guys is it possible to have the crank fail on you and still drive tidy with no engine warning light on?

I changed the oil the other day and ever since at 3000rpm there is a slight noise which manifests itself as a rattle not very loud then its gone it only happens at 3000rpm. nothing on idle.

From cold it has piston slap but when warm this goes and sounds tidy it drives tidy but this noise has me a bit worried.

what are the signs when the bearing & crank has let go?

cheers in advance

mark

 

Yes, it's perfectly possible, given that the ECU has no way of directly detecting such a failure and, thus, there's no DTC for "failing crank or bearing".

Oops. Did you prefill the filter and cold-crank the engine after the change? Is the new oil the same grade and brand as the old?

Loud knocking noises when they've really gone. If this is subtle and appears only at certain engine speeds, one would normally suspect something else, but if it started directly after the oil change there's an obvious link and so it could be a bit of pick-up. Can you localise where around the engine the noise is coming from?

 

thanks mate for the info gonna have to make a visit to a scooby specialist I think to get it checked over its only at 3000rpm before and passed it no noise I should also mention that I had removed my heatshieds from the manifolds and in order to do this I had to use a cold chissle and hammer

Yes did remove crank sensor and pre filled new oil filter also cranked over but no oil light came on or off during that. I have know way of knowing what oil was previously used as I havent long bought the car and it didnt have any service history hence I had it very cheap I used silkolene Pro s 5w40 as recomended by opie oils.

I wouldnt say it was a loud knocking noise just a rattle at 3000rpm car drives fine no warning lights no problems when warm.
Just normal piston slap there is no nock or rattle from idle.
I warm her up by letting her idle till opperating temp is achieved then drive off boost for about 15 mins before giving any beans.
There is a other noise which is clicking but that is the injectors the car is standard.

 

maybe the oil is too thin and is showing a weekness in the engine.

 

could be might change the oil for a thicker one see what happens

 

Did you remove the heat shields at the same time as changing the oil? Also, did you just do the manifold shields or the up-pipe ones too?

It's worth seeing a specialist because nothing actually beats someone sticking their head under the bonnet, but on the basis of what you've said, and especially if you did remove the shields during the oil change, this sounds more like something loose and vibrating than bearing failure. If the uppipe shields are still on, it's probably them.

Caution's good but that's a bit too far. No need to leave it idle until the coolant temp's up, this is what multigrade oils are for. Wouldn't take 15 mins for the oil to fully warm up either.

Do you still hear the noise if you rev up to 3000 with the engine stone cold? If you do, changing to a thicker oil won't stop it. Before you do anything else, have someone hold the engine at the speed when the noise is most obvious, and then try and locate it.

 

thanks buddy theres some sound advice there gonna arrange to get a mechanic to take a look at her

will check the noise from cold in the morning and post up
I only removed the ones on the front of the manifold I think im gonna take the whole lot off to make sure and eliminate them from the puzzle