1998 TDI vs IDI diesels

[homerj1]

Howdy folks,

I've been driving a variety of 93-96 Jetta\golfs with AAZs  and appreciate the simplicity of the idis thanks to our friend Rudolph D.
 
 I'm looking at a 1998 TDi - single owner, - what can I expect issue-wise esp with the Tdi aspect?

thanks

Aivars

[rallydiesel]

That's probably the best year for the tdi. Very similar to the AAZ but with a bit better mileage and power. A vagcom/VCDS cable is a good investment so you can clear codes and decrease your egr duty cycle.

[8v-of-fury]

1998 is an AHU TDI, the good ones

Its just as simple, if not more so then the AAZ and older ME/MF and CR engines. (ok maybe not as simple as an old 1.6 n/a.. but damn close)

just a bunch of wires and sensors added, to better refine EVERYTHING that goes on with the engine. Perfection if you ask me. The PD motors is where they got greedy.. and changed a whack of stuff, and made it complicated as all hell.. mind you they make a butt-load of power

you will like the AHU, a simple bolt on will net you like 35hp and 74 ft.lbs

[homerj1]

Thanks for the info, guys!

A few more questions.

1. Chassis -wise the 98 tdi Jetta is the same as my 96 Golf? Other then engine? ( I've got some 93-97 parts kicking around)
2. What is the cost\difficulty of changing the timing belt?
3. Is there anything specific I need to look for when checking out the car? ie: AAZ pulley wobble? Turbo Issues
4. What is the bolt on that will increase my hp and torque?
5. How much can I alter stuff using Vag-Com?

thanks again, this is a great forum for help and advice.

just got to convince the wife....

Aivars

[ricosuave]

1. yes
2. not too bad ffom what Ive read here
3. the engine isnt an aaz, so you dont have to worry about that - just a general inspection
4. nozzle upgrade, I would guess
5. lots, but its for diagnostic too, a worthwhile investment

[catlin_cava]

I upgraded from running MK3 AAZs to MK4 ALH TDI and its a world of difference I find TDI from IDI(mind you the ALH is damn near impossible to work on when *** breaks) if I could of found a decent shaped MK3 AHU Jetta I would of bought it.

1 power box(250$) will give about 50HP and 70ftlbs of torque, Nozzles are another great upgrade, it will give you about the same power.

TDIs are a blast for power

[8v-of-fury]

$700 of bolt ons and you are a rockett ship! lol

[homerj1]

Thanks for the help. I'm still sort of sitting on the fence, as my 96 Golf aaz is getting a bit tired - floors, and a host of accumulated small things.

So I was looking for a change - but am sort of unsure of the reliability and  parts price costs when it come to sensors and stuff.
How much more get up and go and economy can I expect from a AHU?

Also, I've got a pile of aaz diesel stuff, most of which would be useless.

thanks for your help!

Aivars

btw catlin_cava, did you make it home ok - read your alt. issue. Just think you might have made it home without alt - if you had a IDI? 

[catlin_cava]

Yea we made it, took us 6 hours to change the alt. Its a big job, and if I had an IDI I would of drove it home lol. But the Jetta everything is electric and the alt. Had seized up completly and the motor wasn't turning over anymore.

[homerj1]

Hey Folks, Just an update.....

I bought the 98 Jetta tdi - 284,000 km one owner - no real options - good shape, a few small rust spots, will need in the future some minor floor work, new snows - for $1,100

I was having a CEL issue (glow plug temp), wonky fuel gauge and I also thought the vss was gone - BUT, it was just a broken ground wire at the crazy big black plug ( lots of wires) to the right of the injection pump.

Diesel purged it, new fuel filter - and so far it runs great! Still needs a bit of fine tuning (new vac lines, fuel return hoses)

but most of all, I'm impressed with the performance over my aaz.

thanks again for your help.

Aivars

ps So the question is - Should I remove the muffler, resonator or both?

[catlin_cava]

On my MK4 I removed the cat and I don't have a resinator and she's working pretty good. But I will replace the cat this spring with a highflow one,

I would remove both and just put a flowmaster freeflowing muffler on and you'll be good.