I have heard this is an issue on 4.0 V8s, I plan on looking at a 740 today as a last minute challenge entry, ad states "needs a tune up", owner adds it has a miss. Could the miss be the dreaded Vanos issue or just a vacuum leak.
Owner was not able to advise if miss was at idle or under load?
My Mark VII idle/part throttle issues have been sorted and it runs great. 
It's still waiting for a new owner. 
My (non-vanos) 540i had a bad COP that caused a misfire for a bit. I think VANOS issues present themselves as a rattle.
A rattle is one type of VANOS problem, poor cold running and hesitation at low rpm is a different VANOS problem. If it's for the Challenge, neither would concern me much.
If the packaging of the engine is anything like my M5, simply changing spark plugs is a surprisingly serious job. I think a big part of that is the M5-specific intake, though.
In reply to The_Jed:
Is it in Gainesville for under $2k, if so let's talk
What year is it? Isn't that engine known for the nikasil liner issue?
Keith Tanner wrote: A rattle is one type of VANOS problem, poor cold running and hesitation at low rpm is a different VANOS problem. If it's for the Challenge, neither would concern me much. If the packaging of the engine is anything like my M5, simply changing spark plugs is a surprisingly serious job. I think a big part of that is the M5-specific intake, though.
540i plug changes are not difficult, it's the m5 intake. Coils burn out on those pretty often.
4.0 (M60) doesn't have Vanos. The 4.4 (M62) found in post 95 740s do have Vanos.
Could just be a bad coil
nedc wrote: 4.0 (M60) doesn't have Vanos. The 4.4 (M62) found in post 95 740s do have Vanos.
It's a 98
In reply to aussiesmg:
Crap, sorry. I didn't realize you were already down there, I've been sequestered in a machine shop for long periods of time. It's in Pekin, IL, just Sta-Bil-ized and covered for the winter for $1k.
The_Jed wrote: In reply to aussiesmg: Crap, sorry. I didn't realize you were already down there, I've been sequestered in a machine shop for long periods of time. It's in Pekin, IL, just Sta-Bil-ized and covered for the winter for $1k.
That leaves $1k in his budget to get you & the car down there, and you back home. 
Did some looking for you and the MAF is a common failure point and they are not horribly expensive at under $150. No Vanos in the 98. That wasn't till 99. So I would look at coils and MAF. Coils run about $50-60 a pop.
In reply to petegossett:
I like the way you think. :)
2002maniac wrote:nedc wrote: 4.0 (M60) doesn't have Vanos. The 4.4 (M62) found in post 95 740s do have Vanos.It's a 98
The '98 M62 engine does NOT have VANOS. That is only in the '99-01 M62TU engine. So no pre-facelift car ('95-98) has it. And VANOS going bad shows up as a rattle, but not a miss, in the '99-01 cars. A miss could be sparkplugs, coilpacks, or fuel injectors. None of which are expensive or hard to deal with.
In reply to Chris_V: You're right...my bad. I'm an E32 guy, not really up on the E38s.
bmw88rider wrote: Did some looking for you and the MAF is a common failure point and they are not horribly expensive at under $150. No Vanos in the 98. That wasn't till 99. So I would look at coils and MAF. Coils run about $50-60 a pop.
The M5 guys blame the MAF for everything from a miss to dull paint. In my experience, they're wrong approximately 100% of the time. But it could happen.
There's a VW (I think) replacement that's inexpensive.
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