Thread: Turbo Troubleshooting

My money is on either a restricted drain or too much supply pressure.

Feed line to the turbo is primary (vac pump secondary - using tee piece). Feed line size is 1/8 and approx 0.6m in length.

Return line is 1/4 BSP nipple onto equivalent hose. Again turbo is primary line with tee installed to pick up vac pump return. I believe the route is direct comprising only gentle bend.

I too thought return line might be too restrictive so i disconnected the return line and plumbed in a short hose into 2lt bottle i.e. straight section ~150mm in length into 2lt bottle.

Unfortunately oil was still spurting through the compressor outlet. So frustrating!!

I really don't know, its probably got dodgy seals.

Could there be excessive oil supply to the turbo??

Though the feed line is small in diameter, there is quiet significant flow.

The turbo has done about 0.5 hours of work...at idle

Thanks

Originally Posted by 110Landy86

Return line is 1/4 BSP nipple onto equivalent hose. Again turbo is primary line with tee installed to pick up vac pump return. I believe the route is direct comprising only gentle bend.

That is most likely your problem. You need a separate return for the turbo. Either to the block tapping if your engine has it or to the oil pump cover.

I recall other people having similar problems when trying to use the vac pump return.

Do that first, and if you are still having problems, fit a restrictor to the feed line.

1/4" BSP isn't enough. You need a minimum of 1/2 and inch clear all the way through, 16 or 19mm is much better.

Turbo seals are designed to always leak, but only leak inwards. They leak outwards when the pressure inside the bearing core gets higher than the pressure in the compressor and turbine housings. Usually a blocked drain or an engine with a blowby problem.

There are a lot of $$ spent worldwide on rebuilding and replacing turbos that have absolutely nothing wrong with them.

Regarding restrictors, if you buy a banjo bolt thats designed to be fitted on a T25 then it should have a hole about 1.6mm in it (ball bearing turbos have a smaller hole).
That hole is effectively the restrictor in the supply line.

If you've got the banjo bolt from somewhere else that wasn't turbo specific it might have a bigger hole and be contributing to the problem.

Steve

I just saw the "vacuum pump return" part.
I don't believe you are the first to try and use this and have a turbo spewing oil as a result. I don't beleive you'll be the last either.

Sort out the drain, you can possibly go into the oil pump drive cover. Once the drain is sorted you probably won't need to restrict the supply.

This is my turbo oil drain.



Offender90 (and several others) have the same setup. Not huge, but it works well, and the fall from the turbo drain to the oil pump cover is almost vertical.

Isuzurover - what size is that fitting? 3/8 BSP?

Steve