Slapping piston????

Piston slap?

I don't ever recall having a car with "Piston Slap" but I had Motorbikes with the tell tale "I have been caned" syndrome. Trouble is with Bike piston slap is it is always there. You rev up the motor then back off the revs and you get a nice "Kaggggggggggggg" metal to metal sound, which is there in a more muted stated on idle.

Yours sounds more like insufficient lubrication at the cam/valves when first started up. Might even be gummed rings (Oooer Missus)

I don't know how to fix it but I would start with the obvious. Oil, oil filter change and clean out the oil pickup in the sump. Maybe a good engine flush run through it. To clear up those hard to reach oil ways. Regular oil and filter changes would practically negate the use of such a practice!

Hard to describe a "Sound" using letters the "Kagggggg" is a "K" as in the phonetic "k" and the "aggggg" is in the back of your throat, like you are trying to shift some heinous greeny. (Sorry)

Yep. last oil change was 5 months ago but it is going for mot and service on Saturday. Local & reliable garage - so I'll have a chat with them about it. Piston slap - try a google search and it does exist. Seems more like claggy valves & oil flow problem to me now.

If it is piston slap there's really not much you can do but overbore the engine and fit new pistons. Alltough i've heard of B230 series engines wich has developed piston slap around 200K wich ran fine another 100K. I don't think piston slap can be intermittent. If it's not bad you'll only hear it when engine is cold, always, not intermiitent

With the 1.7 Litre engine, you describe your 400 series as having, It is very easy to deal with a slapping piston. You replace the cylinder liner(s) and piston(s) which are slapping. However, as in all things mechanical it is best to replace all liners and pistons to ensure a matched engine. However, there are a myriad of other faults which can cause this symptom, such as one tappet requiring adjustment etc. To be sure check the Renault FAQs on-line as the engine is a Renault unit. If you have the fuel injected version, injectors can also make a similar noise. Try fuel and fuel injector cleaner in the fuel tank.

Cheers, Peter.

: > Incidentally I do remember a motorbike rally years ago that used to be : > called "piston broke". Clever when you think about it eh? : > >

: > > It'll be tricky to get a good mp3 as there's always other louder noises : > around (unless lifes truly about to go wrong in which case switching off : is : > going to make more sense than running for a microphone ) but anyway I'll : try : > & look silly : > >

: > > Pinking literaly goes "inck inck inck inck inck" with the emphasis on : the : > c : > > labouring goes burrgg & sounds like your Dad driving uphill in 5th : > > piston slap varies dependent on the car but it's more unk unk unk than : ink : > ink ink. It's also worse when cold : >

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Just had MOT, annual service inc filters, oil etc and new brake pads on front for £148. Guy said that the noise was the hydraulic tappets with an oil flow problem and that the new oil change and better quality Castrol oil (!) should solve the problem. Will find out tomorrow when the car is cold and has to work hard...... He also said that at 85k miles it would cause more problems than it would solve to flush the engine oil out as the bits in the system would be moved around and might cause a problem elsewhere rather than at the bottom of the sump. I'll take his word for it anyway. No need to but another car now that the old lady has passed her Test;-))