Rough idle question, 2005 Passat TDI - Page 5

lynnejohn · October 19th, 2012, 06:47

Quote:

Originally Posted by perry-vw-

My 05 has been doing the same thing, rough idle and even smoking on cold start ups. The car is all stock with a BSM completed last spring. I was talking to a friend with a TDI Touareg about my problem and he asked what type of fuel have I been using. I told him that I fill up a Road Ranger and he said that their "crap fuel" could be causing my problem. As I got closer to needing fuel I thought that his idea was too simple and I should try a different brand to prove him wrong. I filled up at Shell and within a couple of days I noticed the rough idle wasn't as bad and the smoking was less. I have filled up at Mobil 2x since then and I have noticed a huge improvement. The rough idle is there just a little bit but it goes away very quickly and the smoking is gone.

I don't know if this is just a coincidence but it is worth a shot.

Well I do always fill up at the same station so I could try using another. On a second note it appears that when the car had the glow plug update they forgot to put in the correct plugs (they were not NGK's as thundershorts had suggested.) It was done yesterday so I don't know if there is any difference.

aja8888 · October 19th, 2012, 07:01

Quote:

Originally Posted by lynnejohn

Well I do always fill up at the same station so I could try using another. On a second note it appears that when the car had the glow plug update they forgot to put in the correct plugs (they were not NGK's as thundershorts had suggested.) It was done yesterday so I don't know if there is any difference.

The correct VW specified glow plugs in the last TSB go around by VW are the 7 volt ceramic tipped NGK branded ones.

lynnejohn · October 19th, 2012, 08:12

Quote:

Originally Posted by aja8888

The correct VW specified glow plugs in the last TSB go around by VW are the 7 volt ceramic tipped NGK branded ones.

The mechanic was surprised that the wrong glow plugs had not throw an error code, but at least it's one less thing to worry about with the New England winter is around the corner. I hope it helps the idle issue but I have my doubts.

aja8888 · October 19th, 2012, 08:24

This has been a see saw adventure with VW. The original glow plugs in the 04-05 Passat TDI's were ceramic 5 volt ones. VW came out with a TSB for a replacement to 7 Volt steel ones and for some reason, that was also an issue (hard starting). Along with this TSB was a code change in the ECU software. Then VW (silently) re-specified the NGK ceramic plugs and a code change again.

It has been a circus with VW on this issue.

aja8888 · October 19th, 2012, 08:27

Quote:

Originally Posted by lynnejohn

The mechanic was surprised that the wrong glow plugs had not throw an error code, but at least it's one less thing to worry about with the New England winter is around the corner. I hope it helps the idle issue but I have my doubts.

Glow plugs won't help with the idle unless they are on (or in some cycle of operation) under 40 F while the car is warming up. Idle is set at 817 (I believe) RPM by the ECU.

lynnejohn · October 19th, 2012, 09:58

Quote:

Originally Posted by aja8888

This has been a see saw adventure with VW. The original glow plugs in the 04-05 Passat TDI's were ceramic 5 volt ones. VW came out with a TSB for a replacement to 7 Volt steel ones and for some reason, that was also an issue (hard starting). Along with this TSB was a code change in the ECU software. Then VW (silently) re-specified the NGK ceramic plugs and a code change again.

It has been a circus with VW on this issue.

Maybe that is why they said the TSB (software was correct) was done, yet the glow plugs were the wrong type. I did get VW to give me a service credit for the labor spent on the plugs (as it should have been done correctly when the TCB was originally done.)

thundershorts · October 19th, 2012, 13:53

Something here doesn't make sense. You can scan to see if the correct software has been installed, or did the vw dealer do a scan. Also a possibility the assumed the software was correct for the ngk's but isn't. The date the gp/recall was performed would be a good start. If after dec 2010, it would be latest, if not it isn't. I thought you had some kind of tune performed on your car?

lynnejohn · October 19th, 2012, 20:38

Quote:

Originally Posted by thundershorts

Something here doesn't make sense. You can scan to see if the correct software has been installed, or did the vw dealer do a scan. Also a possibility the assumed the software was correct for the ngk's but isn't. The date the gp/recall was performed would be a good start. If after dec 2010, it would be latest, if not it isn't. I thought you had some kind of tune performed on your car?

