NOISY ENGINE WHEN COLD

CITMAN · Unread post by **CITMAN** » 22 Feb 2003, 02:09

I have 1995 citroen zx 1.4i with 74000 miles. On starting then engine from cold, the engine seems noisy i.e. knocking noise. However when the engine has warmed its smooth as silk. Has anyone else got a 1.4 zx with a noisy engine when cold. Been told its a design issue with the engine i.e. clearance between crank and bearing.

AndersDK · Unread post by **AndersDK** » 22 Feb 2003, 03:20

Never owned a ZX - but once droved a ZX home for a friend.
Seems to be similar to the old GS(A/X) engine noise, which also was inherent to these models - noisy on start - smooth when warm.
A good old trick is to use the older type engine oils with somewhat thicker viscosity : 15w/40 or 20w/50. These oils sometimes makes magic wonders on engine noise.
C U
Anders(DK)

jeremy · Unread post by **jeremy** » 22 Feb 2003, 03:50

Sound to me as though this may be piston slap. Many older engines suffered from this from nearly new and lasted for years. Its caused by the piston skirt touching the bores and the thicker oil suggested by Anders may help. Otherwise I'd suggest that the engine is treated gently until it has warmed up and the noise has stopped.
jeremy

sooty · Unread post by **sooty** » 22 Feb 2003, 21:52

If its just as the engine starts, it could be where the oil has drained from the crank or camshaft bearings causing the knocking sound till the oil has reached these parts. Or if the engine has no electronic engine management system, it could be that your ignition timing is out or excessive fueling or as Jeremy says could be piston slap.
Sooty

AdrianO · Unread post by **AdrianO** » 23 Feb 2003, 01:24

My first BX (D reg) had 2 engines (not at the same time of course) so noisy at start-up some people assumed it was a diesel. Never did the tappets, as the noise wasn't due to them. My current BX (J reg), still only 27k, is much more civilised at start-up, but also gets a bit quieter when warm -- aren't they all?

Unread post by **alan s** » 23 Feb 2003, 01:37

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Just a thought, but why not firstly either get a stethoscope or a long screw driver & run over the motor when it's cold to firstly identify which end of the motor the noise is coming from.
My BX 16 valve sometimes gets a noise on initial start up that can't be identified as it is a knock but it doesn't sound mechanical & in this case I am suspicious that I may have a head gasket with a small weep that is allowing vry small amounts of moisture into the cylinder #4 which then makes a detonating sound. I can hear it with the naked ear but not with a stethoscope in this instance which is why I've discounted mechanical wear.
By contrast, my previous BX had a clatter that everyone claimed was pistin slap but a sterhoscope test found was in the hydraulic pump. My guess is that it may be tappets which would of course be heard right at the top, but either way, I think you need to determine the general area the noise eminates from before you stand a renote chance of a diagnosis.
Alan S