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VW Jetta TDI



  • gagricegagrice San DiegoPosts: 31,080
    I think that was a great trade-in value. I tried to trade in my 2005 GMC in 2007 for a new Tahoe. I paid $26k for a loaded Sierra Hybrid. With 12k miles the dealer only offered $17k in trade. I sold it myself on Craigslist for $22,500. A car with 100k miles is at the end of the line for me.
  • colin_lcolin_l Posts: 591
    edited August 2010
    That's only about $3K per year depreciation, assuming tax is a sunk cost

    Depreciation doesn't include taxes, and taxes aren't a sunk cost. Depreciation and taxes are both components of the Total Cost of Vehicle Ownership, sure. :)

    A sunk cost is a decision that's already been made and irrelevant for future decisions. Example:

    Repairs made to a car are a sunk cost. The book value of a car assumes that it is running properly in good order. It hurts your pride (and wallet) to fix a car and then sell/trade it, but at the time you decide to do that the repairs actually are irrelevant. It would have been relevant to sell the vehicle *before* it required repair, though. :)
  • shriftyshrifty Posts: 255
    Not bad for a 5? year old car up in the 6 digits, good to know there will be some value left when trading it in. I'm thinking of keeping the car until the wheels fall off, or when it starts to nickel and dime me. Kinda getting a bit concerned about the 120K service, I know that is a big one and about half way there now.

    As for electric, I definitely will not be considering it any time soon. I'm driving over to NYC tomorrow for work (almost 330 mi), then back on Friday which has been almost a weekly ritual now. With a very limited range on electric, I'd be running on gas probably 90%+ of the time. I don't think the hotels would appreciate a 100' extension cord running out the window so I can recharge... :)

    Diesel is way too convenient, I can fill up on the way out, and almost make it home before refueling again.
  • shriftyshrifty Posts: 255
    Completely agree with the torque, however when attempting to use Launch Control, I really couldn't rev much higher than 2500 before the engine almost stalled. I had ESC turned off, left foot on brake, transmission in Sport Mode, right foot on accelerator... and almost stalls. The manual simply says "if equipped", however I was not able to determine by any other means if it is or not.
  • longo2longo2 Posts: 347
    I wish the "VW Superior engineering" you mention didn't include all the grief that us owners of the Mk 5's have to live with, or the unexplained failure of the newer Mk 6 HPFP's that are costing up to $10,000 to replace.

    On a more down to earth point, I am amazed by the lack of 'superior engineering' on my 06' TDi's dip stick!

    You can't tell if your oil level is full, too full or in the operating range without wiping, testing, peering and then repeating several more times trying to get an acurate measure of typical used black diesel oil on a tiny BLACK plastic rod.
    I think another 30 seconds of R&D engineering common sense would have put that dip stick design in the junk bin and came up with something that made some sense.
    A typical Mk 5 VW TDI oil level reading is a total mystery, To add more confusion to the proceedure, the 'book' says you need to drive the car and then wait 3 or 4 min before checking the oil. If you check the level after it's been sitting for a few days, it reads way over full..or too soon and it reads down to the "Ad" mark...seems the VW diesel engine allows a lot of oil to dain back down into the pan.

    Where did that extra oil in the pan come from? Drained from the upper end, where all the Mk 5 damaged cams, lifters and bearing issues are created. :(
  • gagricegagrice San DiegoPosts: 31,080
    Nothing like owning a vehicle to find out where it is weak. I only had my 2005 Passat TDI 13 months and no problems. I bought it below invoice and sold it at the peak of the market. Probably the only vehicle I will ever buy new and make $3000 a year later selling it.

