How smooth and how quiet for VR6?!

[jamiehamy 0]

I might be getting slightly OCD with this, but I want my Corrado to run as smoothly and quietly as possible.

 

I've done the chains, tensioners and lifters and the engine performs well, no issues at all HOWEVER

 

Idle when warm is always seems less smooth than when cold

There is always some 'chatter' from the engine when you rev in neutral.

 

 

In terms of idle, how smoothly do the VR6's actually run? There is no lumpiness or anything like that, more of a faint judder ( like that moment in Jurassic Park actually where you see the water in the glass shake!). Is this normal or can I try and get it smoother? Timing is spot on as I re-checked when I did the lifters at the weekend.

 

In terms of valve train noise, will it ever be as silent as a modern V6 or Japanese car?

 

Any thoughts are welcome, even if it's just to tell me they are old engines and just calm down!

 

Cheers, J

[CazzaVR 0]

To be honest, mate, that sounds about right for a VR6 idle. You always feel a faint judder in the seat of your pants (:lol:) at idle, even though the needle may be stock still. Don't worry about it!

[dr_mat 0]

My own observations after 7 years of (ageing) Corrado VR6 ownership are pretty much this:

- idle is lumpy when the engine is "hot". (Stuck in traffic in the summer, kinda thing)

- idle is lumpy when the engine has done a lot of short journeys

- idle is lumpier when fully adapted, than when you reset the ECU and it's running rich

About the only times it'll idle butter-smooth are after a good long cruise where you're able to drive the car gently to temperature and heat soak doesn't settle in, or when you've just started it cold and it's chucking so much fuel in the exhaust fumes would kill you in one go.

 

As for the clatter .. they all seem to do that, to some extent. You've had all the right bits done, (well, you missed out the oil pump drive gears, but depending on who did the work they might have done that at the same time). And no, it'll never be as smooth as a modern v6... :)

[dan 0]

I've heard a few Golf VR6's idle and they are a lot smoother than the C... if that makes you feel any better :)

[RW1 0]

Mine runs very quietly, idles smoothly and is quiet, not chain or tappet noise at all temperatures.

 

Castrol Magnatec 15w40 oil, Texaco 97 petrol and standard VW paper air filter. 34mpg. Basic settings done. And has that nice VR6 burble at low rpm and VR6 roar at higher rpm they were built with :D

 

(Tesco 99 for a couple of tank fulls recently, the idle was lumpy and the engine always sounded like a grinding machine. :cuckoo: .

Also, use to use a K&N panel filter in the airbox. That caused problems with oiling the MAF which caused rough running.)

 

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[jamiehamy 0]

Ah!

 

Thanks for the responses, much appreciated!

 

Dan - I'm so glad you said that about Mk3's. I've always thought that but wasn't sure.

 

Dr Mat - I did the work myself, so never did the oil pump drive gears, I take it it's worth doing?

 

RW1 - I'm starting back on Shell as I had suspicions of Tesco fuel! Only thing i can't do is the basic settings. I get 35mpg easy tho, so can't be too important?

 

Thanks, J

[dr_mat 0]

Mine has 139,000 miles on it, fwiw, and has never been apart. I expect clatters and knocks ..

[Mawrick 0]

I have been wondering the same thing about mine - but it seem to be that way.

 

What annoys me about it that my mighty old Passat VR6 idle much smoother.......that's a distributor engine and not a coilpack engine like the one in the C - if that makes any difference.....:)

[Purgatori 1]

Mine is a little clattery when cold and a bit lumpy when she's been sat in traffic for a while, but other than that she runs nice and smooth. I use Castrol 15w40 for engines that have done over 75k and fill up with BP Ultimate which she seems to run really well on. I'm under no illusions that she runs as smoothly as a modern car, but for her age I think she runs pretty smoothly.

Maybe we could link video on here so you can hear the engines, that might help??

[jamiehamy 0]

that would be good, hearing how difference healthy engines sound. I'll go up to 15w40 at next oil change.

 

Defo strange that Mk3's and dizzy models appear to be smoother. Does anyone know if doing the Basic Setting on the ECU has a big effect?

[RW1 0]

Its subtle, most noticeable effect is the throttle control near idle is better.

 

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[dr_mat 0]

It'll only have an effect if there was something wrong with the previous adaptation! In principle the ecu is supposed to adapt to the engine all the time, and will hone its tuning every time the crank turns.

