Tappet noise on KV6 normal after many years of non-use?

john116 · 6th November 2019, 05:32

My 2001 75, with 2.5 litre KV6 engine, hasn't been driven for about 5-6 years. Is it normal that it would have some tappet noise. I've only just started it for the first time since a cambelt change, and while it made the tappet noise when I first bought it, after a 20km drive home, it had stopped. It's now back. I have yet to drive it anywhere though as yet.

John

coab · 6th November 2019, 06:13

Drop half a bottle of engine flush in, let it idle until it gets red hot. Then change the oil when it has cooled enough not to scald you. Then refill with a decent quality oil and change the filter.

Take it for a spin and let the new oil work its way around the engine.

T-Cut · 6th November 2019, 08:56

The tappets in the K16 and KV6 engines contain a hydraulic mechanism a bit like a tiny piston inside the large outer cylinder which the cams act upon. To operate smoothly, the inner mechanism must be hydraulically locked with oil. There's a tiny ball valve that allows oil to circulte through the inner tappet. I guess a very long period of inactivity will allow oil to drain out of the tappets. When the engine's started like this, the tappets will be rather noisey until the hydraulic lock is re-established. Only running the engine will recover the problem.

Also note that after a layup, the fuel vapour canister under the rear end will be saturated, so as soon as the engine runs, the ECU will trigget the canister purge valve to operate. On the KV6, the purge valve is mounted on the upper inlet manifold, which acts like a sound amplifier. The solenoid valve emits a quite loud tapping noise that's often thought to be a noisey tappet. This noise will also stop as the engine gets into its normal running condition.

TC

6th November 2019, 05:32	#1
john116 Avid contributor Rover 75 Saloon Join Date: Nov 2018 Location: Sydney Posts: 176 Thanks: 82 Thanked 41 Times in 21 Posts	Tappet noise on KV6 normal after many years of non-use? My 2001 75, with 2.5 litre KV6 engine, hasn't been driven for about 5-6 years. Is it normal that it would have some tappet noise. I've only just started it for the first time since a cambelt change, and while it made the tappet noise when I first bought it, after a 20km drive home, it had stopped. It's now back. I have yet to drive it anywhere though as yet. John

6th November 2019, 08:56	#3
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The tappets in the K16 and KV6 engines contain a hydraulic mechanism a bit like a tiny piston inside the large outer cylinder which the cams act upon. To operate smoothly, the inner mechanism must be hydraulically locked with oil. There's a tiny ball valve that allows oil to circulte through the inner tappet. I guess a very long period of inactivity will allow oil to drain out of the tappets. When the engine's started like this, the tappets will be rather noisey until the hydraulic lock is re-established. Only running the engine will recover the problem. Also note that after a layup, the fuel vapour canister under the rear end will be saturated, so as soon as the engine runs, the ECU will trigget the canister purge valve to operate. On the KV6, the purge valve is mounted on the upper inlet manifold, which acts like a sound amplifier. The solenoid valve emits a quite loud tapping noise that's often thought to be a noisey tappet. This noise will also stop as the engine gets into its normal running condition. TC Last edited by T-Cut; 6th November 2019 at 09:00.. Reason: Only one 'n' in canister TC.

6th November 2019, 06:13	#2
coab This is my second home 2007 57 GOLF GTi EDITION 30 DSG Join Date: Nov 2011 Location: Newport Shropshire and Coventry. Posts: 5,138 Thanks: 2,424 Thanked 1,452 Times in 852 Posts	Drop half a bottle of engine flush in, let it idle until it gets red hot. Then change the oil when it has cooled enough not to scald you. Then refill with a decent quality oil and change the filter. Take it for a spin and let the new oil work its way around the engine.