Hi all,

Just wanted to get some opinions/help from some fellow Fiesta owners who may have had similar problems. Breakdown is below so it's easier on the eye.

Vehicle Details:

• Ford Fiesta MK7 2009 plate, 1.4 litre petrol, automatic.
  • 109,000 miles on the clock

Problem:

• Engine knock on cold start (no check engine light as of yet)
  • Disappears once car hits 1000rpm while idling (this is during engine warm up)

Tests/assessments carried out at home:

• Vacuum leak test while engine is running at optimum temperature:
  • Carb cleaner sprayed onto hoses and areas near air intake to test for any vacuum leaks. No rise in RPM's noticed.
• Oil level is normal, no leaks around head gasket or anywhere visible in the engine bay.

Recent servicing/work done to the car:

• Timing belt, drive belt and water pump changed in Jan 2025
  • New timing belt threw an error code, went back to the garage and they apologised as the timing was not set correctly, slightly off. No errors since correction.
• 4 x iridium spark plugs installed Feb 2025
• Oil and oil filter changed Feb 2025
  • Castrol Magnatec 5W-30 with Liquimoly Ceratec oil additive due to high mileage on car (I highly doubt the Ceratec is the cause of this knock as the knock has only been ongoing for approximately a month, two months after adding the Ceratec additive).

My personal opinion on the root cause:

• Piston slap due to high mileage and age of the car?
  • This is something I've been told is common in older engines and is not an issue to worry about if it disappears after warm up.
• Oil pressure is insufficient?
  • Not insufficient enough to throw a code, which could mean the oil pump is maybe coming towards the end of its life cycle.
  • If the engine knock kept going after warm up, I would assume a rod knock issue.

Sorry for all the jargon but figured it would be good for those who need more information, especially if there are some mechanics on this forum. Happy to do my best to answer any further questions 🙂

For the admins: please let me know if any posting rules or anything has been breached as this is my first time posting.

Cheers!

3 hours ago, SamiE said:

Oil and oil filter changed Feb 2025

• Castrol Magnatec 5W-30 with Liquimoly Ceratec oil additive due to high mileage on car (I highly doubt the Ceratec is the cause of this knock as the knock has only been ongoing for approximately a month, two months after adding the Ceratec additive).

 

I would be tempted to change the oil and filter again and use the correct oil only, no additives