Idling Experiment

TEXAS_TDI

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Dec 20, 2001
I had a VW tech make a claim that a TDI would be fully warmed up in only 20 minutes of idling in 20F weather. I took that bet.

This morning it was 20F according to Weatherbug. It took my car 27 minutes of idling to reach 190F, full operating temperatures.
 

Doug Huffman

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Joined
Apr 7, 2000
Location
Washington Island, on the other side of Death's Do
TDI
Jetta Wagon 2K3 Silver gone to new home
I did a similar experiment in 20F temps recently. Uncle Larry (with a ~500,000 mile diesel Rabbit) and I watched for two practical criteria to be met; would the 2K3 Jetta Wagon TDI reach NOT in ten minutes (no) or would the 'defrost' air be warm enough to loosen the ice from the windshield (yes) in the same time.

He keeps his Rabbit in the barn and doesn't even try to start it without pre-heating the block
 

TurnpikeMan

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Joined
Feb 27, 2002
Location
Rockaway, NJ, U.S.A.
TDI
2002 Golf GLS Indigo Blue
I dont get it???

This week its about 30's here in NJ. After I drive for a while I let the turbo cool down for a bit!

But even after one minute the temp guage moves a little bit down. So I waited for a bout 3 minuits and it lowered a whole space between two bars!!!

So how is it possible that it actually "warms up" at idle??
 

TurnpikeMan

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Feb 27, 2002
Location
Rockaway, NJ, U.S.A.
TDI
2002 Golf GLS Indigo Blue
I also found this to back up my example.
TDI FAQ

And I quote it:
Because the TDI engine is so efficient, it puts less heat into the cooling system than comparable gasoline engines. A TDI engine will not reach operating temperature by idling.
<font size="2" face="Verdana, Helvetica, sans-serif">
 

al_from_canada

Active member
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Nov 2, 2002
Location
Burlington, Ontario, Canada
This is an important topic. According to public opinion, it's not a good idea to idle the TDI for an extended period of time - bad for turbo seals, emissions yada yada yada. As far as i understand, you get in, start it up and go. The motor warms up as you drive, not idling in the driveway.

Now i live in fairly cold conditions which means that when i get in the car in the morning, the interior of the windows begin to fog. Now i set the controls to heat the interior up as quickly as possible but for several minutes my front window is very foggy. This is dangerous as you can imagine.

What do you cold weather guys do to remedy this?
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
In -25 C, with the heater cranked to max (and still not quite giving enough!), and while stuck in a traffic jam, I have had the indicated temperature on the gauge go DOWN.

As long as traffic was moving faster than perhaps 80 km/h, the temperature stayed up. At slower speeds, on city streets ... the temperature went down! At idle ... forget it!
 

snoopis

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Joined
Aug 18, 2002
Location
Arlington, TX, USA
TDI
2002 Golf GLS TDI, 5spd
It seems to me like the car warms up a little faster if I leave the heat off. I turn the temp all the way up, so that the little bit of air that is always blowing is not ice cold, but I don't turn on the fan until the temp reaches about 1/2 way to 190. People say that if your car is overheating in the summer(not a TDI obviously) you should turn on the heat to remove a little heat from the engine. So I guess it would make sense that turning on the heat in the TDI might do the same, but probably not nearly as effective in our situation.

Actually, half the time I don't turn it on at all. It's only a few miles, so I just wear a coat and some leather gloves. No big deal. But I am from Chicago, where temps reach (although not regularly) -30°F to -40°, and now I live in MD, where it doesn't get nearly that cold, at least not yet. So it aint warm, but it's nothing to 6itch about. As long as my windows don't fog up I don't care.
 

Tarbe

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Joined
Nov 20, 2002
Location
USA
TDI
Touareg and Sportwagon Sold to VW
I fueled this evening on the way home. My engine was at full operating temperature and I left the car idling while I pumped 12 gallons.

Ambient temperature was 22 degrees F. The gauge dropped two lines in the 5 minutes or so that it was idling.

Anyone know for sure what temp is at two lines below 190??

Tim
 

Tarbe

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Nov 20, 2002
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USA
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Touareg and Sportwagon Sold to VW
Originally posted by snoopis:
But I am from Chicago, where temps reach (although not regularly) -30°F to -40°
<font size="2" face="Verdana, Helvetica, sans-serif">FWIW, according to Yahoo weather stats, the coldest recorded official temp in Chicago was on January 20, 1985.....-24F.

Tim (formerly of Eau Claire where it has actually been -45F!)
 

Frankenwagen

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Sep 25, 2002
Location
NH
You guys need to get an automatic so you will have a load on the engine all the time to produce more heat.
 

TEXAS_TDI

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Dec 20, 2001
Originally posted by Frankenwagen:
You guys need to get an automatic so you will have a load on the engine all the time to produce more heat.
<font size="2" face="Verdana, Helvetica, sans-serif">Pssht.


Automatics are for the typical lazy American. Real men drive 5 speeds.
 

