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VW Jetta TDI

4751 messages,  Last post on Jun 09, 2013 at 7:21 AM

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What is this discussion about? Volkswagen Jetta, Biodiesel, Diesel, Sedan

Messages Page 473 of 476

#4712 of 4751 Bad fuel gives me the Shudders by longo2

Nov 06, 2012 (11:15 pm)

My 06 TDI really has a sensitive engine. On some brands of diesel the car will go into convulsions between 2000 and 2300 rpms when on cruise control.
 
 It happens when the car is going down a slope and the engine is not using fuel but then when the grade goes back up and motor now needs fuel, it does a violent shake rattle and roll for a second or 2 then it's OK until the next same combination of CC, and road conditions.
 
The only thing I have found that prevents all this drama is changing the fuel brand. I drive about 500 miles a day for 3 days in a row, so each tank is run down to less than 1/4 and then I start looking for a fill up again and hoping for a no-shudder run.
 
I have tried truck stop fill ups and all the major brands...(Shell was the last one that the TDI had big problems with) Then I will have great luck with some no-name brand from some divey place in the middle of nowhere.
 (I have always had great performance from Chevron GAS in my Honda Odyssey, but the Chevron diesel is another story...poor power, bad mpgs and lots of shudders.)
 
So far I have not met anyone behind the counters selling diesel who has ever even heard of Cetane ratings..(I do ask) much less what their pumps might have.
 
Seems some forum posters are having these issues with the new models of VW TDI's but so far nobody with a 06 except me, has mentioned it. One uninterested VW service writer said "it probably needs to come into the shop and have the cam shaft and valve followers changed" A story he probably uses to make his service dept another $2000.00 that day.
 
Not saying the car at 110,000 miles doesn't need the top end looked at, but it will run fine on certain diesel and run like crap after the next fill up from a different location. Covering 2000 miles in 3 days puts me at 4 different stations in 3 different States.

#4713 of 4751 Re: Bad fuel gives me the Shudders [longo2] by cosmo

Nov 07, 2012 (5:20 am)

Replying to: longo2 (Nov 06, 2012 11:15 pm)
We have a "06 and a "11, and had a "04, and have not experienced this problem. I always add Opti-Lube at each fill-up to increase the lubricity of the fuel. It is also claimed to increase the cetane rating and clean the injectors. I also try to always run the tank down until the warning light comes on before refilling. On long trips that is not always possible, but that way I know I always have a tank of mostly fresh fuel.
 
http://opti-lube.com/index.php/xpd-diesel-fuel-improver-product.html
 
You also may want to check your fuel filter.
 
http://www.myturbodiesel.com/1000q/a5/fuel-filter-VW-Jetta-TDI-2005-2006.htm

#4714 of 4751 Re: Bad fuel gives me the Shudders [longo2] by coontie66

Nov 07, 2012 (5:42 am)

Replying to: longo2 (Nov 06, 2012 11:15 pm)
WOW. I have a diesel truck and this is quite a story. I really have no idea but I wouldn't think of the fuel filter as the problem. You need to change every 15K or so. It's been a long time since I saw a vehicle that w as picky about fuel.

#4715 of 4751 Re: Bad fuel gives me the Shudders [coontie66] by longo2

Nov 09, 2012 (6:54 pm)

Replying to: coontie66 (Nov 07, 2012 5:42 am)
You're right, it's not the fuel filter, changed it out last year, shuddering still a mystery.
 
 While on a brief trip the other day, I noticed the "battery" warning light had popped on. Thought it might be the serp' belt or alternator so stopped and had a look under the hood.
 
Somehow the pulley had completely come off the alternator but the belt was still running on the bare shaft! I guess the belt wasn't getting enough grip to spin the alt' enough and the warning light came on.
 
Local VW dealership had to order a new pulley and it will be here in a week.
The Jetta TDI alt' pulley not a solid pulley, but a clutch design, a rather complicated item..designed to grab and pull under load one way, but will free wheel the other way....
 
(Also a very pricy item that requires a special set of tools to take off and install...unless it flies off all on it's own like mine did!)
 
This guy goes through it much better and says..."it's a wear item that should be changed with each serp' belt R&R"...
 
http://www.youtube.com/watch?v=hrFcPqZuO3A
 

#4716 of 4751 Re: Bad fuel gives me the Shudders [longo2] by bpeebles

Nov 09, 2012 (8:42 pm)

Replying to: longo2 (Nov 09, 2012 6:54 pm)
The pulley coming off the alternator is VERY COMMON. If you read thru the tdiclub.com website, you will see.
 
If you think the pulley is expensive.... for a long while, the pulley was NOT A REPLACEABLE ITEM and you had to replace the entire alternator when the pulley failed. In the last several years, the pulley became a separate item.
 
This happened to my TDI around 140K miles. I replaced pulley AND the the failed tensionor.... good to go for another 140K miles.
 
