Is my turbo dying?

[Jake]

('00 VVTi with PHR Stage One GT60 single turbo)

 

My car smells of oil when hot and Scooter tells me there was some blue smoke from the exhaust when I lifted off the throttle as he was following me back from the Ace Cafe the other day.

 

I've noticed that it's losing oil too. Looking under the bonnet when the engine is ticking over after a run there are some wisps of smoke rising from the turbo but I can't see a leak. As near as I can tell the smoke is coming from the centre housing somewhere below where the oil feed goes into the top of the turbo. (between the compressor and the turbine housings)

 

I did a compression test on the engine last week and it was showing 145psi on each cylinder. I believe the compression is a little lower than stock because the engine has a 1.6mm head gasket fitted.

 

I guess I need to take the turbo blanket off and see if I can work out where the smoke is coming from. The engine is too hot to do that at the moment though.

 

Could the problem be the turbo seals?

[Thorin]

Sounds like it to me

 

But then I'm no expert. Just as you'd got it all mapped and sorted too!

[bondango]

('00 VVTi with PHR Stage One GT60 single turbo)

 

My car smells of oil when hot and Scooter tells me there was some blue smoke from the exhaust when I lifted off the throttle as he was following me back from the Ace Cafe the other day.

 

I've noticed that it's losing oil too. Looking under the bonnet when the engine is ticking over after a run there are some wisps of smoke rising from the turbo but I can't see a leak. As near as I can tell the smoke is coming from the centre housing somewhere below where the oil feed goes into the top of the turbo. (between the compressor and the turbine housings)

 

I did a compression test on the engine last week and it was showing 145psi on each cylinder. I believe the compression is a little lower than stock because the engine has a 1.6mm head gasket fitted.

 

I guess I need to take the turbo blanket off and see if I can work out where the smoke is coming from. The engine is too hot to do that at the moment though.

 

Could the problem be the turbo seals?

 

Could be The feed or return line leaking Jake, the oil would be then burning of on the turbo housing or manifold - but i would get it checked ASAP as enough oil leaking can eventially catch fire on a red hot housing(someone on here recently?)

[Ian W]

(someone on here recently?)

 

i believe that was Jake's that caught fire....although not because of this reason iirc.

[Jspec Germany]

Hope not Jake, that would suck. BTW - Why aren't you going to Dragonball this year?

[bondango]

i believe that was Jake's that caught fire....although not because of this reason iirc.

 

Ooops sorry jake,

 

well, i would defo get the feed and returns checked for any leaking, wouldnt take long and worth eliminating.

 

Nija Edit:- Jake was the 1st fire not due to an oil leak? think greg or someone said that in your fire thread?

[Jake]

I don't like the way you said "the first fire"

 

Yeah it was mine that caught fire on the dyno. It was caused by the turbo oil return hose touching the exhaust manifold and melting through.

[Ian C]

Chances are it's an ooze from the return pipe fitting getting on the manifold. However if you get blue smoke out the exhaust it could be internal to the turbo. It'd have to be a really serious internal problem to get oil out of the turbo enough to smoke though, should be one or the other.

 

Edit - that makes no real sense. What I mean is that to get oil out the exhaust means an internal problem with the turbo. To get oil onto the manifold because of an internal turbo problem means it's got to be such a serious problem it's pretty much filling the turbo with oil. I'm sure you'd have noticed a turbo that badly shot. So you should only be getting one of the two symptoms unless you've got two problems at once - valve stems and a weepy oil return maybe.

 

-Ian

[bondango]

I don't like the way you said "the first fire"

 

Yeah it was mine that caught fire on the dyno. It was caused by the turbo oil return hose touching the exhaust manifold and melting through.

 

Jake I have a strange way with words lol

 

wip the blanket off and just check the feeds/returns+fittings, just run your finger round them and make sure they are dry - (turbo cold off course!) and at least its something off the check list

[uk-rich]

a partial obstruction in the drain pipe could cause the oil to pass the seal, was the new drain pipe checked ?

[bondango]

a partial obstruction in the drain pipe could cause the oil to pass the seal, was the new drain pipe checked ?

 

Jake just to add to Rich's post, i seen a car go through 2 BB turbos blowing rear seals and it turned out to be a wrongly routed PCV catch can setup. Basically oil return from the turbo is down to gravity and any pressure in the crankcase will stop hinder the return flow engough that it backs up in the return line. So may be worth checking over the PCV system too.

[Jake]

Update.

 

I've fixed the oil leak but the problem with it burning oil is still there and has got worse. When driving on the motorway at partial or full throttle it seems ok but when I lift off the throttle there is a big cloud of blueish smoke for a few secs.

 

When fixing the oil leak I had the turbo off and tried to take it apart. I got the compressor housing off OK but I couldn't get the backplate off. I removed the four bolts that secure the back plate to the centre housing and the back plate rotated freely but wouldn't come off.

