Jack-E61

Hi gwf545,

in a first guess I would say, do not worry about much when the noise is only in the warm up phase. I had had this noise in my former E34 V8 for years without any dammages. It was generated by the valve adjustment mechanism which controls the tappet clearance. The oil was too viscous to cushion the space between valve head and rocker arm.
By the way, my old engine swapped did not show this symptom, it urged me at any temperature - but rather being warm than cold - as described before.

Regards

jim_in_calgary

Geez,

This thread is a little scary. This is my first post on this site, and I'm glad I found it before buying a 545i. At least I'l know what to listen for when trading in my 330ci on a 545i.

I believe that what Jack E61 was referring to as "piston tilt", and what many of you are describing is in fact what we refer to in north america as "piston slap". Especially many who have been an owner of a v8 powered 1999 and later GM truck.

For research on this topic please have a look at :

http://www.pistonslap.com

The descriptions like "it sounds like a diesel" until fully warmed up sound really familiar. This site has sound files you can compare to the sound you 545i makes, as well as pictures you can compare to Jack E61's pictures.

On that site, the phenomenon of piston slap is described as:
If you look at the photos on this website, you'll see photos of cylinder bore scoring as well as piston skirt wear like the Jack E61 describes.

I'm interested in hearing more about this. If you can't get any traction with your BMW dealer, I'd have competent independent mechanic inspect your cylinder bores with a borescope for evidence of scoring. This would go a long way towards establishing you have mismatched sizing relative to the cylinder bores and pistons residing therein, and in diagnosing the corresponding noise as piston slap.

I will be watching this thread with interest and wishing good luck to you all.

Jim.

jim_in_calgary

One other suggestion I would like to offer.

In addition to borescope inspection, another method of proving unusual wear in an engine is used oil analysis.

Blackstone labs is a well respected provider of used oil analysis services. This lab has developed a relationship with a company called Dyson Analysis http://www.dysonanalysis.com/pages/1/index.htm.

Dyson analysis, and its owner Terry Dyson are extremely knowledgeable, well respected, and I can say from experience, a pleasure to do business with. If you would like to know more about used oil analysis in general, feel free to explore http://theoildrop.server101.com/cgi/ultimatebb.cgi? which I understand to be the world's largest web forum concerning the study of motor oil.

EBMCS03

So the only way to find out if our V8s are getting slapped is to have them sample the oil?

550i now

mine is quiet. 11,500 miles so far

EBMCS03

I hope it stays quiet... and mine too... TWINS!

Edlee

Sounds shockingly familiar. I have it with my M6 during cold starts. I've heard the noises on the M5s are even worse.

I brought up the matter with with the local dealership and they said its gotta do with the exhaust set-up of the M. Now I know its all BS!!!

I think (at least with the M) the piston or piston rings or other moving parts were purposely made slightly smaller so that the engine does not cease when the engine really warms up to operating temperature. But whats the harm in giving a truthful and reasonable explanation? Why can't our dealers just give us plain facts instead of lies?

jim_in_calgary

I really don't think that BMW would design piston slap into an engine. It is an unwanted byproduct when stroke is shortened and pistons are lightened. Short stroke (increased piston tilt angle) and the necessary shortening of piston skirts (shortening of piston within the bore for the purpose of both shortening the stroke and for lightening pistons) contributes to a piston more likely to "tilt" and cause slap. Inexact piston/bore tolerances exacerbate this problem.

When GM moved away from the tried and tested 5.7L 50 year old small block design to the 5.3L new GM small block design, piston slap was the result.

The only way (of which I am aware) to document piston slap short of tearing down the engine and handing the dealer a scored piston is to document this scoring (on the cylinder bores) with a borescope photo, and as a corollary, a used oil analysis showing elevated wear metals consistent with cylinder bore and piston skirt wear.

In any case, the symptoms you are all describing are consistent with piston slap. So is the acknowledgment of the dealer made when the german fellow received a new engine from BMW.

If this problem exists, you need to arm yourself with the knowledge to enable you to convince your dealer to address it.

Jim

gwf545

Jack,

Thanks for the reply & advice. I will try to not obsess about this. Sometimes it's easy to get worried about "normal" noises, especially when others on the board are reporting similar issues that appear to be more serious.

galenpowers

I am having the same problem. Here is what it sounds like:


Here is what caused it: By the way, the BMW dealer played dumb on this. I have seen very few posts where the intermediate valve levers tsb fixed the tapping ticking problem permanently.

These pictures are tough to digest because they were taken through a small opening next to the oil pump with the lower oil pan removed. The showed scored cylinder walls in cylinder six.

Pause and full screen the video for more detail:



This problem was diagnosed by Autobahn BMW Repair in Louisville Kentucky. These guys are great.