Turbo's are great...

[Captain Vimes]

So. I racked up some mileage in my tubby lately and it was a ball.

However, the seals on the turbo now seem to have broken (small clouds follow me when on boost....).

Has anyone else had their pe turbo rebuilt and if so, where? As I understand it, as it's a ball bearing turbo it can't be rebuilt. However I phoned power enterprise and they suggested there may be a rebuild kit  s:? :? s:?  

 The other option would be to fit a bigger turbo. Presumably this would be reasonably straight forward with a little welding? Anyone done it or had this problem?

[Ilogik]

What fitment is it? t25 ect?

There is a few adapter plates available.

Wondering if the PE suffers a similar problem as the TTE with the oilreturn pipe being a bit crap causing it to smoke.

Does it only do it on long hauls or straight away?

[Wabbitkilla]

I've heard of one PE Turbo getting its seals replaced.

[VVT-i]

I had clouds of smoke on boost, the turbo seals were re-done (snail taken off and sealed) but it still threw out smoke. Next thing we looked at was crankcase pressure, so we fitted Krenkvents from ET Performance ( m http://www.et-performance.com/turbo.html m ) and an oil catchtank and it's been perfect ever since, not used a single drop of oil in over a year now. If your not sure that your turbo has gone, try getting Krankvents fitted.. infact even if you get it rebuilt or a new turbo I would still recommend them.


Large Krankvent at throttlebody.

Throttle body - Krankvent - top breather. (some people disconnect the pipe from the throttle body and use a bung, then vent the breather/Krankvent to atmosphere, I have left the throttle body connected as normal and have the Krankvent "inline", no issues in the slightlest.



Small Krankvent (top picture) and oil catchtank.

PCV - oil catch tank - Krankvent - inlet manifold

NOTE:

I no longer have the collapsable hoses that came with the catchtank, complete crap... (those white hoses in the picture) so if you go for a catchtank be sure to buy some good quality hoses suitable for oil vapours etc, if you opt for sillicone hoses you will need  Fluoro Lined Silicone Hoses.


What was happening to me was the crankcase was pressureising through the inlet manifold, the pressure was passing through the PCV (not strong enough) and into the crankcase... the Krankvents are rated to 75psi and stop the pressure getting through. The oil catchtank was put there to give the PCV a little more room to do what it normally does, it has it has the hose from the crankcase, the tank it'self and the hose to the Krankvent to operate in, you also get the bonus of it catching any possible oil vapours and prevent them fouling up the intake tract and intercooler (if you have one)

[Captain Vimes]

Thanks for your responses.

I think (hope) Vvti has hit the nail on the head with the breathers. On my pe setup the rear vent on the cam cover connects to the intake pipe work pre turbo (instead of to the tb - which has a blanking plug). Inside the intake piping there's oil sitting where the vent connects. I think with some hard use it has sucked the oil in from the vent which has clogged the air filter which in turn has caused the turbo to 'suck' more air through the breather - making the situation worse.

I'm going to go for a simple catch tank vented to atmosphere for now (connecting both the pcv pipe and rear vent to one catch tank) and see if the problem goes away. If it works I'll look to add some crank vents back into the system to restore some positive pressure through the engine.

I'll have a go at the weekend and post up the results.

[VVT-i]

Hopefully I'll be corrected if I'm wrong here, so don't take this as gospel please.

Venting the catchtank to atmosphere could cause a vac leak, I have mine connected inline from the PCV (the pipe from the rocker cover closest to the rear of the car) to the inlet manifold... with a Krankvent between the inlet manifold and the catchtank.

On my pe setup the rear vent on the cam cover connects to the intake pipe work pre turbo (instead of to the tb - which has a blanking plug). Inside the intake piping there's oil sitting where the vent connects

On mine.. as I said.. this hose is connected to the TB as normal, with a Krankvent inline on this hose, with the Krankvents being one-way valves no pressure gets into the Krankcase and the engine runs under vacuum, this is what stops oil getting blown into the intake tracks and TB, I felt no need to bung the TB hose and vent to atmos as nothing gets sucked into this breather thanks to the KV and it can breath as designed when not under boost. At the moment it sounds like your venting back into the air intake instead of the TB, if this is before the MAF then your MAF maybe getting fouled up too, I say this because I assume you have the PE induction ket too, so if you think the filter maybe getting clogged then the MAF will be too.. this isn't good for metering the airflow and could cause feuling problems.

I would honestly bite the bullet and get the Krankvents in and keep those hoses connected as normal.. don't vent the catchtank to atmosphere doing it this way.

Obviously make sure your turbo unit is good first though  s;) s;)

[Captain Vimes]

Thanks for all the  info.

I've had a good think about how the vents work and I agree that venting the pcv to atmos and plugging the vac pipes may not be the best idea and I'm not sure that it's what's causing the problem. (The PCV seems to be a 1 way valve which will only allow air to flow out, therefore it shouldn't be affected by the boost. Even if it leaks slightly under boost, it wouldn't be sufficient (IMO) to cause an issue).

Anyway, to test the theory of whether it's the vents or the turbo seals, I've vented the top breather to atmosphere and taken the car for a good drive and it seems to have stopped smoking   s:bounce: :bounce: s:bounce:  . I need to sort out a more permanent solution with the vent using a catch tank but I'm happy the turbo seems fine!

So, I've changed the thread title - Turbo's are great!

Thanks again!

[VVT-i]

When the pistons go up and down the create pressure in the crankcase, the PCV (positive Crank Vent) vents this pressure out of the crankcase and into the inlet manifold keeping the engine running under vacuum. The PCV prevents this vented pressure re-entering the crankase when accelerating.

When under heavy boost the inlet manifold gets pressurized, this pressure... which is obvioulsy far higher... goes down the hose leading to the PCV, as the PCV wasn't designed to take this amount of pressure it is too weak to prevent the pressure entering the crankcase, this results in excess pressure forcing dirty oil etc back through the system ( turbo seals, intake tract, throttle body etc) and eventually blowing out of the exhaust in a cloud of smoke.

(The PCV seems to be a 1 way valve which will only allow air to flow out, therefore it shouldn't be affected by the boost.

Your right.. it is a one way valve.. but the higher boost pressure can pass through it, the Krankvent.. also a one way valve.. is stronger and will work in the exact same way, but the boost pressure won't go through it.


Removing the hose from the throttle body (fitting a bung) and venting to atmosphere will reduce some of the pressure through the breather without it returning to the system via the TB, however this could result in oil being sprayed all over your engine bay, adding a catchtank here will help that as could fitting a small breather filter, but you may only be masking the problem rather than resolving it, the pressure in the crankcase can cause the piston rings to loose their seal, oil can pass through and spew out of the breather (into your catchtank), I feel the best way to resolve it is to prevent it happening in the first place, that is to stop the pressure from the inlet manifold bypassing the PCV, fitting a Krankvent does this and keeps the engine running under vacuum, another Krankvent at the TB side prevents any air going in that side, at the same time you can keep the TB hose connected as normal to recycle the vapours through the system to alledgedly keep emissions down.

It's not every turbo'd car that suffers this problem and I don't think anyone really knows why some do, so I would guess the "level" of theproblem will vary too.. perhaps what you have done will be fine, but if it was me I would be investing in Krankvents as my next addition... just to be safe.