Engine Warm Up Time

I have a 2004 tdi golf, I live in Saskatchewan. I know the general rule is you need to let Diesel's warm up longer than gas engines, why is that? How long is long? Say it's -10c out? And say it's -20 or -30, how long is recommended? At around -10 I world normally let it warm up for like 15 minutes. My wife uses the car the most and I'm pretty sure she doesn't let it warm up very long, what will this specifically harm over time?

I've never dealt with really cold temps but I think you've heard wrong. You need to idle it until you have good oil flow the the extremities of the engine then drive it so it warms faster so your wife is causing less harm than you are.

Diesels tend to warm up slower than gas engines so it may never "warm up" just idling.

30 seconds to a minutes is the longest I'd let a diesel idle after starting up, otherwise, just long enough to get the fluids moving. Diesel engines will not warm up effectively in cold weather without a light load, unlike gasoline engines. Letting a cold engine idle for a long period of time will accelerate wear. I do this, even when I'm in Michigan on the coldest mornings.

Personally, I wait around 30 seconds, then slowly accelerate to 10-15 mph and cruise the 1-2 minutes out of my long driveway. By that point, I'll gently accelerate to 35-45 for a half mile. In my truck, I just watch the pressure gauge and keep the pressure under 60 psi, at low temperature, the pressure sky rockets. By the time the coolant reaches 120, the oil pressure stays at 40 psi, no matter the load or RPM.

D.L said:

Say it's -10c out? And say it's -20 or -30, how long is recommended? At around -10 I world normally let it warm up for like 15 minutes.

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I'm out on east coast, so it doesn't get that cold here...maybe -10C, with the odd dip down to -12c or -15c in January and Feb. I use a Frost Heater at home, but when I can't...like at work, I usually let the engine coolant warm up to 20*C before driving off. It only takes a few minutes to hit that.

I have no idea where I got the 20c...just a random number I picked I think.

PS: I have an Ultragauge installed btw...that's how I watch the coolant temp.

Wow, this is news to me, I'm glad I asked, thanks a lot for the information everyone.

If I could only get my wife to understand that you can't just jump in and switch on the heat and expect to get heat into the cabin! I've tried to explain it to her but for some reason she's got a mental block going on with this.

I occasionally get temperatures down to about 10F my car takes about 7 minutes of drive time to flip off the cold engine warning light and start the temperature gauge moving. It takes roughly the same amount of time even at about 50F.

It also runs really really rough the first 2-3 minutes.

That being said i have a broken wire on the preheater glow plugs, I need a new glow plug harness and have only seen the harness that goes to the engine.

It would be a good idea to check all of your glow plugs, mine has 7.
4 on the engine 3 on the preheater.

https://www.youtube.com/watch?v=qB8b8CCJdfg

Thanks for this thread I found it really helpful...

wooba001 said:

That being said i have a broken wire on the preheater glow plugs, I need a new glow plug harness and have only seen the harness that goes to the engine.

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You have to buy the plug ends for the coolant glow plugs individually:

http://www.idparts.com/glow-plug-connector-b55-bhwa4-coolant-plugs-p-1531.html

Thanks for the link. That is really helpful.

-10C is pretty normal for our mornings. Usually, the idle will go down within 30 sec to 1 minute and I'm ready to drive off. Colder mornings, we sometimes see -25C and the engine is making a lot more noise when started. I have let it warm up no longer than 3 to 5 minutes at that temp before taking off.

I have to climb a hill for the first km or so, and I think that helps to have a small load for the engine to work against right away. Typically, I select a gear that keeps the engine between 1700 and 2000 rpm while going up the hill when the engine is cold.

A frost heater is a good idea. I park in the garage most nights, and when started I just drive away. It's about 8C inside the garage most mornings.

Further to the last post , never underestimate the advantages of insulating your garage. At minus 30
outside , the interior of my garage , as well as the transmission and interior of the car is pleasantly warm after 3-4 hours o frost heater usage. Of course one of my vws has a 1500 watt heater which really warms up everything.