Cold start knocking/ticking noise

[davesurf]

New guy here, I dropped off my 09-1200gs at the dealer for service (24,000miles) on Monday, let them know that its got a knock/ticking noise on cold starts, but goes away as it warms up. The noise is coming from the left side/cylinder. They did the service but keep the bike over night to do a cold start. They called back and said that's not normal, got approval to replace a chain tension-er under warranty. Well that didn't fix the problem, bike is still at the dealer, they submitted more paper work to BMW to dig into it more. Any clues or thoughts as to what it might be?

Thanks
Dave

[adl]

I wouldn't have thought a worn chain tensioner would've sounded much different hot or cold. Is yours an overhead cam model?

[pdxrmccgs]

Your post describes what is generically referred to as the dreaded
hydraulic lifter click in reference to non-BMW engines. It results from
a hydraulic lifter for some reason loosing pressure on cool down
and allowing the push rod a very, very small throw until it hits the
cam or the lifter on start up with the resultant click, click.

Once the engine warms up because of oil pressure and natural expansion
it goes away. Its dreaded cause it is a very minor thing except for
the short clicking you get on start up.

Take all this with a grain of salt as even though I own a 2009 I have
never seen a 2009 engine apart or or any clear schematics on how the
cam/valve system works.

Believe it or not some folks say it is just weather related to a difference
in pressures from weather changes especially this time of year. This
starts to make some sense when you reflect on the fact that the eco
boys insist these engines be sealed up for any venting to the atmosphere.

Please keep us posted on what you find.

[ca1ic0cat]

I recall something about a pressure valve that stops working properly and then has to "pump up" with oil once the engine is started. Maybe it was in the BMW ON magazine? I don't know which bikes this applies to. I do remember that there is a fix available from BMW in the form of a re-designed valve.

[pdxrmccgs]

cat..good heads up. reminded me of a diagram showing the
chain tensioners being loaded by two "pressure valves" (left and right).

http://www.bmwmcchattanooga.com/show...ssembly=191929

The interesting thing is only one of them has a internal spring preload. They
both appear to be what I would call "hydraulic valves" as they appear
to have oil drain holes in them. I would think if the spring were
compromised your valve timing on start up would be off and
maybe some knocking until the "tensioners" were brought up to pressure.

Just a guess.

[marc]

The cam chain tensioner issue mentioned by some was an issue on oilheads, corrected with an updated design for the tensioner on the left side. It was never an issue with hexheads. Hexheads had the newly designed tensioner from the start.

That's not to say that a tensioner can't go bad which is probably why the dealer changed the tensioner, first. It's not a total surprise that the change didn't fix the issue. I'm afraid you may have to have to provide the dealer's motivation. Lots of letters, phone calls, requests to talk to the regional BMW rep, etc., might help.

[davesurf]

:::Update::: they did oil pressure test, all is normal with oil pressure at start up and once its warmed up. They took a mp3 recording of the noise and sent that off to BMW.

[t6pilot]

my 2011 1200gs does the same thing on a cold start after warm up two to three minutes noise goes away. dealer said it was normal

[davesurf]

:::update::: My bike is still in the shop, they are being persistent on pursuing that abnormal knock/ticking noise, gotta give props to San Diego BMW, they got the okay to take off that front black cover on the motor, and to pull the motor out if needed. They are going to look at a tensioner under the black cover (I'm clueless on whats under that cover) first before they decide if they need to pull the motor out of the frame. Will keep yalls posted

[marc]

Under the black cover is the belt that drives the alternator from a pulley on the nose of the crankshaft. Under those items is the timing case cover. Under the timing case cover are the gears that drive the balance shaft from the crank and under those gears is another timing chain. That chain has a tensioner rail driven by a spring tensioner on the left side of the case.