[asffraser]

Hi everyone , iv had this problem of rattle/knocking on startup , seems to disappear as engine warms up this is baffling me sounds like something loose but with it disappearing when warm puzzles me, it's a 1.5dci scenic 2004. Any advise would be great thanks.

Big al

 

[scorpionemotors]

Hi mate, you are of the alternator pulleys breaking up on 1.5 DCI's? Might want to check that yours is intact.
All the best
Dus

 

[saabguy]

When was the oil last changed as well?

 

[asffraser]

Thanks guys for quick replys, is it easy to check pullys on alternator?, I bought the car in November they say they done service before I got it , they have changed timing belt at 47000 there is 52500 on clock now so I was going to give a oil change to see if that helps full synthetic I think . Are pullys expensive is it expensive job? Thanks guys
Big al

 

[scorpionemotors]

Hi Al
Just rotate the engine by hand and look at the pulley to check for cracking. If you can get the belt off it would probably be better to see.
Cheers

 

[asffraser]

Hi all
Am I just checking the pulley on the alternator itself or is there other pulleys below, when I look at alternator when engin is running it looks fine and I can't seem to here any knocking. What other possibility could it b? Really baffled like I say it's when u first start up after few hours standing still , it sounds really loud from inside off car like something hitting bulk head that is best way off describing it .but sounds alot better when warmed up.

Cheers for the advise much appreciated
Big al

 

[madnoel10]

Faulty alternators tend to complain most when they are under load. When the engine is warm switch on all electrics and listen for any change in note or noise. And a duff alternator isn't likely to cause a heavy knock.

You description of the noise would make me think you may have a faulty injector. Faulty injectors tend to cause a sharp knock when the engine is cold and get quieter as the engine warms.

 

[asffraser]

Is it easy to check injectors or is this one for the experts
Cheers all

 

[timddeb]

Mine 1.5 dci has done that from new out of the dealers. Apparently the bottom ends are known for not being too strong.

 

[asffraser]

Hi all for the replies ,a new problem arose this tea time while driving home , the car seemed to pull back as if there was no power this happened twice but it lasted a couple of seconds and then a few minutes later. I do have a slight rough idle now and then could this b a blocked EGR valve or faulty valve. Thanks all

Big al

 

[Ralph]

The pulling back does sound like the EGR but get a long screw driver Handel to your ear and touch the other end to the engine by moving it around you may be able to narrow the noise down be careful of sticking it NR moving bits.

 

[asffraser]

hi guys sorry its been so long been on hols.
im going to do a oil change in next few weeks and replace air filter and diesel fuel filter, i hope this will give some improvement, i toped up engine with some oil and does not seem to be as noisy. another thing iv noticed is when im in nuetral im idling with 4 bars lit when i put slight revs on it feels quite rough but when i continue to put revs on it is fine its just that first time u put revs on. it also affects when pulling away , could this b throttle housing needing cleaning? thanks guys

big al

 

[madnoel10]

Diesels don't have a throttle body but a sticking or faulty EGR valve on a diesel can cause the symptoms you describe.