When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Loud ticking from engine bay and burning oil smell under hard acceleration
Hi,
I've noticed a loud ticking noise from the engine bay that doesn't disappear when the engine is warm. After touching various parts of the engine bay it became obvious that the part highlighted (PCV Valve) in the image attachment appears to be causing the sound. When holding the part the ticking noise and vibration are in sync. Does the PCV valve need changing? One thing I've noticed is there is a burning smell under hard acceleration that lasts for up to 30 seconds and letting off the throttle the smell clears.
Do you take your car to MB for regular maintenance?
Note: A faulty PVC can go two ways, stuck open of stuck closed. If stock open the EVAP recycling system will get clogged up fast. On the other hand, if it's stuck closed, crank case pressure can build and blow the upper or lower gasket as the pressure has to go somewhere.
Do you have oil in your driveway? Can you see oil on the engine? Check your oil level, has it gone down? Are you loosing oil after you already topped it up.
If you are loosing oil and you have not oil on the driveway or on the engine, you have a bigger problem and hopefully warranty will take care of it.
Do you take your car to MB for regular maintenance?
Note: A faulty PVC can go two ways, stuck open of stuck closed. If stock open the EVAP recycling system will get clogged up fast. On the other hand, if it's stuck closed, crank case pressure can build and blow the upper or lower gasket as the pressure has to go somewhere.
Do you have oil in your driveway? Can you see oil on the engine? Check your oil level, has it gone down? Are you loosing oil after you already topped it up.
If you are loosing oil and you have not oil on the driveway or on the engine, you have a bigger problem and hopefully warranty will take care of it.
Thanks for taking the time to help. The car has been 100% dealer serviced. There's no oil in the engine bay that I can see or on the driveway. I've put the vehicle on a 4 post ramp and taken the under tray off, couldn't see any oil on the tray or burn marks etc on the exhaust.
The burning smell only happens under hard acceleration above 70mph e.g. accelerate from 40 to 90, let off the throttle and 5-10 seconds later the cabin smells of burning. The PCV is making a ticking noise within a few minutes of idling from cold and you can feel the vibration in it when you hold it with the engine idling. After a long drive the PCV valve is a lot louder.
10-11-2022, 04:34 PM
