Strange rattle on cold startup

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
My 2011 FR Tdi has started to make a strange rattling noise on startup. It only happens on the initial cold startup if the car has been left for a couple of days. Doesn't do it if you then switch the engine off and back on again. It also doesn't do it when the engine is warm.

The noise lasts for around 10 seconds but when it first happened it lasted around 20/25 seconds.

Here's the weird bit. Generally does it when the front of the car is lower than the rear e.g parked nose forward on a slope.

Had it up on a ramp and can't find anything loose or broken. Even had the undertray off at the front (removed a stone in the process) and all is good.

When in the car it sounds like it's coming from the exhaust downpipe area.

So, any ideas? :)
 

AndyG_TSi

Active Member
Nov 1, 2011
1,174
6
East Manchester
Hi mate: this is just a thought and i'm thinking out loud here:

Where is the oil circulation pipe situated on the Leon, that takes the oil from the sump at initial start up and pumps it round the engine?

all im thinking is this: is it akin to a drink carton thats nearly empty and your drinking throug a straw?

Example,

with the nose of the car pointing down the slope and therefore the oil at a slight angle in the sump, is it taking longer for the oil to initially be picked up and be circulated, hence the rattle when left standing for longer than normal in that position

as said its only a thought and if im talking complete bollocks sorry :lol:
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
All ideas appreciated mate as it's got me stumped!

It's more of a metal hitting metal sound like a coin in a tin. Did think it might be the internals of the catalytic convertor but there are no other symptoms.

Oddly enough, it's only done it once in the last few days and not as loudly.:confused:
 

AndyG_TSi

Active Member
Nov 1, 2011
1,174
6
East Manchester
fair do's mate, as said it was just a thought and made sense to me..

you have checked you oil though just to make sure its at the max on the dip stick?
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
Yup. Oil level is fine. The frustrating thing is it started doing it less than a week after being serviced. Not missed a beat up to that point.
 

Dabbalz

Active Member
Sep 7, 2010
283
0
West Yorkshire
The engine oil has drained into the sump and it's the engine running without enough oil for a few seconds. Is the oil old as in miles done on this oil? A good quality oil will cure this. Have the oil and filter changed. for £100 and a longer engine life you can't go wrong. I'm changing the oil and filter half way between stamped services in our FR.

OK missed the service bit. Have they put good quality oil in and oil of the right weight for our temp range?
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
The engine oil has drained into the sump and it's the engine running without enough oil for a few seconds. Is the oil old as in miles done on this oil? A good quality oil will cure this. Have the oil and filter changed. for £100 and a longer engine life you can't go wrong. I'm changing the oil and filter half way between stamped services in our FR.

OK missed the service bit. Have they put good quality oil in and oil of the right weight for our temp range?

Yup. They used Castrol Edge Professional. Was the cars first service as it's only done 9000 miles. Got them to change the air filter as well.

Had the oil, filter and air filter changed previously when it had done 4500 miles. Bit anal when it comes to oil and filter changes! lol.
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
The engine oil has drained into the sump and it's the engine running without enough oil for a few seconds. Is the oil old as in miles done on this oil? A good quality oil will cure this. Have the oil and filter changed. for £100 and a longer engine life you can't go wrong. I'm changing the oil and filter half way between stamped services in our FR.

OK missed the service bit. Have they put good quality oil in and oil of the right weight for our temp range?


Going into the dealers to be looked at tomorrow. By my description over the phone they also suspect the oil draining into the sump etc. Managed to get it on video this morning as it sounded like a bag of shite. Just hope it's not knackered something...
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
If it s a new car it should be fixed for free anyhow, and if they cant demand they supply you with a new one!!

It's just over 10 months old as I got it in January, so not brand new. I certainly won't be paying for it to be fixed as it was fine before the first service.

Will see what they say tomorrow. :)
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
According to the Technician that watched my vid of the noise, it's the alternator belt slipping. Thinks condensation is causing it to slip. Nothing to worry about, apparently.
 

DBD19

Active Member
Feb 9, 2011
125
0
hey thats strange my FR mk 2 has done the same to me a few times and yes scared the sh@t out of me too.
 

Donny9835

Active Member
Nov 8, 2011
34
1
Wiltshire
wouldnt have thought it was the belt slipping, thats more of a squeal noise... throw some talk on it next time, if it stops its the belt, if it doesnt then its not.
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
I thought a belt would squeal rather than rattle but when the Tech listened to my vid recording he said it was definitely the alternator. Reckons it was slipping due to condensation/damp, making the noise and then stopping as it dried and gripped properly.

Out of my area of expertise so I didn't argue with him. It's logged on their system so if it is something else that does go bang, they can pick up the pieces.
 

Redemption

Active Member
Jun 18, 2011
1,771
6
Hampshire
Took the car back to where I originally got it from and it's booked in for a cold startup test on Friday. Technician watched my vid and said that doesn't sound healthy. Thinks maybe some pulley is slipping but wants to hear it himself. Hopefully it'll make the noise for them!

Dunno if it's related but it's now started to lose power when you go to accelerate after braking, especially on roundabouts. Almost like the car cuts out, has to think about what to do then comes back to life. Really strange and a bit disconcerting.
 
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