Rocker covers corrosion

[John Gates]

Anyone having similar trouble.

I have had the front chaincase cover replaced under gurantee for corrosion by Jefferies, excellent service by the way. Now I am noticing little white threads creeping out from the edge of the black neoprene gasket towards the first fin on each rocker cover, top edge only for some reason. About six to eight are visible on each cover so far, length approc 1 cm.

Bike is June '04 vintage with 9K miles all weathers and no harsh chemical cleaners used.


Also rubber retaining straps on saddle adjustment bars are perished badly.

Good news, now uses no oil and does 50+ per gallon, getting smoother all the time.

 

[Mel]

Yes - I have a the same/similar problem.

1200 - 14000 miles - all weathers - soap and water only - I have corrosion on the timing chain cover - rhs rocker cover just as you describe except the coating is flaking off the fin - also on the rhs cylinder head where it meets the rocker cover - on the rear drive housing around the point where the brake caliper is mounted and under the rear drive.

I have visited Cooper reading and am waiting for a BMW technician to get in touch.

Actually I am s**tting conkers because it has happened suddenly and is getting worse quickly.

I will let you know the outcome of my conversation with BMW.

 

[nadeem]

the rubber straps have been changed now - there's a different design available - mine perished too - got new ones from the dealer...

 

[Yellow Peril]

Its quite funny my rubbers are perishing too. Difference is though my "normal" seat isn't even on the bike most of the time.. but stored in a nice warm dry room.

 

[nadeem]

that's why they've changed suppliers I think - a coupla the new 55 plates bikes ready to go out had perished ones as well...

 

[Schtum]

My December '04 bike with just under 6 K miles, is currently in John Clark BMW, Dundee, having the front engine case and two new cylinder heads fitted under warranty. The paint on the engine case had bubbled badly and there were white spots of magnesium corrosion around the inlet stubs on both cylinder heads. This is in spite of a liberal application of FS365 before I rode the bike off the dealer's forecourt just before Christmas and washing it every time I was out in salty conditions.

I've just got home from dropping off eight VAG alloy wheels to a local metal cleaning and painting specialist. I explained the problem to him. When we got to the bit about water based paint and magnesium he understood what was happening only too well.

 

[Mel]

John - send me an email or join the forum as a sponsor so that I can PM you. This corrosion issue sounds serious and I think it will be helpful for us to be in touch. I have PM'd Schtum with similar.

Rgds

Mel - [email protected]

 

[Pukmeister]

Mine goes into the dealers next Wednesday for its second replacement front timing cover due to bubbling beneath the paint despite being replaced in May and using a corrosion protectant. Luckily my replacement head covers are still ok.

I am a marine engineer and know a thing or two about types of corrosion. What is happening to my cover is called 'galvanic corrosion' whereby two dissimilar metals are in contact and when moisture is introduced it acts as an electrolyte and sets up a battery effect. As the two metals have different electrical potential to each other, one causes the other to corrode as the current flows between them. In the case of my bike, it is an Alloy cover with zinc coated steel bolts. The zinc plating on the bolts is 'sacrificial' ie it should erode first, protecting the other components. I suspect this plating is thin and poor, and is allowing the steel to corrode the alloy.

I asked the dealership if they could fit stainless or titanium bolts but they are only meant to fit the OEM components under warranty claims. If it goes a third time before my warranty expires next year, I will get another cover fitted then immediately change the fasteners for stainless items at my own expense.

If BWM had anodised the covers during manufacture instead of using paint, and then used stainless fasteners, this problem would be alleviated. Also the hard anodised coating would be very resistant to chipping and abrasion from stones and grit, unlike a paint finish.

 

[Mouse]

I too am going to get a new front engine cover under warranty. That's the only part of the bike with any noticable corrosion on it.

I remember reading that it was quite common for owners of earlier bikes to get a replacement cover under warranty, and have it powder coated before fitting it. I might investigate that route when I get round to having mine done.

 

[Mel]

Thanks Pukmeister and Mouse. In particular thanks P for the science lesson.

On the surface (excuse the pun) not a very happy situation. This thread could become important although it's encouraging to hear that dealers are stepping up to the mark.

By the way - whenever I have an important warranty claim I make the assumption that the new work/parts are now under warranty - ie extended beyond the original 2 yr bike warranty. I have always made this clear with dealers at the time and retain evidence of the dates of replacement etc. I have even had service booklets marked with the details. Not a very practical solution to parts that need to be replaced every few moths but at least it costs only time and not money.

 

[nadeem]

Can we see some pics guys...?

 

[Schtum]

I had hoped to have my bike back by now, but a phone discussion with the service manager at John Clark BMW today, revealed that in the course of changing the front engine casing they discovered that the front crankshaft oil seal was leaking. They, therefore, ordered one up and the bike should be ready for collection tomorrow lunchtime. I'll be extremely glad to get back on my bike rather than the R1200ST demo bike which I've currently got on loan.

 

[Wraithwrider]

I've got a small amount of corrosion underneath the rocker covers by the seal. My front cover's fine at the moment but I did notice some bubbling on the fuel filler surround ring. Is this a first?

Peter

 

[Alphason]

I've got a small amount of corrosion underneath the rocker covers by the seal. My front cover's fine at the moment but I did notice some bubbling on the fuel filler surround ring. Is this a first?

Peter

Jefferies changed my fuel filler neck under warranty as the original had corroded around the drain hole.

Keith

 

[BBB61]

At least BMW will replace corroded parts under warranty, unlike Triumph.

Bob

 

[Schtum]

At least BMW will replace corroded parts under warranty, unlike Triumph.

But like Yamaha... SWMBO's Thundercat received new wheels, swingarm, exhaust can, rear shock and brake caliper under warranty because of corrosion.