S65 Exhaust Valves at start up???
06-08-2010, 08:30 AM
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S65 Exhaust Valves at start up???
Was wondering if anyone can tell me if the w221 s65 has some sort of valves in the exhaust which are open at cold start and close once warm? The car sounds totally different (and much better) at start up but it only lasts a few seconds until it gets warm and then it quiets down considerably. I was thinking about removing it if there is a valve so I had the burble all the time. Thanks for the help.
06-09-2010, 01:45 PM
#2
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Was wondering if anyone can tell me if the w221 s65 has some sort of valves in the exhaust which are open at cold start and close once warm? The car sounds totally different (and much better) at start up but it only lasts a few seconds until it gets warm and then it quiets down considerably. I was thinking about removing it if there is a valve so I had the burble all the time. Thanks for the help.
Tom
10-09-2022, 09:38 AM
#3
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What is happening is that on a cold start the exhaust is not being routed through the turbos. Once it warms up the exhaust gets routed through the turbos which muffles the exhaust considerably. I deleted my mufflers on my CL65 and the sound still wasn't too loud because of the turbos.
Tom
Tom
Last edited by Xguy; 10-11-2022 at 11:02 AM.
10-11-2022, 12:15 AM
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OP the reason it sounds so rumbly upon cold start is everything to do with getting heat into O2 sensors and getting the catalytic converters up to temperature. Ignition timing is retarded such that the engine almost fires into the exhaust. This is the magic of modern engine management. The feds want closed loop operation within as short a period of time as possible.
The E55 was much more noticeable then both of the S65s, but the difference in tone is easily heard.
Expect it to be noisy longer from a cold start in low ambient temperatures. In Washington during winter it would rumble and pop on decel to the end of the driveway (350’ or so). Here in Arizona it is ten seconds or less most of the year.
The E55 was much more noticeable then both of the S65s, but the difference in tone is easily heard.
Expect it to be noisy longer from a cold start in low ambient temperatures. In Washington during winter it would rumble and pop on decel to the end of the driveway (350’ or so). Here in Arizona it is ten seconds or less most of the year.
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evilsaint (12-08-2023)
10-11-2022, 12:34 AM
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
Did you check for soft codes (if any?) via a scanner? In case something got stored when swapping the battery causing this behaviour.
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Xguy (10-11-2022)
10-11-2022, 11:40 AM
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OP the reason it sounds so rumbly upon cold start is everything to do with getting heat into O2 sensors and getting the catalytic converters up to temperature. Ignition timing is retarded such that the engine almost fires into the exhaust. This is the magic of modern engine management. The feds want closed loop operation within as short a period of time as possible.
The E55 was much more noticeable then both of the S65s, but the difference in tone is easily heard.
Expect it to be noisy longer from a cold start in low ambient temperatures. In Washington during winter it would rumble and pop on decel to the end of the driveway (350’ or so). Here in Arizona it is ten seconds or less most of the year.
The E55 was much more noticeable then both of the S65s, but the difference in tone is easily heard.
Expect it to be noisy longer from a cold start in low ambient temperatures. In Washington during winter it would rumble and pop on decel to the end of the driveway (350’ or so). Here in Arizona it is ten seconds or less most of the year.
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11-17-2022, 08:55 PM
#8
MBWorld Fanatic!
The time it spends being noisy has everything to do with how long it takes to get it into ‘closed loop’ which is the oxygen sensors making a usable signal for engine management. Don’t lose sleep about it taking less time. Here in Arizona when it never gets under 105 degrees the engine is still at 180 degrees after sitting ten hours. Next to no rumble. This time of year I’m likely pissing off the neighbors daily as I head out. But she sounds bad ***. Lol
