Leaking Koni strut

[Anthony (M5 in Calgary)]

After being an advocate of Koni dampers for my M5, I have recently discovered the Koni front damper on the driver's side of my car is failing. Oil from the damper is covering the strut tube and I'm starting to notice suspension patter over washboard surfaces and minor bumps. The dampers are only a few years old and have had ~35,000kms of easy use.

Having had Bilstiens before (E30 325iS) and finding them to be quite firm, even harsh, I'm in a quandry as to replacement parts.

The car is riding on OE springs and I'm not interested in lowering it since it is already at a nice height. Bilstiens typically jack the front up by about 10mm due to their extreme pressurization so I would fit the thinnest spring isolators possible in order to minimize the ride height change. Internal bump stops will have to be cut down (a well known mod) but still the question: HD or Sport.

Any comments or alternate suggestions appreciated.

Here's a shot of the current ride height:

http://img.photobucket.com/albums/v11/interalian/e55bfc8a.jpg

[bfd]

If you have been happy with Koni, why not get it warrantied? According to Koni's website, you should be able to get it repaired or replaced:

http://www.koni.com/_cars/_general_info/technology/warranty.html

I would contact the dealer you bought the shock from and see what he can do. You should be able to talk him into a replacement.

[Anthony (M5 in Calgary)]

If you have been happy with Koni, why not get it warrantied? According to Koni's website, you should be able to get it repaired or replaced:

http://www.koni.com/_cars/_general_info/technology/warranty.html

I would contact the dealer you bought the shock from and see what he can do. You should be able to talk him into a replacement.


Already checked this avenue. Purchased from a Dinan rep but installed myself so warranty is void. Aside from that, I was told the warranty is only 2 years.

Thanks though.

[pundit]

Already checked this avenue. Purchased from a Dinan rep but installed myself so warranty is void. Aside from that, I was told the warranty is only 2 years.

Thanks though.
Many Koni shocks can be rebuilt by an authorised Koni agent for a reasonable cost. Koni tend be a little sensitive about their reputation so if you can prove the failure was not caused by any abnormal abuse then they may a least meet you part way.

[Anthony (M5 in Calgary)]

Many Koni shocks can be rebuilt by an authorised Koni agent for a reasonable cost. Koni tend be a little sensitive about their reputation so if you can prove the failure was not caused by any abnormal abuse then they may a least meet you part way.

Hopefully true. I am pursuing some form of warranty directly through Koni now. The current reply indicates the need to buy 1 replacement at 50% of list, R&R the part then return it for investigation. Provided their investigation proves a defect rather than abuse or extraordinary wear the replacement is then credited.

This doesn't address the problem of having two differently worn/aged parts on the car or how that would affect handling etc.

As it is getting cold here in the GWN, my desire to R&R dampers in is waning.

[Booster]

Many Koni shocks can be rebuilt by an authorised Koni agent for a reasonable cost. Koni tend be a little sensitive about their reputation so if you can prove the failure was not caused by any abnormal abuse then they may a least meet you part way.

Thats a bummer they are beyond warranty.I know all of the sets I've had on my other cars have held up well. The seals do tend to leak abit though and eventually require some work. I have not personally rebuilt or attempted too yet due to the specific hard to find replacement parts.
If you do intend to abbandon your Koni's and go with newer shocks I'd like to speak for the old ones.I might try to dissasemble and see if they fixable or not. Of course I am not expecting free. Even if they turn up DOA in the end.
Let us know how it turns out.
Vinny
:)

[Jr ///M5]

Hey Anthony, seen your post on the M5 list and meant to write a blurb....

Are your Koni's the Sport adjustable type? I bought mine through Patrick at BMA, they might know something about warrenty work or factory refurbishment, at least maybe point you in the right direction.

As far as using Bilsteins on the M5, you are already running 3mm spring pads, so there's nothing to gain. That's what the factory installed for you...

Try the Koni route first, if you don't get anywhere, let all of us know on this board and the M5 Yahoo board, we will make your voice heard!!!

[GS535i]

My experience with Koni warrenty has been excellent - as long as one has a bill of sale, the age of the shock never came into question. They also offer a rebuild service at ~50% the price of new shocks.
In this case, if there is a concern of left: right wear or balance, have the leaker done under warrenty - and send the other in for a rebuild if Koni deem ir necessary ( they test valve action before rebuilding).

[Anthony (M5 in Calgary)]

Hey Anthony, seen your post on the M5 list and meant to write a blurb....

Are your Koni's the Sport adjustable type? I bought mine through Patrick at BMA, they might know something about warrenty work or factory refurbishment, at least maybe point you in the right direction.

As far as using Bilsteins on the M5, you are already running 3mm spring pads, so there's nothing to gain. That's what the factory installed for you...

Try the Koni route first, if you don't get anywhere, let all of us know on this board and the M5 Yahoo board, we will make your voice heard!!!

Thanks Jr,

I guess I'm guilty of cross posting, but the M5 group has a much smaller subscription than this one. :)

I did get a pretty quick reply from the Koni site regarding warranty so there is some hope. The parts are Sport adjustable but are Dinan parts which are supposedly modified in some way (by Dinan or Koni, I can't say).

At this point I'm exploring my options and using the forum postings to aid my quest, not to slam Koni. Of course, a concern is the replacement of one part when the other will be worn.

