Engine Noise

[1944screen]

When cold my 2019 1.4 Corsa sounds as though it has a tappet rattle,after about 200yds or so it goes and then it is fine.Thanks Mick

[Hopkirk]

Have you checked the oil level?

[1944screen]

Yes I have and I have recently changed the oil and filter

[Buenchico]

I know next to nothing about cars, except that you put petrol in one hole, oil in another and water in a couple more. However a quick bit of googling suggests that, on a relatively new car (where there shouldn't be a great deal of wear to parts), a loose engine heat shield might be the cause of the problem.

[bhg481]

The last Vauxhall I owned had hydraulic tappets. Hoppy's suggestion of engine oil level is very relevant and I would also ask if you have the correct grade of engine oil - too thick at low temperature could result in the oil flow to the tappets being restricted until the oil warms up a bit.

[ZebuSanctuary]

When was timing belt last changed. This can cause tapping at top of engine.

[davebro]

I think it has a chain not a belt?

[ZebuSanctuary]

// think it has a chain not a belt? //

Fair enough!

If only they all (internal combustions) had chains!

[davebro]

but a worn chain will rattle

[davebro]

But a worn chain would be continuous probably. As said this seems like an oil circulation problem - maybe a flush is needed.

[beso]

There is a check valve that stops the oil draining from the head back to the sump when the engine is not running. The tappets will rattle until the oil gets back up to the top of the engine after restarting.

[ZebuSanctuary]

// The tappets will rattle until the oil gets back //

Presumably there is no sensor and therefore the engine management system ignores it?the

I purchased a OBD2 hand held scanner some years ago (£10 from a well known online site). Although it won't tell you the cause, it tells you what the fault condition is along with a useful Pcode.

It has saved me ££££.

[1944screen]

Don't know about the chain, the car has only done just over 20000. The oil is from a wellknown retailer and is the one reccommended for the car.

[Hopkirk]

If it isn't too loud I suspect you can safely ignore it.

[nero2024]

it will till you oil gets round the engine after a bit of a warm

[Paul22118]

I had the exact same issue some years ago, co-incidentally also a Vauxhall. I sought the advice of a decrepit old mechanic of my acquaintance and he simple said to buy a can of 'Molyslip' oil additive from Halfords. Worm the engine, empty the can into the engine (can is small in volume) and it will sort your problem. I did so and astonishingly it was sorted. Try it, it is a well know product.

[davebro]

yeah - gotto get rid of the worms! LOL

[Paul22118]

It is early Dave

[1944screen]

Think I will try the Molyslip first, nothing to lose and it might work. Thanks everyone, will let you know

[tobytronic]

The car has done 20k mls. Don't do an oil flush. Don't put Molyslip in it. There are only two or three reasonable possibilities. The oil filter that you recently replaced is the causing this. Try either another oil filter made by GM Delco, Hengst or Filtron. An hydraulic adjuster is draining overnight and needs changing, not 'cleaning'. They cost about £6 for a top-spec part...
Interestingly there are only a very few different types of design this part. For example a BMW 318i will share the same parts with hundreds of other engines from different companies.
Or the oil used isn't the correct DEXOS 2 Spec oil.

Please do not try snake-oil remedies. It is a simple fault with a simple solution: a hydraulic adjuster is backing-off overnight. Just the one. It is rattling for the first few moments until oil pressure has restored the correct clearance. It has only done 20k and the above suggestions will provide a solution.
Time-served, qualified mechanic. 45+ years experience with own Citroen Specialist repair business.

[Hopkirk]

Listen to this expert