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Discussion Starter · #1 ·
Only really noticed it yesterday, when being MOT'd. The engine sounds...well... as if the tappets want adjusting or something. I don't know if it has hydraulic or solid tappets or maybe it's the injection solenoids clattering. The noise is masked when you rev the engine and as I generally don't drive like a maniac I really haven't noticed any drop in performance. I certainly haven't noticed it in normal driving and when the bonnet is shut, the sound pretty much dispappears. (Perhaps that's the answer, just shut the damn bonnet!)

The MOT gas test was spot on and the car has only done 33,000 miles from new and is in really nice condition, having been regulary serviced and well-maintained.

Can anyone suggest what may be wrong? Or is it just that these engines sound "tappety"?
 

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Do a search on here for Vis valves. It is a well known issue and does affect performance-but is not terminal..................
 

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Discussion Starter · #3 ·
MikeM said:
Do a search on here for Vis valves. It is a well known issue and does affect performance-but is not terminal..................

Many thanks, I'll stick my head under the bonnet tonight and see if I can pin down where the noise is coming from.

Come to think of it, I have always felt that the engine is not as smooth as it should be, with definite surges and flat spots up the rev range when the throttle pedal is depressed all the way to the floor.

Perhaps this was the cause of the problem all along?
 

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jeenie123 said:
Many thanks, I'll stick my head under the bonnet tonight and see if I can pin down where the noise is coming from.

Come to think of it, I have always felt that the engine is not as smooth as it should be, with definite surges and flat spots up the rev range when the throttle pedal is depressed all the way to the floor.

Perhaps this was the cause of the problem all along?
Your description sounds exactly like vis valve problems. A dealer might recommend a complete new manifold at scary prices but often fitting two new vis motors (an easy diy job) sorts it out.

There are two vis motors, both on the lh side of the engine looking from the front. One is a black box sitting on top of the manifold end and the other is a black box right behind against the bulkhead. This pic shows one ringed in grey, the other is behind it.

hth

Mike

 

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Discussion Starter · #5 ·
Although I haven't got matchstick arms and an eye on the end of each finger, they look reasonable to change, many thanks for the cracking picture. I must say that responses such as this give a nice warm feeling that I'm not alone!

Thanks again, I'll post when I have sussed out the source.
 

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Discussion Starter · #6 ·
jeenie123 said:
Although I haven't got matchstick arms and an eye on the end of each finger, they look reasonable to change, many thanks for the cracking picture. I must say that responses such as this give a nice warm feeling that I'm not alone!

Thanks again, I'll post when I have sussed out the source.

Just used a really nice acoustic diagnostic tool with headphones on the inlet manifold area. The idle valve does rattle but after disconnecting it, it wasn't the source of the tappety noise. Putting the probe on the top of the inlet manifold and it was a different story. Metallic plinking noise as if something's loose inside. Not so prevalent on the aft inlet box, though. Whatever is rattling is definitely inside the manifold.

So can anyone tell me exactly what happens when the VIS motors fail? How are they connected to the kit inside? Presumably the rattling is caused by wear in the linkage or connection to the motor because I don't understand how it can rattle otherwise.

Incidentally, I have had quotes of £52.97 and £51.58 + Vat for the motors this morning from the local dealer. Haven't broached the subject of an inlet manifold yet.
 

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Depending on what year your car is, I believe there was a design fault with the manifolds on cars prior to about late 2001 where there is a metal butterfly inside the manifold which rattles and seems to be related also to the VIS valves.I had the same issue and replacement manifold has rectified the fault and as such most dealers will replace the manifold complete as it incorporates new VIS valves with it and solves it all in one go. Not cheap though. As Mike says, have a look at the forum and you will find out anything and everything you need to know about the VIS issue .By the way Mike, how come you have a different coloured oil filler cap? Mines yellow like the dip stick ?
 

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Discussion Starter · #8 ·
genpk said:
Depending on what year your car is, I believe there was a design fault with the manifolds on cars prior to about late 2001 where there is a metal butterfly inside the manifold which rattles and seems to be related also to the VIS valves.I had the same issue and replacement manifold has rectified the fault and as such most dealers will replace the manifold complete as it incorporates new VIS valves with it and solves it all in one go. Not cheap though. As Mike says, have a look at the forum and you will find out anything and everything you need to know about the VIS issue .By the way Mike, how come you have a different coloured oil filler cap? Mines yellow like the dip stick ?

My car is April 2002 so I suppose it could have been produced earlier? Not looking forward to replacing an inlet manifold though which was why I asked just how the motor is connected to the valve, in order to make a better assessment. I don't want to throw money away by buying VIS motors if it's a manifold problem and unless someone can tell me what I need to know then gut instinct says it's a worn internal linkage.
 

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Discussion Starter · #10 ·
ZTalker said:

Superb ZTalker! Just the kind of thing I'm looking for. Seems just changing the VIS motors without a bit of cleaning up may only stave off the inevitable motor burn out again. Of course, my motors may not be burnt out at all, I may just give it a good old clean/lube up to see if it makes any difference. I have noticed the engine is not smooth throughout the rev range and clagged up linkage/butterflies/slides may well be the cause.

I'm not a tight bugger but it's my only mode of transport and the missus gives me grief if she can't use it so I have to get things right first time!
 

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Cannot see vis motors curing the rattle tbh. I will rectify the flat spots you describe. Imo a manifold change is the way to go. It comes complete with motors but cost around £440 + fitting.
 

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Jeenie what Lates is saying is if you are not a million miles from Coventry that perhaps you ought to nip down to his workshop for some friendly diagnosis and a quote.
 

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Discussion Starter · #13 ·
lates said:
Cannot see vis motors curing the rattle tbh. I will rectify the flat spots you describe. Imo a manifold change is the way to go. It comes complete with motors but cost around £440 + fitting.


Yup, I hear what you're saying and it has to be said I remain sceptical too but it has to be worth a shot at removing the motors, giving it a good coat of looikng at and a good clean up first. Obviously if the VIS motor slides are worn then it could well cause the linkage to rattle.

Welll there's nothing else for it but to dive in over the weekend and have a go. I'll be back to post when I've done to let everyone know what I've found.

Bye for now.
 

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Have fun, while you take out the balance motor ( one the end ) remove the plastic butterfly from the manifold and make sure it doesnt jam in the shut position. Clean the edges with a bit of emery paper ( not too much tho ) and give it another whirl. Remember to do all this with the ignition off to prevent fault codes being store in the ecu.
 

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MikeM said:
Your description sounds exactly like vis valve problems. A dealer might recommend a complete new manifold at scary prices but often fitting two new vis motors (an easy diy job) sorts it out.

There are two vis motors, both on the lh side of the engine looking from the front. One is a black box sitting on top of the manifold end and the other is a black box right behind against the bulkhead. This pic shows one ringed in grey, the other is behind it.

hth

Mike
Strewth that is a big picture Mike! what level of subsription do I need to post Pics other than thumbnails or am I doing something wrong?
 

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Keith Alexander said:
Strewth that is a big picture Mike! what level of subsription do I need to post Pics other than thumbnails or am I doing something wrong?
He's hosting his pics elsewhere and linking to them, in this case midnightphotos.co.uk, you are using the uploader on this site, that's all.

MM
 

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Had my manifold changed under warranty some time back, but still notice a rattle on acceleration and definite flat spots at low revs. Definitely not as responsive as I'd like.
 
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