I S4 I - Hilton

Hi people,
Im sad to say that my little baby has spat the dummy on no.1 piston with a cracked gudgeon pin or something perhaps more sinister. Still waiting for her to be pulled down today for inspection. If you ever hear anything like a bearing going in your 1.8t get it seen too ASAP. I was lucky i drove straight to the dealer when i heard the noise. More serious damage WOULD have occurred had i left it unchecked. As the car is it still developes full power but has a horrific clanging/grinding from the block like a metal can has been set loose in the head, but only when off/trailing throttle or idling. Noise seemed to disappear under light and heavy load.
The car is a 99 Australian 180hp (2year old - 51000kms)1.8TQM with 1bar chip from a very reputable tuner. I also have a custom 3inch system from the turbo back. Needless to say i knew the risks. I had actually traded this car in for a new S4 last weekend, which will now have to wait for delivery until the A4 is repaired. (was due to change over in 2days!!!!! missed by |--| that much!!!)
The dealer is going to try and warrant the repair, however it is upto Audi Australia to approve it because the repair cost will exceed $1500 AUS.
I have to say if your not prepared to foot this kind of bill, I would advise careful selection of the types of mods you apply.
Speculatively I think that the chip was not at fault, and it was infact the HKS SSBV which advanced the wear on the engine. The blow off valve causes a slightly rich condition when you vent the already metered air to atmosphere. This in turn causes a slight jolt as the fuel is not burnt properly, even sometimes resulting in a very slight backfire, especially with the 3inch exhaust! I had always noticed the slight hiccup in combustion when quickly backing off the throttle in gear. Jolts between gear changes weren't nearly as pronounced as in gear because i never fully close the throttle with the engine under load. I guess the tuners were right, BOV are not good news on our type of air flow metering. I should have known better, but i was prepared for the worst so i cant complain.
I will be chipping my S4, but i will run with a conservative HP chip, i will never run a BOV again unless the engine management is setup for it. And i will run a more conservative exhaust system IF i even change it.
Hope someone finds this analysis useful in protecting their baby from mechanical failure.

DaveL

&lt;center&gt;<img src="http://pictureposter.audiworld.com/281/valve1.jpg">&lt;/center&gt;&lt;p&gt;U should see all valves and head in my 100kms engine with a BOV, its clean for a car done 100K, NOT ANY carbon deposite has been built up, everyone in the service department was so suprised becoz the mod that ive done, e.g Chip, Blitz BOV, 3" exhaust turbo back and Apexi AVCR....etc
also refer to someone from AW the other day told me about the Carbon deposited will built up in long term with a BOV...
reason on pulling the head and valves out is becoz i had my timing belt snap the other day ( dont blam on BOV becoz its already 100K so sad all 20V are bent and scratch all piston too, : ( so please make sure your timing belt is in peak condition and i think i gona change my timing belt every 50K rather then factory suggested 90k )
but i was so suprised that the engine is so clean inside of the head too.

xr4tic

Unfortunately, I'm well aware of this - no second gear

I S4 I - Hilton

The mechanics pulled the sump and the valve gear before going the whole hog and pulling the engine, but could not find any evidence of damage....
Puzzled by this they cranked with the starter and decided the noise was from the back of the block.
So, they pulled the gearbox.... they cranked with an air gun and discovered the noise was eminating from the dual mass flywheel... seems its had a little too much abuse and is way out of spec for rotational play. They cranked the engine again with the airgun and placed a hand on the flywheel and the noise disappeared.
So they are putting in a new flywheel under warranty.
I expect to pick up the car this afternoon.
Im still a little skeptical that they have diagnosed the problem correctly, but they'll know once they put the new flywheel on. (as i speak)

WYSIWYG

can you post instructions how to replace the clutch

xr4tic

Removal:
Step 1 - pull the transmission
Step 2 - pull of the old clutch

Installation is the reverse of removal



I looked through the Bentley manual, and it doesn't look to be that tough. It will probably take me a full weekend when I swap my trans out, assuming nothing goes wrong.

Cool Craig

amazing pic!! sorry to hear of the resulting damage!!

I S4 I - Hilton

The flywheel was cracked at the centre in a rough round circle. Guess my abusive starts over 2 years were too much for the poor thing. Remarkably the standard clutch was worn but still looked reasonably healthy considering the amount of abuse it has recieved. It still has plenty of bite too when you lauch the car with the right revs and release. The mechanics did say however that they had never seen worse flywheel damage.
The tie-rod ends were also replaced under a local recall at the same time. (something about the seals letting dust in and wearing prematurely)
The whole driveline and engine seem quieter now. The flywheel must have been damaged for sometime and i only really noticed it when it cracked right round.

Well I have my new baby now, im the proud owner of a new brilliant black S4. I have a new found respect for driveline components, suffice to say this car wont recieve the same abuse, it doesnt need it too be quick! I got off lucky under warranty last time, thanks to a very generous service manager, who happens to share my passion for fast cars.