[atifkm]

My 2003 corolla LE slow down during shifting gears. Once shifting completed, it appears to be fine, not that perfect. Why pickup reduces during shifting. Car i bought has only 56,000 kms and driven by old lady. It appears that clicking sound comes from just beside MAF sensor. Is it a PC valve?? (i don't exactly remember it's name), but by listening it was giving the clicking sound, little unsusal. Appreciate if somebody can guide.

 

[shadowtag88]

My 2003 corolla LE slow down during shifting gears. Once shifting completed, it appears to be fine, not that perfect. Why pickup reduces during shifting. Car i bought has only 56,000 kms and driven by old lady. It appears that clicking sound comes from just beside MAF sensor. Is it a PC valve?? (i don't exactly remember it's name), but by listening it was giving the clicking sound, little unsusal. Appreciate if somebody can guide.

because you are right in it is slower during shifting. no car is accelerating
while shifting between gears.
the car is just coasting at that point. there is no force driving the car forward. once the car engages into the next gear, the power produced by the engine is being applied to the drivetrain -> ground thereby accelerating...
is your car a stick or an auto? sounds like an auto..

i do believe you mean the pcv valve. this is used to recirculate air.. i dont think that clicks...

describe the click more... when does it click? high rpms, low? on the gas, off? coasting? accelerating?
high pitched, low?



a clicking could be many things.. depending on the type.. it could mean something like an exhaust leak.. or a heat shield.... depending on how you describe the click...

 

[TrdSpeed140]

the clicking is from the vacuum-switching-valve, it's supposed to do that

 

[atifkm]

it is automatic. I don't remember the device name, but it is just beside MAF sensor. As per TrdSpeed it appears to be vaccuum switch, i am not sure.
Not all cars do loss of speed or power during shift of gears in automatic transmission. Does fuel injectors got clogged. Also let me know whether pcv valve need to be cleaned or not. Only reason car is used sparingly, i don't know this garaging cars need what type of service.

 

[shadowtag88]

it is automatic. I don't remember the device name, but it is just beside MAF sensor. As per TrdSpeed it appears to be vaccuum switch, i am not sure.
Not all cars do loss of speed or power during shift of gears in automatic transmission. Does fuel injectors got clogged. Also let me know whether pcv valve need to be cleaned or not. Only reason car is used sparingly, i don't know this garaging cars need what type of service.

sure injectors get buildup. use some techron concentrate every 6k miles to clear out buildup in the fuel system.

pcv valves could use replacement. you could just use compressed air and blow out dust and stuff. it should run better then.
to test the pcv valve. take off the vaccum hose. and have someone rev the engine as your finger is covering the pcv valve. it should form a vacuum on your finger.
another sign of a pcv valve needing replacement is if theres signs of oil in the intake...

 

[atifkm]

thanks guys, i will try these.
Can you please let me know the exact location of pcv valve, also how can i check oil in intakes.
i am handy for this work, but just need to know the correct part i will open.