knock/tap from top of engine (kv6)!!

Nelspeth · 21st March 2010, 17:10

Hi folks, im in much needed help with this noise on my engine! I bought my ZT about 6 weeks ago with this noise....its a knock/tap from the top of the engine, quite hard to pinpoint though! sounds like its a worn cam or slack tappet.
Now i have already had quite a few opinions on it, most thinking either Inlet manifold or cam/tappet fault, i have just had the front cam cover off and the cams look fine, as do the tappets!!....no ware at all.
I personaly think the noise is to heavy to be an inlet manifold...so now im stuck!!

Any ideas???...

Paul...

markb63 · 21st March 2010, 17:14

vis valves or buterfly sticking , search site as there is a how to check and change them not cheap though £ 100 approx each one x 2 if new needed ........

Cymrudragon · 21st March 2010, 17:24

Check the butterfly valves, take of the motor and wiggle the plastic bar that is attatched to them if they are loose or have become worn you will tell or place a ear on top of the manifold adjasent to the vis motor and you can lisen to them rattle also do the above (post)

Nelspeth · 21st March 2010, 17:49

As said before, the noise sounds to heavy and loud for an inlet manifold.....im not dismissing it !! but is there any other problems people have had that cause this noise!

I know for a fact that both VIS motors are goosed....but im just not convinced the noise is from the manifold....its just too loud

Cymrudragon · 21st March 2010, 17:56

Trust me if they are loose you will tell as you have said the motors are shot so 99% of the time its the manifold, but without hearing it

take it off and have a good look you must have had it off to get to the cam. and the sound of the rattle is like spoons in a blender, yip that loud

What would i do? buy a second hand unit with motors as i have already done this prob solved . cant think of anything else sorry mate.

Nelspeth · 21st March 2010, 18:02

Cheers Cymrudragon.....looks like im just gonna have to bite the bullet and get myself a new manifold, really dont want to buy a 2nd hand one tho....how long will that last???

Paul...

T-Cut · 21st March 2010, 18:02

Quote:

sounds like its a worn cam or slack tappet

Look up 'Slack Tappet Simulator' in the Advanced Search facility. I think that will set your mind at rest.

TC

stocktake · 21st March 2010, 18:06

Pretty certain this is nothing to do with inlet manifold, VIS motors or slack tappet simulator, it's more of a knock, sounds very mechanical. Ear and screwdriver test indicated front bank

Cymrudragon · 21st March 2010, 18:22

Innlet /outlet valves?

what else could it be if you are saying front bank? he has had the cam off.

Nelspeth · 21st March 2010, 18:38

This is what i mean....its not a piston knock, noise is to high pitch and from the top of the engine!
Iv just put some Wynns tappet/hyd lifter treatment in!! see how it goes!

Paul..

21st March 2010, 17:10	#1
Nelspeth Regular poster MG ZT190+ Join Date: Feb 2010 Location: Cheadle Hulme Posts: 94 Thanks: 0 Thanked 1 Time in 1 Post	knock/tap from top of engine (kv6)!! Hi folks, im in much needed help with this noise on my engine! I bought my ZT about 6 weeks ago with this noise....its a knock/tap from the top of the engine, quite hard to pinpoint though! sounds like its a worn cam or slack tappet. Now i have already had quite a few opinions on it, most thinking either Inlet manifold or cam/tappet fault, i have just had the front cam cover off and the cams look fine, as do the tappets!!....no ware at all. I personaly think the noise is to heavy to be an inlet manifold...so now im stuck!! Any ideas???... Paul...

21st March 2010, 17:24	#3
Cymrudragon I really should get out more....... MGZTT2.5 V6 190+ SE 2002 Join Date: Oct 2009 Location: Gilfach-goch Posts: 2,201 Thanks: 0 Thanked 8 Times in 4 Posts	Check the butterfly valves, take of the motor and wiggle the plastic bar that is attatched to them if they are loose or have become worn you will tell or place a ear on top of the manifold adjasent to the vis motor and you can lisen to them rattle also do the above (post) Last edited by Cymrudragon; 21st March 2010 at 17:31..

21st March 2010, 18:06	#8
stocktake Vis Whiz Rover 75 2.5 auto Saloon Join Date: Jun 2007 Location: LEEDS Posts: 20,597 Thanks: 2,057 Thanked 3,056 Times in 1,621 Posts	Pretty certain this is nothing to do with inlet manifold, VIS motors or slack tappet simulator, it's more of a knock, sounds very mechanical. Ear and screwdriver test indicated front bank __________________ Dave... Lost a few stones and a Gall Bladder and part of a bile duct and all of my dignity in the suppository incident

21st March 2010, 17:14	#2
markb63 Avid contributor MG ZT 190 + Join Date: Feb 2010 Location: longbridge ( birmingham ) Posts: 246 Thanks: 0 Thanked 0 Times in 0 Posts	vis valves or buterfly sticking , search site as there is a how to check and change them not cheap though £ 100 approx each one x 2 if new needed ........

21st March 2010, 17:49	#4
Nelspeth Regular poster MG ZT190+ Join Date: Feb 2010 Location: Cheadle Hulme Posts: 94 Thanks: 0 Thanked 1 Time in 1 Post	As said before, the noise sounds to heavy and loud for an inlet manifold.....im not dismissing it !! but is there any other problems people have had that cause this noise! I know for a fact that both VIS motors are goosed....but im just not convinced the noise is from the manifold....its just too loud

21st March 2010, 17:56	#5
Cymrudragon I really should get out more....... MGZTT2.5 V6 190+ SE 2002 Join Date: Oct 2009 Location: Gilfach-goch Posts: 2,201 Thanks: 0 Thanked 8 Times in 4 Posts	Trust me if they are loose you will tell as you have said the motors are shot so 99% of the time its the manifold, but without hearing it take it off and have a good look you must have had it off to get to the cam. and the sound of the rattle is like spoons in a blender, yip that loud What would i do? buy a second hand unit with motors as i have already done this prob solved . cant think of anything else sorry mate.

21st March 2010, 18:02	#6
Nelspeth Regular poster MG ZT190+ Join Date: Feb 2010 Location: Cheadle Hulme Posts: 94 Thanks: 0 Thanked 1 Time in 1 Post	Cheers Cymrudragon.....looks like im just gonna have to bite the bullet and get myself a new manifold, really dont want to buy a 2nd hand one tho....how long will that last??? Paul...

21st March 2010, 18:22	#9
Cymrudragon I really should get out more....... MGZTT2.5 V6 190+ SE 2002 Join Date: Oct 2009 Location: Gilfach-goch Posts: 2,201 Thanks: 0 Thanked 8 Times in 4 Posts	Innlet /outlet valves? what else could it be if you are saying front bank? he has had the cam off.

21st March 2010, 18:38	#10
Nelspeth Regular poster MG ZT190+ Join Date: Feb 2010 Location: Cheadle Hulme Posts: 94 Thanks: 0 Thanked 1 Time in 1 Post	This is what i mean....its not a piston knock, noise is to high pitch and from the top of the engine! Iv just put some Wynns tappet/hyd lifter treatment in!! see how it goes! Paul..