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Happy Fun Vanos Code 71

2K views 17 replies 4 participants last post by  Sailor24 
#1 ·
Brief summary: vanos was making mild diesel-y noises for the past few months. Recently, the noise got louder on bank 2 (like someone shooting the valve cover with a tommy gun, especially when the engine warmed up fully). Saturday the SES light came on with code 71 (intake camshaft VANOS Position Control , Cyl #5-8) and its friends (8c - too much engine noise, D1 through D5 - misfires on cylinders #5-8).

Obviously I can't wait any longer, so the car is parked until I get this resolved.

Until the misfires started last week, it was running very well apart from the noise so I don't think the solenoids or board have a serious problem.

Last night I replaced the D-rings on bank 2, but the old rings seemed fine and the noise & misfires are still there.

What should I investigate next?

Thanks,
Mark
 
#5 ·
2002. I'll check when I get home.


There is one more symptom I remembered that might be useful and, to a n00b like me, seems maybe chain-related. When I would push the gas pedal to rev the engine, as the RPMs increased the noise seemed a lot quieter. When I let off the gas a second later, the noise immediately came back as the RPMs decreased. I also noticed that the really bad noise went away when I held the rpms steady over 2000 or so.



Thanks!
Mark
 
#7 ·
Yes. I doubt it'll fix your problem. They don't usually fail outright and by the time there's enough slack in the chain to make the noise you describe the chain guides and upper tensioner are destroyed and require replacement.
 
#10 ·
BTW in case anyone is reading this thread - I had bank 1 & 2 reversed. From the driver's seat, bank 1 is on the RIGHT side and bank 2 is on the LEFT.


I think it is time to let my mechanic deal with this problem, TBH. Too bad, I was looking forward to it but I don't have enough time.
 
#11 · (Edited)
You might want to have him pull the lower pan and look for plastic bits first. I seemed to cruel to say this before but letting it get to a mechanic and getting this news would be much crueler. The noise you first ignored was likely your lower tensioner dying this causes slack in the chain and often appears as a vanos code on bank one. If you ignore the noise and code, it will let the chains slap on the guides breaking them to bits, then the chain has huge amount of slack and you will get vanos codes on both banks. Just a guess but I think you are going to be footing the bill for timing chain guide replacement.
 
#15 ·
And Sailor's warning is what I was afraid of. Once it starts making noise, it's "too" late. Everything wears out so at some point you're going into the engine regardless.
 
#18 ·
No idea what the cost is. I have only done it once and it took me a long time because I was learning. Think it was 2 weekends, and the parts were outrageous and took a long time to get. You could do the bearings at the same time but that is still a lot more work. You need to drop the subframe and get the upper pan off. These cars are worth a lot more now than when I worked on them. I was throwing motors at them instead of doing guides then disassembling the motor for parts, they are worth more as parts than the price of a good used motor. It is pretty easy to freshen some things up while they sit on the stand. Good motors are worth twice what they were and are very hard to find local.
 
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