I've been hearing a loud intermittent ticking noise at idle. It increases with RPM and will fade away past 3K RPM. Generally I hear it when I'm idling at a stop light, but as I said it's intermittent so I don't hear it all the time. The noise is similar to two shot glasses being smacked together. It's not injector tick as it's much louder than that. It's very hard to pinpoint the noise as it only comes on ~30 seconds at a time. At first I thought it was coming from the valve cover, but it seems almost louder when I'm under the car (on ramps).
I'm taking this to the shop on Monday as I've run out of ideas and skill to diagnose this. I'm guessing it could be a bad lifter, worn oil pump, or bad oil pressure relief valve. I'd like to hear what the M42 experts think.
Here's some more, possibly relevant information:
- '91 318is w/ 141K miles.
- Timing guides and tensioner replaced last year, timing gears looked fine at the time.
- Upper and lower oil pan gaskets replaced last year.
- No oil leaks! Car doesn't burning any oil.
- Oil filter housing gasket + o-ring replaced (as well as the engine mess under the intake) within the last 10K miles.
- I've used both Rotella T6 5W-40 and Mobil 1 15W-50 oil.
- This seemed to go away over the winter, so perhaps it has something to do with outside temperature?
- It doesn't matter if the car has sat for 3 days or I've been driving for 3 hours. The sound will come and go regardless of the engine being cold or thoroughly warmed up.
Thanks!
I'm taking this to the shop on Monday as I've run out of ideas and skill to diagnose this. I'm guessing it could be a bad lifter, worn oil pump, or bad oil pressure relief valve. I'd like to hear what the M42 experts think.
Here's some more, possibly relevant information:
- '91 318is w/ 141K miles.
- Timing guides and tensioner replaced last year, timing gears looked fine at the time.
- Upper and lower oil pan gaskets replaced last year.
- No oil leaks! Car doesn't burning any oil.
- Oil filter housing gasket + o-ring replaced (as well as the engine mess under the intake) within the last 10K miles.
- I've used both Rotella T6 5W-40 and Mobil 1 15W-50 oil.
- This seemed to go away over the winter, so perhaps it has something to do with outside temperature?
- It doesn't matter if the car has sat for 3 days or I've been driving for 3 hours. The sound will come and go regardless of the engine being cold or thoroughly warmed up.
Thanks!
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