Hey everybody, I just wanted to get a few opinions. My datto rarely gets driven and the last time I took it out it started smokin pretty bad. I just thought it needed the carby tuned as it has not been touched in years but then yesterday I was jacking up the rear end of the car and noticed that the inside of my exhaust is coated in thick black oil and this is what was causing all the smoke. It is a 1200 ute with an A14. Just wanted to get some opinions on what could cause this sort of thing. I know that a basic description like this does not provide to much info but any help would be greatly appreciated.

Cheers.

Craig.

That's odd. One of the oil rings on one of the pistons might be stuck or broken? But there must be a simpler explanation ... ???

Give the engine a compression test... maybe it will show bad compression.

Have any of ur mates done services on their own cars lately? Simple explanation mates had some old oil to get rid of and thought it would be funny to see the old datsun spewin smoke.
Also more info: how did it drive was it missing low power strange noises.
I would check my dipstick too.

Hopfully it's just a head gasket and not ring's. Or If your comprestion is good? it could be valve stem seal's?

Good luck..

Yes a leaking head gasket might do that, if it is leaking between oil pressure passage and a cylinder. Bad valve seals will cause smoke, but never seen it put thick oil into the exhaust pipe...

Have a compression test peformed. Or replace with CA18DE.

If it's actually running ok,and it's not getting hot or doing anything ugly my money is on valve stem seals,when there sitting around for extended periods with old seals they end up as hard as christs feet.

wet and dry comp test
leakdown test

oil rings can jam in the grooves while compression rings dont so compression is ok but oil consumption up

valve guide clearance excessive
valve guide seals hard,broken or missing
oil rings u/s
pcv system blocked
oil old and degraded (rings cant scrape it off cyl walls)

change oil (good quality)
warm up properly
then load it up.up a hill is good. make it work. drive it hard (not revs just load)
it'll get worse or better
if it gets worse it was dead anyway

have heard of guys tipping redex or similar into cyl to free up stuck rings

dazza

My coupe is the same, it blows more smoke that a self combusting bilby. I did a hot and cold compression test and it looks like rings and worn ring groves as I have a 50psi difference between the two tests. 175 even hot (low to start with) and only 125 even cold. I would be supprised if I have any valve guide seals left either. I have had a few cars do this to me if they have been left for extended periods then driven every day.