Z4mc feeling flat

I've only used regular unleaded. Every time I've put my foot down the traction has kicked in as tyres are a bit low. Really flies higher up. I know you have to let go of throttle before pressing sport button and on m3s as you're driving and u hit the button it sortve gives the car an instant thud. My m3 did have new tyres and was very well planted and had a major service too.
Not had the chance to put down the power really as the weathers been so bad leaving the roads soaked!
Might be the case really. Just read the reply re vanos seals- now that's worrying. If it was the case that they needed to be replaced, what sort of costs are associated with this? Wouldn't be using bmw main dealers!
 
A few people have replaced the vanos seals and refurbed it on here, some themselves, so I'm sure they can/will answer :thumbsup:

To summarise where we're at though...

1. Needs a service - at around 70k that should be an inspection 1, right ? So full oil and filter change etc., and also valve clearances checked if it's done by the service books (rather than BMW who don't do it on Insp 1 now...)
2. Needs new tyres - along with wet roads, that'll be causing the traction issues
3. Regular unleaded fuel used - that will be causing the ignition timing to retard as said above
4. Sport button not feeling like it should - 1 and 3 would cause that I reckon.

It seems there's a lot you can do, even without servicing it, before looking for scary issues like vanos failure. Which I have seen lots about preventative maintenance on, but can't recall anyone posting that it's actually failed. Change the tyres, fill it up to the brim with V-Power and find a dry road :driving:

Oh, and you don't have to let go the throttle before hitting sport, you can press it any time, but it won't do its stuff until you take your foot off the gas and put it back on. One way to test if the sport button is actually doing something is to engage it, then cruise at a steady speed with constant throttle and knock it off. If it's working you will feel and hear a small but distinct drop in engine revs / speed for the same throttle position. Easier to spot if you hold a lower gear at about 4,000 RPM.

Another question would be, has it been driven hard from cold a lot, or has it been warmed properly to around 85/90 degrees before being pushed over about 3,000 RPM ? Not suggesting you have driven it like that, but your mate might have, and you'll know from your M3 that these engines don't like that sort of treatment.
 
Just to clarify, Vanos seals is not a terrifically difficult job, nor is it a job that has to be done now, even if they have gone bad. You can drive a long happily for the next few years no problem at all, they're just a known weak point that cause low speed bogging and surging at 3k revs, plus reduced fuel economy (amongst others).

On the //M you need to get them done by a garage as the timing needs to be locked, but even so not too bad. So don't panic, I was just suggesting this as a possible cause of your symptom. :thumbsup:

The problem with these sorts of things is that people will throw various problems at you and it can get worrying.
 
I tried the throttle reset, put in some v power and the car definitely feels a lot pokier!
I suspect a full service will improve. Difficult to give it some with water on the roads, rears lose traction. In the m3 on the other hand with top tyres all round the car was far more planted and seemed to have better traction. The drive is totally different.
 
mrmseries said:
I tried the throttle reset, put in some v power and the car definitely feels a lot pokier!
I suspect a full service will improve. Difficult to give it some with water on the roads, rears lose traction. In the m3 on the other hand with top tyres all round the car was far more planted and seemed to have better traction. The drive is totally different.
Click to expand...

What tyres does it have? I have Michelin Pilot Super Sports and find them very good, but never driven an E46 M3, so can't compare. Maybe being slightly heavier helps!

Also I find tyre pressures can make a difference too.
 
Could be valve clearance/ adjustment. Many cars have never had it done. Then a good full service including all filters (oil, fuel, vanos etc).
 
The car drives spot on now after resetting throttle and putting in super. Was speaking to a specialist and he said most would not need it doing if they have been looked after.
 
You must log in or register to reply here.
Back
Top Bottom