Knocking noise on Fiesta 1.25 - The Grey Man
I drove my wife's 98 Fiesta 1.25 Zetec yesterday, and when sitting at traffic lights idling, there is a single knock noise every couple of seconds, at perfectly equal intervals which suggests to me that it is from some moving part either engine or clutch, any ideas what this could be?

Thanks
Knocking noise on Fiesta 1.25 - Malcolm_L
Every couple of seconds would suggest something like the exhaust or something loose.

Can you locate the noise with the bonnet up?

Knocking noise on Fiesta 1.25 - Kingpin
Is it a very slight 'thump' sound from near the dashboard - I remember a problem with these models, something to do with the heater water valve causing a very slight regular noise. Some described it to be like a 'heartbeat' - perfectly harmless design fault.
Anything louder would suggest mechanical engine knocking - unusual on the smooth 1.25 engine.
Knocking noise on Fiesta 1.25 - Blue {P}
Haven't got the A/C on have you?

Sorry to ask such an obvious question but it's easy to overlook that answer!

Blue
Knocking noise on Fiesta 1.25 - The Grey Man
Thanks for your replies so far folks, the car doesn't have a/c so it can't be that. It is kind of like a heartbeat so I cleary need to get the bonnet up with the engine runnning and see if I can pinpoint the location a bit more. It's funny doing a search on the technical matters forum, you find that certain cars have the same little foibles. Our Fiesta has the problem of intermittent failure of the rear wipers and internal boot release due to the dodgy four prong/contact plate connection in the tailgate also the rattling from the vents in the central console which again seems common.

Useful to search this forum before buying your next car, find out what its really like!

Cheers

The Grey Man
Knocking noise on Fiesta 1.25 - Chas{P}
Grey Man,

I think this Ford TSB covers your problem:


TECHNICAL SERVICE BULLETIN No.144/1998

Car and Light/Medium Commercial 07.10.1999

Section: 34 (412-02)

Model: Fiesta '96, built in Dagenham, from 08.95 to 13.08.99 (build codes ST to XT) inclusive
Fiesta '96, built in Cologne, from 08.95 to 06.08.99 (build codes ST to XT) inclusive
Puma, built from 06.97 to 06.08.99 (build codes VR to XT) inclusive
Ka, built from 09.96 to 27.08.99 (build codes TL to XT) inclusive

Markets: All

Subject: Constant knocking sound from the crash padding/fascia when the heater control switch is set to a temperature between MIN and MAX.

Summary

Should a customer express concern about a constant knocking sound when the temperature is set via the control switch to a temperature between MIN and MAX, this is probably caused by coolant flowing through the heater control valve. This sound is transmitted via the crash padding/fascia to the passenger
compartment and can be amplified by any air trapped in the system. The noise should be reduced by installing revised insulation to the heater control valve in conjunction with a modified heater coolant hose.

The cooling system should also be bled according to the instructions in this bulletin.

Parts Required
Description:Heater coolant hose (RHD) FINIS Code: 1087934
Description: Heater control valve insulation FINIS Code: 1087746

HTH

Charles
Knocking noise on Fiesta 1.25 - DL
Where did you get that TSB from??
Knocking noise on Fiesta 1.25 - Chas{P}
I'll email you direct.

Charles
Knocking noise on Fiesta 1.25 - linac eng
Grey man,

I get this on my '97 1.25 also. It is as described in the Technical Service Bulletin posted by Charles. Once I knew what it was i stopped worrying about it!
 

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