Hello all. I have a few questions. I bought the car and it's been running great for 2 weeks. All of the sudden started it one day and it has a rough idle. No check engine light. No codes being pulled. Just a rough idle almost like a big cam. Also, at highway speeds it's shuddering. But doesn't feel like the transmission feels like power loss. I was gonna change the plugs and realized it's not as simple as I would ha e thought. Can anyone give me advice on removing the intake or changing the plugs. Not sure where to start.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Take it to a professional. 760's are not easy to work on unless you're very mechanically inclined. BTW, if you go to the trouble of changing the plugs, you may as well change all the ignition coils as well. That's probably you're problem anyway. I've fixed a ton of cars with a stutter and no codes by replacing the coils.
ASE and BMW Master Certified Technician
Well. I haven't dabbled into removing the j take just yet. There's not a lot of info on how to diy anything besides the hpfp on this engine lol. I have a shutter under load as well. Pretty sure it's something with the engine because of the rough idle. Haven't ruled out transmission though. I have been working on cars for a bit. I have all the software for bmw as well. I'm not afraid of tearing into anything just don't want to do something unnecessary. Looking into vacuum lines tonight.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
intake removal is not that hard, I recently did a full tune up on mine and replaced the cylinder cover gaskets, hardest part is remembering the routing of the wires I suggest taking pictures cause this is not documented too well. also check your crankcase ventilation hose mine was cracked and was throwing codes, I ended up replacing an O2 sensor for nothing
how many miles do you on yours I had ~84000 miles when I took mine out and they were still good but replaced them with these http://www.ebay.com/itm/NEW-BOSCH-45...72.m2749.l2649
Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
I just rolled over 70,000. That's what's funny I have have zero codes. Nothing is being thrown. I would figure the computer would read the shuttering on the highway and rough idle. But I'm getting nothing. Running through DIS last night there was nothing odd about any readings. Vanos, intake pressure, O2 sensors. Everything is reading fine. I really think it's something vacuum related, but I don't see anything obvious. Are there specific hoses to check? Again, I'm new to the E66 world lol.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Based on your symptoms I would check fuel pressure, there 2 fuel filters and one of them has a regulator
Check out this diagram https://www.realoem.com/bmw/enUS/sho...diagId=16_0544
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Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
According to this document https://www.google.com/url?sa=t&sour...LzFLGo0fi-zkUg from 50 to 120 bar, take a look at this post
https://www.google.com/url?sa=t&sour...dvA1v_c9jGWA-Q. From post #12
Ok. So fuel pressure good everywhere. No codes whatsoever. Plugs and coils changed. New CCV's. Still there.
Any other ideas?
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Well, bought ccv's for the car. Gonna swap those on and see if that helps.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Hello,
I bought my 2004 760LI, changed the fluids & fuel filter so I know where I stand. Someone on Bimmerfest forum or this forum, sent out maintenance manual link. I found a mechanic who is knowledgeable of BMW's & have been taken care of all of the issues I had with my 760. My BMW has not seen the dealer since I had it inspected. The issue you have I had too & so I had the plugs & coil packs changed. Also had the 760 decarbon been running great since.
Manfred E....
2004 760LI
how does it behave if you rev to 2500? do you get the same shudder as when your driving?
Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
I decided to spruce up the intake a bit. I'll post a final product picture once I get it all back together.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
I would say that your rough idle and the shuddering from driving are not related, I'm currently experiencing a similar shudder as what you described I diagnosed it down to the control arm bushing on the driver side and the stabilizer link, apparently if you don't pre-load the suspension when you torque the bolts down the car will chew up the bushing and mess up your alignment royally
20170818_173424.jpg
Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
a few more things to look at
Last edited by sigmaes; 08-30-2017 at 08:39 AM.
Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
Thanks for the info. The suspension is really fresh. Nothing looks out of place. Also the shutter is only under load. If I take my foot off the gas there is nothing. Smooth as silk. It also is fine if not under 2000rpms. Still has me stumped. I replaced both MAFs when I did the plugs. Also check fuel purge valves. No fuel in them.
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Ah ok I misunderstood, mine was the opposite only shuddered when I took my foot of the gas,
Did u get a smoke test yet?
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Last edited by sigmaes; 08-30-2017 at 08:55 PM.
Black 1988 735i - (first car ) ** currently MIA
Silver 2005 X5 3.0 - RIP
Black 1990 750il - junked
Monaco Blue 2006 760Li - Current
I haven't. But I did find some unpromising evidence today. The fuel pump purge lines have fuel in them.....from what I have read this means my fuel pump diaphragm is failing?? Looks like I'll try a rebuild of the diaphragm before looking at pumps!!
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
Hi,
if you have fuel in purge lines, in 99% of this cases are the HPFP (high pressure fuel pump) diaphragms are failing. From your dealer or Bosch you can buy a HPFP unit, but no spare parts, there are not any. But, we have got a solution for this problem. With help of Contitech we've find a suitable material which is able to fix this issue effective. Do not use the magnafuel repair kit, this will fail. If you need a kit, just write me a PN. We've fixed round about 60 cars with this kit (my own included), no failures!
Regards,
Heinrich
Ok. So update. Previously had no codes whatsoever but the rough idle. Idle will now come and go. Be smooth and then rough. I rebuilt the diaphragms in both pumps and now I get a code. 2772 purge valve. And there is a check engine light. So my question is......can they be cleaned or do I need to physically change it? Also had pretty high maf readings. Any insight??
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2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
So i haven't gotten much feedback on this one, but i wanted to share the most recent findiings. I replaced the diaphrams in the HPFPs (both) and the Tank Venitlation lines (both). Previously i had absolutely no codes. Now, i'm getting the following:
2924 - Rail Pressure Control, Bank 2
272C - Additive Mixture Adaptation, Bank 2, Control limit reached
2733 - Fuel mixture adaption, Sumcheck error, Cylinder Bank 7-12 (or bank 2 again)
Any ideas on this?
2001 E38 (Stroker Motor) / 2004 X5 4.8iS / 2006 760Li V12
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