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Discussion Starter #1
Hi guys, luckily I have found most of the info I have required by searching etc., but I seem to have hit a bit of a wall with this one...

I have recently finished turboing the del sol, and I'm burning oil like mad, any help would be greatly appreciated :)

Symptoms:
cold start - no smoke
cold idle - no smoke
running cold - no smoke
warm start - no smoke
warm idle - no smoke
acceleration/boost - no smoke
deceleration - little bit of smoke
deceleration then blipping throttle - quite a lot of smoke (seems blue)
using about half a litre of oil maybe every 500 or so miles

Now, based on the research I have done, I feel as though it is oil control rings, or could be valve stem seals, but due to it not smoking on cold start I am swaying towards rings being the culprit.

Now I have tried to find out what the standard size the rings are, and I'v got about 4 different sets of numbers, so does anyone know the definitive size for standard rings in a d16z6?

Specs:
stock D16z6 - 85000 miles
Stage 1 Crower cam
Garrett T28 7psi
Tuned on Crome


Cheers guys!!!
 

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Discussion Starter #3
Okay, turbo had a little shaft play when out of the car (dry) less then 0.5mm, on the car full of oil it has barely no movement at all in any direction.
I will get some pics of my oil return as soon as I can :)
 

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Discussion Starter #5
As it stands at the moment the valve cover and pcv pipes are just venting to atmosphere (with a gutted pcv valve) til I can afford a catch can... Sucks working part time for minimum wage :/
There is a tiny tiny bit of oil on the exhaust tip but compressor and turbine side of the turbo seem dry, need to check more thoroughly when it's light though..
Cheers for your help folks, does it not sound like the rings then? If its as simple as the oil return il kick myself :)
 

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Classic Man
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wet exhaust turbine? sounds like an oil drain problem to me.

also post pics of your PCV setup. if u are pumping boost into the block, same problem will happen.
 

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are you running an oil feed restrictor on the turbo feed line? if not, get one.

this could also be your valve guide seals.

but if the turbine is wet with oil it most likely is the turbo, especially if your not running a restrictor.
 

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Classic Man
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are you running an oil feed restrictor on the turbo feed line? if not, get one.

this could also be your valve guide seals.

but if the turbine is wet with oil it most likely is the turbo, especially if your not running a restrictor.
since when was restricting oil (the only thing keeping the turbo alive) a good idea?

to me it makes a lot more sense to provide an adequate drain, which would solve the real issue...
 

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since when was restricting oil (the only thing keeping the turbo alive) a good idea?

to me it makes a lot more sense to provide an adequate drain, which would solve the real issue...


i used to think like that.
most turbos only need 30-40 psi of oil pressure to work properly. hondas make 50-70psi sometimes more. thats alot. oil drain is important but just as important to not over feed the turbo.
 

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I have my PCV setup the same way as you - tube from the breather to the ground, and a gutted PCV valve with a tube pointing down. Had no issues for 12k miles at 8 psi

What size oil feed line are you using?
 

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Turbos are different. Turbos dont just require 50psi and its all good. Most journal bearungs need a ton of oil. So a small line with higher pressure. Mitsibishi turbos are the only ones they reallu rec to do that. Ihi mostly
 

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Classic Man
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i used to think like that.
most turbos only need 30-40 psi of oil pressure to work properly. hondas make 50-70psi sometimes more. thats alot. oil drain is important but just as important to not over feed the turbo.
how can you "over feed" a turbo oil? what happens?
 

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1988 Honda CRX
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Re turbo oil feed restrictor.

For a ball bearing you only need a splash.

Plain journal bearings need more oil. To little does damage, to much does not really hurt anything in the turbo.

A smaller line means more pressure feeding into the line, but less feeding out of it into the bearing.

A bigger line means more oil flow to the bearing, but more is taken from the rest of the engine where it is also needed. An oil pump only pumps so much and all we can do with clearances and restrictors is control how it is shared or distributed.

A good drain back is essential.

If the turbo is leaking oil, you should see it in the inlet ot exhaust systems.

If the oil is not showing in the inlet and exhaust you have fucked oil control rings at least.

Have you done a compression test. While not always conclusive it is another indicator.
 

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Discussion Starter #14
Thanks for the advice guys, I pulled the o2 bung out and it's black and sooty but not very oily, I'm running a 4an line with a restrictor, 2mm I think.
I had a can of wynns oil treatment stuff lying about so i put that in, now it only smokes on hard engine braking, and even then it's not as much as it was before, does that help anyone diagnose anything? Haha
I will do a compression test as soon as I can, I'm sure I can find someone with one they can lend me :)
The drain I have is about 11-12mm internal diameter, but looking at it it may be slightly kinked, I guess that won't be helping anything?
As for my pcv system I gutted the valve so it's open, then ran a line down to near the ground, and the valve cover is the same, and the bit on the intake iv blocked up.
 

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For a turbo car your crankcase vent is probably a bit small but that's not the main problem.

Oil is entering the combustion chamber under vacuum from the engine running against a closed throttle.

This is exaggerated by extra pressure in the crankcase from restrictions in the breather system.

The oil almost always gets in past the valve stem seals or rings.

Poor valve stem seals show up as a puff of smoke on starting after being left standing for some time and smoke on throttle application after overrun with a closed throttle.

Poor rings do not smoke after standing and smoke mostly only after throttle application after overrun with a closed throttle.

It's your rings.
 

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Dan

No argument. It could also very easily be the drain, but I would expect that to show as oil in the charge pipe or exhaust pipe which he kinda but not convincingly claims is not the case.

Certainly the drain needs fixing either way.

Certainly the breather needs fixing either way.

If the problem still exists after those easy fixes, fix the rings.
 

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Classic Man
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ah i thought he said his turbine wheel was wet, which would lead me to think theres oil in the exhaust for sure

i guess all we can do is guess since we only got a computer screen with some letters on it to diagnose with!!
 

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I saw that and interpreted it was slightly wet and not enough to really conclusively indicate a leak. I agree, to see and touch it would help a hell of a lot. Also Dan, you have a lot more experience with turbos than do I.
 
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