Turbo boost pressure

How relivant is it to set the boost pressure when the turbo is replaced.
Is this not done automatically by the ECU ??

Cheers
Ady

[Chris_Rogers]

The initial factory setting is done as follows:

Disconnect actuator from wastegate.

Apply 1.5 psi to actuator servo.

Adjust actuator rod so the pin can be inserted straight in when the wastegate held closed.

You can vary the setting to taste to some extent, but the ECU will control boost once the inital setting presure is overcome.

Thanks Chris

Any thoughts on my last post in "1400 for valve stem seals thread"

Cheers
Ady

[Chris_Rogers]

Any,

I've had a look at your post to the valve seals thread, I've chosen to reply here as that thread is now too long for easy reference.

Clearly you still have some concerns and without seeing the car it's not easy to determine if the problem is worth worring about.

Some thoughts:

Is there excessive oil consumption? Volvo would consider more than 1 litre per 1000 miles excessive!
My T5 (146,000) uses about a litre every 5000 miles, this is about average.

Have you changed to a fully synthetic oil recently? If ordinary oil has been used up to now, changing to fully synthetic will tend to remove existing carbon deposits and lead to high oil consumption / smoke. 5W/40 grade is usually better for older engines.

If the old turbo has been leaking oil into the induction system for some time it may take a while for this to clear.

Double check the breather system and make sure it's really clear. Clean out as much of the induction system as you can including the throttle body and idle air valve. Make sure the drain hole on the charge air cooler is clear.

What happens if you remove the oil filler cap with the engine running at idle? Does the smoke still appear from the exhaust are there excessive crankcase fumes from the oil filler hole?.

I assume you have now replaced the Lamda sensor and there are no trouble codes shown by OBD.

Chris

Sorry for the delay in replying, I have been checking oil consumption. – in reply to your thoughts -

“Is there excessive oil consumption? Volvo would consider more than 1 litre per 1000 miles excessive!
My T5 (146,000) uses about a litre every 5000 miles, this is about average”.

-The oil consumption is over 1 litre per 1,000 mls.

“Have you changed to a fully synthetic oil recently? If ordinary oil has been used up to now, changing to fully synthetic will tend to remove existing carbon deposits and lead to high oil consumption / smoke. 5W/40 grade is usually better for older engines”.


-It has allways had 10/40, Castrol magnetec (semi) and I have just changed to Shell helix plus (10/40 semi). Turbo Technics loosely suggested that magnetec may encourage carbon build up on the turbo shaft.

“If the old turbo has been leaking oil into the induction system for some time it may take a while for this to clear”.

-Point taken, its now 300 mls on.

“Double check the breather system and make sure it's really clear. Clean out as much of the induction system as you can including the throttle body and idle air valve. Make sure the drain hole on the charge air cooler is clear”.

-I think the breather is clear, I can blow through the pipes ok (oil filler cap off) the pipe work seems slightly cleaner (than before the turbo was replaced), I am not sure about excessive crank case pressure – there is mist/smoke coming from oil filler hole and dipstick on idle but if press mt finger on the dipstick tube for 20 secs and release –there is no pressure build up. I f I remove the oil filler cap when smoking it makes no difference. At idle I am sure the smoking is slightly worse when the air con compressor kicks in (I don’t know why)????


“I assume you have now replaced the Lamda sensor and there are no trouble codes shown by OBD.”

-No havant replaced it yet - as I am not sure its failed because its faulty or if the smoking concern is turnig the light on(still 2-1-2). It never comes on with short trips 10-15 mins at a time.


I am thinking it is not a breather issue as it will still smoke if – the fat breather tube is vented to outside air and the oil filler cap is removed and the dipstick is lifted out of its hole – do you agree that the smoke could not be caused by a breather / crankcase pressure problem or is there anything in this I have overlooked.

What further checks can I do ?



Cheers

[Chris_Rogers]

It would seem the smoke problem is not related to crankcase pressure as it seems to make little difference to the condition when the crankcase is vented to atmosphere.

It would seem to be either:

Valve stem oils seals
Or
The turbo is leaking oil into the exhaust system.

One thought is that that there is insufficient back pressure in the exhaust at idle to keep the turbo oil seal on the exhaust side sealed, has the cat been removed or it's contents removed?
I think there is a plug on the exhaust pipe near the O2 sensor where back pressure and CO2 content can be measured. May be worth measuring the back pressure at idle, I can't remember the expected figures, but I'm sure someone will.

Ref the Cat

No history of Cat or contents being removed.

Passed last MOT emissions OK (March 1,500 mls ago), would that indicate the Cat has to be there ?.- (co content then was 0.09% at 2901 rpm)

I have felt that the exhuast is very smelly but have not heard any rattle (as if Cat has broken up.)

I will look for the plug in the exhuast but how can I actually messure back pressure.??

The concern of -( Hot idle -leave for 5 mins-rev to 4,000 rpm to see lots of blue smoke from exhaust which will not clear unless driven or sometimes will go if just returned to idle).-
If the concern was stem seals would you expect the smoke to clear if the revs were held at 4,000 rpm (stationary/off boost)?

Cheers

[Chris_Rogers]

I've never had to measure exhaust back pressure but given a suitable adaptor the pressure should be within the range of a tyre pressure guage.

I can't explain why but I've a feeling that you are doing very small mileage and the engine is gummed up, I wonder if it's worth taking it on a long fast run an see if it improves (take lots of oil with you!).
The turbo cars just don't like small town mileages.


My experience with valve stem seals (on my wife's old Ford Orion) is that there is usually a lot of smoke when the engine is first started and it tends to diminish after that.