wrong oil ?

Can engine oil which is thicker than recommended cause engine "rattle" or
"knocking" ?

 

I would have thought it would have to be very much thicker than normal.
Depends on the engine though as to what it can tolerate. A bog standard
Vectra 1.8 can take almost anything dependant on the climate.

Oil's cheap. If you think it's the problem drain it and start again.

--
Malc

Rusted and ropy.
Dog-eared old copy.
Vintage and classic,
or just plain Jurassic:
all words to describe me.

 

Well I got a mate to service my astra. He put 10w40 in . I dont know what
was in before. now the engine is noisier.
Most oil checkers online recommend 5w30 with a few saying 5w40.

 

What does your manual say? It's a possibility that the thicker oil is a
problem. I wouldn't drive it too far until you're absolutely sure.

--
Malc

Rusted and ropy.
Dog-eared old copy.
Vintage and classic,
or just plain Jurassic:
all words to describe me.

 

thanks for replying...
the handbook says..
We recommend using vauxhall engine oils with the following qualities and
viscosities
ACEA A3/B3 SAE 0w-30
or
ACEA A3/B3 SAE 5W-40
or
ACEA A3/B3 SAE 10w-40

For commercially available oils..only the following viscosity classes are
permitted
SAE 10W-30 (or higher than 30)
or
SAE 5W-30 (or higher than 30)
or
SAE 0W-30 (or higher than 30)

 

This is getting beyond my knowledge of oils and engines. Personally I
wouldn't have said it's too far wrong but....

--
Malc

Rusted and ropy.
Dog-eared old copy.
Vintage and classic,
or just plain Jurassic:
all words to describe me.

 

Depends how old your Astra is. Up until about 2003/4 standard oil for
Vauxhalls was 10W/40 semi synthetic. With the push towards 20,000 mile
service intervals or even worse Flex Servicing, Vauxhall moved towards
5W/30 fully synthetic at about twice the price.

http://www.carbibles.com/engineoil_bible.html is also worth a read.

 

Modern engines can use smaller oil passages with the thinner oils now
specified. But 10-30 even 20-50 is not so much thicker as to cause your
rattles. Oil viscosity varies TREMENDOUSLY with temperature - synthetics
less so.

If you noticed a rattle after an oil change - especially if the new oil
is synthetic which has better hot film strength - its prabably
coincidental - unless your friend ran the engine dry until he realised
he hadn't put the new oil in yet....

Brian W