Technical Knock knock...

[bongomongo]

Hi guys,

Whos there? My 1.3 diesel Fiat 500L engine knocks loudly when I try to accelerate like a big thump and jolting, this only happens when the engine is cold once its warm it doesnt do it. I cant drive it until its warmed up. Does anyone know what this might be?

Samantha

 

[Greasytrucker]

Any warning lights on the dash?

 

[bongomongo]

Hi Greasy
No warning lights i can see

 

[Greasytrucker]

Any smoke of any colour when you first start it or when it’s jolting? Is it clattering when it’s jolting?

 

[varesecrazy]

Hi guys,

Whos there? My 1.3 diesel Fiat 500L engine knocks loudly when I try to accelerate like a big thump and jolting, this only happens when the engine is cold once its warm it doesnt do it. I cant drive it until its warmed up. Does anyone know what this might be?

Samantha

Is it a manual gearbox?

Hear it when starting.. Or when driving?

 

[bongomongo]

No smoke that I can see on start up or when its jolting i will have to double check that though, sometimes I see a puff of smoke when driving. Its a automatic a manual I wouldn't be able to drive (woman here).
Its sounds ok when start up only when I put foot on pedal it will make a loud thump like a hammer hitting the engine, so I have to wait about 5 or 10 minutes for it to warm up and then its ok.
I have noticed the smell of diesel or fumes in the car so ive stopped using the heater

 

[Greasytrucker]

Think @varesecrazy asked the right question. Sounds like it could be more gearbox rather than engine related then. If there’s anyway you could post a video of it making said noise I’m sure somebody can confirm this. Short of that without any warning lights or fault codes it’s just a guessing game

 

[varesecrazy]

Its a automatic a manual I wouldn't be able to drive (woman here).
Its sounds ok when start up only when I put foot on pedal it will make a loud thump like a hammer hitting the engine,
I have noticed the smell of diesel or fumes in the car so ive stopped using the heater

Quite possibly the Dog Bone engine mount..
That will Slap the floor

Any fuel or oil smell wants investigating..

Open the bonnet and have a look..

Anything damp or oily post a pic here

 

[Cornish Ian]

Hi guys,

Whos there? My 1.3 diesel Fiat 500L engine knocks loudly when I try to accelerate like a big thump and jolting, this only happens when the engine is cold once its warm it doesnt do it. I cant drive it until its warmed up. Does anyone know what this might be?

Samantha

When I first read this thread my first thought was a dripping injector although probably not so common now as it used to be. Does the car tick over smoothly especially when cold or could it be missing on one cylinder. One important thing to check is to make sure there is no sign or smell of diesel in the engine oil. Also check for any rise in oil level which probably means it’s being diluted with diesel.