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Billy, Trainer/ Master Technician
Category: Car
Satisfied Customers: 4911
Experience:  Trainer 18+ years - master tech. 20+ years, SAE member
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I have a knocking coming from the car after getting the

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I have a knocking coming from the car after getting the brake checked and also when I am idling after 30 seconds the temp shots up and warning of high temp but as soon as I rev abit it drops what could this be
JA: Where exactly do you think the noise is coming from? And how long has this been going on?
Customer: Knocking earlier today only came out of the garage yesterday and the temp has only just started
JA: What is the model/year of your Volvo?
Customer: s40 and 2006
JA: Are you fixing your S40 yourself? What have you tried so far?
Customer: not fixing myself and nothing as I don’t know much about cars
JA: Is there anything else the Mechanic should know before I connect you? Rest assured that they'll be able to help you.
Customer: nope

Hello and Welcome! I'm Billy and I will assist you with your inquiry. I understand that having car problems can be frustrating so please feel free to ask if any further info is needed.
If you get prompted for a Premium service or a phone call, please ignore that, cause I don't think it is needed at this point.
My apologies for the delay, thank you for your patience.

Let me know the exact engine you have or post the license plate.

Customer: replied 10 days ago.

Thank you. I will check now and be back with you.

Kindly let me know while at it if the knocking happens when the vehicle is stationary, or only when moving.

Customer: replied 10 days ago.
When moving but nothing when braking

Does it happen all the time, or when on uneven surfaces or potholes?

Customer: replied 10 days ago.
All the time

As it is moving you get a knocking noise all the time? Is the noise coming from the front?

Customer: replied 10 days ago.
I am unsure where it coming from sound central but can’t be to sure I am more worried about the temperature issue

Since the noise is not present when the brakes are applied, the brake calipers could be a bit loose. So I would recommend double checking the brake job. And then check the suspension and the subframe for any loose bolts or worn suspension items. I'm getting to the temperature issue.

Customer: replied 10 days ago.
Ok thanks

If you have no coolant loss, and if the temperature only raises when at idle, and when the engine is revved, the temperature gets back to normal, the most likely cause would be a worn water pump. However, I would first check and see if the fans are working. And if they are, then replace the water pump.

Customer: replied 10 days ago.
Ok thank you it’s in the garage within the week

Thank you for your trust. Cheers.

Billy and 4 other Car Specialists are ready to help you