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Whats Wrong With The Rb25?

On Edge

By On Edge,
in Engines & Forced Induction

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On Edge Veteran

On Edge

Posted
Posted

Hi there

My RB25 series 2 has been playing up, and to be honest is giving me the s...ts

It has been burning white smoke for a while now, more so on low load

i replaced spark plugs that were fouled and it is running again an the smoke is pretty much gone at idle but appears when accelerating.

Most of you would say it is turbo, i have an aftermarket garrett ball bearing and it may have a leak in the oil line. The turbo feels down on power.

Now i thought it was low compression/cracked piston before the spark plugs, but with new plugs motor sounds smooth an turbo sounds and feels weak.

as a side note the car has blowby, could it be a problem other the engine thats creating it?

On deceleration the car backfires loud and frequently

also when hot it can be common to not hold idle

Any help is appreciated :P

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On Edge Veteran

On Edge

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Best bet do a compression test first to suss that out. How much blow by are we talking? Like filling a catch can up?

well i dont have a catch can ( have to get one) but can see it spit oil out the hks pod filter, and has blown the dipstick out, seems like excess

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PM-R33 Grand Master

PM-R33

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Posted (edited)

Just double check over all the standard emission lines coming from the cam covers and make sure the one way check valve or something isn't blocked causing it to pressurise the crankcase. Probably a long shot but the dipstick blowing out is a bit strange with the standard emissions gear.

Only time a dipstick should blow out is if your crankcase can't breath through the cam covers so it finds the path of least resistance, the dip stick.

That or your engine has actually cracked the ringlands. So yep, compression test time I would say.

Edited by PM-R33
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OMGGTR Mentor

OMGGTR

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white smoke... man honestly ur saying its not the turbo yet ur saying the turbos behaving low on power... ?

Do a comp test which i think will just give u peace of mind ... more or less its the turbo..

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The Bogan Grand Master

The Bogan

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Cracked the ringlands / blocked vent/hole in piston, to blow out the dipstick you first need to pressurize the crankcase, a blown turbo wouldn't do this would it ?

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On Edge Veteran

On Edge

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Just double check over all the standard emission lines coming from the cam covers and make sure the one way check valve or something isn't blocked causing it to pressurise the crankcase. Probably a long shot but the dipstick blowing out is a bit strange with the standard emissions gear.

Only time a dipstick should blow out is if your crankcase can't breath through the cam covers so it finds the path of least resistance, the dip stick.

That or your engine has actually cracked the ringlands. So yep, compression test time I would say.

i will check the pcv valve an everything else again :D

put new spark plugs recently as the old ones were fouled, is idling perfect and is not blowing smoke at idle

there is some oil steaming from under the turbo when its warm.

so i am suspecting the turbo oil return line needs replacing.

Hopefully thats all it is :banana:

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Jdfnq Proficient

Jdfnq

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Silly question..... But how much oil is in the car????

It sounds a little like it has been overfilled when last serviced.....

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On Edge Veteran

On Edge

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Silly question..... But how much oil is in the car????

It sounds a little like it has been overfilled when last serviced.....

nah its not that, it was filled correctly. ive burnt heaps lol to the point where the oil light comes on, an have refilled it a few times

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Rolls Grand Master

Rolls

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Posted (edited)

First do a compression test to rule out piston rings and it just generally being a worn motor. If this comes up good then I would be looking at the turbo oil seals leaking.

You say it is white smoke, is it definitely white smoke and not blueish smoke? Because white smoke indicates burning water/coolant which creates steam and a light white smoke. Oil is generally more of a blueish tinge, if it is indeed white you could have a partially blown head gasket.

Edited by Rolls
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