too hot or way too cold.

Mercedes have a coolant temp gauge that actually displays the correct coolant temp.

[bullwinkle]

I wouldn't let it sit and warm up-mine smokes and starts to load up with carbon if allowed to idle excessively-it does warm up quicker than 10 minutes, though-you might want to check the stat suspended in a pan of hot water with a thermometer-I've had a few that didn't close all the way and opened early. I also wouldn't put a lot of stock in the factory gauge-after 20+ years, they're usually off a little.

[Hatterasguy]

Actually the engine really isn't "warm" until the oil pressure drops off to 1.5 bar or so.

My SDL takes a bit to warm up, the 606 warms up about twice as fast.

[jayb79]

If you have the heater cranked it will take even longer to heat up. If you want it to heat faster it needs more load. I f i leave mine idling i turn on the lights and the rear defrost to give it some load and it heats a little faster. My TDI beetle has a harder time heating up than my 87td. Remeber diesels are heat engines and they use there heat very effiecently.

[oparrott]

Thanks for all the useful comments! I can stop worrying now. Cheers!

[dannym]

I usually let it warmup until I see the needle start to move off 40 then drive conservatively until it reaches operating temperature.
Then I get on it!

Danny

[rg2098]

Interesting, mine usually reaches 80 after a few miles and doesn't go any higher under any circumstance.

[pawoSD]

Mine takes about 2 miles worth of conservative driving or about 15 minutes of idling to reach its normal operating temperature, my dads takes about twice as long and runs cooler in general, probably a t-stat issue but it still gets up to 80-81C so we're not concerned for now.