Just purchased car, loss of power

[Xr6kav]

Hi guys, 

 

I recently bought a fg xr6 turbo a few days ago. It has 77,000kms on it. Only mod it has is a Herrod intake. The car had been sitting for 6 months. Battery wasn’t the best.

Day one I took it for my first test drive, power was great and could really hear the stock blow off valve when boosting (at the time I didnt know if they are meant to be that loud or the after market intake made it louder). 
 

day two I backed it in and out of driveway was a bit hard to accelerate, felt like spark plugs were slightly fowled but went away after a few minutes but notice this when car is cold now. 

Day 3 I removed the battery to give it a charge and noticed a clamp on the intercooler pipe was loose and pipe had come out slightly so I put it back in and tightened the clamp. I decided I wanted to wash it but windows were down and battery was out so I connected a battery pack to wind window up but it didn’t work so I connected a big battery and eventually got the windows up. I charged the original battery for only 3-4 hours whacked it back in and took for a spin and could barely feel the punch of the turbo and blow off valve noise slightly only in first gear. The car drives really smooth when warm just feels under powered. No engine light or fault codes. I tried removing boost solenoid and just connecting wastegate straight to turbo but made no difference. I replaced the battery, still nothing. I connected my scanner to check boost pressure and it says it’s running 14 psi on full throttle. I disconnected a intercooler pipe to feel power difference as I couldn’t believe it was boosting that much then drove it and it was very slightly under powered but not as much as it should be when disconnecting the turbo. I could hear turbo spooling loud and clear after disconnecting pipe. 
 

In all honesty the car feels like it’s running 2-3 psi but very smooth to drive with no fault codes. My next move will be changing the spark plugs and fuel filter but I can’t see these making a dramatic difference. 
 

Sorry for the long post, just trying to give as much detail as possible to see if anyone would have any suggestions? 

Thanks in advance. 

Edited 20/08/22 11:41 AM by Xr6kav

[Tom Tucker]

Hey mate, sorry to hear you're having problems straight away. It's really difficult to diagnose what exactly is going on. It's really a process of elimination. I'd suggest fully servicing the car, including fuel filter. If you're doing spark plugs, consider replacing the coils too (oem only).

Double check all your hose clamps on the intercooler hot side.

Maybe just change the battery out. A buggered battery has undone many before.

Keep us up to date with progress

[Rab]

Not sure if it helps, but mine felt similar when I blew the intake hose off

 

Sure asll the piping is connected properly?

[Xr6kav]

Yes I checked all the piping a few times already. 
thank you for the suggestion. 

 

17 hours ago, Tom Tucker said:

Hey mate, sorry to hear you're having problems straight away. It's really difficult to diagnose what exactly is going on. It's really a process of elimination. I'd suggest fully servicing the car, including fuel filter. If you're doing spark plugs, consider replacing the coils too (oem only).

Double check all your hose clamps on the intercooler hot side.

Maybe just change the battery out. A buggered battery has undone many before.

Keep us up to date with progress

Yes I will be doing the spark plugs and fuel filter. I replaced the battery already but still no difference.

Thank you for your response

Edited 21/08/22 04:41 AM by Xr6kav

[Puffwagon]

It can be tricky to spot a leaking connection and they are easily missed. If you want to be sure there are no leaks you should get it smoke tested.

[Xr6kav]

You’re right I might add this to the list of things to try. The only way I have currently tested is hearing for one while someone accelerates and disconnecting pipe before throttle body and checking for pressure which felt good but not accurate. Explains why BOV noise is gone but what doesn’t make sense is that my scanner shows 14 psi of boost which should be right for a standard set up? 
 

on the first day I got the car (pre problem) the factory BOV  noise was really loud. Would anyone know if they have a loud noise naturally? Only mod is the herrod air intake. 
 

thanks for your suggestion.

[biddie_fiddler]

Not sure if I've missed something, but you keep talking about this BOV sound from the factory BOV. Might just be my experience, but I never heard the factory unit making any sort of noise before I removed it. It acts more as a diverter valve if I'm not mistaken. When you are on boost and get off throttle, the BOV "diverts" the air back into the intake. BOVs that you may be thinking of release this air to atmosphere giving you that classic BOV noise. So, to me, if you're hearing air escaping then I don't think its coming from the factory BOV.

Who knows though, maybe the herrod intake makes the BOV noise louder. Wish I knew, I blocked mine the week of owning the car 🤣

[k31th]

The factory BOV is not loud unless it's "diverted" to atmosphere and even then it's a light "pshhhh" sound, not a quick "pshtt" sound you get with "horn-shaped" aftermarket BOVs. It could also be mal-functioning (e.g. not diverting) and that could cause the turbo to make "gobble gobble" noises from the air not actually being "diverted" and making it back to through the intercooler to the turbo outlet and the compressor wheel.

[Xr6kav]

On 22/8/2022 at 10:21 AM, biddie_fiddler said:

Not sure if I've missed something, but you keep talking about this BOV sound from the factory BOV. Might just be my experience, but I never heard the factory unit making any sort of noise before I removed it. It acts more as a diverter valve if I'm not mistaken. When you are on boost and get off throttle, the BOV "diverts" the air back into the intake. BOVs that you may be thinking of release this air to atmosphere giving you that classic BOV noise. So, to me, if you're hearing air escaping then I don't think its coming from the factory BOV.

Who knows though, maybe the herrod intake makes the BOV noise louder. Wish I knew, I blocked mine the week of owning the car 🤣

Yes I understand I’m trying to determine whether that was normal or not to hopefully give me a clue to help me find the problem. 
 

So I loosened the same intercooler pipe I tightened the other day and took for test drive and the “BOV noise was back” so now I know that noise was not normal as I didn’t know anyway better as that was the way I bought the car and funny enough with clamp loose it still showed around 14psj boost which now I think must be a mistake measured off the scanner and now I’m leaning more towards a wastegate issue. The turbo was replaced 20,000kms ago but the has recently sat for 6 months. 

I will be playing with wastegate in the next couple of days. 
 

thanks for your input guys.  

[biddie_fiddler]

It's pretty unlikely the scanner is wrong. The scanner is reading values directly from the ECU. So if you're seeing 14psi on the scanner, the ecu is also seeing 14psi. 

The sensor could be faulty I guess, but I've never heard of this happening before. 

Your problem may be elsewhere. If you have the scanner, you should check for codes too, check for misfires as well. Could be the spark plugs acting up