E30 Zone

Driving home in the snow/sleet today I suddenly realised that my motor had quietened down quite a lot (M20 b25)

I started paying close attention and it being a very cold and damp day (little above 0º) and having the heating on full, my temp gauge never made it to half way until I hit a bit of traffic near the end of my journey, at which point my tappy tappy returned.

I'd not noticed before but it seems that with a cool motor the top end is quiet, as soon as it warms the tapping starts.

What do you reckon, wrong oil grade or cack handed valve gap adjustment (twice) ?

I would double check the oil, Mine is the same never warms up until either i hit traffic or i do a at least 10 miles.
I know the oil would be a little more viscous at this low temperature but not that different.
Had the car been running long? if the engine was could then some expansion could change the tapping at the top.
I have totally re-built my top end with new parts and it still taps noticeably but this seems common to all 6cyls.

Well the oil that's in there is a fairly standard 10W40 Shell brand oil. So it should really be OK. The engine warms up properly, almost hitting the half way mark. Yesterday was exceptional that it took 20kms of driving to get there !

I've rebuilt the head on mine but not with new parts (I dismantled it and the engineering shop who skimmed it did the reassembly and told me there was no need for any new parts so in theory it should be ok), I did the valve clearances once before firing it up and again after 1000kms. It's now done another 1500kms or so.

I wasn't overly worried until there was thread recently about how people love the sound of their M20 engines and turn off their stereos to hear it, whereas I turn my stereo up to drown out the tappety tap

I would think that as the engine warms up the noise should quieten down a bit...metal expands, so surely the set tolerances should close up a bit?

sihooker wrote:I would think that as the engine warms up the noise should quieten down a bit...metal expands, so surely the set tolerances should close up a bit?

thats what i always assumed, weird really but some times things seem to get louder lol

sihooker wrote:I would think that as the engine warms up the noise should quieten down a bit...metal expands, so surely the set tolerances should close up a bit?

Exactly. Hence the question about the oil, its the only thing that I can think would cause it to be noisier when warm.