Tap Tap Tap of a 95 e34 525

[shelldrake]

140k miles on my 95 525. Runs strong, no apparent problems. Oil changed with synthetic every 4-5k miles.
Its been about 4k since last change, 5-30 for the cold New Hampshire winter. At idle speed, the motor starts to tap, quite noticable after about 30 seconds of idle time. Runs back to smooth and quiet after bringing up revs fora few seconds.
I have heard valve adjustments are needed as routine maintainance on this motors and was just wondering aloud on the forum if this sounds like typical adjustment scenario, or if you all think there may be other issues. Thanks a bunch.

[jjdickm]

try switching to a higher octane fuel for the hotter months. if you already are you my want to try to get the valve adjusted it might quiet it down some but it may still be present after the adjustment

[Rustam]

140k miles on my 95 525. Runs strong, no apparent problems. Oil changed with synthetic every 4-5k miles.
Its been about 4k since last change, 5-30 for the cold New Hampshire winter. At idle speed, the motor starts to tap, quite noticable after about 30 seconds of idle time. Runs back to smooth and quiet after bringing up revs fora few seconds.
I have heard valve adjustments are needed as routine maintainance on this motors and was just wondering aloud on the forum if this sounds like typical adjustment scenario, or if you all think there may be other issues. Thanks a bunch.

m50 engine does not require valve adjustment since they have hyrdaulic lifters that self adjust each time the car runs - they get to fill with oil. I saw some info on this on the internet long time ago. I think someone said that the lifters were "no good". When oil pressure sablizes the lifters stop making noise. Look further in this direction - consider conditions of those lifters...

[yaofeng]

140k miles on my 95 525. Runs strong, no apparent problems. Oil changed with synthetic every 4-5k miles.
Its been about 4k since last change, 5-30 for the cold New Hampshire winter. At idle speed, the motor starts to tap, quite noticable after about 30 seconds of idle time. Runs back to smooth and quiet after bringing up revs fora few seconds.
I have heard valve adjustments are needed as routine maintainance on this motors and was just wondering aloud on the forum if this sounds like typical adjustment scenario, or if you all think there may be other issues. Thanks a bunch.

Hydraulic lifters making noise at start up is very normal. As long as they quiet down afterward. Don't know what BMW said how long. On my SAAB the shop manual says lifter noise up to 15 minutes following engine start up is normal.

[Omega]

Typical hydraulic lifter rattle. To be expected after high mileage.

I am by no means an expert but believe it's usually caused by crud in the oil blocking the oilway in the lifter. Increasing revs increases the oil pressure, clearing the crud and allowing the lifter to pump up - until the next time... Also as oil gets hot it thins, allowing the crud to float about, hence the ~30 second idle before rattle.

I ran an engine flush through mine the last three oil changes and it seems to have worked. 4k miles later, no rattle.

The alternative is to try and find the one that's blocked/failing and replace it. It's difficult to find the "one" and obviously you can replace them all, but that's mega $$$ - Well it was at my indy. If memory serves me right, it was about £18- per lifter * 24 lifters + labour making a total of around £700.

If it comes back, I'll live with the rattle. Over here(UK), the car isn't worth more than £500 on a good day due to the high gas prices and associated running costs. I love my BMW but it's becoming cheaper to scrap it and buy another (BMW natch! ) than have anything major fixed!

After looking at the e34 tourings on this site I've decided that I want one next. I don't wan't my current one to go bang just yet, but....