Motorraum: VANOS noise fixed.......but another problem.

[Glacier]

I think you mean 'synchronized' cylinders.

No INPA laptop I'm afraid. Surely BMW DIS would have found something like incorrect timing in the cylinders?

The coils were OEM BMW.

Yes the 'before' cat sensors are important as you say but, I think there would be a fault code if one was broken.

New valve cover gaskets went on.

Again, if the MAF was suspect I would expect a fault code.

But there aren't any : No

Thanks for your input.

[memyselfundich]

you don´t need a fault code for the component for not working as fast / accurate as it could. Might not be enough to pass the threshold for the error to be logged, but still might cause erratic problems... I drove around with that defect coil, and was getting really annoyed with the lumpy ride - and I didn´t have any fault codes either. I just switched the Spark plugs from ngk to bosch and thought the spark plugs where crappy...

What gaskets haven´t you switched yet? Air intake gaskets? Have you resetted the adaption stuff, and driven for 30 or so miles?

[McTube]

Zitat von Glacier

But there aren't any : No

Do not ever overestimate diagnostics. There is a bunch of things it will not see, but an experienced mechanic will....so I agree with the above answers.

[Glacier]

Yes, you are probably right.

The air intake manifold gaskets were done at the same time as the PCV valve, and I checked for vacuum leaks by spraying brake cleaner all around the engine to see if there was a change in the idle........nothing.

When I tried to reset the adaptions there was a message saying "Module not responding". Even so, I have driven about 300 miles since the re-timing so I would have thought the DME would have learned the adaptions by now.

I wonder if there is a burnt valve or something?

Oh well, I'll keep trying to find what's wrong and will report back if I find anything.

Many thanks again for all your suggestions.

[macgyver52]

Hi Glacier,
it looks like i have the same problem with my 740i.
It also has the startup rattle, but i try to ignore it until it gets worse.
The more annoying problem is the vibrating engine in the same rpm range.
Do you or anyone have a solution by now?
I checked nearly everything, but i can´t find the reason.

[Glacier]

Hi Stan,

not sure but, I think the startup rattle is caused by the oil draining from the vanos units, No.1:

 RealOEM.com BMW E38 740i timing gear timing chain top - VANOS

When I changed the the two units I also changed the oil check valves, No.8:

 RealOEM.com BMW E38 740i Cylinder Head Attached Parts

So, I'm not sure if it was the check valves, vanos units or a combination of both that cured the startup rattle. The vanos units change certainly fixed the ticking/tapping diesel-like noise

I did as 'Memyselfundich' suggested and got myself INPA. Here are some live data pictures of the cylinders:













I'm not sure what all that means so, maybe some of you German experts could confirm that they don't look too bad. Or do they seem not to be very well synchronized?

Now.......... I have been doing more investigating and I found that these parts on the nearside rear wheel have some play in them, No.2 & 5:

 RealOEM.com BMW E38 740i REAR AXLE SUPPORT/WHEEL SUSPENSION

When the wheel is rocked at 12 & 6 o'clock there is about 1/4 inch movement. Nothing at 3 & 9 o'clock.

So, I have come to the conclusion that maybe I have been looking in the wrong place all the time! Most probably I did time the engine correctly and, by a crazy coincidence at that exact time, the rear balljoint started to make the car feel lumpy? And that's why I wasn't getting any fault codes from the engine.

Of course this is all guesswork until I have changed the offending parts. I may as well change the other rear bits too and I have got the parts from good old Ebay-de:

 REP SATZ QUERLENKER_HA 7ER E38 KOMPLETT 10-TEILIG NEU! on eBay (end time 14-Mar-11 13:00:40 GMT)

Waiting for this:

 Advanced Keyword Product Search --- Sealey & Draper Tools - CCW-Tools

More expense!

I will report back on my findings.

[memyselfundich]

The Rear axle parts are a piece of crap... they will be worn out in about 5000 kilometers..

The Idle doesn´t look tooo bad. just that they are off is bit strange, they should be the same.

What else have you replaced?

[Glacier]

Zitat von memyselfundich

The Rear axle parts are a piece of crap... they will be worn out in about 5000 kilometers..

The Idle doesn´t look tooo bad. just that they are off is bit strange, they should be the same.

What else have you replaced?

Two years ago I did the front end suspension arms with parts from ATP and they seem to be holding up ok, so I thought I'd get the rear parts from them too. Oh well, if they don't last, at least I'll know how to do it again then.

Besides the vanos units, I haven't replaced anything else.

Has anyone got any INPA live cylinder data to compare with mine?