some blue smoke from catch can :(

[white-gt]

ok so ive been having some running issues with it feeling more flat than normal, took it to a local dyno garage and got it inspected.;

while doing a leak down test cyl 4 was passing some air but all the rest are tight, we rotated the engine and it held pressure solid after that..

so on the dyno not pushing hard, revs held at 2500rpm and raising boost pressure we start to see blue smoke comming from the catch can but no noticeable smoke from the exhaust.

im told its either piston rings or head gasket but needs opened up to find out for sure.

so, is the smoke diagnostic correct?

and if so, without talking about a large forged bill whats my best options ? standard toyota parts ? im not looking at going past say 230bhp on my hybrid setup.

im sure he said he will rebore the cylinder or something also..

any thoughts ? thanks

[amatthews45]

So somewhere in the cylinder your passing air. So that would explain a rebore but would start with cheaper solutions first

What rocker/breather set up are you running maybe its just to ristrictive. Causing oil to burn in the tank

When was last service? Using good oil?

[white-gt]

my rocker cover has both pipes going to the catch can and the inlet manifold pipe is blocked off this was only done in the last month, before i only had a breather on the left and a pipe going from the cover to the inlet mani.

i changed the oil and filter about 2 months ago using shell stuff i usually use, recently had the fuel filter changed and fueling checked but it was running lean before i done that as the fuel pump was dying and i didnt know, it was only when it was on the dyno we seen it was up at 15 afr around 4k rpm, so fuelling is now spot on..

[Ollieh17]

does the catch can have breather on it?

[amatthews45]

well maybe your producing to much crank case pressure causing oil to burn up.

I would be seeking enlarged breather holes with better lines and a breather on the tank.

Isnt there baffles in the crank case that can be removed.

I would be sorting these issuses before stripping down the block.

Would of though your exhaust would smoke if you had piston issuses

[white-gt]

the catch can has a breather on it and two inlet pipes, so both outlet pipes on the cover are going to the catch can and the inlet manifold pipe is now blocked off..

does that make any more sense ?

[white-gt]

i done a compression test twice now from 2 different places and they said it was spot on at 150 psi across all 4, so how is that possible if on a leak down test it showed a leak..

the breather is oily and dirty but i dont suppose that would effect the colour of the smoke as its clearly coming out

[FMuscle]

Doesn't sound like a proper, functional system to me... the air filtered by the OCC should be sucked back in your inlet. AND you should have one OCC (oil catch can) per hose between the cover and the piping/inlet, as pressures, or vacuum is different between them...

[FMuscle]

What kind of catch can are you running? How's the filter in it? do you empty it from time to time?

[white-gt]

ok i see what your saying but surely a fault would have shown before say 300 miles have been covered since i change the setup.

its just a metal catch can with 2 inlets or oulets both the same basically and a breather on the top,

so your saying one pipe from the cover to the catch can and the other outlet on the cover should be going to the inlet manifold the way it was before?

[white-gt]

the filter is oily, not been cleaned in months tbh

[white-gt]

http://www.ebay.co.uk/itm/0-5L-0-5-LITRE-OIL-BREATHER-TANK-CATCH-CAN-WITH-12mm-1-2-OD-BARB-BLACK-ROUND-/290565037637?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43a7069e45

[amatthews45]

Sounds like you need to reconfigure your breather set up.

Little things before a mayor rebuild just sounds like your building up to much crankcase pressure

[FMuscle]

I bought someting similar once, it didn't even have a filter element in it... I just received my saikou michi dual custom can, I can tell it is much better than ebay stuff.
This is the model I chose
This is their info page, for a good understanding of what a real OCC is.

[FMuscle]

This also:

Edited September 17, 2014 by FMuscle

[white-gt]

ok i kinda understand.. but the smoke coming out is bluish so does that not mean burning oil ? i dont see how it can have too much crank case pressure just because one isnt going to the inlet manifold though, all that does is take in air so what difference would having a pipe from the over to the inlet do?

[white-gt]

garage guy has told me its due to piston 4 and nothing i do externally will stop that now..

checked the timing and it was spot on, check with a camera for piston head damage but looked ok..

[amatthews45]

Well thats my view anyway

I think your running to much pressure in the cylinder head making it burn oil out the catch can.

If you wanna strip apart the block and spend loads first go for it.

But in my view start with the simple cheaper things and go from there.

Good compression and ok results from leak down would make me look at alternative solutions.

A cheap catch can prob doesnt help.

Dont some people run one line to catch can and one to vent?

[white-gt]

no i agree mate start cheap.

but why would the leak down test show a leak that we could hear in cyl 4 and feel it comming thru another cylinder and we then turn the crank and it doesnt do it again

just been quoted £480 inc vat for all new pistons full gasgket kit and rings..

[amatthews45]

Not sure why the leak down would do that then not do that

Thats out my expertise but I would of though smoke would come out the exhaust

[white-gt]

i agree.... well i'll swap that pipe back over to the inlet manifold anyway

[white-gt]

Looks like u might have been right after all! Compression test is fine still so I've swapped the hoses back over and cleaned the filter .

[amatthews45]

Thats good! Glad you started with the simple things

Just think could of cost you a lot of money and had the same problem.

if I was you I would get a race spec rocker and reduce the crank case pressure might free some bhp doing that

[white-gt]

Swapped the hoses back to how they where and it's now rather Smokey thru the exhaust and revving at 2k rpm after sitting for 3 weeks

[amatthews45]

Give it a run and then report back about the smoke