Also I undid the bolts that hold the centre housing to the turbine housing but they wouldn't come apart either.

I noticed there was quite a lot of sideways and vertical play in both the wheels - there's not supposed to be is there? I believe that a mm or so of in/out play is alright but not in the other two planes, is that right?

 

 

 

to get oil out the exhaust means an internal problem with the turbo. To get oil onto the manifold because of an internal turbo problem means it's got to be such a serious problem it's pretty much filling the turbo with oil. I'm sure you'd have noticed a turbo that badly shot. So you should only be getting one of the two symptoms unless you've got two problems at once - valve stems and a weepy oil return maybe.

OK the oil leak is fixed now. I need to work out why it's smoking so badly from the exhaust on over-run. Is that likely to be a turbo problem? It doesn't do it on cold start.

 

Jake just to add to Rich's post, i seen a car go through 2 BB turbos blowing rear seals and it turned out to be a wrongly routed PCV catch can setup. Basically oil return from the turbo is down to gravity and any pressure in the crankcase will stop hinder the return flow engough that it backs up in the return line. So may be worth checking over the PCV system too.

Thanks for that. I'm not sure what the 'PCV' system is or how to check it. Could you explain it a little for me please?

[uk-rich]

there should be very little turbo shaft play, if there is, the excessive movement damages the seals

[bondango]

Update.

 

I've fixed the oil leak but the problem with it burning oil is still there and has got worse. When driving on the motorway at partial or full throttle it seems ok but when I lift off the throttle there is a big cloud of blueish smoke for a few secs.

 

When fixing the oil leak I had the turbo off and tried to take it apart. I got the compressor housing off OK but I couldn't get the backplate off. I removed the four bolts that secure the back plate to the centre housing and the back plate rotated freely but wouldn't come off.

Also I undid the bolts that hold the centre housing to the turbine housing but they wouldn't come apart either.

I noticed there was quite a lot of sideways and vertical play in both the wheels - there's not supposed to be is there? I believe that a mm or so of in/out play is alright but not in the other two planes, is that right?

 

 

 

OK the oil leak is fixed now. I need to work out why it's smoking so badly from the exhaust on over-run. Is that likely to be a turbo problem? It doesn't do it on cold start.

 

Thanks for that. I'm not sure what the 'PCV' system is or how to check it. Could you explain it a little for me please?

 

 

Excessive up and down play aint a good this as said. For reference anyway on the PCV system, which is alaso a culprit for blowing the front crank seal..

 

http://www.max-boost.co.uk/max-boost/Gotchas_2JZGTE.htm

 

have a read of the PDF file aswell which goes into the operation in more detail.

 

Ive seen people run small filters from cam covers which IMHO is a bad thing, as the whole PCV system relys on a vac source for its operation.

[Wez]

Are you sure its oil and not fuel thats coming out the exhaust?

 

Is the smoke only occuring after you have been giving the car some stick?

[geoffvalenti]

Update.

 

 

I noticed there was quite a lot of sideways and vertical play in both the wheels - there's not supposed to be is there? I believe that a mm or so of in/out play is alright but not in the other two planes, is that right?

 

'kin 'ell Jake, you just go from one problem to another. Fcuk knows what you must have done in another life to deserve this lot

 

OK, the turbo has only got 2 planes of movement, axial (in and out) and radial (up and down)

 

My understanding is that a certain amount of play is permissible in either plane, but less in the axial than the radial

 

You'll really need to get the specs from the turbo manufacturer and measure the movement with a dial test indicator to be sure.

 

To give you an idea, here's a link to doing an inspection on a set of standard twins. the process is similar with a single http://www.mkiv.com/manual/manualtt/turbo_inspection/ti1.jpg

 

Thanks for that. I'm not sure what the 'PCV' system is or how to check it. Could you explain it a little for me please?

 

PCV system stands for Positive Crankcase Ventilation and is basically a pipe from the inlet manifold to the crankcase to extract fumes and burn them in the engine rather than venting them to atmosphere.

If the PCV valve becomes blocked you can build up excess crankcase pressure which can cause oil to blow past seals.

Here's the link for that one, although it may have been altered slightly on your car depending on what inlet manifold you're running. http://www.mkiv.com/manual/manualtt/emisson_control_system/index.html

 

HTH

[Jake]

there should be very little turbo shaft play, if there is, the excessive movement damages the seals

I guess I need to get the turbo to a specialist then. I presume these things are serviceable right?

I wonder if it's worth getting the bearings and seals replaced or whether I may as well buy a new turbo.

 

Excessive up and down play aint a good this as said. For reference anyway on the PCV system, which is alaso a culprit for blowing the front crank seal..

 

http://www.max-boost.co.uk/max-boost/Gotchas_2JZGTE.htm

 

have a read of the PDF file aswell which goes into the operation in more detail.

