Hi guys,

Ok, so my last post proved fruitless in my search for an answer. Hopefully this may provide an answer or at least a step in the right direction.

So, renault megane 2004 1.9dci.

New turbo fitted. Turbo spins when engine running, checked that tonight. When you drive and accelerate you can hear the turbo spin up, but there is no boost. It drives like a non turbo diesel.

Any suggestions??

Thanks

Andy

Split hoses, or not connected hoses?

Not familiar with that particular car but a few suggestions:
Split or loose hoses.
Wastegate/bypass stuck open (various reasons why including a rogue signal from the ECU if it has one).
Split intercooler.
Gaskets popped out.
Air filter blocked/wet.
Cat converter collapsed blocking exhaust.

Is there any fault codes stored or pending?

no fault code stored.

Will check hoses but sure they are all ok, will double check.

As for a split intercooler, dont really know how to check that!!

Keep em coming guys!!!

Thanks

Andy

EGR valve playing up can have that effect too leaving the car down on power but with the turbo still audible.

Compressions ok ?

Checked and double checked all the hoses ?

EGR valve ?

Have you checked the Live Data from the ECU ?
Diagnosed a bad throttle body on a new shaped Clio and no fault code was stored but by looking at the live data the throttle body trace was bloody awful

The Laguna 1.9dci's are prone to split intercoolers

I will be having another look tomorrow and if I find anything will post up. I still think it might be something to do with the vacuum but time will tell. SWMBO is wanting her car back......

and I want to get on with building a kit car....

Not sure about the approved way of leak testing an intercooler but i just took mine off and filled it with water, making very sure to dry it out properley before refitting.

Have a serious look at the actuator for the EGR valve. This may be a seperate vacuum operated unit on the Laguna as it is on a number of cars cars. If this is plying up it can have the effect of reduce engine power by a massive amount: The ECU thinks it has enabled the EGR so accordingly reduces the flow through the air intake to compensate. Though the MAF on the air intake can see the reduced airflow the ECU can't work out whats going on and doesn't have a way of compensating. You could try disconnecting the lead to the actuator to see whether the car runs any worse than it already is. If it is runs the same then the chances are you have found the cause. Rather than replacing the actuator you can bypass it with a simple circuit comprising two resisters and a diode. Worked a treat on mine and better MPG too.

I'd go for hoses, split intercooler or stuck wastegate especially if black smoke on load, try manually moving wastegate to see if it opens and closes OK.
Cant see it being EGR if youve recently changed turbo unless it was doing the same previously and if it was your diagnosis was wrong, tried the mass airflow sensor ?
Seems like everyone points towards the EGR with a diesel when sometimes its something as simple as a split hose.
Cheers,
Bob