TDI vs. 2.0 & 1.8T

[timdog]

Re: TDI vs. 2.0 & 1.8T

holy crap I'm behind the times.

[dubCanuck1]

Re: TDI vs. 2.0 & 1.8T

Well, I'm quite partial on the diesel front, but let's not say it's all roses and champagne.

The big things are the EGR clogging up, but if you're not on warranty, pull the EGR setup and block it off on the turbo and back of EGR valve like I did. That fixed it for me.

In the winter, they are a little more grumpy than the gassers on start, but this is simply because the head has to heat up a little. That's what the glow plugs are for. And I wouldn't be worried about them freezing; they heat up to 400 C in about 2 seconds. The glow plugs are intended to heat the air in the combustion chamber to a degree that is more optimal for the pressurization and combustion of diesel vapor.
You can actually run a diesel without them, but starting is a lot more of a chore as the engine must rely on the repetitive compression/combustion in the engine to build the appropriate temp.

They DON'T (MKIV) come with a block heater or an oil pan heater. I'm not sure a magnetic oil-pan heater would work. Are the alloy oil pans ferrous? I don't think so (correct me if I'm wrong)? Most people who want to plug the car in get an in-line coolant heater from crappy tire and mount it into the upper rad hose. This will warm and circulate some coolant, in turn heat the block and head. We've left the wife's TDI out in -35 and it did start, but, as mentioned before, it was grumpy. I'm sure your 1.8T would be a little bit as well.

Since you already own a 1.8T, you know the maintenance items of a forced-induction vehicle. In the winter, you might want to switch to a lighter-weight oil, so that starting is easier.

In case you're not already in the habit of checking it, check your turbo probably every 50000K. Contrary to what seems to be popular belief, they don't last forever. Having your turbo rebuilt (or at least knowing it's going so you can plan for a new one) semi-regularly will help you out big time.

As for the mileage, they are better than the 1.8T for sure, and WAY better than the VR6, but depending on what you get, don't bet your pension on always getting 1000 km to the tank. My wife's is an auto, which uses the 11mm pump. In town, I get about 600-800 kms (depends how often I've been driving/flogging it.) On the highway, the best I got was 900...from CAlgary to Hope BC, where I either found a diesel shop or called in diesel for delivery.

The 5 speed vehicles are the ones that you'll see the 1000 km per tank on, and that's usually highway driving. Expect to see 800-950 in town, and probably 800 at best in the winter, with the treated fuel and warming up accounted for.

[stefan]

Re: TDI vs. 2.0 & 1.8T

i'm not sure if the fuel system will self prime. when I upgraded my injectors, we definitely had to crack an injector or two loose in order for fuel to start flowing again. There was no way it was starting from being bone dry. But yeah, running out of fuel shouldn't be an issue.. its not often gas stations are that far apart

[stefan]

Re: TDI vs. 2.0 & 1.8T

The big things are the EGR clogging up, but if you're not on warranty, pull the EGR setup and block it off on the turbo and back of EGR valve like I did. That fixed it for me.

reducing the EGR duty cycle to a minimum with a VAG-COM will give a simmilar result, but really, since the spec for diesel in canada has been improved since last october, this shouldn't be as much of an issue anymore.

[timdog]

Re: TDI vs. 2.0 & 1.8T

The big things are the EGR clogging up, but if you're not on warranty, pull the EGR setup and block it off on the turbo and back of EGR valve like I did. That fixed it for me.

I have NO idea what that means.


Thanks for all the info. This is helpful. I actually don't have a 1.8t anymore. I had an '02 GTI up until a couple months ago when some lady ruined my life as I knew it and I totalled my car. Finally got the settlement about a month ago and I'm looking at TDIs because of cost-saving.
about 100,000km on the one I am looking at. Anyone know somewhere I can get it quickly inspected for a good price??

[timdog]

Re: TDI vs. 2.0 & 1.8T

In case you're not already in the habit of checking it, check your turbo probably every 50000K. Contrary to what seems to be popular belief, they don't last forever. Having your turbo rebuilt (or at least knowing it's going so you can plan for a new one) semi-regularly will help you out big time.

how do i check the turbo? is this something a mechanic has to do? what should i be looking for?

