Car back with new engine fitted

[HYFR]

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.

Totally agree....tis the high revving that gives the RS 4 its unique character

[ArthurPE]

BMW had the same issues, huge problem in the States
the nikasil was susceptable
iirc they changed to alusil which is more durable
(see post 5, page 2, this thread)

imo starting the car and driving right off to get it warmed up is important
I like to keep the revs ~3000 to 6000 (light load) until warm...
keep some air moving thru the cylinders, blow the unspent fuel out...

I've seen oil analysis on RS4's
some have very low fuel levels
others pretty high
my guess? service duty...
getting warm fast, mating everything up, and getting the oil hot (burns the fule off, low vapor pressure), low fuel
short trips, no high loads, etc., high fuel dilution

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.