It will learn more quickly by doing the basic settings procedure, but it's only usually worthwhile when you have made major changes to the engine in a short period of time.

[RW1 0]

True of the Lambda probe but not the throttle. That requires Basic Settings to be engaged.

 

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[Yandards 0]

Another option is to consider the DG Autotech chip remap, most VR6 owners report better idle behaviour and smoother power delivery with the flat spots removed.

 

If you really want to go crazy then the same thing can be said of switching to the MK 3 Golf style OBD2 engine managment, this uses an idle stepper motor instead of an ISV and again the reports from people that have had this done lean towards smoother idle, increased fuel economy and driveability.

[VRTrickster 0]

Im obd2 and I cant say my idle is that much better, but it does run a lot better for sure. I to have been chasing a smooth idling VR, but Im now coming to terms of the fact that I am asking for too much.

 

My idle is lumpy, like has been said when hot. It sort of pulses if anyone knows what I mean?

 

I also think that the cams, light flywheel and stiffer engine mounts contribute to this?

[andy 0]

I rebuilt a VR6 top end and chains a few years back, new valves, guides, seals, tappets, injectors cleaned, mounts, chains and tensioners replaced. I can honestly say that is the smoothest VR6 I have come across, it was as good as you could ever hope for. After the new tappets had pressurised for the first time and the clatter had faded (nervous time!) she settled down into a really good solid stable idle. You could hardly feel it running by putting a hand on the engine cover. I have since felt another one that had the same work done and it was similar (not quite as good though!). Certainly my VR is nowhere near that smooth at idle, but I know one day, when its rebuild time, it can be.

[Yandards 0]

Im obd2 and I cant say my idle is that much better, but it does run a lot better for sure. I to have been chasing a smooth idling VR, but Im now coming to terms of the fact that I am asking for too much.

 

My idle is lumpy, like has been said when hot. It sort of pulses if anyone knows what I mean?

 

I also think that the cams, light flywheel and stiffer engine mounts contribute to this?

 

Yes, the tweaks to both the cams and flywheel will affect the idle note considerably, stiffer mounts should have no effect on the smoothness of the idle but will provide more feedback of the engine noise than stock mounts.

[vornwend 0]

Would fuel injectors be a factor? Ultrasonic cleaning? Last time I was at D&G we discussed this as a non critical option

[Kevin Bacon 5]

The orginal VR6 injectors are 30 years old in terms of their design. Even new or reconditioned their atomisation compared to a modern injector is poor. But they do the job. Big improvements can be made to the VR6 using modern management, injectors, coils and a better map etc etc.

[herisites 0]

more of a faint judder ( like that moment in Jurassic Park actually where you see the water in the glass shake!). Is this normal or can I try and get it smoother?

 

How old are the engine mounts? Are they genuine? I recently replaced my gearbox mount from a nackered old GSF mount to a new genuine VAG mount (pricey but worth it!) and the idle is a LOT smoother than it was. Ok mine is an R32 but Kev's found the same with his VRT. New engine mounts make a big different to the smoothness of the engine IMO!

[dr_mat 0]

And using genuine VW ones helps a lot in the smoothness stakes.. Maybe not for ultimate stiffness but they are better at damping the vibrations.

[herisites 0]

And using genuine VW ones helps a lot in the smoothness stakes.. Maybe not for ultimate stiffness but they are better at damping the vibrations.

 

Definitely! I had a GSF gearbox mount on mine, and it lasted less than a year. I was getting vibrations on idle and part throttle (traffic etc), juddery clutch and notchy gear change. Fitted a VT one I had lying around, the gear change was a lot better and power delivery felt tight etc but the car would vibrate a LOT on idle. Now bit the bullet and fitted a genuine VAG one and it's smoooooooth :clap:

[big ben 10]

i need new mounts all round really, vf engineering mounts are the hardest things going :(

[RW1 0]

The ideal compromise is to fit the rear two mounts as standard VW and a stiffer mount at the front centre like Vibra-Technics 950m (VR6).

 

The reason for the stiffer mount is to assist the gear changes. The standard VW unit flexes too much and as a result the cables in the gearchange get jammed inside the cable sheaths. This happens when the engine is under a lot of load such as 1st gear / full throttle. Vibration feedback through the 950M is minimal.

 

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[big ben 10]

i am defo getting vibra technics, crazy dave took me out in his VRT and it was best of both worlds :D