[Benjamin]

Re: TDI vs. 2.0 & 1.8T

I am a TDi nut, so my opinion is a little bias you can say. I jus went and looked in the autotrader and the TDi's are going for cheap right now, and if I only had the money.
To answer the question on the turbo, you really can't check to see how well it is doing unless you pull it all apart, check the vanes, and the play in the shaft. The best question you can ask is if the car is chipped, if they used the correct oil and changed it on time, and didn't let the car idle for long periods of time. Some chips lead to high boost which puts a strain on the turbo if not kept in check by a boost valve. Correct oil, well the turbo is cooled by oil and if the wrong oil is used and not changed the turbo wears a little quicker. Might not happen for a long time, might happen tomorrow, you are playing with fire. Idling with a TDi is bad for long times. 5 mins is fine, even the occasional 10 mins won't probably hurt anything, but long idle's are bad for the turbo. If you want the ultimate bible on TDi's, go to www.tdiclub.com they have more answers then I have questions.
I can't really comment on costs for stuff because I am an apprentice mechanic and boss lets me get parts cheap (Worldpac) and I do all the labor. I can tell you this, if you do get a TDi, go to the recommended shop on this forum. From what I have read his labour rate is good, he is honest, and does good work. A good TDi mechanic is not always easy to find, but a good one will save you more money down the line. The timing belt, if you get the new kits that have been out for awhile you can make it wait every 160,000 km's, instead of the 100,000 km's on the old kit.
In terms of chipping and performance, well its a slippery slope, one that I have falled down. When you get into it, you can make these things move when you want to. You won't without a lot of money and time catch chipped vr6's, or 1.8t's, but you will beat them at the pumps. If you want performance, power then stay gas, if you can sacrifice some, then a TDi probably will work for you.
Oh, last thing, in terms of how long will it last, mine has about 320,000 km's on it, and it started every cold morning, without being plugged in. The car was a little cranky for the first 2 mins (idling to allow the oil to circulate), but it drove fine after that.
Hope this helps a little in your decision.

Benjamin

[dubCanuck1]

Re: TDI vs. 2.0 & 1.8T

The EGR is the exhaust gas recirculation system. What it does is take exhaust gasses from the hot side (turbine) of your turbo and route some of them, via a pipe, back into your intake manifold. This is supposed to reduce some of your emissions, but what happens is that the sooty exhaust fume mixes in with the hot, oily vapor from the Crankcase valve and essentially makes tar buildup on the inside of your intake manifold. Over time, it will reduce the diameter of the intake manifold until your car is pretty much starving for air.

Changing the EGR config is one way to combat this. The other is to put a better filter in to filter the oily mist from the Crankcase Valve. Both setups are available if you search on TDIClub.

For me, I was just so pissed off that I had to clean my setup that I just deleted my EGR Completely.

[bart]

Re: TDI vs. 2.0 & 1.8T

do that vag-com mod and it will always stay clean, even better do that and get the pd150 one which has better flow

[Vulcan]

Re: TDI vs. 2.0 & 1.8T

I get around 1000 km in my 04 TDI 5 speed in the city all the time. My best tank of fuel was just over 1300 km (all hwy in one straight throught trip) before the fuel light came on....The mileage is outstanding and the torque makes them a fun car to drive.

[RobG]

Re: TDI vs. 2.0 & 1.8T

Go TDI, you will never go back.

[stefan]

Re: TDI vs. 2.0 & 1.8T

with upsolute and big injectors, the worst I can do is 700km on a tank, but that significantly spirited driving (ie racing up to panorama ski hill). However, my last trip out to the coast, I was still getting over 1000km, even with the mods.

[Canadian Turbo]

Re: TDI vs. 2.0 & 1.8T

A chipped TDI is a lot of fun!

[Red90]

Re: TDI vs. 2.0 & 1.8T

with upsolute and big injectors, the worst I can do is 700km on a tank, but that significantly spirited driving (ie racing up to panorama ski hill). However, my last trip out to the coast, I was still getting over 1000km, even with the mods.

Just to note that many people are talking about vented tanks (I am). No point in vent guts on the diesel.

Also there is a big difference in economy on the newer PD engines versus the older engines so it is important to know what engine people are talking about.

[stefan]

Re: TDI vs. 2.0 & 1.8T

yes, EPA rates the non-PD ones as getting a little better mileage then the PD's.

Not sure how much difference you would notice. I know my dad traded in for a PD, and he said it was noticeable, but still pretty damn good mileage.