 

Ive seen people run small filters from cam covers which IMHO is a bad thing, as the whole PCV system relys on a vac source for its operation.

Thanks. I'll have a read through that when my hangover subsides a bit.

I do have a hose from the cam cover with a small filter on the other end.

[geoffvalenti]

 

Ive seen people run small filters from cam covers which IMHO is a bad thing, as the whole PCV system relys on a vac source for its operation.

 

TBH, as long as you're cool with the environmental issues, venting the crankcase to atmosphere is the way to go

PCV systems were only ever installed for emissions reasons. IMHO a catch can with a decent filter after it will do the job admirably.

 

In a performance engine, you really don't want to introduce oil fumes into the inlet manifold for a myriad of reasons not the least of which being detonation.

 

So as long as you're not a tree hugger, just vent those fumes

[Alex]

TBH, as long as you're cool with the environmental issues, venting the crankcase to atmosphere is the way to go

PCV systems were only ever installed for emissions reasons. IMHO a catch can with a decent filter after it will do the job admirably.

 

In a performance engine, you really don't want to introduce oil fumes into the inlet manifold for a myriad of reasons not the least of which being detonation.

 

So as long as you're not a tree hugger, just vent those fumes

 

That's not strictly true.

 

Crankcases are meant to run at a slight depression - about 20mBar below atmospheric. Partly for emissions purposes but also to increase the longevity of the main seals (cam and crank) and also to help drain oil from the turbo(s). Breather systems are split into two circuits: Primary, or part throttle, and secondary or WOT. As the names suggest they both operate differently depending on how the engine is loaded.

 

In summary if you run your WOT breather to atmosphere, then the lowest your crank case pressure will ever be is atmospheric. Actually, slightly above atmospheric as you have the pressure drop along the breather pipes acting to hold the pressure up a little bit.

 

If you bin the connection to the plenum from the intake side camcover (the primary breather) then you won't have a vacuum source at part throttle and so will again be running your cankcase at atmosperic pressure or above.

 

As for oil vapour charge dilution, a well designed breather system shouls carry over about 0.5 to 1g of oil per hour. I would suggest that if you are carrying over enough oil to dillute your intake charge then you should be trying to fix the route cause and get some rings that seal (or a less worn engine) rather than trying to cure the symptoms by putting a catch tank or separator on.

 

Incidentally, if you run a connection to the plenum, you must retain the PCV valve.

[geoffvalenti]

Ok then

 

Even I'm not stupid enough to argue with someone who designs engines for a living

 

But I will ask the question; On a turbo engine, at WOT, where do you get the vacuum from? Obviously not the inlet manifold, as that's above atmospheric pressure.

 

Just interested

[bondango]

Via the intake side, both cam covers are linked centrally, the turbo side cam cover is then linked into the intake tract before the turbo. Even the big powered supra's that dont run an intake still need an evac system in place. Were running one similar to this..

 

available from summitt Racing.

[geoffvalenti]

Thanks!

Learnt something else today

[b_have]

Via the intake side, both cam covers are linked centrally, the turbo side cam cover is then linked into the intake tract before the turbo. Even the big powered supra's that dont run an intake still need an evac system in place. Were running one similar to this..

 

[qimg]http://img.photobucket.com/albums/v256/spitwad/newebay242.jpg[/qimg]

available from summitt Racing.

 

Me Too, (crankcase evacuation system) although mine is plumbed into the midpipe so as not to compromise my wideband.

[dandan]

I'm a fan of the downpipe slash cut breather system as well. If I end up running a single it will have pretty much the same breather system as that (with a few additions as well though).

 

Related to one of jake's earlier comments, isn't the stock head gasket 1.6mm thick before being torqued down?

[Ian C]

 

When fixing the oil leak I had the turbo off and tried to take it apart. I got the compressor housing off OK but I couldn't get the backplate off. I removed the four bolts that secure the back plate to the centre housing and the back plate rotated freely but wouldn't come off.

 

Also I undid the bolts that hold the centre housing to the turbine housing but they wouldn't come apart either.

 

Pictures please The turbos I've seen have six bolts holding three metal bars on that secure the exhaust housing to the centre cartridge, so not sure what you mean there.

 

I noticed there was quite a lot of sideways and vertical play in both the wheels - there's not supposed to be is there? I believe that a mm or so of in/out play is alright but not in the other two planes, is that right?

 

Um, no. If it goes up and down and/or side to side then as it spins it widens the apeture in the bearing seals (like using a drill to open up a hole bigger than the bit diameter, only at 100,000rpm) and oil comes out into the exhaust.

 

 

If you need to go down that route I've heard good things about Turbo Dynamics and they do DBB stuff. No idea why your turbo would be shagged though?

 

-Ian

 

PS don't ever touch my car in case it's contagious