2.4d Overboost issues

[bigbeat]

Happy new year everyone!

As a treat a few months ago I treated myself to a remap for my V70. (2.4D 163KW version).

It had ben driving fine up until this morning. Under light load I'm getting a flutter. So I cannot get on a steady 'boost' pressure. The car then goes into overboost protection. So that I cannot get any boost pressure.

Using the Torque app I ham getting the following codes;

P0234 Overboost condition
P0101 Mass air flow performance problem
P2A00 O2 sensor circuit range

P0234 was the only code first displaying. I'm now getting the other two. Which makes sense, If I have too much air the mixture will be off and foul the o2 sensor.

In my root cause findings I initially thought there is a boost control valve on these engines but cannot find one.
Am I right in saying there is not one? Or is there something located on the turbocharger?

I cannot see any vacuum lines to anything and going to assume that there are none.

So my thought train is;

Check air leaks and make sure everything is tight
MAF sensor clean / replacement
Wastegate issue?

[seanc]

In case this helps, I had only P0234 on my D3 5 cylinder S80 which was caused by the Pierburg boost controller (think that's the correct name) it lives at the back passenger side of the engine bay.
I replaced mine, but I have read that you can dismantle it to access and clean a filter screen that can become clogged.

[bigbeat]

Was it attached to the engine or to the bulkhead?

[Kev0607]

Originally Posted by bigbeat

Happy new year everyone!

As a treat a few months ago I treated myself to a remap for my V70. (2.4D 163KW version).

It had ben driving fine up until this morning. Under light load I'm getting a flutter. So I cannot get on a steady 'boost' pressure. The car then goes into overboost protection. So that I cannot get any boost pressure.

Using the Torque app I ham getting the following codes;

P0234 Overboost condition
P0101 Mass air flow performance problem
P2A00 O2 sensor circuit range

P0234 was the only code first displaying. I'm now getting the other two. Which makes sense, If I have too much air the mixture will be off and foul the o2 sensor.

In my root cause findings I initially thought there is a boost control valve on these engines but cannot find one.
Am I right in saying there is not one? Or is there something located on the turbocharger?

I cannot see any vacuum lines to anything and going to assume that there are none.

So my thought train is;

Check air leaks and make sure everything is tight
MAF sensor clean / replacement
Wastegate issue?

As far as I know, there is no boost control valve (some refer to it as a solenoid) on a euro 4 and newer engine. The turbo actuator is electronically controlled on these engines, whereas the older euro 3 had all kinds of vacuum lines that go to the vacuum engine mounts, vacuum pump, turbo control valve, boost solenoid and eventually the turbo. Assuming your car is a euro 4, you won’t have all these vacuum lines. You’ll have a vacuum pump and that’s about it.

Have you checked the boost pipes that go to the turbo and intercooler for splits?

I’d suspect the MAP sensor (Manifold Absolute Pressure), if the pipes all look fine. Someone recently had a PO234 code and that turned out to be the issue. Its not easy to access though, so expected some skinned knuckles. Its on the intercooler, behind the passenger side headlight. Could be worth giving it a clean and/or replacing it.

Note: The original is Bosch, so replace it with the same. Its not a job you want to be doing again in a hurry.

See post number 40 on this thread.

https://www.volvoforums.org.uk/showt...=302878&page=4

[bigbeat]

Thanks for this. I have ordered some cleaner , give it a clean first and see what that does.

That looks nice a tricky to get to! The pipes look in good condition from what I can see. The only one really leaking is the crankcase breather. I'll give everything a clean and see what happens.

The pipes are not easy to get off!

[seanc]

Originally Posted by bigbeat

Was it attached to the engine or to the bulkhead?

Yes, it's on the bulkhead and it looks like this https://www.ebay.co.uk/itm/402365987...mis&media=COPY

[bigbeat]

Originally Posted by seanc

Yes, it's on the bulkhead and it looks like this https://www.ebay.co.uk/itm/402365987...mis&media=COPY

I've looked and have not got this. Will try the MAP sensor first and feedback if it fixed the issue

[Kev0607]

Originally Posted by bigbeat

I've looked and have not got this. Will try the MAP sensor first and feedback if it fixed the issue

https://www.ebay.co.uk/itm/402365987...mis&media=COPY

I think that's a DPF pressure sensor. I watched a chap doing a DPF clean on an XC90 and that part looks the same as what he put the chemical cleaning additives into (via the tubes).

[bigbeat]

I've gotten a bit further. Using Torque app I have completed a before and after of changing the map sensor.

Before it was sitting at 78 Celsius. Now after changing it on idle it is sitting at a more respectable 17 Celsius so one thing cured sort of.
I cleaned the MAF and it looked okay however my next step would be to replace this?
I'm still getting a wastegate noise flutter even on gentle throttle.

Am I right in saying the wastegate is electronically controlled?
New MAF sensor first or ECM?

[Kev0607]

Originally Posted by bigbeat

I've gotten a bit further. Using Torque app I have completed a before and after of changing the map sensor.

Before it was sitting at 78 Celsius. Now after changing it on idle it is sitting at a more respectable 17 Celsius so one thing cured sort of.
I cleaned the MAF and it looked okay however my next step would be to replace this?
I'm still getting a wastegate noise flutter even on gentle throttle.

Am I right in saying the wastegate is electronically controlled?
New MAF sensor first or ECM?

Its electronically controlled on the euro 4 and newer engines. What year is your car? If its a euro 3, its vacuum controlled.

Are there any codes relating to the MAF? If not, there's not much point in changing it. Same with the ECM... that would be very expensive.