Noisy valves


#1

I have an 06 volvo s40 with a 2.4l non turbo. When I reach about 2200 rpms I hear the valves tapping. When I put the car in park and rev the motor up the valves don’t make any noise. I hope someone has an answer on where to start.


#2

I don’t know why you can hear it sometimes and not others. But if you are hearing valve noise which you haven’t heard before, a valve clearance measurement is probably a good idea. I did one a couple weeks ago on my 1.6 L Corolla and it was simple as pie to do and took less than an hour. Making valve adjustments if the clearance is incorrect can be complicated and expensive, but just doing the measurement probably won’t cost much.

Edit: Assuming your oil is in good shape, oil level and pressure are ok.


#3

Could the noise be more of a chatter than a knock? Maybe similar to rattling a few BBs in a tin can. My first impression is you hear detonation or spark knock or valve chatter which are all the result of the fuel igniting too soon due to any of several reasons. You might try a tank of 94 octane and if that reduces or eliminates the noise then detonation is the problem.


#4

My vote is for this being a spark knock problem.In many cases this can be caused by an EGR system fault so that’s what I’d look at first.


#5

If it turns out to be pinging (spark knock), make sure the spark plugs are in good shape and have the correct gap. Over miles driven, the electrodes wear, and the gap widens. A too-wide gap will produce pinging. When this has happened to me – like if I forgot the change the spark plugs on time – I’ve noticed the pinging more when the engine is under load, like going up hills, rather than tied to a particular rpm.


#6

If it’s pinging…
Since it’s a volvo…
Check to see that you’re runnung the correct octane fuel.
( owner’s manual )


#7

Your car should have a knock sensor that prevents that valve ping. Even without a code, a knock sensor can fail. They can be tested before you replace it.