M42 cold start ticking

[duboy]

I just replaced my chain tensioner, didn't fix the problem. When the engine is cold, it sounds like a sewing machine M20 for just a few minutes. i usually let it idle for a minute or two then drive off slowly. By the time i'm two minutes in to the drive, the engine is quiet, no ticking. it is quiet after a warm start, doesn't have any problems starting, or idling. the e30 is new to me, i know the head was rebuilt by the PO though. any ideas?

[DesktopDave]

One of your valve adjusters is leaking down.  It'll take a few minutes for oil to refill the leaky unit.  I'm told you can test them individually but I'm not sure how.

I haven't done this myself, but I've heard that some Marvell Mystery Oil might be the ticket.  Some say a bit of ATF will quiet the problem but that sounds risky to me.  Do you run synthetic or conventional motor oil?  What weight?  If you go with slightly thinner oil it might help a bit too.

[duboy]

i put in 20w50 conventional oil. on this last change. should i try something thinner like 15w40?

i guess the real question is, can i continue to drive it this way, or should that be something that gets looked at asap. (there are other things i need to spend a bit of money on mechanically, trying to tackle the most important things first)

[DesktopDave]

It's not critical.  They do that to annoy you.   I've had cars with soft lifters rattle like that for years.  Beats adjusting the valves every 12k miles (like on my 525iM), that's for sure.

I'd definitely change over to 15w40 synthetic on your next change, a 5 quart jug of Mobil1 is only ~$30 at Wally World.  You can usually find some coupons for free filters at Pep Boys or Advance Auto with five quarts.  The engine might leak a little more but it'll definitely run better.

New to the e30 or BMWs in general?

[BimwadM42]

While digging around in the TIS last night, I came across a BMW bulletin that essentially said not to worry about noises from soft lifters.

[nicknikolovski]

Thats normal, if noise continues during warm start, then I would change the lifters but in your case it is ok. Using a lower weight oil will help. I used to use Mobil 1 5W-50 but it is too thin now. I then switched to a Fully Synthetic Valvoline 10W-50. Not as good as Mobil 1 but does the job.

I also heard that after a oil & filter change (for bucket type hydraulic lifters) , run the engine at 3,000rpm to bleed the lifters properly. Can anyone verify this?

[duboy]

It's not critical.  They do that to annoy you.   I've had cars with soft lifters rattle like that for years.  Beats adjusting the valves every 12k miles (like on my 525iM), that's for sure.

I'd definitely change over to 15w40 synthetic on your next change, a 5 quart jug of Mobil1 is only ~$30 at Wally World.  You can usually find some coupons for free filters at Pep Boys or Advance Auto with five quarts.  The engine might leak a little more but it'll definitely run better.

New to the e30 or BMWs in general?

thanks for the info Dave, i'll try the oil next change. Not new to E30s or BMWs, i've had a whole slew of E30's but they were all variants of the M20, right now this 318is joins my E30 M3.

Nick, i found this: http://www.enginebuildermag.com/Article/48377/toubleshooting_bmw_hydraulic_bucket_tappet_problems.aspx

i might try that when i do my oil change next.

[DesktopDave]

thanks for the info Dave, i'll try the oil next change. Not new to E30s or BMWs, i've had a whole slew of E30's but they were all variants of the M20, right now this 318is joins my E30 M3.

I haven't seen an M3 in years.  They're getting to be very rare these days.  Glad to hear another one is in safe hands!