Final update as of December 2010 - VW extended the warranty on the glow plug system only for cars that had the glow plug recall done. See the bottom for details.
This does not apply to TDI model year 2003 and earlier. Some information and the videos by jsrmonster aka rocketchip.com . If you are having cold start problems, please vote in an informal poll on this forum topic: http://www.myturbodiesel.com/forum/showthread.php?t=2182
In mid 2009, VW issued recall "emissions service action 28E6 R8" to change out the original ceramic glow plugs on cars with pumpe duse engines with steel glow plugs for all pumpe duse engines with Bosch glow plugs. NGK plugs were not included in the recall. Models with pumpe duse engines were the Jetta, Golf, New Beetle, Passat, and Touareg TDI. The dealer also had to do a computer flash to change glow plug voltage from 7V to 5V for the new glow plugs. The computer program controls glow plug voltage by pulsing voltage to the glow plug relay.
The problem is that once winter came around, many people who had the recall done found that their cars had a hard cold start or wouldn't start at all! Therefore, VW suspended the recall and began working on another computer flash. In July 2010, they started to test revised programming. In Nov 2010 they sent out letters extending the glow plug system warranty on the cars only to those which had the recall done.
A diesel engine ignites fuel through compression. Glow plugs are used
to create a hot spot in the engine cylinder which help ignite the fuel on cold
conditions. They also run for a little while after start for faster engine
warm up. This reduces emissions and makes for smoother running. Glow plugs which aren't working well can cause poor starting. The glow
plugs on these engines are located at an angle in the cylinder head. Below is a
picture with the wiring and covers removed for illustration. Related links
if you have a Passat TDI - 1000q:
glow plug removal B5 Passat . If you have a mk4 Jetta, Golf, or New
Beetle, see 1000q: glow plug
Older engines used steel glow plugs but VW switched to ceramic starting with the 2004 TDI engines. This may have been to reduce the wait for the glow plugs because they light up faster and/or for emissions. Cold engines (both diesel and gasoline) create much more emissions than warmed up engines. The reason they were recalled is because the tip can break off or carbon can build up around the tip, breaking it off during removal. If the tip breaks off and the engine is running (or cranked while stopped), it can cause major damage to the engine and turbo. You cannot just replace ceramic glow plugs with steel plugs because the voltage is different and it will cause damage to the glow plugs. Therefore, changing the glow plug type also requires a computer flash.
Below is a picture
showing some of the differences. ALH is the 4 cylinder TDI engine in model
years 1998-2003. BEW is the engine
in 4th generation VW TDI model yearss 2004-2006. BRM is the engine used in the
5th generation 2005.5-2006
The old ceramic BHW glow plugs were marked Bosch 0 250 302 0 02. 7v for
7 volt. VW # was n 105 916 01.
The recalled-recall BHW 5v glow plugs were marked Bosch 0 250 402 004 5v. VW# n 105 916 07.
Other glow plugs should be marked 5v or 7v.
Dealing with it if you haven't had it done
If you didn't have the recall done or live in a warm area you aren't affected by cold start problems. In this case, if you have cold start problems it's from worn out glow plugs, bad glow plug wiring, or something else. If the car never had the recall done the original fragile design glow plugs are still in there and should be replaced with the more robust design.
If you had the recall done but not the final corrective flash program and live in an area which sees close to freezing temperatures, you'll notice rough starting when it's cold. Some people had gotten loaner cars from the dealer while others haven't. If you can't get a loaner car, using an engine coolant block heater will help keep the car warm and make it easier to start.
If you have a "performance chip", any later flash by the dealer will overwrite the old flash.
If you are experiencing cold start problems and don't want to spend the money
on an aftermarket chip, try the following steps:
-call VW and complain.
-use powerservice diesel fuel additive (white bottle) - it'll help with cold starts in general and raise fuel cetane
-when the glow plug light goes out, turn the key to start. Do not wait for the glow plugs to cool off because they are not lit after the light goes out. They will light once the engine is started. Immediately after the light goes out, you can also turn the key to off, then immediately back to on for 2-3 cycles to try to keep the glow plugs lit as long as possible and not cool off. The heat from the tiny glow plug dissipates into the heavy metal engine after it stops glowing. Make sure you don't have a weak battery since this won't help cranking either.
-install an electric engine block heater or park in a warm(er) garage
-remove the rubber elbow before the intake manifold and heat the intake manifold and cylinder head with a hairdryer before every cold start.
-sue the responsible parties. In my opinion, every TDI that had the recall done and has cold start problems due to the glow plug system, probably developed starting problems because of the recall. If your starting problems cause loss of use of your vehicle, you may be due compensatory damages or at least a loaner car. Cold starts are also effected which could cause failure of emissions testing or an unacceptable level of cold start emissions due to stalling and flooded engines. However, I'm not an expert and this website page or anecdotal accounts on anonymous web forums don't count as evidence. Bringing successful lawsuits are expensive so consult an attorney for legal advice. If this seems reasonable, feel free to post your opinion in the myturbodiesel.com forums.
VW started to fix the botched recall in July 2010. For the BEW engine,
it may involve 4 new glow plugs, 4
new injectors, 1 new control unit, 8 bolts, and 4 screws. The bolts and
screws are for the injector holding bracket. Attached below is a receipt
showing the repair.
It appears they changed the part number for the fuel injectors since the parts catalog still shows a different part number. Other engines may involve different part numbers.
VW sent me this letter which extends the warranty as mentioned in the letter. It only applies to cars which had the recall done. The dealer solution is to install new glow plugs and reflash the computer. You cannot just install the glow plugs without the reflash.
The car doesn't start as well as it originally did but it's still 5-6 times better than the botched recall. The invoice references TSB 2024842. The part number for the new NGK glow plugs is VW# n 105 916 09 (n10591609). The difference between the original Bosch glow plugs and the NGK glow plugs is that the NGK have a steel sheath halfway down and a rounded tip instead of the narrow tip on the Bosch plugs. Here is an example of a used on from a mk5 Jetta.
Here is the new glow plug. This is why the NGK weren't included in the
original recall - the mk5 Jetta already had this type of sheathed glow plug.