8 replies to this topic

[FreddeB]

Hi

 

I have some problems with the boost in my car.

When i accelerate from low revs i get good boost (about 1,3 bar). But when the revs came up to about 3500 rpm the boost drops down to about 0,5 bar.

 

I have the K04 turbo, charge cooler, 3" exhaust, Open air filter. I only know that it´s a stage 3 map, i don't know the fabricate.

 

I have tried to find the problem but now i run out of ideas.

The following is checked.

I have made a pressure test of the boost system and there is no leaks from the air filter to the inlet into the engine.

 

I checked the thin vacuum hoses, and they were good.

 

I have change the blow off valve to a forge.

 

I have change the both solenoids (boost and vacuum).

 

I have disconnect the hose to the wastegate "controller" and accelerate the car, now there should be very much boost.

But there are no different. I also tried to force the wastegate to be closed with a thick metal thread, no different.

 

I have tried with the original intercooler to see that the chargecooler was ok. Same problem with both.

 

I have disconnect the exhaust to check that the catalysator was not burned, it was ok with good flow (no blocks).

 

I have changed the hose between the AFM and the turbo inlet to a metal tube, because i heard that the hose could collapse.

 

I have dismounted the turbo to check for cracks or if there was to much play on the turbine, i think it looks good.

 

Does anybody have a tips for me where to search for the failure?

 

best regards Fredrik

[TFD]

It is strange that you dont see a difference when disconnecting the boost vacuumhose on the turbo or made the wastegate stuck. My initial thought would be the wadtegate itself. 0,5 bar is most of the times the wastegate minimal pressure. If the spring is knackered, there's not gonna be very much boost for a long time. Probably your boostsolonoid and ecu are pushing everything to get the desired level of boost? Is your boostsolonoid ok? This one is directed by the ecu right? Faultcode? You changed your bov. Was this before or after the problem occured? If this is afterwards, what bov was installed? Set up correctly with the right pressure/spring? Just some thoughts.

[Duncan VXR]

Unplug the boost solenoid electrical plug if its holding boost above actuator spring pressure you need to look at the turbo / wastegate setup. Penny valve or actuator could be sticking DG

[FreddeB]

Hi Now i checked some more things. I disconnect the electrical from the boost solenoid, no difference. There are no faultcodes. I checked the penny valve and it closes good and is not sticking I tester the acuator and it holds the pressure and the spring feels ok. I checked for movement on the acuator when i drive and it is not moving when i press the throttle . It only moves when i drop the throttle, so its ok. I change the bov after the proplems started, its a forge and i use the yellow spring. In disconnect the vaccum pipe to the bov and drive, no difference. I have checked the clutch switch (i read that it maby was connected to the bov), works ok. I have drive a little now and it feels that i lose more pressure when the engine is realy hot compares to when i pressed the throttle first time when its cold (73 deg). Could the turbo harsh when it gets realy hot? The problem started after that i fixed a leak in the chargecooler. It was a leak that i run with for a long time. Could the turbo have over run so the bearings is broken and harsh when it is hot? Best regards Fredrik

[Ormes]

Collapsing intake? ...still got the rubber hose?

[FreddeB]

No, i got a metall tube from the afm to the turbo. Best regards Fredrik

[tibby]

Hello,

Is it an 'open Forge' ?

Like this?




Or a Forge recirculated one?



Noticed in the picture above, the Forge is fitted WRONG!

Maybe try the Bleu spring from Forge? Be aware with some jerkiness.....(like the set up above)
When using the Forge in the opposite way (and the correct one) you can use the green (softest spring) and you can eliminate a bit jerkiness...

When using Forges like above (open and closed ones) please inspect o rings and pistons for damage and or wrong fitted. Maybe losing boost when damage????



If you mean the recirc valve on the turbo itself....forget everything i said :-)


Maybe something you can check rapidely......

Edited by tibby, 10 September 2016 - 04:42 PM.

[Johnturner]

I lost a considerable amount of boost and 100hp. The problem was a vacuum pipe falling off the recirculating vslve which is next to the vacuum store.

[FreddeB]

Sorry, i meant forge recirc valve (fitted on the turbo). I have checked the vaccum pipes (i put air from the compressor in them and checked for leaks) Today i mounted off the turbo and took off the compressor house to see if there were any damage. Looks good😩 Best regards fedrik