    Sounds like I was lucky to sell it, with the problems that model has. I loved driving the little wagon. I hated getting in and out. That will be the last sedan I ever buy. I have all but given up on ever owning another diesel. Just too many obstacles and premiums to pay. Now they are being smogged in CA. If I drove a lot of miles it may be worth the hassles.
  • oli1oli1 Posts: 33
    I mentioned that exact nusance I have with the A3. It just didn't make sense to me, after 35 years of owning vehicles and working on them, for you to check the dip stick when it is warm. When it is cold you get an accurate measure of how much oil you have because 99% of it is in the crankcase.
  • hello Members, I have heard when shutting A tdi down it is best to wait a minute or 2 so the turbos cool down and they will go longer without any defects or breaking down. If anyone is out there with some good advice and answers to this scenario would be greatly appreciated Thank You Roadmaster45
  • fho2008fho2008 Posts: 393
    While I dont have a TDI, I think this is what you needed to do in the past, with any turbo engine. With modern engines, I dont think you need to do this.
  • colin_lcolin_l Posts: 591
    edited August 2010
    In short, you are correct. Longwinded technical explanation coming up...

    Letting turbochargers cool was a necessity in the past because of 3 main reasons:

    1. They were not watercooled, oil-cooled only.

    Today's OE turbochargers are all oil and watercooled. This helps keep the center section temperature down considerably.

    2. They had sleeve bearings.

    Today's turbos have sealed ball bearings which are much more durable. They spin a lot better too, which helps efficiency.

    3. Significant improvements in oil technology, especially synthetics.

    I strongly advocate the use of full synthetic oil in all cars, but it is especially helpful in turbocharged vehicles as it will help prolong the life of the turbocharger.

    In summary, a modern turbo should last the life of the engine. I believe the TDI uses a Garrett variable vane turbo, which is very high tech. It will go well over 100k miles with no trouble on a stock engine.

    The only cooling I would advocate is after a very hard drive, such as 30+ minutes during steep mountain driving. And even then, you are fine after 2 minutes of driving out of boost at lower speeds or idling. This is completely unnecessary for normal travel or commuting.
  • alltorquealltorque Posts: 535
    edited August 2010
    Nothing to do with the TDi engine, specifically, just good practise for any turbocharged engine. Pulling into a service area, say, after a run down the motorway, (Interstate), the turbo will be very hot, (I've seen turbos on test-bed engines get to pale yellow and certainly beyond cherry red). The bearings are very small and only contain a minute amount of lube oil. They rely on a flow of oil to keep them cool, (relatively speaking). Just switching off the engine stops the oil flow and even the best of lube oils will eventually form coke, choke the bearings and .......... BANG ...... goodbye turbo. Allowing the engine to idle for 1 - 2 minutes allows the turbo to cool and fresh "cool" oil to flow through the bearings, so no coke formation.

    If, prior to reaching your destination you have a period of gentle running then the turbo will already have cooled sufficiently so this idling period is far less important.

    Idling before switch-off is a good habit to get into to help ensure your turbo enjoys a long life. The effects of abuse won't show up for quite some time but they will come and bite you - or the next owner - one day.

    AFAIK this idling procedure is strongly recommended, here in Europe, by all the manufacturers using turbos, whether gasser or diesel. VW, Audi, Skoda and SEAT certainly recommend it and everyone I know with a turbo engine uses it............and the vast majority of them drive diesels; Audi, VW, Vauxhall (GM), Ford, SAAB, BMW et al.

    Just my two penn'orth.

    ETA : I was writing my post whilst Colin was posting 4252. His is a better tech post but I think we're both singing from the same hymn sheet. Amen to the use of synthetics. The VW TDi's are fussy about lube but for reasons other than the turbo.
  • bpeeblesbpeebles Posts: 4,085
    You are mistaken! VW does not use "watercooled" turbocharger on TDI. This is one reason that synthetic oil is MANDATED for all VW turbocharged engines.

    Allowing turbocharger to cool down before turning off engine should be standard procedure.

    Note: This 'cooldown' can be as simple as driving gently for a mile or so. This is how most people drive anyway before arriving at their destination. The real concern would be pulling into a 'rest area' immedeatly after traveling 65+ MPH... this is when a specific cooldown should be performed.
  • m6userm6user Posts: 3,174
    This could be a dumb question but isn't traveling at a steady speed on the interstate at a low rpm somewhat running the engine gently? Is the turbo fully engaged when rolling down the interstate? I thought it was for boost under fairly heavy throttle.
  • bpeeblesbpeebles Posts: 4,085
    edited August 2010
    You are correct that the turbocharger gets hottest while under 'boost' However, NO ONE drives under 'boost' for more than a few seconds at a time. (boost = accellerating)