Being a bit of a perfectionist, I may just put a pair of Bilstien Sports on the car just to put the issue to rest. In the meantime, the car will be wallowing through the winter - too freaking cold to be swapping shocks in an un-heated garage. :D

[bfd]

Something doesn't make sense. First, let's assume for a second that Koni agrees to provide you with either a brand new replacement or rebuild.

You think one new Koni shock is going to be *worst* than a new set of bilstein shocks, which you readily admit will be firm (if not harsh) AND will raise your car up?

Unless your other 3 shocks are also leaking or have ALOT of miles, e.g., in excess of say 100,000, I would stick to a new one.

As for Dinan, supposedly they have Koni or whoever built shocks to their specs. But who is to say that its not just a regular old adjustable that you can tune. In any event, I would have Koni rebuild or provide a replacement that is to Dinan "specs".....

btw, I'm not bashing Dinan cuz I really like their albeit pricey suspension systems for the street, but I would have gone straight to Steve Dinan if my shock leaked. Good Luck with this!

[Traian]

Anthony, I know this is a bit OT, but do you mind telling me how you've found the Konis so far? Both performance wise, and in particular, is the ride much rougher / stiffer / noisier than stock?

[632 Regal]

replace both shocks, dont go with Bilsteins http://www.bimmer.info/~regal632/Bumpstops.htm
you dont need to mess with the stops unless lowered like mine. the only advantage with bilsteins is the removal of the stock bumpstop. their warrantee is worse.
The Dinan shocks as far as I know are revalved and not the same as a stock one, thats why I would recommend replacing both.

[BigKriss]

Many Koni shocks can be rebuilt by an authorised Koni agent for a reasonable cost. Koni tend be a little sensitive about their reputation so if you can prove the failure was not caused by any abnormal abuse then they may a least meet you part way. Yeah, thats what I was thinking. Go get the shocks rebuilt, should be cheap. I was thinking around aus$150 for two shocks. Koni's are the best shocks out there right? So if you buy some other brand your downgrading the "performance". Did you run the shocks on full soft?

http://www.toperformance.com.au/why_fs.html - click on faq
(http://www.toperformance.com.au/why_fs.html)

[Anthony (M5 in Calgary)]

Many Koni shocks can be rebuilt by an authorised Koni agent for a reasonable cost. Koni tend be a little sensitive about their reputation so if you can prove the failure was not caused by any abnormal abuse then they may a least meet you part way.

Re-building may well be an option - I'm exploring this one.

On the question of "abnormal abuse" - beyond bending the strut rod from accident impact or a wheel ripping pot-hole, how would they know? I've only driven the car on the street and have not subjected it to anything unusual nor have I ever hit a large pot-hole. The roads in Calgary are not billiard table smooth, but they don't have craters.

[Anthony (M5 in Calgary)]

Anthony, I know this is a bit OT, but do you mind telling me how you've found the Konis so far? Both performance wise, and in particular, is the ride much rougher / stiffer / noisier than stock?

I like the Konis, they ride well and are firm enough for my needs on such a heavy car. Having said that, one man's firm is another's "need Viagra". :)

[Anthony (M5 in Calgary)]

Something doesn't make sense. First, let's assume for a second that Koni agrees to provide you with either a brand new replacement or rebuild.

You think one new Koni shock is going to be *worst* than a new set of bilstein shocks, which you readily admit will be firm (if not harsh) AND will raise your car up?

Unless your other 3 shocks are also leaking or have ALOT of miles, e.g., in excess of say 100,000, I would stick to a new one.

As for Dinan, supposedly they have Koni or whoever built shocks to their specs. But who is to say that its not just a regular old adjustable that you can tune. In any event, I would have Koni rebuild or provide a replacement that is to Dinan "specs".....

btw, I'm not bashing Dinan cuz I really like their albeit pricey suspension systems for the street, but I would have gone straight to Steve Dinan if my shock leaked. Good Luck with this!

For the record, I'm not bashing Dinan either. I'm just surprised by the warranty of only two years (as stated by my supplier) where Koni's warranty is lifetime for the same basic part. As for going straight to Steve, that is no different than dealing with the supplier I bought them from, the same supplier that said the warranty was 2 years and void if not installed by an authorized shop.

On the question of one new part in the car, yes, wear is a concern and there will be a difference between the two sides after 35,000km. The back shocks are not Koni anyway, they are the standard M5 SLS units which work fine and will be staying on the car. An un-balanced suspension is not something I want to mess with and without a suspension dynamometer, "tuning" would not be very accurate - the adjustment knob only affects rebound damping.

One new Koni "worse" than matching Bilstiens? Unknown. I've had Bilstiens on a couple of cars (2002 and 325iS) and they were firm but not harsh. The ride height change is a concern though.

[Anthony (M5 in Calgary)]

Yeah, thats what I was thinking. Go get the shocks rebuilt, should be cheap. I was thinking around aus$150 for two shocks. Koni's are the best shocks out there right? So if you buy some other brand your downgrading the "performance". Did you run the shocks on full soft?

http://www.toperformance.com.au/why_fs.html - click on faq
(http://www.toperformance.com.au/why_fs.html)

No, they were never run "full soft" nor have they been excessively adjusted. Usually they are left 1/2 turn from soft for winter and changed to 1 turn from soft for summer driving. As supplied by Dinan, the adjusters were 3/4 turn from soft.

Maybe Konis are the best shocks. It doesn't change the fact that I have to mess with my suspension again and in winter to boot. If I have to take both dampers out and send them for re-build I'll be without wheels as this is my daily driver.