hunting odd turbo behaviour - 08 RDX 308K km - no codes thrown
11-16-2022, 10:14 AM
#1
Instructor
Thread Starter
hunting odd turbo behaviour - 08 RDX 308K km - no codes thrown
Well with one thing fixed its time for another.
I noticed on my partners 08 RDX that the turbo will spool up and hold boost under max acceleration, but will appear to bounce or go up and down under lesser than max acceleration. I cleaned the intercooler carefully prior, done spark plugs, oil change was just done, changed the air filter to a Acura OEM one, and serviced other fluids.
I have been religiously scanning it with a NT510 Elite scan tool and no turbo overboost, underboost, or other codes were found. Whatever is happening is not picked up by the sensors as this code scanner individually checks the SHAWD, engine, emissions, and other modules (49 of them to be exact). The only code that comes up is under body electrical where i need to replace the HVAC doors if i remember correctly.
The car drives normally, does not surge, but that gauge bothers me.
My current thoughts are a mild vacuum leak somewhere or i did not seal the intercooler properly when i put it back on. I do not hear grinding or odd noises when the turbo does spool, and it is still peppy.
I've read a few threads of people talking about torn or holes in the air intake so i will start there. I will also lubricate the bypass valve actuator next weekend to see if it helps, however it makes all the sounds it should from what i can tell.
Car has 308 k km and was serviced with synthetic oil for its lifetime by the previous owner.
This post is to log the investigation and fix that is required or overall findings
I noticed on my partners 08 RDX that the turbo will spool up and hold boost under max acceleration, but will appear to bounce or go up and down under lesser than max acceleration. I cleaned the intercooler carefully prior, done spark plugs, oil change was just done, changed the air filter to a Acura OEM one, and serviced other fluids.
I have been religiously scanning it with a NT510 Elite scan tool and no turbo overboost, underboost, or other codes were found. Whatever is happening is not picked up by the sensors as this code scanner individually checks the SHAWD, engine, emissions, and other modules (49 of them to be exact). The only code that comes up is under body electrical where i need to replace the HVAC doors if i remember correctly.
The car drives normally, does not surge, but that gauge bothers me.
My current thoughts are a mild vacuum leak somewhere or i did not seal the intercooler properly when i put it back on. I do not hear grinding or odd noises when the turbo does spool, and it is still peppy.
I've read a few threads of people talking about torn or holes in the air intake so i will start there. I will also lubricate the bypass valve actuator next weekend to see if it helps, however it makes all the sounds it should from what i can tell.
Car has 308 k km and was serviced with synthetic oil for its lifetime by the previous owner.
This post is to log the investigation and fix that is required or overall findings
11-16-2022, 12:09 PM
#2
Well with one thing fixed its time for another.
I noticed on my partners 08 RDX that the turbo will spool up and hold boost under max acceleration, but will appear to bounce or go up and down under lesser than max acceleration. I cleaned the intercooler carefully prior, done spark plugs, oil change was just done, changed the air filter to a Acura OEM one, and serviced other fluids.
I have been religiously scanning it with a NT510 Elite scan tool and no turbo overboost, underboost, or other codes were found. Whatever is happening is not picked up by the sensors as this code scanner individually checks the SHAWD, engine, emissions, and other modules (49 of them to be exact). The only code that comes up is under body electrical where i need to replace the HVAC doors if i remember correctly.
The car drives normally, does not surge, but that gauge bothers me.
My current thoughts are a mild vacuum leak somewhere or i did not seal the intercooler properly when i put it back on. I do not hear grinding or odd noises when the turbo does spool, and it is still peppy.
I've read a few threads of people talking about torn or holes in the air intake so i will start there. I will also lubricate the bypass valve actuator next weekend to see if it helps, however it makes all the sounds it should from what i can tell.
Car has 308 k km and was serviced with synthetic oil for its lifetime by the previous owner.