    I have a turbocharged Subaru... if I keep it under 'boost' for more than 12 seconds, I would be traveling over 90MPH. (I love the look on my wifes face when I pin her to the seat with raw accelleration)

    The heat in the turbocharger is directly related to the amount of exhaust-gas flowing thru it. While traviling on hiway at 65+ MPH, there is a lot of hot exhaust rushing thru the turbocharger. The oil-flow over the bearingis the only thing keeping the bearings alive. If you pull into a restarea and immedeatly shut off the engine. A phenomanon known as "heat soak" occours. You have stopped the flow of cooling-oil over the bearings while the turbocharger housing is still VERY hot. This latent heat can literally cook the stagnant oil which is sitting in the bearing-housing. This is called 'oil coking'

    On the other hand, if you get off that very same highway and drive a few miles to your destination... this allows enough oil to flow thru the turbocharger housing to carry the heat away. There is much less latent heat to 'soak' into the bearings.

    All VWs (turbocharged or not) have an oil/water heat-exchanger. This allows the hot oil to 'dump' its latent heat into the antifreeze... which then carries the heat to the radiator so it can be eliminated.

    VW uses OIL COOLED VNT (Variable Nozzle Turbocharger).... this type of turbocharger does not have a "wastegate" to route the hot exhaust gasses around the turbine. Instead, the VNT flows ALL the exhaust thru the turbine at all times. This is more efficent... but creates more heat too.

    Hence - I ALWAYS idle my TDI for 2 minutes if I pull off highway into a restarea

    Does this answer your question?
  • m6userm6user Posts: 3,174
    Yes, nice explanation. Is this somehting that VW points out in their owner's manual to do if it is intergral to engine or turbo life?

    Also, this is something that I wouldn't want to worry about everytime I pull off the interstate to a rest area or to get a bite to eat. It seems like a small thing but kind of a pain. I like to pull in and jump out especially if I have to use the john. I know it's a small price to pay for great mpg but those small prices start to add up...higher fuel cost per gallon, longer warm up for interior heat, loss of heat in stop/go traffic, oily hands at fueling, synthetic oil mandatory, hunting for stations that carry diesel(many don't in metro areas), higher intitial cost for vehicle. These things do add up to an overall experience which may or may not be fully offset by the money saved on fuel depending on the person. Just my thoughts.
  • fho2008fho2008 Posts: 393
    You could carry a second car key so it can idle and be locked. I'd love a TDI, hopefully someday, and there are two stations in my town I know that sell diesel, and a third that might, I rarely go to em.
  • eliaselias Posts: 2,120
    peebs, i'm pretty sure that for my x-country TDI cruises, the turbo was boosting for hours/days at a time. I think boost is necessary to go at highway speeds in desolate areas of I-80 (~100 mph).
    in these sorts of drives, ABSOLUTELY i would let the engine idle for maybe 30 seconds or a minute at most to help turbo cool down at a rest area after hundreds of miles of highspeed driving.
    I don't bother with a cool-down delay for the turbo on east coast highways since the speeds are closer to 75 than 100.
    ps - Those rest areas (outhouses) in the I-80 nevada desert are no prize.
  • fho2008fho2008 Posts: 393
    If it came with a boost guage (or you put one in yourself) we would know for sure, but as far as I know you use the turbo only when accelerating, not going along at a steady speed.....even 100mph or more.
  • eliaselias Posts: 2,120
    edited August 2010
    fho2k8 ,
    at each increasing steady-speed point, once a certain road-hp level is required of the engine, the turbo will be boosting from that speed all the way up to top steady-state speed.
    if that's not the case, please elaborate, and i'll make a note of it and will wake up Isaac Newton to let him know! :shades:
  • colin_lcolin_l Posts: 591
    Are you certain of that? What model number is the turbo... I seriously doubt a variable vane modern turbo would not have a watercooled center section.
  • andys120andys120 Loudon NHPosts: 18,578
    If it came with a boost guage (or you put one in yourself) we would know for sure, but as far as I know you use the turbo only when accelerating, not going along at a steady speed.....even 100mph or more.

