groovetek

Hey guys, this is my first post here - now... I bought a 98 2.8L 30V quattro tiptronic... and there are a couple drivetrain quirks - wondering if any chips would fix it.

Something that confuses me is the power delivery of the engine/transmission. It's a 5 speed tiptronic.

Lets say I'm at low speeds, and in 2nd gear, and under 1.8K'ish RPM. If I press the accelerator, it has a nice instant response and I feel the pull of the car at the engine speed increase.

THEN... once I hit around 2.1-2.2k revs, the revs drop back down to like 1.9k'ish revs, and I can feel the car suddenly not pulling as hard anymore! In fact, the climb through the rest of the gear feels sort of slow, until I hit like 4K+...

What is wrong?!?! I look at the gear indicator - it's not shifting up to 3rd FOR SURE - I'm positive on this.

What is annoying is that, if I downshift to 2nd and take a corner, most of the time I will end up being below 2K rpm just after the corner, and even though I'm flooring it, I just can't get it to power out properly - it will do what I mentioned above.

It happens EVERY TIME - and is 100% reproducible. In fact, the only way to avoid this, is to shift up higher in 1st gear so that I miss the whole <2.2k'ish rpm band...

It happens in every gear from 2nd onwards, but most noticeable in 2nd.

It does NOT happen in 1st gear - but regardless I feel the engine isn't quite as punchy as it SHOULD be in 1st gear (from 0to 2.5k' rpm it's just not very kick-starty! I tried a 0-100km... it felt really curbed during the first couple of seconds when it struggled to take off).

Any help would be greatly appreciated.

THE SECOND PROBLEM is as follows:
I'm noticing that when I'm accelerating (even just normal gentle acceleration), and let go of throttle (even when gently), the engine has some kind of thumping sound, and the car gets a kickback... as if i hit a big bump and kicking me back for a split second...

It doesn't always happen - and the severity varies... but generally speaking, between 1.5 and 3k engine revs this is the most obvious. Once I'm above a certain rpm, it doesn't seem to happen as much I think.

Also, on the opposite side of things, when I accelerate, it seems as though it doesn't engage the rear wheels the second I press the throttle, and the end result is that it sort of kicks in the rear wheels a little - if I'm not gentle, this results in a sort of forward jolting motion (and a clunking sound), since the engine revs slightly before engaging the rear wheels...

This isn't really a problem compared to the first thing, but yeah, if I could alleviate it it'd be nice too...

Any help or expert advice would be greatly appreciated, thanks.

I had the car fully checked out - everything is fine, no error codes, engine compression is perfect. I even recently just had the transmission mounts and engine mounts checked, and the 120,000km major service done, which included cleaning throttle body, replacing all filters, changing engine oil, spark plugs, etc...

but STILL the same!! ARGGHHH HELP ME!

akula-ssh

Below around 2500rpm the torque converter is slipping since you just don't have enough torque to otherwise get the car going; after that the TC locks up. You must be keeping your car at too high a gear too often...

groovetek

hmmm... i guess that makes sense... but it seems to be locking on abit suddenly - or at least it should lock on later, so that it doesn't drop my revs so fast - cos i really do lose alot of rate of acceleration!

edit: does your car do the same? i know u have a diff model and diff engine as well... but seeing as you have a tiptronic too it'd be nice to know...

akula-ssh

The power loss part, that is.

psychobabble

The 'power loss' that you're feeling seems endemic to tiptronic a4 2.8s. However, I think it happens at different RPMs in different cars. Mine happened at about 2800 RPMS but mostly when the engine is under heavy load (e.g. up steep hills, with 3 adult passengers, etc.). I thought the GIAC chip would take care of it, and it did to some extent, but not entirely. I am pretty positive that it has nothing to do with the trans, probably something with timing retard or some other engine management feature.

Your trans issue is correctable with the GIAC tip chip. In stock form the trans 'searches' for the proper gear more than we'd like. Since the torque converter locks up somewhere around 2500 RPMS, any down or up shifting at this point could produce the condition you are experiencing. It's not a malfunction but a feature designed into the trans to decrease harsh shifts believe it or not. I say this because I've upgraded my trans valve body and torque converter and the condition subsided.

groovetek

Thanks for that - it's good to know that nothing seems to be technically wrong...

But it REALLY is annoying when I come around a corner in 2nd, have the accelerator planted, and the revs dropping at 2.2k'ish revs back down to 2k...

definiltely locking on abit too aggressively!

upgrading trans valve body and torque converter - what does that involve and how much did that cost?

petenice00

Here are two posts from members on scaudi.com and passatworld that had the L10 upgrades:

http://scaudi.com/sc/index.php?showtopic=2681&hl=level10

http://www.passatworld.com/forums/showthread.php?t=181081&highlight=level10

Unless you get in on a group buy, both parts will run you 1400 plus in parts, then labor on top of that. I wouldn't be surprised if you get in around 2K. Now is a good time to ask for that bonus.

I experience both problems you described, even with the tip chip. Typical Audi auto transmission design 'flaw'.

groovetek

And these upgrades would totally get rid of the problems I have described?

I'm confused about how there are different levels and so on... but certainly is an interesting read.

thanks for that petenice00

Reuben

Hi guys.Anybody experience a drivetrain vibration, when the steering wheel is turned under accelaration. Any solutions? Dealer says the rear diff must be replaced.