Hello, on occasion, not every day, when cold there is a ticking or tapping sound when cold which gets louder with revs. It goes away after a 1 mile drive . On reading various articles I believe it to be either the timing chain tensioner or hydraulic lifters. Some Q's
1. How can you tell which it is ?
2. If lifters - is it easy to isolate which one?
3. How much will it cost to change the tensioner if it is the problem?
4. How much to change lifters if they are the problem?
5. How 'urgent' is it to get the problem fixed - am I likely to cause a bigger bill if I leave it a month for funds to build up?
thanks in advance.
M42 - ticking sound when cold
Moderator: martauto
unlikely to be the tensioner if it goes away once the engine has warmed up. more likely to be the hydraulic tappets which will quieten down once the engine oil has been able to circulate round the engine and lubricate them - notorious on the M42 engines. you can normally hear where abouts the noise is coming from - if it's the front of the engine it may be the chain/tensioner but if it's the top it's likely to be the tappets.
most of what i've read indicates this can sometimes be helped by changing the oil, only other option is to replace tappets but that's expensive. just make sure you let the engine warm up properly if possible before using it.
most of what i've read indicates this can sometimes be helped by changing the oil, only other option is to replace tappets but that's expensive. just make sure you let the engine warm up properly if possible before using it.
Or pehaps even a dodgey exhaust manifold before you go and condem the tappets! i take my iS to a bmw specialist and he's diagnosed my iS with a small hole in the exhaust manifold. And i have the same syptoms as you! IIRC its usually cylinder 1 that tends to crack. 
HTH
HTHAs the exhaust manifold heats up, the manifold expands which "seals" any small holes up. But obviously of the hole is too big you will still get ticking noise (possibly) and it'l be louder. 
Sorry dave - wasn't really suggesting you were wrong - just backing up that the manifold is an option as mentioned above.
In fairness though mine only does it for a short while too cos, I'm told, that the gap closes up as the metal expands with the heat.
In fairness though mine only does it for a short while too cos, I'm told, that the gap closes up as the metal expands with the heat.
E46 M3 CSL but dreaming of another E30.
This is probably just my notion as well but if I start the car in the garage on the level floor and let it warm up the engine won't make the sound. However if I drive the car out of the garage and stop it with its nose facing up hill - I have an incline on the approach to my garage entrance - go away for a few minutes to close up the garage then get back in the car - start it up it is more than likely to make the noise. Not sure why parking the car with its nose facing up hill would make it do it - as I say maybe just coincidence but it doesn't do it every time which makes it a bit harder to track down.
hi guys. . . .i think its defo the tappets! happens to mine quite abit . more in colder weather. . . .abit tappity on start up. . .but i then leave the car to warm up before i drive her. after that shes smooth as anything. in warmer weather, when started it doesnt make tappet noise. i believe the oil is warmer therefore it gets around the engine alot quicker and lubricating the tappets etc. but ive been told its nothing major, just make sure you take care of oil on the these motors. . . especially the m42 lumps!
I think i rememeber a test which was on the zone a while ago, which you could do which gives you more of a point in the right direction.
Start the car up with the bonnet open, rev fairly high so you can hear the tapping and then turn the engine off. If the tapping still occurs after the engines off it could be tappets or exhaust manifold. If the tapping stops it could be your injectors.
I *think* im right but prepared to be proved wrong!!
Start the car up with the bonnet open, rev fairly high so you can hear the tapping and then turn the engine off. If the tapping still occurs after the engines off it could be tappets or exhaust manifold. If the tapping stops it could be your injectors.
I *think* im right but prepared to be proved wrong!!