This post is to log the investigation and fix that is required or overall findings
I noticed on my partners 08 RDX that the turbo will spool up and hold boost under max acceleration, but will appear to bounce or go up and down under lesser than max acceleration. I cleaned the intercooler carefully prior, done spark plugs, oil change was just done, changed the air filter to a Acura OEM one, and serviced other fluids.
I have been religiously scanning it with a NT510 Elite scan tool and no turbo overboost, underboost, or other codes were found. Whatever is happening is not picked up by the sensors as this code scanner individually checks the SHAWD, engine, emissions, and other modules (49 of them to be exact). The only code that comes up is under body electrical where i need to replace the HVAC doors if i remember correctly.
The car drives normally, does not surge, but that gauge bothers me.
My current thoughts are a mild vacuum leak somewhere or i did not seal the intercooler properly when i put it back on. I do not hear grinding or odd noises when the turbo does spool, and it is still peppy.
I've read a few threads of people talking about torn or holes in the air intake so i will start there. I will also lubricate the bypass valve actuator next weekend to see if it helps, however it makes all the sounds it should from what i can tell.
Car has 308 k km and was serviced with synthetic oil for its lifetime by the previous owner.
This post is to log the investigation and fix that is required or overall findings
12-09-2022, 09:45 PM
#4
Instructor
Thread Starter
Cleaned the maf, replaced pcv, the varying is lesser than before.
I am tempted to refresh the turbo vacuum lines with silicone tubing to see if there are any potential cracks. As long as the turbo doesnt go out (which this does not seem to be indicative of) then i am happy
I am tempted to refresh the turbo vacuum lines with silicone tubing to see if there are any potential cracks. As long as the turbo doesnt go out (which this does not seem to be indicative of) then i am happy
05-28-2023, 02:46 PM
#6
Instructor
Thread Starter
So its been a while and it has not thrown any codes still.
I suspect its a boost leak based on how the vehicle drives. Between 80-100kmh acceleration it seems to struggle and then launches off past 120 and the boost bar remains at full level.
I've observed a few different methods of hunting for these leaks, and will check all the pipes and the turbo itself. I dont suspect its an issue with the turbocharger in the sense of a turbine/seal failure as the car can make full boost on WOT. On half throttle the leak presents itself more with reduced performance compared to previous.
I am hoping its just a tear in a pipe as turbos are worth their weight in gold up here with yards wanting 1000$ plus for them (supply and demand).
My volvo's turbo by comparison fetches 200-300 cad.
I suspect its a boost leak based on how the vehicle drives. Between 80-100kmh acceleration it seems to struggle and then launches off past 120 and the boost bar remains at full level.
I've observed a few different methods of hunting for these leaks, and will check all the pipes and the turbo itself. I dont suspect its an issue with the turbocharger in the sense of a turbine/seal failure as the car can make full boost on WOT. On half throttle the leak presents itself more with reduced performance compared to previous.
I am hoping its just a tear in a pipe as turbos are worth their weight in gold up here with yards wanting 1000$ plus for them (supply and demand).
My volvo's turbo by comparison fetches 200-300 cad.
06-12-2023, 12:50 AM
#7
Instructor
Thread Starter
Well after inspecting the turbo closely and verifying no wear on the wastegate actuator, no odd sounds when revving to 5000 rpm i determined the turbo was fine.
Changed the transmission fluid and reset the TCM and the car has had its acceleration restored. I suspect the old fluid was worn out and caused odd shift points which resulted in premature activation of the wastegate and blow off solenoid. On normal acceleration the gauge sticks to the top with no wobble.
Going to mark this as solved. Will still change the BOV gasket as its cheap but was surprised that everything was in order and a transmission fluid change solved this problem.
Changed the transmission fluid and reset the TCM and the car has had its acceleration restored. I suspect the old fluid was worn out and caused odd shift points which resulted in premature activation of the wastegate and blow off solenoid. On normal acceleration the gauge sticks to the top with no wobble.
Going to mark this as solved. Will still change the BOV gasket as its cheap but was surprised that everything was in order and a transmission fluid change solved this problem.
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