Hi all,
Looks like i'll be back off to the garage with my newly acquired 45000 mile X reg Mondeo 1.8 Zetec.
On acceleration there is a strange noise, its not there if driven steadily, but if for example I slow to around 35mph in 4th gear and then give it the gun to accelerate there is a noise, over and above the engine noise, the best way i can describe it is like rushing air or a like a fan.
It will do it in all gears but seems to be worse if you slow down and then re-apply the throttle.
Sorry for the vagueness but anyone any ideas so i can go back a bit clued up?
PP
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hi
sounds like an air leak from the inlet manifold iam not sure though is this a turbo car or is it normaly aspirated
could just be the way it was designed,
Kind regards
J Stephenson
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Well done James.
I was just thinking the same.
as you "gun" it, you raise inlet manifold depression. You increase the vacuum there. This causes increased air movement. Noise is air movement. That really is all that noise is.
So, likely that you have a leak.
One reason why air intakes are at the front is to keep the noise away from you. The other is to suck unimpeded airflow in.
look at your exhaust at tickover. Stick your hand next to it.
Be impressed at just how much air movement there is.
Equal and opposite volume at the intake.
Now think of the volume when "gunning".
MUCH more than you think.
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Hi
before you go to the dealer that sold you the car take it to an independent and have them look at it if its what we suspect then get written proof from the idependant with a quote keep the quote to you're self then take the car to the dealer who sold it to you show them the written info and when they quote you a price (unless its covered by the cars warranty you did get one didnt you ?) they should repair it for free,
if me and sean are correct it may be due to a warped inlet manifold or a holed gasked i hope its the second
good luck
J Stephenson
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Again, brilliant work James.
Forgive me if I sound patronising, but you truly are spot-on. A very bright poster.
Please consider also a Jubilee clip that is loose. It's not a Jubilee clip, as they cost 3p more, so it will be a spring clip that needs relocating, and when you "gun" it, engine movement opens the gap so you hear it more.
Thanks James. A lovely piece of work. I'm indebted.
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"as you "gun" it, you raise inlet manifold depression. You increase the vacuum there"
Are you sure, Sean? Yes, an increased volume of air flows but the depression (vacuum) goes. Ever observed a vacuum gauge connected to an inlet manifold?
Driving an old Ford with the vacuum wipers would also demonstrate this point!
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Thanks for the replies do far gents. Engine is 1.8 Zetec Petrol, no turbo!
Just to add to my original post, i've noticed that I cannot recreate this noise by revving the engine with the vehicle at a standstill or coasting out of gear, it only makes the noise under load.
Does this still point to the inlet manifold being at fault and if so where is this manifold located and am I likely to be doing any damage by driving the vehicle while the manifold is failed/failing?
The supplying dealer is a car supermarket located around 40 miles from me, they have told me to book into a Ford dealer of my choice and have given me details to arrange for payment to be billed directly for any work.
Many thanks again for your invaluable advice.
PP
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Peter,
The above suggestions are all sound, but can I would like to ask one question. Despite the noise, does the engine rev freely to maximum rpm in the gears ? If it does, I go along with the inlet air leak theory, but if revs are at all restricted it could be the other end - a partially blocked exhaust, and most likely the Catalytic Converter. Not easy to prove, but observing inlet manifold vacuum is a clue - vacuum should be fairly steady on a steady throttle (around 21 ins of mercury at 1500rpm +) - if it drops away significantly as revs increase (don't go above about 3,500 at kerbside) it points to an exhaust blockage. The noise you would be hearing is the high pressure exhaust gas escaping somewhere other than the tailpipe.
Regards, Adam
Whatever is rightly done, however humble, is noble.
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Spoke to Ford dealer yesterday, they doubt it is the inlet manifold as they very rarely fail apparently. They seem to think it's an exhaust problem so Adam u may be right.
Getting it looked at properly next week so I'll post the result.
Thanks again,
PP
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Car is booked into Ford main dealer for 12th August.
I now have another odd front end noise which is a rather loud creaking, seems to get worse when turning or cornering.
The car has just had two new CV joints fitted last week.
Any ideas?
PP
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I have exactly the same problem with my 1.8 Mondeo. I have tried a few things, based on the premise that the noise was pinking. Indeed Shell Optimax seemed to cure the fault for a while, but the car seems to 'get used to it' after a while and it now has no effect.
I have heard stories of blocked cats in the past, but surely this would be associated with a dramatic loss of power and or unusual emissions readings?
p.s. my car starts this noise at around 2000 rpm and it stops below 3000 rpm. Is yours like this?
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The noise doesn't seem to be related to the rpm, more to the gear and how I'm applying the throttle.
I can get the noise reproduced in each gear at different revs, it's very odd and I'm hoping that the Ford dealer who it is booked in with can cure it as it's annoying the hell out of me.
The other creaking noise I mentioned is now a permanent feature so I hope the dealer is able to rectify that too.
I'm also experiencing a very notchy third gear, I've not noticed anything similar on my four previous Mondeos', so I know something isn't right so they've got quite a list of jobs to be getting on with, I'm glad I'm not footing the bill.
PP
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The description sounds very much like a clutch problem I have not see for about 20 years. I think it was called 'clutch thrash', and was apparently caused by a faulty clutch pressure plate. This caused a harsh vibration through the gearbox when accelerating in any gear. Does anyone know if this fault is still a possiblity?
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UPDATE:
Mr Mansell you got it in one! Clutch diagnosed as being at fault, don't ask me exactly which bit of it as I got lost when it was being explained to me. New one fitted yesterday and it's spot on.
Also had an obstructive third gear which turned out to be the synchro, so that has been replaced too, along with two antiroll bar link arms that were creaking.
Total bill just under £800, am I glad it was on warranty!
I must add that I can't fault Ford's of Winsford after sales department, excellent throughout, allowed me to use a Ford garage of my choice and agreed to pay in full for all parts and labour needed - well done to them.
PP
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