Overboost

[W210VIP]

Just seeing if anyone knows what cause an overboost on a W210 e320cdi?

Would a disconnected air filter to radiator housing cause this?

 

[oigle]

No. Wastegate failure - actuator or gate itself, or stuck vanes in turbo if you have that type of turbo.

 

[W210VIP]

Thanks oigle. I have a vnt! What about a split in the boost/ic pipes

 

[LostKiwi]

Thanks oigle. I have a vnt! What about a split in the boost/ic pipes

That gives under boost.

 

[Doug1234]

Partially blocked catalytic converter coild as well

 

[W210VIP]

I’ve been searching the forums for days and everyone has said it’s either vnt canes or a split pipes

 

[W210VIP]

I hear escaping air

 

[om613]

Check the vacuum function operating the VNT and the mechanism itself for restriction (crud).

 

[om613]

So a boost leak somewhere.

 

[LostKiwi]

A boost leak on the boost control circuit would do it.

 

[W210VIP]

Check the vacuum function operating the VNT and the mechanism itself for restriction (crud).

Done. There is a lot crud. But actuator moves when gas pedal floored.

Carried out egr shunt but there is a possibility that valve is stuck partially open as I’m getting more white smoke upon acceleration.

Next step is to take aprt egr and blank it.

Then it’s the turbo

 

[W210VIP]

A boost leak on the boost control circuit would do it.

Where is this?

 

[LostKiwi]

Where is this?

I'm not familiar with your engine.

 

[W210VIP]

Damnit

 

[oigle]

There will be a vacuum/boost pipe going to your vnt controller. If that is split or loose and losing pressure, that will give you the overboost. You just need to locate the offending pipe/hose.

 

[W210VIP]

Is it normal to hear the turbo whistle when you left of accelerator. It’s sounds as if it has a blow off valve. Like a whoosh

 

[oigle]

Mine does not do that. That normally only occurs where you have a throttle butterfly - mine doesn't have one. Yours could. I don't know your motor well enough.

 

[W210VIP]

Wish I could get more help Oigle

I play around today and tapped the egr with a hammer to possibly close egr. The engine shuttered!

 

[alexanderfoti]

Wish I could get more help Oigle

I play around today and tapped the egr with a hammer to possibly close egr. The engine shuttered!

You probably knocked a bit of carbon lose and into the engine....

It sounds like your VNT vanes are potentially jammed if you are hearing these noises on decel.

 

[W210VIP]

You probably knocked a bit of carbon lose and into the engine....

It sounds like your VNT vanes are potentially jammed if you are hearing these noises on decel.

That sounds like it could do that.

Gonna have the egr blanked off this week so make sure shunt is working then it’s time to take turbo apart.

Is the turbo disassemble and assemble a lengthy job