1.9 tdi (90) 1Z Top End Rebuild time?

[rjc98rjc98]

Top end rebuild question:

Hello. I have a 1999 a4 1.9 tdi (90) 1Z

Nearly 170k on the clock, cambelt due at 180k. Audi history to 40k then unknown till 100k when I took over. Has since been serviced every 10k with correct spec FUCHS / mobil 1 oil and Mann filters.

Tappets (lifters) are getting slightly noisy and getting small amount of smoke on start up from cold - worse if have been doing short journeys. Start up smoke is usually absent once hot or for few days after a motorway run.

My plan was to change all the lifters at 180k with the cambelt.

Questions: How long is is safe to run with a noisy top end like this? Is it an annoyance rather than dangerous? Should I be replacing the cam at the same time as the lifters so it is all new? Anything else in the top end that I should consider doing while I'm at it?

Thanks in advance.

RJC

[zollaf]

hmm, a 1z. thats whats in mine. i did the same as you but at 105k. it wasn't noisy but just off the road having some other stuff done and i wanted to see how worn out the bores were to see how quickly i needed to get another engine. turns out the bores were fine, just glazed but still had factory honing marks. some time with the honing tool had them looking great, then some new rings.
the head was skimmed, new lifter, valves ground etc..
the head was cracked on no1 and 4 but not leaking so i re used it with no problem. the spare engine i have is also cracked exactly the same. the cam was perfect.
now, it depends why yours is noisy. is it just a worn lifter i.e. worn internally, or the top worn out. if its the top, it could destroy the cam. if its internal, it could last forever.
if you still have the egr connected, you will need to clean all the manifold internally, and while at it might as well do the ntercooler and all pipework. inspect the bores and if glazed, whip the pistons and rods out and do the bores/rings and shells. grind the valves, new seals etc.., blank off the egr and when its all done, fit a new chip for a bit of extra poke.
where in the world are you.

[adamss24]

That's a bit too early for a rebuild. Also 1z has not been fitted to a4 in 1999, that engine has been dropped long time ago and never made it in the a4 ! You should have a AFN/AHU/AVG engine in there either 90 or 110Bhp. Check the spare wheel well for the factory options sticker in the boot !

As Zolaf said, replace the lifters and only fit genuine INA in there, cam should survive an atomic blast, pistons should look as fresh as the day it left factory- I have oppened engine with over 300k and the bottom end was still in good nick ! Key is freqvent oil changes with quality oils and long trips ! Your's being a 1999 model might have a flasheable trough OBD ECU or a non flasheable MSA15 ECU which will require chips soldering onto the mother board, it's what we call a remap or chip tune. Best bang for buck and safe to 150Bhp on stock turbo ! Some bits will bolt on from other engine: pd130 turbo is a popular upgrade as well as transporter 2.5 Tdi injector nozzles which can boost power up to 180Bhp...

[rjc98rjc98]

Thanks for the replies. Its def a 90bhp, and I thought it was a 1Z when I last looked but I may be wrong - it was a time ago.
I'm going to be removing the rocker shortly anyway to do the gasket so can eye-ball some of the top end then. Hopefully its just a case of lifter replacement.

[green A8]

As others have said 1Z engine in a '99?

I've pulled apart a couple of AFN's (110BHP) for re-build, both at around the 200K mile mark and been very impresed with the lack of bottom end wear. The top ends have been in similar condition to the bottom. If looked after and treated to quality oil I can see no reason for them not to last for a good 400K+

Perhaps if your engine has been neglected in the past it might have a bit of a sludge issue. Maybe it would benefit from an oil flush?

Hope this helps.