3L + Turbo oil blow by (1 Viewer)

[ChrisPBacon1]

Hello ya'll,
Ive got some, what i think is excessive oil blow by coming out where the breather tube connects to the valve cover.
Wondering if this is normal or theres an issue? And if its the latter, what are my options to solve it?

Checking oil frequently, doesnt seem to be using excess oil, no odd white smoke, still black and no other issues.

'97 hilux with a 3L +CT20 turbo off a 2L

 

[4Ruster]

I'm having a hard time seeing where your crank breather hose is connected to. It should be post turbo or you will be pressurizing the crankcase.

 

[GTSSportCoupe]

Also, put a screw clamp on the hose where it connects to the valve cover.

You can do a simple blow-by test by unscrewing the oil filler cap and just sitting it in the hole. If it just bounces around but stays over the hole, it's fine. If it flies off and you see rhythmic puffs of smoke, its not fine.

Generally if the engine starts fine, without needing extra glow and/or stuttering you're probably fine. Especially if you're not going through oil either.

 

[Eurasiaoverland]

I'm having a hard time seeing where your crank breather hose is connected to. It should be post turbo or you will be pressurizing the crankcase.

It should be pre-turbo. Post turbo sees the positive pressure.

Some degree of oil will always be present in the ventilation system. That is not the original ventilation hose. The original had a spring clamp so I would replace with something similar. Also, make sure the hose is not rock hard and cracked at the end. I would imagine your hose just vents to atmosphere, which is fine from a crankcase pressure point of view.

If your engine is breathing excessively, the piston rings and/or bores are worn but up to you when you feel it needs rebuilding. Or until it is putting so much oil into the intake system that is runs away.

 

[hiluxjeremy]

So not exactly the same situation but, the stock crankcase vent hose fitting on my '90 era 3L was very small, like 3/8'' id. I haven't seen a '97 to compare. Increasing the size of this fitting and hose accordingly had a dramatic effect on lowering high rpm mystery oil consumption for me. I went to a 3/4" id. Process involved pulling valve cover, opening up hole and welding in short piece of mystery material I had lying around with appropriate dimensions. My thinking being the volume of air getting shoved around in crankcase by rotating assembly was forcing a fair bit of oil vapor out the small fitting. Bigger fitting, more room to breathe, less loss.

Reasonably common mod in go-fast land. Could be right out to lunch on the why, it worked for me.

But if you're not a losing anything on the dipstick get clamped and move on.

 

[AirheadNut]

Is a hose just disconnected while taking photos or is something missing from this nipple on the intake? That would definitely blow an oily mist at your valve cover if it is open.

Otherwise I’d concur with what has already been said: stick a hose clamp on it and see how it does.

 

[ChrisPBacon1]

It should be pre-turbo. Post turbo sees the positive pressure.

Some degree of oil will always be present in the ventilation system. That is not the original ventilation hose. The original had a spring clamp so I would replace with something similar. Also, make sure the hose is not rock hard and cracked at the end. I would imagine your hose just vents to atmosphere, which is fine from a crankcase pressure point of view.

If your engine is breathing excessively, the piston rings and/or bores are worn but up to you when you feel it needs rebuilding. Or until it is putting so much oil into the intake system that is runs away.

Yep it just vents down below. No catch can or anything.

 

[ChrisPBacon1]

Is a hose just disconnected while taking photos or is something missing from this nipple on the intake? That would definitely blow an oily mist at your valve cover if it is open.
View attachment 3496759

Otherwise I’d concur with what has already been said: stick a hose clamp on it and see how it does.

Nope. Just took the photo as is. Does appear that way doesnt it? Most diagrams ive looked at it appears that is supposed to be routed to the valve cover (cylinder cover)...but i cant tell for sure.

 

[Eurasiaoverland]

Nope. Just took the photo as is. Does appear that way doesnt it? Most diagrams ive looked at it appears that is supposed to be routed to the valve cover (cylinder cover)...but i cant tell for sure.

That should not be left open. As the original engine was normally aspirated, the crankcase vented into the intake via that port. Now that it has forced induction that port needs to be sealed and should not be connected to the valve cover.

If oil is being blown out of that port onto the engine then your turbocharger is leaking oil (not good).

 

[GreenPump]

This is what it should look like.

 

[AirheadNut]

In a turbo application the nipple on the intake elbow needs to be capped off and the hose from the valve cover routed either to atmosphere or to a catch can and the turbo intake. Otherwise the turbo will pressurize the crankcase and blow out the dipstick and possibly some seals. With the nipple on the intake open you will have a significant boost leak and be down on power.

 

[ChrisPBacon1]

In a turbo application the nipple on the intake elbow needs to be capped off and the hose from the valve cover routed either to atmosphere or to a catch can and the turbo intake. Otherwise the turbo will pressurize the crankcase and blow out the dipstick and possibly some seals. With the nipple on the intake open you will have a significant boost leak and be down on power.

Capped em off, with a little bit of a janky zip tie solution. But heading to the auto parts store here shortly to get what i need to do it properly.

Thanks Gents! Wealth of knowledge.

 

[ChrisPBacon1]

And by capped off, i mean i capped the intake nipple off and zip tied it. And zip tied the hose from the valve cover. Ill report back with some photos.

 

[4Ruster]

It should be pre-turbo. Post turbo sees the positive pressure.

Some degree of oil will always be present in the ventilation system. That is not the original ventilation hose. The original had a spring clamp so I would replace with something similar. Also, make sure the hose is not rock hard and cracked at the end. I would imagine your hose just vents to atmosphere, which is fine from a crankcase pressure point of view.

If your engine is breathing excessively, the piston rings and/or bores are worn but up to you when you feel it needs rebuilding. Or until it is putting so much oil into the intake system that is runs away.

my bad I meant pre turbo. Should run into the air cleaner box

 

[ChrisPBacon1]

No more oil blow by after some c-clamps on the intake and the valve cover. And it actually seems like its running cooler ET's...