Rattle on Start

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Shoppinit
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Re: Rattle on Start

Post by Shoppinit » Thu Oct 18, 2018 8:38 am

I wouldn't recommend doing that on an RS6 unless you pull fuse 29 first otherwise you'll send lots of fuel into the cylinders. Also, it's likely the car will start after a couple of seconds.

Yeah, 10 seconds max.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
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MeTsU
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Re: Rattle on Start

Post by MeTsU » Thu Oct 18, 2018 9:30 am

Shoppinit wrote:
Thu Oct 18, 2018 8:38 am
I wouldn't recommend doing that on an RS6 unless you pull fuse 29 first otherwise you'll send lots of fuel into the cylinders. Also, it's likely the car will start after a couple of seconds.

Yeah, 10 seconds max.
In my previous post - I took for granted we were carrying on the theme of fuse pulled - apologies, should have stated that. We certainly don't want to bore wash.
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mavada
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Re: Rattle on Start

Post by mavada » Thu Oct 18, 2018 10:57 am

Ok thanks.
Brings up the following question:

When storing the car for months, is it ok to do this once a month or so, to prevent rust/ dry out of parts and seals etc.?
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Shoppinit
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Re: Rattle on Start

Post by Shoppinit » Thu Oct 18, 2018 11:00 am

Yes. You must. Run the engine regularly and get it up to full operating temperature. Also, you should rotate the wheels if you can. If not then over-inflate or use tyre cushions.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Shoppinit
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Re: Rattle on Start

Post by Shoppinit » Thu Oct 18, 2018 1:22 pm

Obviously, do this in a well ventilated area. :|
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Re: Rattle on Start

Post by R5XVB » Thu Oct 18, 2018 8:42 pm

It can be noisy even after an overnight, yes using the correct oil...

Thanks shall look toward the hydraulic tappet as the issue, makes sense.

Appreciated.

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Re: Rattle on Start

Post by PipRS6 » Mon Oct 22, 2018 11:48 am

Mine has maybe a half second of rattle on cold start. It is due an oil change so will be interesting to see if that changes at all...

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Re: Rattle on Start

Post by R5XVB » Sun Nov 11, 2018 5:41 am

Oil change resolved it, also moved onto 5w40 and engine made no rattle upon a cold start.

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Re: Rattle on Start

Post by BreadmoC5 » Sat Nov 17, 2018 9:03 pm

I am having a similar issue to this, getting a good few seconds of rattle on start from cold, trouble is though there is also a misfire at the same time. Having pulled to codes all cylinders on bank one are showing misfire codes. Could this just be tappets also? As the cambelt was done a couple of months ago we have been wondering about the cam chain on the rear of the head. Has anyone on here had cause to replace that chain?

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Shoppinit
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Re: Rattle on Start

Post by Shoppinit » Sat Nov 17, 2018 9:35 pm

I’d definitely want to double check the timing. That could cause misfires.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Re: Rattle on Start

Post by BreadmoC5 » Sat Nov 17, 2018 9:46 pm

Hmm yes, the misfire clears completely quite quickly (20 seconds max) and then she runs well.

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Re: Rattle on Start

Post by Mɐʇʇ » Sun Nov 18, 2018 4:18 pm

I'd be doing a bit more diagnosis - this could be part of the same thing, or 2 seperate issues entirely. How bad a misfire? Are we talking one cylinder, or a whole bank being a bit wobbly?
If you pull the fuse and crank it from cold, does it spin nice and evenly? If you pull the fuse, crank it for 20s, pop the fuse back in and fire it up, does it come up on all 8 instantly......

I do find generally it idle's smoothest about 1 minute after starting, once all the lifters are fully pumped up etc, but also while it's still cold so it's running a little richer. Once they're warm, they run a snifter on the lean side for the nicest idle - which is just a function of the way the intake has a little reversion on a manifold injected V8 - so they really want to idle a little richer than 14.7:1 for the most "V8" noise at idle. Maybe 12 or 13:1. (Which is why they also sound a little nicer when you pop it into drive - puts a little more load on the motor). But it still should come up on all 8 instantly.
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Re: Rattle on Start

Post by BreadmoC5 » Mon Nov 19, 2018 7:58 pm

Cheers, thats all good info for me. I am away now so cannot try cranking with the fuse removed, I have left the car with my local specialist so we shall see what he comes up with. As above though it is showing codes for misfires on all cylinders on bank one. We have been wondering about cam chains as it has (just once) brought up a cam timing code so I wondered if the rattle could be cam chain or tensioner related.

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Re: Rattle on Start

Post by Mɐʇʇ » Mon Nov 19, 2018 9:04 pm

Ah - well I suspect if you've got the codes for multiple misfires on 1 bank, you might have a smoking gun then, in line with Shop's thought above....
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