180 V6 Engine Noise

[stuamurr]

Hi all got an MG ZS 180 2002 with 72000 miles, and it has started recently making what seems to be a tapping noise at all engine revolutions and temperatures. Im an advanced driver so do maintain revolutions quite high all the time but generally speaking most cars thrive on this kind of treatment. I put in GTX Magnatec to try to lubricate the valves and pistons and eleviate the noise but to no avail. I have also noticed flat spots on several occasions which has required me to fully open the drive to overcome the problem. Another symtom I feel is worth mentioning is I can hear what sounds like the inlet manifold sucking quite hard when at slow speeds. This is my first V6 so not sure what to do next. Your help is much appreciated!

[Rob]

Do a search for VIS valves, and I think you will find the answer to your problem. A common problem with the KV6


By the way

Im an advanced driver so do maintain revolutions quite high all the time.

What? why does being an advanced driver mean this?

[adam6177]

reckon it means he Revs the nuts off it!

[1955diesel]

Originally Posted by Rob

What? why does being an advanced driver mean this?

Because you are taught to keep the engine in the "power band" at all times. It does not mean that you rev the nuts off it, that would go down as lack of mechanical sympathy.

You won't break a K by reving it.

[Junior24]

Stuamurr, have you completed IAM training?
Only ask because I'd quite like to do that...

[stuamurr]

IAM Senior Group Observer and done some RoSPa training too. Also been out with the local traffic cops and Police Class 1 Instructors at Tulliallan Police College in Fife, very worthwhile endevour can honestly say once you have done IAM or RoSPA advanced you are far more confident and alert and your skills are greatly improved. Yeh you are quite correct 1955 diesel I maintain revolutions around the 3-4000 mark most of the time which gives more flexibility and stability when driving.

Originally Posted by stuamurr

I maintain revolutions around the 3-4000 mark most of the time which gives more flexibility and stability when driving.

Don't want to imagine how much this is costing you on fuel.

[1955diesel]

Surprisingly, it makes little difference to fuel consumption or engine wear.

[Rapid Silver]

You will probably find that if it's a constant tapping noise this will be you inlet manifold begining to fail, rather that the VIS valve motors.

This is a known failing on the KV6 and potentially expensive to replace as no-one's currently worked out a successful way of repairing it.

I wouldn't have thought you need to keep driving your car at over 3k rpm all the time, at their is torque at lower engine revs due to it being a V6.

[Grey]

Originally Posted by Rapid Yellow

You will probably find that if it's a constant tapping noise this will be you inlet manifold begining to fail, rather that the VIS valve motors.

This is a known failing on the KV6 and potentially expensive to replace as no-one's currently worked out a successful way of repairing it.

I wouldn't have thought you need to keep driving your car at over 3k rpm all the time, at their is torque at lower engine revs due to it being a V6.

I had this with mine, just after I brought my second ZS180 so it was covered by warranty, around £500 otherwise!

[Spinner]

Lots of threads talk about VIS Valve and Inlet Manifold problems.
Please can someone give me a definitive way of diagnosing which it is, VIS or Manifold? I don't understand how a manifold can "go wrong" to cause a chattering noise (but then I've only ever worked with "simple" engines, many years ago). Also, if I have to get a BBA remanufactured manifold, does it contain the VIS valves, or do I have to get those separately?
Thanks...

[Rapid Silver]

Originally Posted by Spinner

Lots of threads talk about VIS Valve and Inlet Manifold problems.
Please can someone give me a definitive way of diagnosing which it is, VIS or Manifold? I don't understand how a manifold can "go wrong" to cause a chattering noise (but then I've only ever worked with "simple" engines, many years ago). Also, if I have to get a BBA remanufactured manifold, does it contain the VIS valves, or do I have to get those separately?
Thanks...

Vis valve motors are separate from the inlet manifold.
If you have ever seen inside the inlet manifold and how complex it is, you'd understand how they fail due to engine oil mixing with the grease which is present inside as a lubricant for the butterfly valves etc inside.

[Spinner]

Thanks for giving me a clue as to what each does. I have a loud chattering from the left rear of the engine (as I stand at the front). How do I know whether it is the manifold, or the valves?

[shroonie29]

Read this
http://forums.xpowerforums.com/showt...083#post365083
If you feel upto that,
Remove this (pic shows VIS Power Actuator removed) & fix the actuator if it's faulty.Also when the actuator is removed check the arm it atatches to in the plenum moves freely in & out.

A couple of shots of a plenums' internals




Shroon

[Spinner]

Thanks for your pics, now I know what I'm looking for... and the article by Sheddist is superb, thanks for pointing me to that... Will have to take a good look at the motor now, and see what I need.
Sounds as though it should perform like new!
Thanks again...

[stamford]

It sounds as if the actuator arm is failing, quite possible with that year and mileage. What you may have is the spheres in the arm wearing out and being no longer connected to one or more butterflies, hence rattling butterflies and not being held in position when operated by the VIS motor.

Like Shroonie has mentioned, remove the motor unit in question and have a feel for what the end of the arm is doing. If it is free to move in various planes, then it is not fully connected to all 6 off butterflies. If it has a good purchase and only moves left to right, then it may be it had become disconnected from the cam spigot behind the VIS unit, this may be down to the arm getting too tight due to oil contamination and faulty VIS motor.

Mine failed some time ago and it has completey fallen apart and was not connected to any of the 6 butterflies. BBA do not strip the plenum unit as I have been informed from other members on other forums. It is a real pig to work on and a crap design. When I pull my finger out I shall have something available to replace this.

[Craig 180]

well pull your finger out quickly Mick

[stamford]

Seems I have a stalker

[Spinner]

Thanks, Stamford...

Oh dear, so there are more things that can go wrong!

I'm not certain what you meant about BBA not stripping the plenum - did you mean that a "reconditioned" manifold still needs more work doing on it? I saw a reference to them having recon manifolds on the shelf ready to exchange for yours, thought they would bolt straight on?

[stamford]

I don't want to get in too deep with this, but I have been informed that they do not strip the plenum to that level. Quite what they do I do not know.

The plenum is a sealed unit, ultrasonically welded, both VIS motors are bolt on. Some garages say the plenum has gone and replace the whole lot, when infact it may just be one or both motors failing.

The bottom belly plate of the plenum is a real SOB to part cleanly, so quite how they do this without damaging it is beyond me, unless they have new moulded parts made and sacrifice this piece.

The 180 is not all bad, I still love mine, once the silly items have been sorted it is as good as any other in its class.