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Nov 12

Posts: 1

Sailingkate says:

F800ST Piston Slap

:mad: Yep I'm really mad and wondered if you could guide me on how best to handle this situation....

I bought an F800 in early 2008, looked after it very well with full BMW services and garaging it. I took it with 3000 miles from the dealer and put about 17000 on the clock. I went to buy a new BMW bike the other week and was offered £4000 part exchange. The bike is in good condition and was just having the once over when I got a call from the BMW dealer saying they could not take it because there was a noise from the engine when it was cold and it has suspected PISTON SLAP! How can that be possible? 4 years old and not worth a penny? What is the best proceedure in this case and what could I expect as the best outcome? I'd really like to continue with the next BMW but I'm quickly loosing confidence, this never happened with 2 Japanese bikes I rode prior to the BMW and yet the BMW is the most expensive of all of them. Any advice much welcome, thanks

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  • Posted 2 years ago (25 November 2012 12:24)

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Mar 10

Posts: 1035

bmwgs says:


take it to a bike garage and get a 2rd guy to check the bike if they say the same thing sell it on ebay.

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Nov 07

Posts: 2424

smidget says:


Is this a BMW dealer we are talking about here?

Suspected 'piston slap' not heard that terminology in a long time.

If this is from the dealer whom you purchased the bike from then I would ask for this diagnosis in a detailed written report stating that you intend to contact Trading Standards as the bike is clearly not fit for purpose if the engine is only capable of covering 20,000 miles when serviced by BMW approved dealers who have issued the service invoices to state that they have correctly serviced the bike on your behalf.

As has been stated get at least one other opinion, do not inform the person/s you choose that the engine is suspected of 'piston slap' just ask them to do a cold start up and ask them for their honest opinion as to their thoughts as to any noises they think you should take note of.

Piston slap = A condition which even trained engine mechanics can often mis-diagnose even after many years of experience dealing with engines. Physical measurments of components is the only true test as to this condition.

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May 09

Posts: 2571

ally600 says:


the bmw "salesman" is an arse..............i doubt there is any issue with your bike..............its just that the dealer dont want a trade in..............just the full ticket price in their advise is go to triumph, they love taking business off of bmw, will give you a decent trade in price and a better bike.............ive seen many a gs owner disappointed with the running costs of a gs with hefty garage pal just traded his gs in for a adventure 1200 and hasnt stropped grinning since:wink:

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Apr 08

Posts: 3042

AdieR says:

I just wonder

if your dealer is having a quiet time at the moment, and telling you that you need to have major work done (with the associated expense of that work)? I highly doubt a 20k mile bike is suffering piston slap (although without seeing / hearing the bike I could be wrong).

Noise from cold - some bikes are noisier than others, and mostly these noises disappear as it warms up (oil flow).

Out of interest, in the time you've had the bike, have you ever noticed any change in the bike's character over those 3 years (eg, noisier / different types of noise / down on power etc).

If your servicing dealer is the dealer your trading in with, I'd be wanting to know how / why they've only "spotted" it now at sale time, and why they haven't noticed it when in for service. Whilst some faults do occur randomly, most develop over time, with symptoms (noises / lack of power / strange smells) etc getting worse as time goes on. 

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Apr 08

Posts: 3042

AdieR says:

Found this

on a Fazer site, mention of an F800ST with "possible piston slap", no mention of age / mileage though.,5335.0.html

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Nov 08

Posts: 879


Seems there have been a at least a few full engine swaps and rebuilds (with possibly revised pistons) at relatively low mileages - seems mostly 2007s or thereabouts.  It's just one of those worries, I have a car where some have had engines swapped under warranty at low mileages for piston slap, so I get a bit paranoid at listening to it...

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Feb 08

Posts: 817

Andy949494 says:

Known limitation of some...

If you look at the F800 forum you will see that there was a change to engines made to reduce it but that the older engines do make more noise and some old engines were replaced under warranty for particularly excessive slap. The only other weakness F800s might suffer from is the petrol pump which causes stalls when the bike is idling with less than half a tank of fuel (which I had to get replaced as it was pretty dangerous).
I have a 2006 F800s and I notice that compared to a new F800 test bike my bike has always made more noise than I would hope for when cold but is fine and has kept going for 2 years with no extra oil consumption.
I think you need to get a second opinion on the state of your bike and preferably an experienced  BMW dealer... You might find the F800 Forum will also help with giving you the info ...
Also did you buy it from the dealer in question? If so you have much more leverage
I think if it was me I would explain to them that I wouldn't buy a BMW if that is how they treat existing owners and see what they will do. There is a known fault and there is no limit to manufacturing faults on the sale of goods act so they should not leave you high and dry...
Even BMW dealers are struggling to sell at the moment so they should be helping you - if they won't buy from another dealer.

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