Hi All,
intermittent misfire with a puff white smoke under load then a loss of power for a while then goes to normal ish ever since i changed the engine oil from castrol 10-40 mag to 5-30 and cleaned out the K&N air filter and using her for 160 mile daily round trips, i have now changed the oil back to 10-40 and changed the air filter to a standard one.
The above problems still exist but nowhere near as bad, all this happens between idle and 2000 rpm above this she runs like a train

TD4 126000 on the clock
EGR valve removed
bmw cyclone fitted
inlet manifold cleaned new gaskets all round
ron eco bypass fitted and airflow meter changed
new glowplugs fitted
new bosch low pressure fuel pump and filter fitted
silicon intercooler hoses fitted
new high pressure fuel sensor and harness fitted

All the above was done 2 years ago

I have a feeling that the injectors could do with replacing and i accept that the problem could be nothing to do with the oil and air filter and just my bad timing lol

Any ideas guys

Check your egr, turbo, intercooler hoses for tightness of the clips !

If the injectors haven't been replaced then get them checked. It is very difficult to tell which one isn't right as they compensate for each other. Autologic suggested my no 1 & 4 were wrong but ended up being 3&4.