MBAdon

I picked up a 09MY C63 last week and was wondering if I could relay my driving experiences and get an opinion on a few things.

1) Downshifting in S mode. My first WOT pull on an empty freeway was awesome but upon releasing the gas pedal the car downshifted violently enough that the engine breaking caused enough slipage to engage ESP and the flashing lights. Similar excessive downshifting upon release of the throttle has occured during onramp pulls, not engaging esp but with enough engine breaking downshift that it seems abnormal and probably dangerous if I was in a turn. Does the ECU just need time to "learn" or is this abnormal?

2) ESP kicks in a lot in S mode during acceleration. I do have the PP w/ LSD and I am not at all used to this much power so I may just need practice but ive noticed that giving it much gas at all in 1'st gear always results in ESP and flashing lights. Easing my way through 1'st and gassing it to before the kickdown bump also has resulted in ESP and lights. This is going in a straight line. Should this be happening or should the car not be allowing itself to put down enough power to loose control in a straight line?

3) I got a check coolant light and am well read up on the head bolt issues now. It looks like there was some coolant bubbling out of the fill cap but the dealer said he would do the coolant pressureization test for me before my factory warranty runs out in 3 months. Any other suggestions?

4) I find the transmission a little unpredictable and I dont really understand the kickdown bump. Plenty of downshifting occurs before the bump. Can you please explain the kickdown bump? Sometimes when giving it a lot of pre-kickdown throttle the car has awesome acceleration and sometimes it goes into insane rocket ship acceleration. I haven't quite found the threshold between the two and would appreciate advice.

Im loving this car! I'm coming from a 200HP Honda so I know I need more practice with a vehicle of this caliber. It will probably be a long time before I even try ESP Sport mode.

Thanks for your advice and for this excellent board!

CoolBDPhenom03

Welcome and congrats!

I'll do my best to address your points with my limited knowledge...

1. I think it will take a little while for the car to relearn your more conservative driving habits. Sounds like the previous owner drove it like they stole it all the time. However, I will say that some folks who have had a persistent issue did have actual problems, so I'd keep an eye on that or have the tech check it when they inspect your coolant. It could also be that you let of the throttle around the time a shift would occur. Try driving in M or S with paddles and see how she handles.

2. ESP Sport will allow some slip and judging by how the previous owner may have driven it, it's probably normal. Tire choice also has a lot to do with it, so feel free to reply with that info for more insight.

3. I could be nothing, it could be serious. Best make sure your dealer is read up on the entire notice. That test should tell a lot. Worst case scenario, it's the head bolt issue. Best case scenario, someone overfilled the coolant.

4. I don't know what you mean about "kickdown bump," but that could be my own ignorance.

MBAdon

Thanks for the reply.

My tires are Dunlop SP Sport Max TT with half tread left.

As for the dealer he knew all about the head bolt issues. People might find it interesting here that my dealer said it usually only happens to garage queens that aren't driven much for years then are suddenly driven hard. I know this is contrary to what I have read here.

It is my understanding from reading the manual that the point of resistance in the gas pedal right before it hits the floor is called kickdown and it has a specific function. I may be wrong.

Thanks!

johnnyblaze

Congrats on your purchase.

CoolBD is on point with the learning points in the cars transmission and ecu. It takes time for it to relearn your ideal driving.

Also, no one really knows when or if they will get the headbolt issue. Its not always hardly driven cars that are affected, nor is it any certain mileage. Make sure you get the coolant issue addressed quickly so it doesnt surprise you later. I would suggest getting an aftermarket warranty also, or renegotiating with the dealership to get a warranty. Could save you A LOT of money in the future.

Good luck and drive it like you stole it.

CoolBDPhenom03

Good point about renegotiating for an extended warranty.

As for the tires, what size are they? For example, I run 285's in the rear so they are less likely to break traction compared to 275's or 265's.

MBAdon

Hmm. My tires are 255/35 in the back, 235/something in the front stock wheels. How big can I go on stock wheels?

CoolBDPhenom03

Those are kind of skinny, so it's not surprising that you're losing traction. Most folks here run 265 or 275. It think you can easily run most brands of 275's with out rubbing, especially if you're on stock suspension.