M13A VVT Engine Rattle mainly at start up. Chain tensioner?

Can anyone offer me some advice on an engine 'rattle', rather like the sound of loose plastic trim but it definitely isn't that. Other symptoms include; longer than expected cranking at start-up (esp. in winter), mainly happens when cold and the engine throttles back (usually disappears when engine is warm). A 3rd Gen 2018 Jimny. M13a VVT engine with only 30,000 miles. Done the usual such as oil change, plugs, battery etc. No Code or engine warning light but I strongly suspect chain tensioner to be the cause. Any thoughts or similar experiences? Help would be much appreciated as I've not long owned a Jimny.

They're usually fairly good on chains. Have you checked all the exhaust heat shields they are a much more common source of rattling when cold?

Thanks for replying, I do appreciate it. I have checked for loose exhaust/heat shields and all seems ok. I will double-check though since you highlight it.

Yes, one of the reasons I like the later M13 engine because it has a chain. I've probably watched too many YouTube videos but wondering if the check valve (if it has one) on the tensioner could be faulty preventing correct pressurisation. I guess the only option is to take it to the garage and have it inspected.

Thanks again

If the noise is coming from the engine, It might be one of the hydraulic tappets draining oil and then slow to refill, or possibly the VVT mechanism.

A car with 30k miles shouldn’t have an issue with the cam chain.

Do you have the correct grade of oil? If it is too thick it might take too long to circulate when cold.

DrRobin wrote:

If the noise is coming from the engine, It might be one of the hydraulic tappets draining oil and then slow to refill, or possibly the VVT mechanism.

M13A engines have "shim-over-bucket" solid lifters.

Thanks for that. One of the first things I did was an oil change (5W30) so it should be ok. Interesting what you said about the VVT Mechanism though. I was thinking about buying an M13 engine as a teaching aid for myself. At present I don't have the time or skills but eventually want to be more hands on. For now it'll be heading to the garage. I'll post back with info for others.