Knocking On Startup

[trickywoo 0]

I've got a rattle / knock (can be seen as a vibration on the bottom pulley) from cold, sounds like the cambelt end of the engine on my 1.6. It goes away when warm and does not seem to be oil pressure related (the guage rises to 3/4 soon after start-up).

 

I've put a new filter and 10w40 oil in and its still the same.

 

Its had a new water pump and cambelt in the last 12months.

 

Is this the sort of thing a knackered cambelt tensioner would do?

 

Any other ideas?

[eddie_1.9 1]

It's possibly worn big or little ends (or both). As it warms up the all components expand and it takes out the slack and the rattle goes away.

[j_turnell 137 3 Cars]

As above does sound like a big end rattle, but best to check that nothings loose in the engine bay like air box on manifold or cam cover rattling, just to rule these out.

[Redtop 14 2 Cars]

Chain driven oil pump?? My mates car sounds a bit rattly and that's what he thinks it is. It's not really doing any damage and it's mgone when warm so he's not to worried as it ain't gona be doing a lot of miles

[eddie_1.9 1]

Also I just happended upon this (but have no experience of it myself), it could be the bottom pulley. No quite sure how or why but poeple have had your symptoms and say it was cured by fitting a new bottom pulley. I guess its not the pulley it's self but the shock absorbing rubber breakes down or something?

[trickywoo 0]

Thanks for the replys. I know these knocking noises are hard to pin down but having heard / seen a big end failure in an Impreza I don't think mine sounds the same (not as hard a knock as that).

Might have a go at a new pulley and maybe have the belt cover off to see if anything is catching on it.

I'll let you know if I find anything.

[aeinstein 0]

hate to sound dumb, but was it making the same noise before you changed the oil?

 

i've heard somewhere that if the oil is too thin in a xu, especially a higher mileage one, then it can be detrimental.

 

just another idea to add too the rest! you are right about knocks/rattles, they are nigh on impossible to diagnose over the internet, even for an expert.

 

al

[trickywoo 0]

hate to sound dumb, but was it making the same noise before you changed the oil?

 

i've heard somewhere that if the oil is too thin in a xu, especially a higher mileage one, then it can be detrimental.

 

just another idea to add too the rest! you are right about knocks/rattles, they are nigh on impossible to diagnose over the internet, even for an expert.

 

al

 

It was yes. I've only just got the car. It was fine on the test drive and then for a week (150miles ish). Then it started on Sunday out of the blue. I've not been above 4K revs or loaded the engine.

I was worried they had put sawdust in the engine (to silence the knock) so I changed the oil but it was quite clean.

I put a genuine Peugeot filter on. I was thinking about a 15w40 oil. Would that make much difference?

[aeinstein 0]

i use that castrol gtx high mileage stuff, but i can't be chewed to check in the garage, though i'm 99% sure its 15w 40. i got no complaints with it, it uses less of this than the shell helix oil i was using before.

 

i was told to avoid synthetics because the 1600 engine was designed (before synthetic oils were!) to run on gloopy mineral stuff, so thats what i'm sticking to.

 

others probly have other ideas, especially those running mi16s cos a local lad with a mi only uses mobil 1 and swears by it...

 

al

 

 

and while i'm thinking of it, my pals mi16 had a full rebuild cos it was rattling. he got the bottom end rebuilt, but it was still rattling. turns out a small screw in the t/b butterfly had worked loose and ended up getting sucked into a cylinder. full head rebuild later hes happy but well over a grand lighter!

 

just goes to show, it could be all kinds of things.

 

more interesting than useful i know!

 

al