EGR & Lambda DTCs

[cheshired5]

Why pay for a smoke test when you've got VIDA?
As I said, if your i/c is leaking, your MAP psi will be down so just view your MAP psi....... for free.

[A lex]

Well, ill just pay him to diagnose it one way or another. He can also use the smoke test to check the vacuum engines mounts etc if needs be.

Which sensor do I need to live monitor for the MAP psi? Manifold absolute pressure or something along those lines? Ive no particular plans for this afternoon, so could give that a whirl...

[cheshired5]

Yes MAP stands for Manifold Absolute Pressure.
It should read or be very close to 1 bar (14.7psi) with ignition on engine off and max around 31-32 psi out and about under full load.

[A lex]

Jolly good. Will give it a shot and report back later.

Looking on to the aircon rad and then intercooler from front of car there is a reasonable accumulation of oil along the bottom edge.

[cheshired5]

Originally Posted by A lex

Looking on to the aircon rad and then intercooler from front of car there is a reasonable accumulation of oil along the bottom edge.

That may mean nothing.
When my turbo to i/c pipe leaked, there was a reasonable accumulation of oil everywhere, now there's none.

[A lex]

OK been out and driven it.

Managed to catch it in the act. Areas highlighted in RED correspond to me feeling the reduction in power in the car and the orange triangle of doom appearing.

During all runs, throttle pressure was constant at around 50%, and there were no gear changes. i.e. all are in-gear accelerations.

First occurrence looked like this, with a flat line:



All subsequent ones look like this, with a more pronounced dipping curve - I experienced this about 5 times in total, but only screen grabbed two of them.

Every time they set the 2xECM DTCs for MAF and Ho2S.





Any thoughts on this Cheshired (and others?)

(peak boost recorded as 2700hPa, which is about 39psi). Car is Polestar mapped if that makes a difference?

[A lex]

And these oily deposits were not there two weeks ago on the undertray/guard:

[cheshired5]

Whether those figures are excessive I suppose depends on how Polestar is used to increase power.
Does it allow for greater rail pressure and more turbo boost?
If it does, is everything else up to coping with it?
Your frankly colossal turbo boost is no doubt the reason why that pipe is spitting oil everywhere and your i/c may be about to blow.
I was getting overboost problems when my turbo was kicking out 20 psi....... Yours is producing around 24-25psi.

My overboost was solved by cleaning the boost control solenoid which is easy to get to on a Euro3 163, yours may be different.

[A lex]

Ill break out my Google-fu and try to find out about the Polestar stuff.

Im not sure if the euro4 engine even have a turbo boost valve/solenoid.... I know the vanes are electronically activated.

Thanks for the continuing input. It seems I might finally be on the road to a diagnosis.

[diro]

Alex,
I did mention in my previous post about turbo boost leak issues that you may have and what potential reason for that can be
1. gasket between tcharger and resonator(silencer)
2. gasket resonator/high pressure pipe
2. intercooler

Looks like you have that.
Well, my advice get this part and you will forget about the gasket problem
http://www.ebay.co.uk/itm/VOLVO-V70-...item46277984b3

These gaskets is a weak point. During a time they get softer besides your car is remapped and extra boost will just increase a chance to get them blown. There must be no oil on the i/c or high pressure pipes.

You must replace i/c as well im afraid.
If you remove anti skid plate or whatever it called Im sure you'll find more oil accumulated in the i/c area

Forget about about the turbo charger control valve. It doesnt have it. You are right - this turbo charger is controlled by ecu and has electronic actuator. Its not vacuum related.

Your mechanic can check engine pads/mounts but those dont affect boost pressure unlike earler euro3 models.

That boost loss shown in graph maybe potentialy caused by EGR for example which may seize at some stage. More revs/min - more fresh air and less exhaust gas. That how it should work but in your case maybe at some point like I said EGR just gets seized and you have boost and power loss. Its hard to tell at the moment but we are going right direction now.