Engine Rattling/Tapping

[MattX2C]

Hi all,

I have done some searches over the internet and forums about this but thought I would make a post about it.

I picked up my ZS180 a week ago and plan to get it serviced pretty some as its due the cambelt change.
Anyway, the first couple of days were fine, but recently I have noticed a tapping/rattling coming from the engine both at idle and in gear.

From what I have read it could be;

Loose manifold heatshield,
Broken Manifold,
Failed VIS,

what is the VIS unit?

Is there anything else it could be? Any DIY things to try to solve it?

Is it just a case of tightening a bolt up, or does the heatshield need to be welded?

Any advice would be great.

[Maxxed_Ross]

first off, welcome to the site! If you've a problem that needs sorting this is probably the best place to be


After it was serviced did you check that they put the right amount of oil in? Sounds silly but I have heard some horror stories of garages making a mess of simple stuff

Don't suppose you know what type and weight of oil they used?

[MattX2C]

Originally Posted by Maxxed_Ross

first off, welcome to the site! If you've a problem that needs sorting this is probably the best place to be


After it was serviced did you check that they put the right amount of oil in? Sounds silly but I have heard some horror stories of garages making a mess of simple stuff

Don't suppose you know what type and weight of oil they used?

Thanks for the quick reply.

It hasn't been serviced yet, I am going to get one done asap.

If it was low on oil, would it cause the tapping? Wouldn't the warning light come up?

Also maybe something to note, there doesn't seem to be any noticeable lack of performance. I am generally being quite careful but I wont lie, I have put my foot down and it goes as expected really.

I guess the first thing would be to get under the car and check the manifod heatshield. Its just a pain with it getting dark well before I even get home from work.

[stamford]

A hard one to diagnose correctly without being 'there' to hear it. The only way to know for sure is to either hear it close up or get a sound clip uploaded. Could be any of the items you mentioned, depending upon the level of degradation.

and to our world

[Maxxed_Ross]

Originally Posted by MattX2C

It hasn't been serviced yet, I am going to get one done asap.

my mistake, I ready that part of the post a bit too quickly

It may be due to the level of oil, but it it has only just appeared then probably not. You tend to notice taps and rattles after a service if the wrong type of oil, or not enough, has been used. Engine flushes can also cause tapping as it can strip away some of the protection on moving metal parts

I think your self diagnosos sounds to be the most accurate. I could well be manifold related. If you're not niticing a difference in performance it's unlikely it's the VIS motor. You do feel a considerable drop when that stops working

[MattX2C]

What does the VIS actually do out of interest?

Heard it mentioned on ZS related sites, but never heard of them being on any other car!

I'll have a closer listen tonight and try to eliminate obvious things first.

The vis motors are located to the left of the engine bay as you look at the engine and are attached to the inlet manifold if the rattle is coming from that area of the engine bay then it's more likely likely thats were the problem lies there are loads of threads on loads of sites explaining what vis motors are and their function and also possible repairs there is also a valve on the right hand side of the inlet manifold near to the throttle body which rattles as well but is totally normal.


And may i add Weclome to the site.

[stamford]

Variable Intake System (VIS)

Two separate electric motor housings that are known as the 'balance valve' and 'power valve'.

The balance valve controls the opening of the inlet tracts from the throttle body of which there are two main plenums. The power valve operates an actuator arm that in turn opens up 6 of butterflies that give you the kick at around 3k.

If you were to fit a home made VIS indicator system you would see these opening and closing and this always serves a useful purpose in being able to see what they are doing, or in some cases not doing!

[Maxxed_Ross]

Originally Posted by MattX2C

What does the VIS actually do out of interest?

Heard it mentioned on ZS related sites, but never heard of them being on any other car!

As said they vary the intake system slightly to alter the power curve at certain RPM's. One in the middle and one quite near the end

It's roughtly similar to the Honda Vtec system... sort of

[carmadbaker]

Originally Posted by MattX2C

What does the VIS actually do out of interest?

Heard it mentioned on ZS related sites, but never heard of them being on any other car!

I'll have a closer listen tonight and try to eliminate obvious things first.

where bouts are you in the UK matey? if your close to a member on here.....run round to his/her place and im sure they would notice a manifold rattle a mile off probably all been there before