Hello


After much reading around the web, still trying to solve a persistent issue with my 2202 Volvo S80. Under the advice of 2 mechanics as well (one a dealership and one independent) this car has had a lot of parts replaced. (throttle body, throttle wiring, refurbished ECU, MAF, alternator). The car still acts up. Am beginning to think these Volvos had a design issue, and it's not just parts failing. Or hopefully it's something simple nobody has thought of yet.

Ongoing and current symptoms:


Car runs great for a while. Shows periodic CELs, that reset after a few starts. Or (worse) car runs great for a while, car enters reduced engine performance mode. Rough idle. Pull over, start it up again, usually with a few starts it's running OK again.


I bought a Bluetooth OBD II code reader which I hope to monitor performance with when the car is acting up. With the reader I just read the logged codes, and reset them to start fresh. Here is what the OBD II reports:

P0068
P0221
P0507

The P0068 and P0221 are familiar numbers, and have been around over several repairs.

Hoping for some help and ideas here... sorry, it's my first post.


Thanks!

 

P0507 is related to the idle control valve, the other two are related to the throttle position sensor. Have you done a vapor test (aka smoke test) to check for any vacuum leaks or intake manifold leaks or tried spraying carb cleaner on the outside of part joints to see if it sucks in and changes the idle? Could be something like a cracked air boot etc. I assume with the replaced throttle body everything is very clean inside (quite often these issues are caused by very dirty throttle bodies - which can happen when the PCV clogs up etc.)

 

Thank you for the reply. I haven't personally done that - think my mechanic did a vacuum leak check on it but will have them check again when I take it back armed with more information.

Was driving it hard today and also triggered the other TPS sensor (P0121 confirmed after checking what I saved earlier). Got this OBC reader with a Bluetooth Torque app on the phone that can reset the reduced engine performance condition once it triggers. Kind of funny watching the engine return to normal operation as soon as I clear the code - a crutch when I need it

Oh... yes the throttle body should be clean. I had it replaced about 1 year ago under advice of the dealership. Problem kept reoccurring - so I had them do the wiring and throttle body replacment under warranty again under advice from my other mechanic (took a week or two of arguing at the dealer but they did it).

 

Update. Checked for vacuum leaks with the carb spray method - could not find any. Drove car hard twice this morning and repeated tripping fault codes (P0068 and P0221). After more reading, decided to pull cable on accelerator pedal and cleaned with contact cleaner. Remated, we'll see how it goes. Have not tripped codes yet over 3 short trips. Starting to think all Volvo mechanics immediately jump to throttle body as source of problem due to all the problems they have had - but in my case with having that replaced twice perhaps the issue could be this simple? I hope so.