Deep noise when accelerating at 2k-3k revs when cold

Soldato
Joined
18 Oct 2002
Posts
9,223
Noticed a strange noise coming from my 02 1.6 Focus, especially when the car is cold. When accelerating in 1st and 2nd gears between 2k-3k revs, there is a change in engine sound and it sounds very deep and much louder than it does throughout the rest of the rev range.

It's hard to explain, kind of louder, deeper and echoey. Doesn't sound right to me at all.

Any thoughts?
 
This occured to me but it sounds more like an engine noise coming from the front of the car. Its confusing as it only seems to be at low revs when the engine is cold.
 
cold air being sucked into a cold engine hence making it sound a lot stronger and deeper than when warm?

my r32 does it. if its cold, and its pretty cold outside, the mid range engine noise is very deep and strong.

Doubt its anything to worry about.
 
I have a similar noise coming from my 02 1.6 Focus Zetec. I took it to the dealer and they replaced the back and middle of the exhaust but it hasn't fixed it. When i get to about 30 in 4th it goes and then returns changing in to 5th and then disappears again when i reach 38-40. I can also hear it through all the gears but goes quicker, its more noticeable up the range. Change into 5th at 28-30 and it is very noticeable.

I agree about the cold thing, it goes after about 30-40 miles of driving. It hasn't got worse but it annoys me not knowing what it is.
 
I would say mine disappears within about 5-10 mins of driving. I have had the car for about 2 months now and last week was the first time I have noticed it. Has only done 23k miles and strictly speaking its due a service (was done 2k miles ago but as this car hadn't been used it was done 1 year ago).

Wish I could describe the noise better :p
 
Mine is going in for MOT and service in June so ill get them to have another look at it then. I need to go for a longish run to determine when the noise goes. I only do a couple of miles a day - if at all. Weather is nice (for March!) at the moment so i'm cycling to work.
 
Manifold gasket? My old Corsa had an eroded gasket and when the engine moved under acceleration a gap was opened between the manifold and exhaust causing a louder than normal noise until the thing had heated up and expanded enough to close the gap. It didnt have the bendy bit you get where the exhaust meets the engine.
 
Mat said:
Manifold gasket? My old Corsa had an eroded gasket and when the engine moved under acceleration a gap was opened between the manifold and exhaust causing a louder than normal noise until the thing had heated up and expanded enough to close the gap. It didnt have the bendy bit you get where the exhaust meets the engine.

Sounds plausible - is it easy to 'see' if i get the car in axel stands?
 
It wasn't on the Corsa, the exhaust fitted around the gasket and was secured either side so you couldn't see it. If you can get the exhaust off the manifold you will probably see the gasket just sitting there in the end of it.
 
Quick update on this: I've found my noise is in all gears upto around 1600 - 1700 rpm then it disappears. Any ideas?
 
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