M157 Warm start rattle solved 😁
08-15-2022, 04:02 PM
#1
Member
Thread Starter
M157 Warm start rattle solved 😁
So for a while I have had a start up rattle that I thought was the timing chain tensioners rattling untill they built oil pressure.
The car is a 2015 E63 and already had the check valves fitted.
It drove me insane and only happed on a warm start after being left more than 5 mins. Never on a cold start.
So I had new tensioners fitted and no change.
Then I noticed it would also do it when I pressed the brake hold function.
Bingo found the issue and the tick that sounds like timing chain, turns out it's not the timing chain.
On a warm start and when you press the brake peddle hard the turbo actuator flutters in and out fast, this causes the lose waste gate to rattle, I confirmed this by watching it then by holding it from rattling with a large metal bar (it was hot)
So the cause is fluctuations in vacuume to the actuators causing the waste gate to tap tap tap tap on warm starts. I'm suspecting the one way valve needs to be replaced in the vacuum pump.
Just thought I would share.
Now to solve why my car burns oil and randomly smokes blue smoke out of both the tailpipes enough to see it in mirror only on over run after a hard run. Never under full power or at idle no burning oil, just under high vacuum when you let off the throttle ? Maybe turbos ? Maybe stuck pcv ?
No misfires, no power loss, all runs smooth. Just burns oil on the over run.
Good compression on all cylinders.
The car is a 2015 E63 and already had the check valves fitted.
It drove me insane and only happed on a warm start after being left more than 5 mins. Never on a cold start.
So I had new tensioners fitted and no change.
Then I noticed it would also do it when I pressed the brake hold function.
Bingo found the issue and the tick that sounds like timing chain, turns out it's not the timing chain.
On a warm start and when you press the brake peddle hard the turbo actuator flutters in and out fast, this causes the lose waste gate to rattle, I confirmed this by watching it then by holding it from rattling with a large metal bar (it was hot)
So the cause is fluctuations in vacuume to the actuators causing the waste gate to tap tap tap tap on warm starts. I'm suspecting the one way valve needs to be replaced in the vacuum pump.
Just thought I would share.
Now to solve why my car burns oil and randomly smokes blue smoke out of both the tailpipes enough to see it in mirror only on over run after a hard run. Never under full power or at idle no burning oil, just under high vacuum when you let off the throttle ? Maybe turbos ? Maybe stuck pcv ?
No misfires, no power loss, all runs smooth. Just burns oil on the over run.
Good compression on all cylinders.
Last edited by Osgee; 08-15-2022 at 04:04 PM.
08-15-2022, 05:10 PM
#2
Out Of Control!!
Join Date: Jun 2004
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2014 E63S; AMS 100 octane ecu tune; edok tcu tune; BB intakes; dyno tuned
08-16-2022, 07:16 PM
#3
turbo actuator flutters in and out fast
Any luck in resolving this?
