Losing Engine Oil
 

Hi Guys,

Yet another question:

Some time ago, I overhauled my engine and took the opportunity to skim my valves, pistons and block.

Ever since then, I've noticed that my Oil catch tank seems to fill up pretty fast. My Oil catch tank is connected to both the crank case vacuum as well as to where the PCV valve is.

Before the overhaul, I used to not need to top up any engine oil between intervals, but nowadays, I need to top up every month or so. I change my oil and filter around every 6000km. My car is not spewing out any white fumes either

I'm using Shell Helix Ultra 5w40 and have been doing so since I got the car till now. I'm also using Denso Iridium Ik20L and I rev the car pretty hard. Change is normal above 4K and i redline the car pretty often. I reside in Singapore where Humidity is high and temperature is usually around 32 deg celcius. I also have the timing set at 16 Deg and running a K&N cone filter together with JR cables. Other than that, the power plant is stock.

My question is:
What can be causing me to lose Oil unlike last time?
Likely to be from PCV or crank?

Hello,

In anycase, I am running in Hong Kong and would have the same bazzard weather as you would in Singapore.

I am also using SHELL Helix ( 15W-50) I would use something more thick for engine oil as to 5w40 in our turbo cars.

post a pic. I'm having a hard time picturing the setup.

I'm picturing that you have both the breather line and pcv line connected to the same catch can, which then vents to the atmosphere...correct?

if so, remove the pcv line and plumb that back to normal and report back.

Braineack..

Tt's correct. is piping both the pcv and crank case via a T joint to the oil catch can with the other outlet going to atmosphere a bad thing?

you've removed the major vacuum source from the crankcase, so whatever compression your rings may be losing is causing oil to be pumped out of the lines.

i suggest you remove the line from the pcv side and return it to oem. See if that doesn't cure it.

braineack.
Thanks for the reply.
I've done a compression check and the cylinders seem to all be ok...
I'm not sure i follow your chain of logic
Can I trouble you to elaborate to me please?

The PCV vacuum source from the crankcase on the intake side of the motor pulls vacuum on the crankcase removing pressure when under vacuum situations. This allows your rings to stay seated. If you install the PCV line back into the intake manifold like it was from the factory with a good working PCV valve it could solve your problem. Check your PCV valve though, you should only be able to blow through it one way. If not, you'll introduce positive pressure to the crankcase under boost.
My version. I'm sure brain can explain it more simply.

Sorry for the late reply.

The Oil was spewing out even faster with forced induction and my Carbing Oil catch can quickly filled up and start to exit from the exit pipe. Strangely, after that, i had a whole load of WHITE smoke spewing from the exhaust only at idle and after the car had warmed up. Smoke cleared when I drove off.

I did as suggested, basically to pipe the PCV line back into the intake manifold, and i emptied the oil catch can. The WHITE smoke problem seems to have disappeared. I cant figure out the rationale though.