Popping noise on start up

[nismine01]

I used to have a 300TDI Disco I, at one stage it was making a similar noise to this noise on my TD5.

It turned out to be due to a timing belt idler having disintegrated and the valve timing was out causing a little pop back through the inlet manifold to be heard at the air box. It was constant in that case.

With the TD5 it is only momentary and I am wondering if it may just be a sticky lash adjuster because it goes away within seconds of start up.

Any thoughts out there? :o

Regards



Mike

[relatively normal]

Any more details available? Is it when cold or hot start up? Is it a 'pop' through the inlet/airbox like your last car?

Could it be oil starvation to say a lash adjuster/lifter which makes a noise that when started up then gets an oil supply which quietens it down again?

When was its last oil change? run an engine flush through it and new, maybe slightly thicker oil and filter.

[nismine01]

I hope the noise is not "relatively normal".
Only happens when cold, first start of the day, doesn't seem to matter the cycle of service.
It does sound like air box for the noise, I am using Penrite 5-30 and I will not change to a thicker oil, the only thing I can think of is lash adjuster 'bleed down', overnight.

Mike

[bee utey]

You've got LPG enhancement fitted from memory. Your gas regulator may be allowing a small amount of LPG to dribble into the inlet manifold overnight. This will knock loudly for one revolution or so. Try turning the engine off at night after driving the last 5 minutes with the gas switched off.