www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums TDIFAQ Articles Links Meets
Orders TDI Club Cards TDIFest 2014 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You



Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI 101

TDI 101 Got a simple/basic TDI question? Are you a newbie (new to the forums). Feel free to post your question here.

Reply
 
Thread Tools
Old January 23rd, 2013, 16:28   #1
joelbert
Veteran Member
 
Join Date: Aug 2012
Location: NJ
Default Coolant warning light on cold days

In the last few days it has gotten colder here in NJ. With temps in the mid teens (F) the coolant warning light flashes after I start the car, and continues to flash for the first trip of the day. After I stop the car and restart it the flashing goes away. Yesterday I did a long trip with it, got to full operating temperature, and the light did not stop until I turned the car off and back on. Today I did a 2 mile trip as the first of the day and same thing, the light did not come on after the first trip of the day even though the car was still pretty cold. I am turning the key, letting the glow plugs glow for about 25-30 seconds and then cranking. It starts in a few seconds, and idles kind of rough at about 1100 rpm for the first 40-60 seconds with a fair bit of white smoke. Then the idle calms down a bit, and I drive off.

According to the owners manual the light indicates that the car is low on coolant (it isn't) or the car is too hot (15F today when I started it). I checked the coolant reservoir today before I started it, and there were no signs of ice, so I doubt that the coolant mix is way off and freezing to confuse the sensor. A couple weeks ago I used vag-com to check that the coolant and fuel temp sensors were working okay and they seemed fine, but that was starting from about 40F

Any ideas?
joelbert is offline   Reply With Quote
Old January 23rd, 2013, 16:36   #2
Ski in NC
Veteran Member
 
Join Date: Jul 2008
Location: Wilmington, NC USA
Fuel Economy: 48-52 typical
Default

Coolant level in normal band as viewed min/max stripes on side of bottle?

Gunk can get on bottle level sensor probes. Sometimes these can be cleaned by sticking an old toothbrush in fill hole. Two metallic rods originating from plug on side of bottle.
__________________
2001 Jetta TDI 5sp Stock 201k mi
1981 Rabbit IDI 4sp Sold at 339k mi
1990 S-10 4.3 4wd 5sp 154k mi
1986 VW Pathfinder 1.6 45hp Marine 4700 Hrs
2001 Cummins 8.3 420hp Marine 1660Hrs..REFIT DONE!!
Ski in NC is offline   Reply With Quote
Old January 23rd, 2013, 16:43   #3
Art van Law
Veteran Member
 
Art van Law's Avatar
 
Join Date: Dec 2010
Location: PVD, RI
Default

Yeah, same thing happens w/ my '03. Any time temps are low, say <25F the chime and light come on upon first start in the morning. I too have checked the coolant reservoir and found the level ok. All I do to cxl the light after 5-10 minutes of running is turn off the ignition and upon restart, the light stays off.

I'm guessing the sensor in the coolant reservoir is malfunctioning, and there's no significant repercussions?
__________________
5 spd, ventectomy, 2" lift, EGR delete

Art van Law is offline   Reply With Quote
Old January 23rd, 2013, 16:46   #4
joelbert
Veteran Member
 
Join Date: Aug 2012
Location: NJ
Default

Actually a little above the max band. Has been at about that level since I got the car in late August. I haven't done anything that involves the coolant, except bumping the engine coolant sensor a few weeks ago when I reinstalled the tandem pump. I noticed a little coolant drip the next day, wiggled the sensor in it's mount, and the leak went away. I do have a spare sensor I got after that just in case.
joelbert is offline   Reply With Quote
Old January 23rd, 2013, 16:46   #5
Vince Waldon
Veteran Member
 
Vince Waldon's Avatar
 
Join Date: Apr 2009
Location: Edmonton Alberta Canada
Default

G12 shrinks quite a bit in the cold... so if your coolant level is ok but low it may trip the sensor when cold and then appear to be fine later.... or a few miles down the road when it's warmed up.

So, worth checking the level with the engine stone cold just to rule this one out.
__________________
Vince Waldon
Edmonton AB Canada
2001 silver TDI Jetta, Malone Stage 1.5
2001 blue TDI Jetta, Malone Stage 3. Grrrr baby... very grrrrrrr!
1970 Bay Window bus... not so grrrrr
Vince Waldon is offline   Reply With Quote
Old January 23rd, 2013, 16:50   #6
mcracer516
Veteran Member
Default

My 04 Jetta does this every winter on the first cold day/morning, I add an ounce of water or less and it stops.
mcracer516 is offline   Reply With Quote
Old January 23rd, 2013, 16:59   #7
joelbert
Veteran Member
 
Join Date: Aug 2012
Location: NJ
Default

Mine was a little above the upper band when I checked it this morning before starting it. I may try cleaning the sensor. When I checked the fluid this morning there seems to be a filter inside the opening to fill it reservoir, is it removable? I did not spend lots of time studying it because of the temperature.

Is it okay to ignore this if I have coolant, and am pretty sure that the engine really isn't overheating?
joelbert is offline   Reply With Quote
Old January 23rd, 2013, 17:41   #8
Ski in NC
Veteran Member
 
Join Date: Jul 2008
Location: Wilmington, NC USA
Fuel Economy: 48-52 typical
Default

Yea, if coolant temp is ok on gauge, bottle level ok, and you are getting heat out of vents, I'd say safe to ignore alarm.
__________________
2001 Jetta TDI 5sp Stock 201k mi
1981 Rabbit IDI 4sp Sold at 339k mi
1990 S-10 4.3 4wd 5sp 154k mi
1986 VW Pathfinder 1.6 45hp Marine 4700 Hrs
2001 Cummins 8.3 420hp Marine 1660Hrs..REFIT DONE!!
Ski in NC is offline   Reply With Quote
Old January 24th, 2013, 15:33   #9
sisyphus
Veteran Member
 
sisyphus's Avatar
 
Join Date: Dec 2008
Location: Appleton, Maine
Fuel Economy: 47-49
Default

My wife's 02 does this, too. I ignore it.
sisyphus is offline   Reply With Quote
Old January 24th, 2013, 16:07   #10
fruitcakesa
Veteran Member
 
Join Date: Feb 2007
Location: Vermont
Fuel Economy: 48.1- the 03's first tank!
Default

My 02 did this for years and all the attempted fixes were NG .
A new reservoir bottle cured it.
__________________
2002 Jetta TDI wagon auto 204k. Wife's car, the workhorse

2003 Jetta TDI 5 spd manual 203k+ my new ride now with working turbo
fruitcakesa is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
coolant temp warning lite flashing when cold lilsmoker OBD Scanners 5 October 5th, 2007 20:18
Coolant Level Warning in Cold Weather jaberoo VW MKIV-A4 TDIs (VE and PD) 4 September 27th, 2006 09:08
Low Coolant Warning Light in Cold Weather jaberoo VW MKIV-A4 TDIs (VE and PD) 5 January 6th, 2005 20:41
Cold start... coolant temperature warning maebee1 VW MKIV-A4 TDIs (VE and PD) 4 December 22nd, 2004 05:18
Flashing Coolant Warning Light on Cold Start skiier__dude999 VW MKIV-A4 TDIs (VE and PD) 7 December 21st, 2004 17:29


All times are GMT -7. The time now is 01:04.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2014
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2013, All Rights Reserved
Page generated in 0.16085 seconds with 12 queries
[Output: 95.36 Kb. compressed to 81.10 Kb. by saving 14.26 Kb. (14.96%)]