Veep

Well-known member
Joined
Nov 12, 2000
Location
New Britain, CT
TDI
Golf GLS, 2000, Silver
There's something to be said for a little warmup time. I recently posted about my fuel filter drain failure. Had I not done a warmup, I would have been stuck on the side of the highway instead of a secure parking lot.

FWIW I warmup my car with the heater control full clockwise and the fan off. After about 12 min. at say 20*F the temp gauge is in the middle of the three bars on the bottom of the scale.
 

TEXAS_TDI

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Dec 20, 2001
Originally posted by TurnpikeMan:
A TDI engine will not reach operating temperature by idling.
<font size="2" face="Verdana, Helvetica, sans-serif">Once again the TDI FAQ is wrong. It's not the first time, it won't be the last.

I don't normally let my car idle very long. Usually only about 5 - 10 minutes. Enough to get the heater somewhat warm and melt any ice on the windshield. But, IMO, idling doesn't hurt anything. Truck drivers routinely let their trucks idle a minimum of 8 hours per day, 7 days per week, 365 days per year, and easily get 500k miles on a motor before an overhaul.
 

Chuck101

Well-known member
Joined
Aug 13, 2002
Location
Tallahassee, FL
AL-
Do a search for TDI Heater and you should find some information on how others on this board are warming their TDIs. Luckilly, here in FL, we are somewhat immune to the cold weather problems, tho it is sopposed to get into the teens F tonight... Ugg.
Time for some Crown Royal warmth.....
 

Davin

Top Post Dawg
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Jan 4, 2001
Location
L.A.
TDI
2001 Golf GLS 5spd blk/blk
Originally posted by ProjektZwoTDI:
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TurnpikeMan:
A TDI engine will not reach operating temperature by idling.
<font size="2" face="Verdana, Helvetica, sans-serif">Once again the TDI FAQ is wrong. It's not the first time, it won't be the last.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Depends on what your definition of "operating temperature" is.

When the idiot gauge on the dash reads 190* (and when it first hits it, the engine is really only at about 160-165* or so... check with vagcom), my oil temp is still around 110*. I think that warm oil is just as important as a warm block when considering whether or not the engine is up to "normal operating temp".

I wonder how long it would take for an idling engine to bring the oil up to 180*+, or if it ever would.
 

RiceEater

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Aug 13, 2001
Location
96595
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gray 2k2 Jetta GLS
As I previously stated the thermostatic valve has globe isolation valve type characteristics. The thermo pellet doesn't pop open the valve until about 100F and I guess some people need to do the experiment. Observe the valve in a pot of water and see that it suddenly pops open and not in a linear fashion. No, it is not reasonable for it to close at 100F just because it opens at 100F. Butterfly valves or shutters are much better at controlling a wide range of flow.
 

TurnpikeMan

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Location
Rockaway, NJ, U.S.A.
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2002 Golf GLS Indigo Blue
I still say if the temp guage goes down while stopped in my driveway after a long drive...... How is it possible for the temp guage to move up when there is no use of the engine???
 

oilhammer

Certified Volkswagen Nut & Vendor
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Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
My A3 TDI will not warm up if left idling..at least for any amount of time I have left it idle. It warms up quick enough if you drive off right away, however. I have noticed that a few weeks ago my wife and I were stuck in a traffic jam in 20 degree weather...the temp gauge usually rides at half way, but it krept down to about 1/3 from stop-and go traffic. I also noticed just this afternoon during a post-120k maintenance test drive that the gauge started to go down on the highway after cruising at about 95 MPH for 3 minutes or so...temp was around 25 today. My '91 NA Jetta will warm up a little faster at idle, and even in super cold weather the heater seems to be hotter and the gauge will not drop as far down as the TDI. I think the TDIs are just super-efficient!
 

TEXAS_TDI

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Dec 20, 2001
Originally posted by TurnpikeMan:
I still say if the temp guage goes down while stopped in my driveway after a long drive...... How is it possible for the temp guage to move up when there is no use of the engine???
<font size="2" face="Verdana, Helvetica, sans-serif">I don't know. How cold is it in your driveway? Maybe, if it got below zero around here, the needle wouldn't move. But 20F is freakin cold around here. And my needle moved all the way up to 190F in about 27 minutes of idling. I also did not have the heater on in the car. So none of the motors heat would be taken away. That might have also made a difference.
 

snoopis

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Aug 18, 2002
Location
Arlington, TX, USA
TDI
2002 Golf GLS TDI, 5spd
Originally posted by Tarbe:
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by snoopis:
But I am from Chicago, where temps reach (although not regularly) -30°F to -40°
<font size="2" face="Verdana, Helvetica, sans-serif">FWIW, according to Yahoo weather stats, the coldest recorded official temp in Chicago was on January 20, 1985.....-24F.

Tim (formerly of Eau Claire where it has actually been -45F!)
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm actually from Zion, but the record for Kenosha, WI, which is much closer than Chicago, was -31°F on 20 Jan 1985. Of course I was 6 at the time so I don't remember that. I guess the wnidchill must have been somehow distorted in my brain to become an actual temp. My bad.
 
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