2004 T6 Compressor Bypass Valve missing???

[Katronite]

Hi all.

Long time user, but new member.

I have a kind of noob question.

In my S80 T6 2004 (B6294T) I'm strugling with a lack of boost, after an BSR upgrade.
Its not really a lack of boost, but more like nothing really happened with the power, after this upgrade.
I keep getting the ECM 6806 fault, and therefore looking for some kind of leakage og defective valve or something.
ECM 6806 is the only faultcode I get.

I have installed a new (old) TCV, just to sort this away, but with no luck. (I might be in a situation, where the other TCV also is failing)

I have orderred a new one, just in case, together with a new pressure sensor. Coming in this weekend.

But here comes my little problem. I have on earlier cars replaced the CBV (Compressor bypass), but cant seem to find this/these on my 2004 T6.
I know on the older models, Volvo used a diverter valve, but this I cant really locate.

Are the Turbos on the B6294T again with a built in CBV, as the TDO3/4 Mitsu models??
It seems stupid, if they removed this bypass valve all together, so hopefully someone can point me in the right direction.

Please help..

Regards.

[SuperHerman]

I did a little reading based on the ECM 6806 code and it may be that the computer is not happy with the signals it is getting.

I don't know what a "BSR upgrade" is, but from what I have read if the stock Volvo parameters are changed one needs a tune on the software side or the computer will code.

I believe the turbos are TDO3s, that is what my XC90 with same engine used. I don't recall a CBV - the diaphragm works with the TCV to control boost - boost pressure sensor is also in the mix. Pretty straight forward design.

Places to look are hoses, make sure they are not breached and routed correctly at the TCV (common to turn two around). After that what is the condition of the waste gate flapper? These are known to crack or bind up (had both problems). Other than that I would look into a software tune.

One last item - you can try using a mini-vac to see if your diaphragms are working correctly and at what psi they are moving.

[Katronite]

Thanks for the reply.

My mistake about wrong description of the BSR upgrade. BSR is a software upgrade. You buy it online (BSR is located in Sweden, and are specialists on Volvos). When you buy it, its shipped on a PPC unit, So you can do the softwareupgrade yourself via OBD2. You then get the opportunity to switch between original and softwareupgrade just by downloading. The PPC unit can also do a simple error readout.

The BSR guys told me to look for leaks after the turbos, and in their experience, its often the diverter valve. (CBV's are not built in on the turbos on T6 1999-2006)

As I'm informed from My good Old friend, Google, the Diverter Valve / Bypass Valve / Overflow Valve is the same on All models, But I cant locate it on the late B6294T.
On the B6284T and early B6294T, its located just below the intake manifold, on the pipe that connects the IC outlet to the Throttle body, But Thats not the case on late B6294T.

Just Wanted To Know, If anyone can "point to" where its located, before I take Everything apart.

The diverter valve might Even have been replaced with something else, But as far as I can tell, then the OEM diverter valve is supposed to fit all S80 T6 from 1999-2005, with all engine types.

[SuperHerman]

I will post what I recall based off my memory for my 2004 XC90 with same engine.

Working from the turbo - passenger side - from the diaphragm a short vacuum line goes to hard line hose pipe that runs on the back of the upper part of the engine. This hose rarely fails. From here it starts again with a rubber vacuum line and goes into a plastic T fitting (driver side of car near the transmission dipstick or upper left corner). These break from time to time. One end of the T goes to the second turbo diaphragm - these fail very frequently from the heat - and the last of the T goes to the turbo control valve that is located near the airbox. It is common for people to turn hoses around here - and this will cause an over-boost.

So if you have not touched any of your hoses - pull the hose that goes from the turbo control valve to the T- fitting and use a vacuum pump or slight air pressure and check for leaks.

The turbo pressure sensor is on the intercooler hard plastic - left lower corner of radiator area..

This is what I recall of the set up and its parts.

[Katronite]

Thanks.

The system and the hose to the wastegate holds pressure. When I put in 1bar (14,7psi), it holds that pressure for a long time (30sec or so), so dont think the problem lies in this end.

Both the hoses and the TCV is coloured Yellow, Red and Blue, so its quite easy to see where everything goes.

The TCV seems ok, at activates when I put 12V on it. Nonetheless I have ordered a new one, just in case.

Do you know what the big T-like valve in front of the airintake box does?? One hose goes directly to the side of the intake manifold, and the other side goes under the air- and fusebox. (Guess its going to the brake unit) The final tube goes to some kind of external part, deep down. Cant see it, and cant get my camera down there. (might be a petrol breather box or something)

I tried (Very carefully) to put in a manual boostcontroller between the TCV and the two wastegates, and set this to roughfly 12psi, witch I guess is more or less the boost that a software tuning makes, but nothing. The pressure does not exeed 6-8psi like original, so I´m now more or less convinced, that I´m looking for a leak after the turbos.
This also points in the direction of what BSR told me, that I need to check the Intercooler and hoses, wastegate flaps and this Diverter Valve (CBV). Its most likely to find the error on the CBV or the IC, but as you mention, the Wastegate flaps can crack.

I still havent found this or those Diverter Valves.

