Blowby ruining my oil?

[TRD_ZERO]

I've recently just got my car going after blowing a ecu and running the new engine rich for abit while trying to sort the tune out.

I've accepted the fact that I've probably glazed the bores so the rings won't bed in correctly. I took it for a pretty decent 35km drive going through the rev range right up to the 6500 rev limit that has been set. Let's just say I didn't take it easy. Ran great suprisingly.

On return we just sorted a couple things out, saw the engine breathes quite heavily on idle through the cam cover breathers. Was told that what freshly built motors do as rings are not bed in yet. In my case it has been running rich with the old ecu so it might never bed in cause I've most likely glazed the bores.

Now because of the heavy breathing will that decrease the more I drive it or is that dependent on if the bores are glazed or not?
With this blowby will the fuel keep passing the pistons getting into my oil spoiling the oil? When pulling the oil cap off to see what the breathing was like at idle I got a good whiff of fuel. Keeping in mind I just changed the oil before we took it out.

Any advice appreciated
Car is a blacktop turbo.

[Dell'Orto]

There should be bugger all blow by on a new motor, they arent bedded in but they're as tight as fit as they'll ever be. What rings did you use?

[TRD_ZERO]

Bought new 8.9:1 pistons and rings from Toyota. Don't know exact brand of rings though.Whatever revhead sent. Why is it breathing so much? Or is that normal? I'm just worried the heavy breathing/blow by is cause from glazed bore from running it rich initially.

[Grrrrrrr!]

did you replace valve stem seals? any chance one wasnt pushed on properly and is pissing air into head?

[gt4dude]

are you actually blowing out oil?? mine breathes out air but fkall oil, from the first startup, done over 2000kms run in, still the same

[Dell'Orto]

How much short running did you do while sorting the tune?

[TRD_ZERO]

Stem seal were replaced with head overhaul. Idled a couple time at afew minutes a time to check for leaks or just to make sure it idles. And took it for two drive in attempts to tune. But ecu was no good and eventually died. New ecu wired in and safe idle fuel ratio dialled in then timing checked then took it out. Didn't throw much oil out the breather. But why does my oil stink like fuel enough that it's not the same as any other oil I've changed.

[gt4dude]

i dont understand how or why you correllate crank case breathing to piston ring seepage

[Mr Revhead]

Bought new 8.9:1 pistons and rings from Toyota. Don't know exact brand of rings though.Whatever revhead sent. Why is it breathing so much? Or is that normal? I'm just worried the heavy breathing/blow by is cause from glazed bore from running it rich initially.

Wow must have been a while ago! Will be genuine Toyota.

[Truenotch]

Over-fuelling shouldn't glaze the bores - it usually does the opposite (cleans away all the oil) which can leave damage.


What oil are you running and how rich was the mix initially?


Pulled the cap off while the cars running to feel how much pressure is escaping the crank case?

[TRD_ZERO]

Yeah it was a long time ago Mr Revhead.

I thought because I ran it too rich in the beginning it's caused the heavy blowby/breathing past the pistons causing more crank pressure than usual causing fuel to get into the oil. When on idle the breather whistles.

It ran really rich in the beginning can't tell you how rich via ratios but in a single garage(door open) idling for a minute or two the smell of it was so bad it burnt my throat when breathing. When trying to tune twice just driving a 100m the car died the sparkplugs were too wet had to wait a few minutes before it would start again or change the plugs. My oil also smelt really fuely and so I've changed it about 4 or five times now.( before I actually took it out for a real drive)

I'm using castrol gtx 20-50 mineral oil.

So then I need to find out how fuel keeps getting into my oil and making it so smelly. Going to get the injectors cleaned before I take it out again.

[Grrrrrrr!]

Random question.... Was it running ridiculously rich because you left the hose off the fuel pressure regulator?

[andyztouring]

How much bore wear was there?,if you have too much bore wear ,nothing will stop blowby,apart from a rebore ,oversize pistons and rings .

[TRD_ZERO]

No was running the factory fuel reg when was running rich. Now running afermarket reg.

Do you mean how much bore wear was there when I put the new pistons in. Can't tell you exactly I sent the block away to get honed with rods and pistons to check all clearances. I didn't assemble the bottom end but all was given the ok by the engine builder who balanced everything.

[limbo]

After my rebuild my car filled its catch can with oil twice, but that calmed down after the first 1000ks, So maybe you just need to drive it more to make sure everything beds in.


Does anyone have a video of what a catch can hose flow should look like on a healthy engine. Mine has quite a bit of water vapour in it.

[AE82 FXGT]

With the main cause of concern for you being the smell of fuel in your oil, are you sure your injectors are OK? Not staying open, leaking or anything silly? Just thought I'd throw that out there.

[QikStarlie]

drive it hard. (long as tune its good) i wouldn't worry about it breathing a bit to start with, long as its not pumping the oil out. just get out there and drive it.

[TRD_ZERO]

Not 100% sure about sticky injectors so I'm going to get them cleaned and tested. No it's not pumping oil out. Just worried spoiling the oil then running a bearing.