Hey all,
I have issues with my golf R underperforming of late.
It seems to be when the air temp is at or above 25 degrees, under load the car feels like a dog on the freeway in 4th/5th W.O.T, like the engine timing is being heavily retarded.
I've tried logging boost with a cheap Bluetooth adapter and the Torque app.
Car had a Stage 1 APR tune, no other mods.
As November came along performance seemed down, this was actually after installing a new clutch with SMFW.
Trying to improve it, I changed the DV to a GFB DV+
Then I added a Volant intake
I put in a new PCV valve (there was some diaphragm bypass)
Changed spark plugs and gapped at 0.028"
Then autotech HPFP (and new cam follower), and changed software to Stage 1+
Still little improvement.
Then today I had a new N75 put in while my timing belt and water pump was done.
The mechanics commented that it felt fine yesterday (when it was 20deg), but it didn't feel like it was boosting right today (25 degrees). I had the exact thoughts as them, it felt beautiful driving yesterday morning, and a dog this afternoon.
I've attached some plots of the boost.
As you can see, it's kind of all over the shop.
Sometimes it struggles to climb, other times it overshoots and drops very rapidly to around 17psi before picking up again.
I've had it smoke tested briefly, but no-one seems to offer pressure testing so I'm thinking of making a DIY pressure tester.
What can I log to help diagnose this problem?
I can't seem to be able to log requested/actual boost on this Torque app, but I might try get a ross tech cable this weekend.
My thoughts on what it could be:
Cat is partially blocked?
A temp sensor is out?
Map sensor?
MAF sensor?
Hose/boost leak?
Knock sensor?
Carbon buildup on intake manifold?
Whatever it is, it seems quite dependent on ambient air temp, however cooler temps could just be masking the problem due to more power, as the boost still seems inconsistent at lower temps.
Cheers!
P.S I'm in the Sydney area (north) if anyone has any mechanics they specifically know are good at logging and diagnosing these hard to troubleshoot issues (preferably an APR dealer).
PPS. With the SMFW in, it caused the whole cabin to vibrate.
I couldn't stand it and went back to a DMF after a few months. Fortunately the mechanic refunded.
I never heard back if the clutch was unbalanced, or if maybe my engine vibrates a bit more than normal and hence doesn't like the SMFW.
The reason I mention this, is if my engine vibrates a bit more for some reason, this could potentially cause issues with the knock sensor?
I have issues with my golf R underperforming of late.
It seems to be when the air temp is at or above 25 degrees, under load the car feels like a dog on the freeway in 4th/5th W.O.T, like the engine timing is being heavily retarded.
I've tried logging boost with a cheap Bluetooth adapter and the Torque app.
Car had a Stage 1 APR tune, no other mods.
As November came along performance seemed down, this was actually after installing a new clutch with SMFW.
Trying to improve it, I changed the DV to a GFB DV+
Then I added a Volant intake
I put in a new PCV valve (there was some diaphragm bypass)
Changed spark plugs and gapped at 0.028"
Then autotech HPFP (and new cam follower), and changed software to Stage 1+
Still little improvement.
Then today I had a new N75 put in while my timing belt and water pump was done.
The mechanics commented that it felt fine yesterday (when it was 20deg), but it didn't feel like it was boosting right today (25 degrees). I had the exact thoughts as them, it felt beautiful driving yesterday morning, and a dog this afternoon.
I've attached some plots of the boost.
As you can see, it's kind of all over the shop.
Sometimes it struggles to climb, other times it overshoots and drops very rapidly to around 17psi before picking up again.
I've had it smoke tested briefly, but no-one seems to offer pressure testing so I'm thinking of making a DIY pressure tester.
What can I log to help diagnose this problem?
I can't seem to be able to log requested/actual boost on this Torque app, but I might try get a ross tech cable this weekend.
My thoughts on what it could be:
Cat is partially blocked?
A temp sensor is out?
Map sensor?
MAF sensor?
Hose/boost leak?
Knock sensor?
Carbon buildup on intake manifold?
Whatever it is, it seems quite dependent on ambient air temp, however cooler temps could just be masking the problem due to more power, as the boost still seems inconsistent at lower temps.
Cheers!
P.S I'm in the Sydney area (north) if anyone has any mechanics they specifically know are good at logging and diagnosing these hard to troubleshoot issues (preferably an APR dealer).
PPS. With the SMFW in, it caused the whole cabin to vibrate.
I couldn't stand it and went back to a DMF after a few months. Fortunately the mechanic refunded.
I never heard back if the clutch was unbalanced, or if maybe my engine vibrates a bit more than normal and hence doesn't like the SMFW.
The reason I mention this, is if my engine vibrates a bit more for some reason, this could potentially cause issues with the knock sensor?
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