When I bought the car I took it to my dealer who checked the VW computer records to see if the TSB was done. They said it was done and there were no outstanding recalls on the car. I can do the scan, but I have no idea what software version I'm looking for. I did do the Malone ECU tune but I also own the programmer as well. When nothing simple was working for the rough idle, I programmed the original ECU version (the programmer can hold 4 or 5 versions) to insure it was not partly the fault of the tuning. The entire glow plug check started last week when it got down into the 20's here in CT and the car started very poorly the next morning. So I had them check the glow plugs and they saw some variance on the glow plug resistance and checked them to find they were the wrong ones. So the car starts well, but I have not had any time to see if the rough idle is still there (I fully suspect it is.) I'm still hoping to find the mystery rough idle issue as I rather like the extra power from the Malone tune, but I have not heard back from him after a couple emails.

thundershorts · October 20th, 2012, 04:35

The tune would have overwritten the older vw software/bosch plugs when you loaded it, Had the newer software/ngk plugs been installed, it would have done likewise. The newer software/ngk plugs were never installed on your car. Now that you have 7v plugs vs the 5v plugs which came out, the question may be what voltage/heating duration/afterglow is incorporated in your tune. Some tunes apparently for the 5v bosch, increased the heating times. Your present tune may be in fact proper for a 7v plug as indicated by the damage to the 5v bosch gps. A good indication may be the cold starting smoothness. At least you won't damage the 7v plugs running them at lowe voltage, they just won't get as hot as fast. Glad you got the ngk's done, as it may help in ruling out causes of your rough idle warming up.

abctdi · October 20th, 2012, 08:34

Just a reminder. The glowplug debacle and extended warranty ends on 31 October, a few days from now.
Even though I only have problems when very cold and/or at high altitude (8000 ft +), should I try to get the latest setup in place of my steelies?

lynnejohn · October 20th, 2012, 13:02

Quote:

Originally Posted by thundershorts

The tune would have overwritten the older vw software/bosch plugs when you loaded it, Had the newer software/ngk plugs been installed, it would have done likewise. The newer software/ngk plugs were never installed on your car. Now that you have 7v plugs vs the 5v plugs which came out, the question may be what voltage/heating duration/afterglow is incorporated in your tune. Some tunes apparently for the 5v bosch, increased the heating times. Your present tune may be in fact proper for a 7v plug as indicated by the damage to the 5v bosch gps. A good indication may be the cold starting smoothness. At least you won't damage the 7v plugs running them at lowe voltage, they just won't get as hot as fast. Glad you got the ngk's done, as it may help in ruling out causes of your rough idle warming up.

The newer VW software was loaded in the car as I put the original code in the car several weeks ago, and the dealer verified this week it is correct. So if Malone did not change the glow plug settings, then I should be fine with it.

As far as the rough idle, I really don't notice it like before (so far.) I don't see how it should make a difference as last month the rough idle was apparent even after driving 1 1/2 miles down the road to get coffee. At this point if the glow plugs fix it I'll be happy as this thread is getting to long.

lynnejohn · October 20th, 2012, 13:03

Quote:

Originally Posted by abctdi

Just a reminder. The glowplug debacle and extended warranty ends on 31 October, a few days from now.
Even though I only have problems when very cold and/or at high altitude (8000 ft +), should I try to get the latest setup in place of my steelies?

Thanks for the reminder as the VW dealer had mentioned the end of the warranty.

thundershorts · October 20th, 2012, 15:05

you had said that you put original coding back in several weeks ago. If so you had 5v plugs running at 7v. abctdi, If I were you I'd get the ngk's alomg with the software update done.Smooth easy starts at low temp and smoother idle. I've had mine in for 2 years.

lynnejohn · October 20th, 2012, 19:04

Quote:

Originally Posted by thundershorts

you had said that you put original coding back in several weeks ago. If so you had 5v plugs running at 7v. abctdi, If I were you I'd get the ngk's alomg with the software update done.Smooth easy starts at low temp and smoother idle. I've had mine in for 2 years.

I believe that's how it was when I got the car and who knows how long it had been that way. The car did come from Nevada so there was a chance it never needed to use the plugs.

thundershorts · October 20th, 2012, 19:53

the gp's are always functioning, regardless of ambient temp. I did some work in Sandy Valley, Nevada a couple years ago in Winter, -20f at night, tee shirt daytime.