Hey guys, new to the forums obviously, literally got nowhere else to go aside from an over priced mechanic. I like to try and fix problems myself before turning to them so any help or tips would help.


So, the problem. I took my mates advice and blocked the blow off valve to my XR6T, It gave me a sick CHU CHU CHU CHU for about a day and then I noticed something odd. When I boot it and get to approx 4000RPM - 5000RPM (using turbo) i hear a bit of a thud and instantly lose power, goes from 4000rpm down to 3000 and continues to drop even though my foot is still down. The only way to continue gaining speed is to remove my foot for 3 seconds or so and then accellerate again. This happens almost every time.

I removed the caps from the BOV location and put the stock BOV back on, checked all the pipes to see if the pressure had cracked something or pushed a pipe off the connection but couldn't see anything, changed all hose clamps and made sure it was all connected all looks fine. But i still have the same problem, it only started doing this once i blocked my bov and now its changed back the problem is still there.

Further note; i used to her a SHHHHHHH as powering up and a PSSSSST as i took my foot off (indicating the blow off valve was working) now I can't hear any type of air flow or any indication that its still working? its almost like the blow off valve is still blocked. i did hear a slight chu chu chu this morning when i tried it even though the stock bov is on?!?!

The only thing I personally can think of is the bov not opening and recirculating the air? I'm at a loss though, why would it not be opening? how can i test if its the BOV thats broken?
Any tips or solutions would be greatly appreciated.

Kind Regards!

UPDATE:

Okay so I took the BOV off again, checked it all, WD-40 incase it was jamming up etc, noticed hose that connects to the vacuum was really long, like almost bending in half long, gave that a trim so it wasn't at risk of bending and cutting off the air altogether. took it for a spin and we're getting somewhere! started to hear a bit of air flow when accelerating but no PSSSSH when taking the foot off. It took off nice and quick, smashed through first gear no worries up to 7000 rpm, hit second gear and the traction control warning came up which instantly threw it back into low power mode and the BRRRRRR came on again. I noticed now its only doing it when traction control comes on..

Is it possible the BOV is fked and needs replacing? would this be a reason for the issue perhaps? if the bov isn't opening properly it would make sense, atleast in my mind.. Some feedback when possible.

If the car is stock there is no way it should hit 7000 rpm ever. And i know as i have one. 5500 / 5600 is around the redline territory on BAs.

Take it to a workshop that has a code reader and get it scanned for faults and go from there before you blow up the engine.

As with the blow off valve mine makes noise sometimes but because its plumbed back into the crossover its fairly quiet most times. The Bosch branded original blow off valves are usually very reliable though.

thanks for the reply.

Fixed the problem though; ended up being the blow off valve vacuum hose was too long? as it was sucking air it was folding in half from the pressure which wasn't opening the bov properly which was causing a whole heap of other issues. All working as it was before, no issues anymore.

Good job. Just keep it away from 7000 rpm lol.