The reason for the pulley issues is because on the TDI engine the alternator pulley has a SPRAGUE CLUTCH. This one-way clutch allows the alternator to 'overrun' when the engine is decellerating.
 
DO NOT put a solidly-installed (non SPRAGUE) pulley on TDI engine.

#4717 of 4751 Re: Bad fuel gives me the Shudders [bpeebles] by longo2

Nov 10, 2012 (2:29 pm)

Replying to: bpeebles (Nov 09, 2012 8:42 pm)
"The pulley coming off the alternator is VERY COMMON"
 
That I didn't know!
 
From what I have now learned about it from checking this forum and others,
seems it's a "wear item" along with the serp' belt and tensioner that VW doesn't mention.
 
I now wonder, if for some strange reason...this worn out pulley acting up is the cause of my "shuddering" issues between 2000 and 2400 RPM. If it is causing a sudden alternator load on the engine when starting to pull up a grade on CC, then a different qualities of fuel, might..might, be able to create the shuddering effect.
  
 It's a long shot, but so far the alternator clutch pulley is the only suspect I have.

#4718 of 4751 Re: Bad fuel gives me the Shudders [longo2] by bpeebles

Nov 10, 2012 (8:33 pm)

Replying to: longo2 (Nov 10, 2012 2:29 pm)
It is EXTREMELY unlikely that an alternator pulley could fail in any way that you would feel it in the way the vehicle drives. I am confident you could cross "alternator pulley" off of your list of possible culprits. (or move it wayyy to the bottom of suspects.)
 
A for being a "wear item", this is simply a point of view. Eventually ALL machines will wear out. Using this logic... Your entire vehicle is a "wear item" too.
 
Another example- The Timing Belt has a specific replacement interval in miles. However...at the same time EVERY moving component that touches the TB is susceptible to wear and should be replaced at the same time the TB is replaced. These other components are not specifically mentioned in the TB replacement interval... but if you do not replace them, you are ASKING for failure before the next scheduled TB replacement. (Pullies, tensioner, bearings,waterpump, seals....etc.)
 
In other words -- the waterpump will NOT last as long as 2 Timing-Belts.... so it makes sense to replace the waterpump when the engine is torn apart to replace the Timing Belt. ( Because the TB needs to be removed to replace the waterpump) Most of the cost of TB replacement is LABOR...not parts. Would you want to pay for the same labor AGAIN before the next TB replacement? (along with the associated inconvenience of unexpected downtime)

#4719 of 4751 Another Repair by rrollntdi

Nov 19, 2012 (10:56 am)

I had a check engine light come on last week... It was a throtle body that needed replacement this time, about $600. I had a pressure sensor go in May ($200) and a door lock mechanism ($400) go about a year ago. I'm considering trading in my '09 Jetta TDI sedan since it only has 77K miles and I've already had to shell out $1,200 in repairs. Not to mention that the 80K mile ($400) DSG fluid change is due soon.

#4720 of 4751 Re: Another Repair [rrollntdi] by bpeebles

Nov 19, 2012 (7:06 pm)

Replying to: rrollntdi (Nov 19, 2012 10:56 am)
I am curious - how can a "throttlebody" go bad? It is simply a ventrui in which a butterfly valve moves.
 
Fo rthat matter - What kind of "pressure sensor" costs $200?
 
It sounds to me you need to consider changing your MECHANIC.... not your vehicle.
 
Oh- I agree with you about the cost of maintaining the DSG xmission... this is one reason I always drive a manual xmission. In over a million miles of driving, I have never EVER had any xmission problems. (all the way back to 1979 VW Scirocco)
 
It seems silly to pay MORE for a fancy xmission and also have to pay MORE to maintain it.

#4721 of 4751 Re: Another Repair [rrollntdi] by longo2

Nov 19, 2012 (9:00 pm)

Replying to: rrollntdi (Nov 19, 2012 10:56 am)
Had my DSG fluid and filter changed at 40,000 miles and again at 80,000 the service writer almost hugged me saying hardly anyone ever does it and then can't understand it when a DSG replacement costs over $4,000 and VW gives them the bill.
Last change of fluid/filter cost $270.00 at the dealership, not cheap by any means, but a much better deal than a new DSG.
 
I think VW originally thought the DSG option could be sold to customers by claiming it was a 'lifetime fluid' set up. Same mistake of a lot of other new cars being sold these days with automatics.
  
 One thing I know for sure, no a/t is "lifetime"...they produce iron filings, brass cuttings, melted plastic, rubber, aluminum shards, and fiberous clutch debris that when all combined is a circulating liquid sandpaper going through the tranny.
 Then there is the natural breakdown of the fluid itself....through heat and pressure, it's like a baby, and needs to be changed often and for the same reason.

Messages Page 473 of 476

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