Black oily residue from the exhaust pipe - Isuzu 6BD1T

one simple thing to do is use an engine oil thats specced for 2 stroke GMs...............these oils generally burn a lot cleaner ,and dont make the putrid stink you get from worn 71 series GM exhausts..............I have always used them in vintage motorbikes that tend to burn a lot of oil..............no stinky exhaust is good PR.............especially when every 10 miles there a TMR sign inviting cardrivers to rat out a smoky truck.

Thanks John.
I’ve always used Castrol RX Super. I guess I’d rather to find out what’s causing the issue but will certainly take your advice on board.
Regards
Ash

Photos during investigation. The turbo outlet pipe to intercooler, the outlet of the turbo and the exhaust brake which has. No oily residue just soot with my fingerprint in it.

There seems to be a bit of oil coming from between the two sides of the turbo where my finger is in the picture below

Old diesel engines burn oil.....simple fact..........which is why the greenies hate them...and dont let the engine idle for long periods ,cause it will blow smoke soon as it gets hot again,and starts to burn the oil in the exhaust away ......the turbo gets very hot due to gas turbulence,and burns away all the oil and carbon on the metal,but the black settles further down the pipe where things are cooler.......one thing to be wary of is exhaust repairs where you hammer away at the pipe and muffler........the loosened carbon will blow out a thick black cloud ,and get you a smoke notice.

I understand what you mean John.

Thing is it just started doing it in a very short time ie per a few kms. I agree that she’s an old engine but would expect the soot and smoke from it to increase gradually as things wear.

Given how quickly she starting sooting it makes me think something “went” rather than wear suddenly got worse.

I’m not sure hence being on this forum so that I can learn from the experience of others.

You need to keep an eye on the air side of the turbo........remove the hose periodically and check for oil in the hose.............about the biggest disaster with a turbo is a bearing fail that will pump oil into the intake air ,and the engine will over rev burning the oil.......and cant be shut down...........I always think that this is a good reason for having an exhaust brake......with the brake slide closed ,the engine cant rev,and will probably be able to be stalled with the clutch.

Thanks John. At this stage I’m a bit stumped.

Everything appears ok except for the oil at the bottom of the turbo in the photo above.

Not sure where to go from here. Does this mean the seal on the intake side has gone?

Hi Jon_d

It is a Garrett but I can’t read the model
Number.

Was hoping to get that so maybe track down a parts manual.

I would think along the lines of a damaged seal or the oil pressure line is leaking.