406oc.co.uk

just wondered how to check if turbo or sensor knackered cos dont seem to be spooling up, went for a drive and drives ok , bit slow without the turbo.
hopefully not the turbo cos was fine this morning, then missus went into town ok, then went to come home and wasnt right, plesae help

Only real way to check is to remove the air inlet pipe to the turbo from the compressor housing and try manually spinning the turbine / shaft by hand... if its siezed its a service kit and an afternoon of rebuilding!

Another way is to watch the air hose from the intercooler to the inlet manifold when you rev the engine you will see the hose start to collapse, this means that the engine is sucking the air in and not being forced in by the turbo.

I suggest that you do that first then wait for the engine to go cold before checking the compressor wheel / shaft !

will try that tomorrow hopefully.cant see any pipes move but have a hissing noise at front by radiator

i was told the other way to check was to use something like wd40 and spray it round the joints one at a time, and if theyre leaking engine will rev a bit cos of sucking it in, if thats a good idea or not!!

took it to a friends garage today and fault says boost system failure, so hopefully just a leaky pipe, if i can find the bloody thing!!!!!

Did you watch the hose from the intercooler to the inlet for collapse under accelleration?

had a quick look this morning and doesnt collapse, just moves a little with the engine revving.

been looking at boost pipes today and dont see anything obvious, but really dont know what im supposed to be lookin for.
may be putting car up for sale as it is soon and get a 306 or other small car for now.should be able to get about£500 or near hopefully as is mot'd till june or july and taxed till end of year and could be an easy fix if u know what ur doin

Try taking the black hose of the turbo's compressor housing and spinning the turbine with your fingers, if this spins freely then it may be your electronic boost control valve..... approx £30 from the stealers !

If you don't check the things I'm sugges'tin then you ain't going to find the problem and resolve it !

tried the turbing and feels ok so gonaa see about gettin valva tomorrow.is it the one that comes off small pipe off boost pipe from the intercooler

podu wrote:will try that tomorrow hopefully.cant see any pipes move but have a hissing noise at front by radiator

i am amzed you did not pick up on this niz.
to me that would mean your intercooler is leaking, its common for the 406 intercooler to pop the ends off and fail.

But is the hissing from the front of the rad ( fan side ) or from under the bonnet?

I must admit I didn't pay much attention to that....lol
tbh the stock cooler holds decent pressures... its just not that good for cooling the charge ! !

The hissing could just be from the Idle Speed Control Valve or union ( ISCV ) these tend to leak a little and make a hissing noise, but its not enough to cause a loss of boost... only something like the intercooler is going to cause that or, a faulty recirc / diverter valve... you know the black bosch one!

If it does turn out to be the cooler, for the money I'd go onto eBay find an uprated unit and use that, instead of the std one... it'll be cheaper and will give you lower charge temps ! Just check the dimensions before hand ! lol

when revving it earlier the pipe that goes over engine to intercooler collapses slightly,looks like one from turbo to intercooler if im right!

podu wrote:when revving it earlier the pipe that goes over engine to intercooler collapses slightly,looks like one from turbo to intercooler if im right!

nope thats the pipe from the airfilter>turbo inlet. from your description

the pipe comes from right of intercooler, from metal pipe that comes off the turbo is the one im on about