Hello , I have been having a problem with my 2.5 V6 X-Type for a while now , but didnt look into it too much due to thinking it wasnt the chain or its tensioner.
basically , when my car was sitting for a 3 to 12 hours lets say , it will 60% of the times make a second short rattle (chain-like) with oil lamp flickering. But , if I leave the car for couple of days or more , for some reason , it never rattled. And its hard to find from which part the sound comes, i once thought it could be starter , seemed to come from.there , so I got it rebuilt , but the problem consists.
I dont have any fault codes except for cats effeciency and sometimes gross leak (maybe because of a gas cap im assuming). Idle is perfect , engine is whisper quiet , maybe needs belt tensioner replaced soon. Its happening for over a year now.

I would be extremely glad if anyone could help me out , maybe give me a few pointers on what should I check next.
thank you in advance!

 

Engine rattles and a oil light flickering.......you should check you oil level immediately and if that is showing at a normal level, then I would suggest not to drive the car until you have the oil pressure verified by a mechanic ASAP.
If the pressure is low, it could be due to a failing oil pump or internal oil gallery blockages, driving the car while it has this problem could be catastrophic for the engine.

There may already be bearing damage occurred, but your mechanic might choose to drain the oil and pull the sump to check for telltale fine metal deposits if he suspects that has occurred.
Shot bearings will be noisy and the additional wear adds clearance which will diminish oil pressure as well as it they allow too much oil to pass through them.

Hope for the best.

 

If oil level and pressure is good, then you might then be looking further at whether there is undue cam shaft wear or a problem with the VVT system.

 

thank you for reply ! I am not sure about the moment when engine starts and rattles , but overall oil pressure is good. No metal shavings or etc in the oil , its very clean. Car is whisper quiet when warm, works and drives perfectly with no faults. Only occasional rattle on startup. Oil level is in between min and max , maybe it should be closer to the Max side?
However , perhaps oil itself can affect this ? What type of oil should I use? In summer we have over +25°C , and in winter up to -20°C. API-SJ 5W30 ? Because now I have 10W40 semisynthetic
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Generally you can do a vehicle search on your preferred Oil brand's website and obtain the compatible recommended type they produce for your vehicle.
I tend to use Penrite which is a good brand in Australia and New Zealand, but not likely available in the northern hemisphere.
Their website recommends a 5W/40 Full synthetic with extra Zinc for the X-Type petrol range. 5W30 is an alternate, but you need to ensure whatever your choice, it meets the appropriate specifications.
Here is a chart I found on another thread of the various fluids so you can see the relevant specs required.




You originally mentioned your oil light is flickering on...hence I was worried about the actual pressure you were getting.

 

​​​​​​Thank you for your help! I now actually believe oil filter and oil itself might be the problem with wrong viscosity and drain-back.

 

Thank you very much again! I followed your guidance , and I ended up with conclusion of VVT system. Not sure yet which actuator is at fault , tending to believe the one on bank 2. As I understand , in many other cars the VVT actuator has a spring that can fail, so stretching it or replacing with a stiffer one fixes this exact problem. And on many cars it can be done without even removing/loosening chain , just popping off valve cover, unscrewing bolts of VVT actuators front , and thats it.
DO you think it is doable with X-Type's 2.5 V6 engine the same way , not needing to remove chain , just popping off valve cover and switching springs?
I cant seem to find any information of it for this car, but in the photos I found it , from the looks of it, doesnt seem as simple as in other vehicles.