[SuperHerman]

See here for the hose you are asking about: viewtopic.php?f=10&t=88390

Let us back up - when you did the BSR upgrade did you do anything else? Was the car functioning correctly?

I don't think the car has a diverter valve.

The waste gate flapper seat can crack or the flapper pivot can bind up - but again how did the car perform before?

[Katronite]

Before the upgrade, the car ran fine i guess. Bought it in february, So not That used to Old Volvos. But I guess it ran fine.

IT still runs great, But I just dont have Any boost gain (power gain) after the software upgrade. 1.gear is better, But 2, 3 and 4 are basicly the same as before.

Only New Thing is this ECM-6806 code, That reads out every time I have driven the car.

This weekend I installed a brand New TCV and pressure sensor, But with No result. Well it did solve an issue with the engine purging a bit under moderat acceleration with low to midrange RPM.
But still the same in the top end. Runs like Stock...

I cheked this purge valve That you linked to, and it seems to be ok, and reacts fine to 12v.
The tubes and returnblok valves also worked fine.

I'm still searching for the turbo bypass valve, or compressor bypass. (CBV)

Singleturbo cars with TDo4 turbo Has the CBV built in, But not on the smaller TDo3. Therefore the twin setup on T6 engines Has a Diverter Valve instead. This Valve was located on the Hard plast tube, connecting the throttlebody to the IC outlet. When going off the throttle, it diverted the backpressure directly to the inlet plastpipe above, after MAF.
But from 2003/4 and onward, they relocated or removed the bypass valve.

Where the heck did they Put it??

I cant believe That its completely removed, as this is bad news for the turbos.
They must have Come up with something else, or just relocated this bypass valve to some stupid location.

I'm still confused about a few other valves, and their funktion, But I'm not sure how to upload pics in here.

[Katronite]

Update:

I have spend a few ours this evening, to play around with this PPC unit from BSR.

As I mentioned, I havent had this specific car for more than 6 months.

I bought it from a middle aged woman, who just lost her husbond. The car is a MY2004 S80 T6 Executive. (So she said, but pretty sure Executive was dropped in 2003, and from then on, the top spec was Summum.)
The car is fully serviced through the years, and only had 165.000km (106k miles) on it. The past 7 years, it has only been running 20.000km (13k miles) Service has been done every year, as the milage had not been reached.
The car is mechanicly in very good condition, and that is confirmed by my own Volvo repair shop.

But, the car is 17 years old, and that makes some things weak, high or low milage...

As mentioned, I have replaced the TCV and the pressure sensor to new ones. I have replaced vacum lines and oneway valves to the purge valve, and chekked if the valve itself reacts to 12v.
The vacum/pressure lines to the wastegates can hold -0.5 vacum for atleast 10 sec.

Tubes to and from the IC is ok.

Still to do:
Pressuretest the IC, and check the wastegate flaps and diaphrams.

And I still have no confirmation on the Bypass valve, and havent found it either.

This evening, I did an error readout again, and still ECM-6806. Deleted and reinstalled the BSR software. Went for a drive, and again ECM-6806.
Then another delete, and installed the original software, and went for a drive. Same thing... ECM-6806.... Only this one error, and nothing else.
If I delete the errors, and drive the car slowly, no errors appear, so might be conviced that shit happens at the pressureside of the turbos.

Running the car with and without the software tune, the car feels the same. That is also confirmed by "SpeedLogic" app. This also confirms that the car runs fine, with no major issues.
The car is rated to do 0-60 in 7.6sec stock, and mine is doing 0-60 in 7.8. (4 tries +/- 0.1sec) I get exactly the same timings with the BSR software installed.
BSR stage 1 is rated to do 325hp 450nm. Thats a 50hp/50nm gain. Old car maybe just 30 or 40, but at least something you should feel, or at least see in acceleration timings.

This upcoming weekend, if the time allows it, I will do a pressuretest of the IC, and maybe even take a look at the wastegate flaps.

Is it possible for any of you guys with VIDA, to screenshot a diagram of both vacum and pressure system on the 2004 T6 B6294T???

[SuperHerman]

Try this Volvo dealership: https://parts.volvocarsofmarietta.com/

punch in your information and go to the engine section - scroll down and look up both turbo charger and intercooler sub-sections.

In the intercooler section - you will find this part number listed: 1275883 - it is called "Overflow Valve".

Have you checked all your plastic pipes for cracks? It just seem odd that the car was find until you changed the software, unless you disturbed something.

The thing with Volvo is they only sell the entire turbo/manifold/and related as one big assembly so there are no single parts sold.

Also look here for possible problem spots: https://www.dtcdecode.com/Volvo/ECM-6806

[Katronite]

Thanks for the link.

Just what i was looking for. But do need to follow up on this, as I´m pretty sure mine is not like this. This is what I remember from older T6 engines, that the overflow valve is fitted on the pipe between IC and Throttle body.
As I recall there´s a clean pipe going between IC and Throttle body, with nothing else connected than the pipe to the T-Valve, controlling the vacumpump.
I dont recall having a second turbocharger boost sensor mounted either, nor the temp sensor.

Need to check up on this...

I will reply later tonight, when I have time to check.