Strange problem, car won't boost....

[i l k e r]

hi all,

I parked the car about a month ago and haven't started/driven it until today.

It started the first time and it idles, revs and drives fine but it won't boost beyond 6-7 psi even though it's set to run 18psi.

when it reaches to 6-7 psi there is a whinning noise much like a wheel bearing whinning and it won't boost beyond that even though the revs keep raising :confused:

any ideas???

[michael tierney]

sounds like a leak!

[i l k e r]

I thought that too but it was perfectly fine when I parked it. And all the hoses and vacuum tubes are new.

[Scoff]

fetch the air filter off and have a look at the compressor wheel, make sure that it hasn't sucked anything up and snapped/bent a blade, then check for play. a leak does seem like the more likely thing though.

[Scoff]

bare in mind that the leak might be in the form of a duff dump valve, or a hole in an intercooler, or a perished carb-top O ring, etc etc.

[i l k e r]

fetch the air filter off and have a look at the compressor wheel, make sure that it hasn't sucked anything up and snapped/bent a blade, then check for play. a leak does seem like the more likely thing though.


I already did that and it's fine. time for a leak test then :boring:

thanks for the input guys.

[i l k e r]

bare in mind that the leak might be in the form of a duff dump valve, or a hole in an intercooler, or a perished carb-top O ring, etc etc.


none of the above I don't think but could this be actuator related do you think Chris?

[Scoff]

none of the above I don't think but could this be actuator related do you think Chris?

nah, not likely. you have to wonder what is causing the noise.

other ideas off the top of my head:

stuck choke flap
throttle not seeing 100%
air filter occluded
wastegate penny in turbine has slipped, or is sticking open
random leak elsewhere in boost circuit

[i l k e r]

nah, not likely. you have to wonder what is causing the noise.

other ideas off the top of my head:

stuck choke flap
-removed

throttle not seeing 100%
-it wouldn't rev all the way down if that was the case??

air filter occluded
-tried filter off, it's the same

wastegate penny in turbine has slipped, or is sticking open
-checked it's fine

random leak elsewhere in boost circuit
-will check and report back





ahh the joys of C1J :dearme:

[i l k e r]

fetch the air filter off and have a look at the compressor wheel, make sure that it hasn't sucked anything up and snapped/bent a blade, then check for play. a leak does seem like the more likely thing though.


running out of the ideas I took the compressor housing off and one of the blades is slightly bent :crap:

I'll try and straighten it and see how it goes :cry:

[Adam L]

Remember those fins are very deilcate, there's a good possiblity you've bent it yourself taking the housing off.

[i l k e r]

Remember those fins are very deilcate, there's a good possiblity you've bent it yourself taking the housing off.

I know Adam, good care taken whilst taking the housing off...

I've already straightened it and put it back together, time to put it back on the car and test drive :devil:

[i l k e r]

right this is getting ridiculous now.

tried to pressure test the system for leaks today and the strangest thing has happened.

as I try to pressure the system it feels like I'm trying to fill the void, air enters through the compressor housing and it vanishes. I couldn't even put 1psi into the system.

there seems to be no leaks, so the only thing I could think of is a huge crack in the exhaust housing letting all the air out before I can pressurise the system.

ideas please :(

[dave j gtt]

:ashamed::ashamed:

[i l k e r]

no cracks on the turbine housing.

don't know what to do now.

any ideas people?

[Brigsy]

Did you block the inlet on the turbo whilst doing the pressure test?

[Tony Walker]

Do you have the original exhaust recirc pipes on and anti perc fan? sounds like you may be sending pressure down to the perc fan causing a whining noise? The valve can be prone to sticking/failing. Not sure what your problem is when your pressurising the system? how are you trying to pressurise it?

[clee]

You have sealed the intake off right ?

[i l k e r]

pressurising the system from the turbo intake so that's sealed.

no anti perc fan or any other std. unwanted pipes etc.

[Brigsy]

Compressor housing sealed to the backing plate properly?

[i l k e r]

Compressor housing sealed to the backing plate properly?


yes mate it definetly is.

[Brigsy]

Strange:confused: Are you using a compressor to pressurise the cct? Must be able to hear a leak that big?

[i l k e r]

strange ain't the word my friend. Yes I'm using a compressor to do the test and it doesn't sound like ther's a leak. It feels like it keeps filling with air.

I think I'll remove the whole boost circuit off the car and try it that way:eek:

[Tony Walker]

what intercooler do you have? if its the gt tuning breadbin one, they have a tendecy to be battered by the clutch release arm. mines popped a couple of times there, definetly sounds like a boost leak tho.

[i l k e r]

problem solved :)

I took the bumper off to have a butchers at the i/c piping then realised there was a snapped jubilee clip, but because it was stuck on the silicone it wasn't visible. Changed it, put the bumber back on and it's all back to normal now :agree:

thanks for all the input :agree:

[raj]

problem solved :)

I took the bumper off to have a butchers at the i/c piping then realised there was a snapped jubilee clip, but because it was stuck on the silicone it wasn't visible. Changed it, put the bumber back on and it's all back to normal now :agree:

thanks for all the input :agree:

well thats yours sorted, just mine left now:brickwall: