20v keep blowing turbo, help please

[mac2226]

Hi George did you find the problem why it was killing turbos?

[twoqu]

Oil pressure sounds more reasonable than before.
I would have thought that fuel diluting the oil would have made it thinner but it certaintly would effect its lubricating propieties. Then again your oil pressure seemed higher and you were using a thicker grade oil!
The only test you can do really with the injectors is to see whether they leak when pressurised by connecting them up to the fuel rail out of the head and pressurising the system. It might be obvious which if any leaks. Due to the potential hazzard it might be better to have then looked at by someone with the proper kit (ASNU)! Bit frustrating to have to spend money on something that might be ok but what price piece of mind?

[george21]

Oil pressure with new 10/40 semi.
On cold 5.5 bar
On hot 1.8-1.9 bar
When throttle aplyed pressure goes up to 5.5 bar with revs.
I think it is possibility that wrong fuel delivery can cause that .
Injectors overflows
Cleans cylider bores
Makes blowby and thins oil
Oil can not flow from the turbo to the sump fast enough
Oil with petrol lubricates turbo bearing not enough and bang
turbo ****ed.

Is any logic there, is that possible?
How do i do a test on injectors?
I know on k-jet it's easy, 5 coke bottles, jumper wire and clock.
I guess here it is a bit harder?

[twoqu]

If its possible I would go back and measure the oil pressure cold and hot again and see whether its dropped compared to what you had before.
I would also remove the wastegate cap and physically examine the spring. Either post a pic or measure the total height and ideally the wire thickness so we can determine whether it is a stock one.
Shouldn't really have a strong smell of petrol in relatively fresh oil so that might indicate an injector issue which for piece of mind might warrant a test session for leaking and flow.
Of course none of this might be the cause of your problem. The boost profile for that Volvo turbo according to PRJ is a 1.9 bar peak and 1.7 bar redline! How marginal that is I don't know but of the two turbos surely the one with the smaller turbine would be more likely to overspeed. Whether the extra 0.3bar base is necessary to achieve that I am unsure as the profile was quoted on a 1.9 bar spring and a flat out N75 by the look of it!
The K27/26 also has a similiar profile. So in theory neither should have been knackered at the boost levels you have quoted. We know that the stock oil system is adequate for most needs and that the KKK turbo are usually pretty durable.
As for the fuel pump, essentially it is the wrong spec for a 20V. The 10V pumps are biased towards high pressure for the K-jet and less volume whereas the Motronic wants higher flow with less pressure. At sometime might be worth looking at say a 044. Can't see a connection between this and the turbo issue!

[george21]

why is petrol spell is in your oil? in my opinion look there first...
buy few s2 standard turbos so you can get them fried...
put it to standard springboost injectors...
got some photos of your problems?

1. Why it's smels petrol i don't know
2. Standard turbo fitted
3. Standard boost
4 what photos, damaged turbo?

[rxl]

why is petrol spell is in your oil? in my opinion look there first...
buy few s2 standard turbos so you can get them fried...
put it to standard springboost injectors...
got some photos of your problems?

[george21]

I'm not sure if that's the cause of your problems, but it won't be helping that's for certain. With the new software and RS2 turbo I've had to tweek mine up a little to stop it creeping open as the boost comes in on WOT applications but my base line boost is still less than 0.5, it's around 0.45.

I'll get that down to 0.4 bar then!
Another thought i done nothing to the fuel delivery apart from changing lines all the way. I mean it is standard setup for ur quattro with standard pump etc. maybe i'm runing lean on high boost? Normaly those pumps pump around 5-6 bar not sure about how many litres tho. Maybe it is stupid thought but..

[K Simmonds]

I'm not sure if that's the cause of your problems, but it won't be helping that's for certain. With the new software and RS2 turbo I've had to tweek mine up a little to stop it creeping open as the boost comes in on WOT applications but my base line boost is still less than 0.5, it's around 0.45.

[george21]

You might have a non standard spring in there, PRJ maps for stock WG spring so best to fit one.

spring is standard, just somebody before me had a play with the top screw. i tried to get it right to standard boost pressure and i did to 0.7 bar. but aparently standard boost pressure is 0.4 bar. is that posibility that on the high boot those 0.3 bar diferent could cause my turbo to overspin?

[newsh]

You might have a non standard spring in there, PRJ maps for stock WG spring so best to fit one.

[twoqu]

As long as the AAN ecu is unimmmo it should be ok.
Without the N75 the spring pressure should be in the 0.4 region so it needs a small adjustment for stock settings at least.

[george21]

Should be more like 0.4 bar.
Petrol in the oil is never good as it compromises the lubrication properties of the oil!
Depends if it is overfuelling or whether the injectors are leaking. Still something else to kick you in the ****!
Its a shame we can't point the finger definitively at either the lubrication system or abuse of the turbo.
Would have been better to revert back to a more std set up to trouble shoot it. Guess thats not possible once the ecu has been modified.

That it is what i want to do revert it back to standard and just run it to see how things goes( that is what i should done it first place, but wanted to be a smart ***) i still got ecu from aan, is that will fit?!
i just need a standard software. still have original injectors. So only mods staying is rs2 manifold and 3" system
So you saying standard spring boost is 0.4? I got 10psi which is 0.7 bar

[twoqu]

Should be more like 0.4 bar.
Petrol in the oil is never good as it compromises the lubrication properties of the oil!
Depends if it is overfuelling or whether the injectors are leaking. Still something else to kick you in the ****!
Its a shame we can't point the finger definitively at either the lubrication system or abuse of the turbo.
Would have been better to revert back to a more std set up to trouble shoot it. Guess thats not possible once the ecu has been modified.

[george21]

Well, changed oil to semi 10/40 to run about and disconected n75 to see what boost spring is holding, what it should be, around 0.7 bar? Also notised a smell of petol from oil i took it out and while breather was out, smell of fuel from sump, is that normal?
Another thing can i run about with k24 turbo while mapping it's for k27 with 440 green giants?

[twoqu]

I guess oil is cheaper than turbo's! The lubrication system is pretty robust on these unlesss you go mental on revs. Might be worth trying a cheap reasonable quality oil with say a 10 rating as an experiment.
Of course if the problem was already present and we don't know what oil grade was used previously then we are clutching at straws really without any definitive suspect. If the engine was out of a forum members car we might be able to look at any previous posts for clues.