    Very little power is required to maintain steady speeds on level roads which is why this type of cruising delivers high mileage even at high speeds. I can tell you after 100,00+ miles of watching the boost gauges on Saab Turbos that they only deliver boost above 3000RPM or so, way more than you'd cruise at.

    I can't recall whether the TDI Sportwagen I drove had a boost gauge but there was so much low RPM torque that I'd be surprised if the turbo was on boost except when you accelearate.

    2000 BMW 528i, 2001 BMW 330CiC

  • fho2008fho2008 Posts: 393
    We basically said the same thing.......the turbo is used for acceleration (and fast acceleration at that, not gradual, unless going uphill), not when traveling at a constant speed, even if you are cruising at 80 or 100mph.
  • dwpcdwpc Posts: 159
    edited August 2010
    The potential result of a hot-turbo shut down is "coking"; oil flow stops in a near red-hot turbo and the oil bakes to a solid in the turbo's oil passage. Eventually, no oil gets through and the turbo welds itself together. At turbo speeds of 100,000 RPM, failure is instantaneous and very expensive replace.

    I've driven turbo cars for 30 years and its in my driving routine to idle for a few seconds after starting before loading the engine, and for about 30 sec. when I shut down. I did with ancient MB turbodiesels and I did it with my bi-turbo gasser Audi too, though it had water-cooled turbos and syn oil, and even a after-run waterpump to cool hot turbos after the engine was turned off. Its just a prudent habit with worth-their-weight-in-gold turbos. Turbos have better technology now, but are also a lot more complex than old school simple turbos (on diesels) that would go forever without much worry if you watched out for coking; I put 450K miles on one in a Mercedes. I think a few seconds at idle before shutdown is a good investment.
  • fho2008fho2008 Posts: 393
    Agreed, but as as said before by others, with newer turbos, most people are not using the turbo the last few miles before they get home, so it has plenty of time to get oil circulated, "cool down" etc.
  • eliaselias Posts: 2,120
    ~100 mph steady-state in my VW TDI requires "wind-out" RPM - 3500 rpm or so (?) - seems like we agree plenty of turbo at that RPM.
    100 mph is a moot speed here on the east coast, but was fun travelling fast like that in the desert. again, in the desert, at 100 mph, i sure did let the turbo cool down after cruising for many hours. and i have no doubt the turbo was working all those hours except maybe on some downhills. air resistance is incredible at high speeds; required "road horsepower" from the engine increases exponentially as speed goes up.
  • kyfdxkyfdx Posts: 63,183
    I wouldn't assume that turbo use is a function of RPM..

    Once your car is up to speed, even 100 mph at 3500 rpm, your throttle position will be the determinant of how often the turbo is on... If you just need slight throttle pressure to maintain that speed, then the turbo will likely be taking a break..

    Of course, at that speed, even slight uphills will cause you to mash the throttle to maintain speed... but, on perfectly level ground? I think little turbo action...


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  • m6userm6user Posts: 3,174
    Is the turbo being used the only determinant in the amount of heat is present, hence a cool down period? Does VW recommend this cool down period in their owners manual? If not, why not if it is a proven method of increasing turbo longevity?
  • fho2008fho2008 Posts: 393
    No I do not agree, as our host said in the message after yours, "I wouldn't assume that turbo use is a function of RPM..

    Once your car is up to speed, even 100 mph at 3500 rpm, your throttle position will be the determinant of how often the turbo is on... If you just need slight throttle pressure to maintain that speed, then the turbo will likely be taking a break..

    Of course, at that speed, even slight uphills will cause you to mash the throttle to maintain speed... but, on perfectly level ground? I think little turbo action..."

    Just because your car has a turbo, you think you use it most of the time?
  • eliaselias Posts: 2,120
    hey there fho,
    100 mph is near the top speed of a 2006 TDI, and I continue to understand that the turbo is working/boosting plenty at that speed.
    Your final question is not so respectful, but the answer to it is "no".
    best regards , and let's find a new subject to discuss! :)
  • sebring95sebring95 Posts: 3,238
    edited August 2010
    How can 100mph be the top-end for an '06? My '00 would do 130 and don't ask how I know :P
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