Car knocks

[isohail72]

Hi guys. I have mercedes s320 cdi 2006, i have changed engine oil and filter, after that when i drive car around 2500 to 3000 rpm, car knocks, jerks.
Any idea why its happening pls?
Thx

 

[Tonygw]

HI
What kind of knocking / jerking is it? Is it a regular deep knocking from the bottom of the engine kind of knock? Or is it more gearbox related? Need a bit more of a description to go on please.

 

[isohail72]

HI
What kind of knocking / jerking is it? Is it a regular deep knocking from the bottom of the engine kind of knock? Or is it more gearbox related? Need a bit more of a description to go on please.

Its like, if i am driving at the speed of 60 and gas the pedal, then car try to stop, knock.

 

[optimusprime]

Iso Have you changed the oil before ? And if you have did you use the correct oil for your engine ? . So it sounds like your oil is to thick and not getting around the engine . Tell us what you did >







'

 

[isohail72]

Iso Have you changed the oil before ? And if you have did you use the correct oil for your engine ? . So it sounds like your oil is to thick and not getting around the engine . Tell us what you did >







'

Hi, I have taken out the oil from the oil suck machine, 5 litre oil came out, then I put new oil, 9 litres, and changed the oil filter, but didn't put new rubber washers of oil filter.

 

[Tonygw]

what spec of oil did you use? and is 9litres correct? Did it reach max on the dipstick or over the max mark?

 

[isohail72]

Can see on the first photo, car engine was hot and showing this much oil. Second photo used this oil.

 

[isohail72]

what spec of oil did you use? and is 9litres correct? Did it reach max on the dipstick or over the max mark?

Dip stick never show correct amount of oil.

 

[Deleted member 149005]

Hi, I have taken out the oil from the oil suck machine, 5 litre oil came out, then I put new oil, 9 litres, and changed the oil filter, but didn't put new rubber washers of oil filter.

5 litres out and 9 lites in suggests it might be overfilled.

any leaks from not using a new seal?

 

[isohail72]

5 litres out and 9 lites in suggests it might be overfilled.

any leaks from not using a new seal?

No visibility of any oil leaks!!!

 

[Petrol Pete]

If it leaks from the oil filler cap 'o' ring you will know about it immediately ! The other o rings on the filter holder are internal....and are usually supplied with the new filter ??

 

[Deleted member 149005]

Is the knocking related to engine speed (ie it does it when in neutral) or to road speed (ie all gears at a certain speed)

 

[isohail72]

When drive car and put foot on the gas it knocks, unless I am on a higher gear. Do you think it could do anything with the gear box, I don't know when the ATF was changed in this car, on the service book it was changed 60k miles, now its on 110k. but may be someone changed it and didn't put on the service book?

 

[isohail72]

Is the knocking related to engine speed (ie it does it when in neutral) or to road speed (ie all gears at a certain speed)

Engine speed, doesn't knock when its neutral.

 

[isohail72]

If it leaks from the oil filler cap 'o' ring you will know about it immediately ! The other o rings on the filter holder are internal....and are usually supplied with the new filter ??

So do you suggest I change the oil filter?

 

[Petrol Pete]

No, just saying if the 'o' ring is accidentally left off the oil filler cap oil is sprayed everywhere and it would be hard to miss a leak that big.
You changed the oil filter when you changed the oil, usually the oil filter is supplied with all of the new 'o' rings required (4 I think) unless your engine oil filter arrangement (replace from the top of engine) is very different to what I am used to in MBnz. ?

 

[isohail72]

No, just saying if the 'o' ring is accidentally left off the oil filler cap oil is sprayed everywhere and it would be hard to miss a leak that big.
You changed the oil filter when you changed the oil, usually the oil filter is supplied with all of the new 'o' rings required (4 I think) unless your engine oil filter arrangement (replace from the top of engine) is very different to what I am used to in MBnz. ?

Cant see any leaks at all.

 

[Petrol Pete]

It could be something as simple as the gearbox mount worn out, especially if it only knocks under load. Open the bonnet rev the engine and see if the engine 'dances' around, could be engine mounts worn.

Neither are big expensive jobs.

 

[isohail72]

Should oill be check with cold or hot engine?

 

[isohail72]

It could be something as simple as the gearbox mount worn out, especially if it only knocks under load. Open the bonnet rev the engine and see if the engine 'dances' around, could be engine mounts worn.

Neither are big expensive jobs.

I have already checked, no signs of engine dancing.