KV6 Tick
 

2nd post in day seems like I'm not having much with my 75
The past few weeks the car had developed a tick on start up I thought it would be the tappets but it started getting worse it lasted longer than few seconds sometimes a couple of minutes so I bought a can of seafoam threw it in and for a day the noise did come back but today it did again this morning so I'm starting to think that perhaps it's not the tappets the noise seems to be coming from drivers side rear but I couldn't pin point it. It does come up with revs but it's more prominent on idle. Also the engine is very smooth and feels completely normal even when the tick is present which baffles me even more.
I'm going to include a video it's not the best as it's from the cabin but you can hear the sound
https://youtu.be/7W_-TpM6Iqk
Thanks in advance

Just to add a few things that I forgot to mention I use Mobil 1 0w-40 and that sometimes turning on the ac seems to quieten it down

Sounds exactly the same as mine did. I used hydraulic lifter cleaner which seems to have cured it for the last 3 months.

Seafoam is exactly that it's quite popular in the us with a lot vids online of it curing valve tick but you're meant to drive about 100-200 miles for it to work and then changing the oil I've only done about 40 miles since putting in so may have not worked yet but I'm thinking if it's any of accessories making the noise or belts or manifold

Could it be the 'Slack Tappet Simulator' (STS) as I call it?
Click: https://the75andztclub.co.uk/forum/s...rchid=17845112
Contrary to RAVE, the STS often occurs within seconds of a cold start (especially when the engine's not been run for a while and the fuel vapour cannister is saturated). The tapping follows the engine revs and will persist for quite a while. It's part of the emissions control system and and is quite harmless.



TC

Just went to try this but no tick today maybe the demons possessing this car are having a day off what can I say 😂

When/if it happens again, you can confirm if it's STS by unplugging the connector to the cannister purge valve. It's mounted on the right side of the upper inlet manifold (as you look at it).

TC

Knowing my luck it probably will although the sound seems to be coming from other side and not the purge valve worth a try regardless

Unfortunately I unplugged the purge valve but the tick was still there I'm going to do an oil change as its coming up I do them every 6 months or 3k miles see if that will do anything

Hello Thanos,

0W40 is not recommended by MG Rover for any 75/ZT engine. For the KV6, 10W40 is listed so I suggest that you first change to that grade which is perfectly satisfactory for our climate. Your hydraulic tappets certainly shouldn't be contaminated with your oil change regime of every 3,000 miles :angel: but the presence of the noise for a period from a cold start could point to the extremely low viscosity oil you're currently using.

So I'd start with an oil change as you mentioned, but to 10W40 semi-synthetic. You should have plenty of money left over for a bottle (or two) of good wine!

Simon