Car back with new engine fitted

[P_G]

So Audi got the design right but the cold rev limit wrong?

If Audi can claim "wrong oil" can cause this kind of damage, what does that mean and what is the mechanism whereby this "wrong oil" does the damage?

Genuinely curious.

I'm not saying they got the rev limit wrong, far from it. However you could say that all cars have a rev limiter but you invariably don't drive them to that limit in any car the minute you turn the key, you wait for it to warm up properly and perhaps with the RS4 it could take a little longer. 9.6 litres is a lot of oil to get warm compared to the normal 4 or so litres in most other cars.

I'm also curious about the wrong oil situation. I'm not even sure that with all the engines that have been repaced / cleaned there is a common cause. If there was it would be easier to understand and mitigate?

[sonny]

I was surprised that the RS4 cold rev limit is 7k, MRC remaps see a 5k cold rev limit, which I totally agree with for obvious reasons.

[Brooner]

yep i agree 7k cold limit is a bit hi mine will have the 5k limit when Doug has worked his magic

[k3ukr]

My car had both heads removed for inspection ,when I picked it up the engine was half assembled to go back to the factory, as I have had a lot of high performance cars I always let them heat up properly and cool them down ,

The pics I posted didn't show u much but the uploader wouldn't let me upload any more pics I will try again tonight .

[2manytoys]

The RS4 is an enthusiast car, I really don't think anyone would rev it to even 7000rpm when cold. I don't think I even hit 5000 when it's cold.

[P_G]

You would be surprised Mal, I have even heard from my dealer that some owners have asked for it to be removed as they don't understand why it is there when the car has 8250 rpm. Much like the argument of M5/6 set default at 400bhp when it has 507.

[2manytoys]

Maybe I think like this because the RS4 is such an expensive car in Australia. At $180,000+ I'd think most owners have more sense here. I guess there are some people out there that either don't care or don't know I suppose.

[MB2]

Whilst I am surprised people drive around with little/no mechanical sympathy & I always make sure my bike (air cooled) & car are completely warmed up before using the 2nd half of the rev range, I must admit that my father cheerfully thrashes his car warm (brand new R32 Passat) so maybe if more common than like to think. I also recall the manual says there isn't an actual stop at 7000 for safety so people could conceivably ignore even the 7k advisory limit with a cold engine if they want.

[PetrolDave]

I also recall the manual says there isn't an actual stop at 7000 for safety so people could conceivably ignore even the 7k advisory limit with a cold engine if they want.

When I went for my test drive (on a dealer demonstrator back in 2006) the salesman took it to the 7000rpm limiter straight off the forecourt, and it definitely IS a limiter, despite what the manual says.

And 3500rev limiter may have buses running up your arse as you exit junctions and promptly hit the limiter.

Try driving with a self imposed 3500rpm rev limit - you'll still out-accelerate most cars, and all buses, on the road.

[ArthurPE]

what dealer was this work done at? in Scotland?

not sure whether the 7000 is a hard limit...
not going to find out thru experimentation either

[P_G]

It's an ECU imposed limiter much the same as if your EPC ligt came on. Feels like it is misfiring when you hit it. Same thing as PD with a dealer demo'ing the car to me.

[ArthurPE]

It's an ECU imposed limiter much the same as if your EPC ligt came on. Feels like it is misfiring when you hit it. Same thing as PD with a dealer demo'ing the car to me.

I hit the 8250 one tonight
3rd gear
up a decent grade
pulling like a train
really surprised me...in a good way

[PetrolDave]

I hit the 8250 one tonight
3rd gear
up a decent grade
pulling like a train
really surprised me...in a good way

This is one of the things I love about the RS4 when compared to a B6/B7 S4 - the RS4 loves revs and it's real easy to get to the rev limiter, but the S4 just ran out of breathing and really struggled to get near the rev limiter.

[neckarsulm]

Does this sound familiar? It's from Evo guide to Jag XKR. Would explain RS4 software update higher rev cold start map to prevent bore wash from overfuelling;

The V8 engine was designed to be the lightest in its class and, as part of the weight-saving measures, the aluminium bores were lined with Nikasil. However, the sulphur content in fuel, which was high at the time, dissolved this coating and reduced compression. Not all cars were affected, but those used mostly for short journeys tended to suffer most, as the engine’s tendency to over-fuel when cold exacerbated the problem.

Failing engines were all replaced under warranty with new units complete with steel bore-liners, but if the car you are interested in still has a Nikasil engine it’s vital to check it carefully. Sluggish starting points to the problem – it’s likely to be due to low compression. Oil around the tailpipes is another danger sign, but to remove any doubt the engine should be compression-tested at a main dealer.

[parlee-king]

just because a car is fairly expensive and niche it doesn't mean that owners are sensible or respect the car

For example I have a mate who worked at a Porsche OPC and he reckoned that the majority of new Boxster where owned by decent owners who looked after their car, whereas 911 (997) owners had much less respect for the cars. his reasoning was most average workers could stretch themselves to a boxster (2.7?) but a 997 was purchased new with somebody with considerably more disposable income, hence the easy come easy go attitude. Last spring before I test drive an RS4 I looked at a few 57/08 997 but found a lot where err not exactly mint.