Cabin noise at cruising speed (120) excessive or normal

MB-Sting · 9th February 2009, 18:30

Hi

When I drive 110 on the speedo the car is pretty quiet inside but once I go past 120 (2500rpm) the engine noise about doubles and you can almost not have a normal conversation in the car. Is this normal for the Scorpio suv or can something be done.
Note that the previous owner removed the CAT and put in a straight pipe + original silencer box. Could this cause the noise or is it just normal engine noise?
I cannot decide if it is engine or exhaust noise.

GTO · 9th February 2009, 21:48

Quote:

Originally Posted by MB-Sting

Note that the previous owner removed the CAT and put in a straight pipe + original silencer box.

That's the most likely culprit. That annoying sound is exhaust resonance / drone from a badly designed exhaust. Switch back to stock.

Atlblkz06 · 10th February 2009, 00:05

I agree with GTO. Unless you have an intake/cam or something done to the car, I'd go back to stock. Your post is a bit confusing though. Straight pipe = no silencer. Simply removing the cat shouldn't lead to a huge in crease in sound levels.

Samir Taheer · 10th February 2009, 14:57

Looks the cars only been De-catted. If the exhaust was the culprit, i would'nt have thought there would be that much of a difference between 110 and 120. Could it just be worn rubbers? The cabins not as well sealed as it used to be and he's just hearing excessive tyre noise and wind noise + the engine?

Atlblkz06 · 12th February 2009, 11:44

Engine "drone" is when the engine and the car create a standing resonant wave. This is very sensitive to the engine RPM since that's its source of energy to build up. this is probably why its so sensitive to speed.

Thats my take anyway.

9th February 2009, 18:30	#1
MB-Sting Newbie Join Date: Jan 2009 Location: Pretoria Posts: 9 Thanked: 0 Times	Cabin noise at cruising speed (120) excessive or normal Hi When I drive 110 on the speedo the car is pretty quiet inside but once I go past 120 (2500rpm) the engine noise about doubles and you can almost not have a normal conversation in the car. Is this normal for the Scorpio suv or can something be done. Note that the previous owner removed the CAT and put in a straight pipe + original silencer box. Could this cause the noise or is it just normal engine noise? I cannot decide if it is engine or exhaust noise.
	() Thanks

10th February 2009, 00:05	#3
Atlblkz06 BHPian Join Date: Jan 2009 Location: Atlanta Posts: 164 Thanked: 20 Times	I agree with GTO. Unless you have an intake/cam or something done to the car, I'd go back to stock. Your post is a bit confusing though. Straight pipe = no silencer. Simply removing the cat shouldn't lead to a huge in crease in sound levels.
	() Thanks

10th February 2009, 14:57	#4
Samir Taheer BHPian Join Date: Sep 2008 Location: London & Pune Posts: 459 Thanked: 278 Times	Looks the cars only been De-catted. If the exhaust was the culprit, i would'nt have thought there would be that much of a difference between 110 and 120. Could it just be worn rubbers? The cabins not as well sealed as it used to be and he's just hearing excessive tyre noise and wind noise + the engine?
	() Thanks

12th February 2009, 11:44	#5
Atlblkz06 BHPian Join Date: Jan 2009 Location: Atlanta Posts: 164 Thanked: 20 Times	Engine "drone" is when the engine and the car create a standing resonant wave. This is very sensitive to the engine RPM since that's its source of energy to build up. this is probably why its so sensitive to speed. Thats my take anyway.
	() Thanks