2003 acura tl slows down too rough right before i come to a stop (especially down hil
03-28-2015, 08:53 PM
#1
2003 acura tl slows down too rough right before i come to a stop (especially down hil
2003 acura tl. recently purchased with 160k miles. A/T
P1259 vtec system malfunction. P0420 catalyst system efficiency below threshold bank 1.
31- 2 engine retard command (pfinh) signal failure.
61- 2 gear position signal failure.
Only on downhill and level roads when i have my foot off the brake/gas pedal and when car is coasting under 20mph it slows down on its own a lil rough then goes back to normal. Like when im coasting up to a stop sign it will slow down (15mph range) rough make a faint brrrr sound then release to normal . And if I try to accelerate at the moment it's slowing down it accelerates really fast. Braking helps because problem only exists in around 15mph- 5mph (approx)..but after i come to a full stop and press gas the car accelerates perfectly...i noticed at moment when the car is experiencing that rough slow down if i put it in nuetral the roughness goes away... im not a mechanic never had opportunity to learn but i am a technical very accurate person. I know i am capable of doing the work myself. Just dont have too much experience on cars. .. im a master carpenter by trade..i restore homes not cars ...i would love to take care/baby and restore this car as much as possible. Just dont know where to start...any tips..advice? Might it be the codes that i have making the car slow down rough? If i clear these codes will this problem still exist?
This problem happened after i changed the oil n filter i used 10-30 high mileage synthetic(autozone rep recommended that one) then after 2 weeks i took car to oil change place and they said u need thicker oil and they put 10-40 high mileage synthetic. Now the problem exists but it comes n goes...i always warm car up for 15 minutes .. the guy at oil change said its probably a sensor problem he also brought to my attention i need to replace my motor mount..might it be the spark plugs or oxygen sensor or solenoid or rocker arm..oil pressure switch? Diagnosing a car feels like detective work and honestly i dont know where to start.....Any words of wisdom or guidance will be greatly appreciated ! Will ship bottle of wine! to whoever can help me figure out this problem.
P1259 vtec system malfunction. P0420 catalyst system efficiency below threshold bank 1.
31- 2 engine retard command (pfinh) signal failure.
61- 2 gear position signal failure.
Only on downhill and level roads when i have my foot off the brake/gas pedal and when car is coasting under 20mph it slows down on its own a lil rough then goes back to normal. Like when im coasting up to a stop sign it will slow down (15mph range) rough make a faint brrrr sound then release to normal . And if I try to accelerate at the moment it's slowing down it accelerates really fast. Braking helps because problem only exists in around 15mph- 5mph (approx)..but after i come to a full stop and press gas the car accelerates perfectly...i noticed at moment when the car is experiencing that rough slow down if i put it in nuetral the roughness goes away... im not a mechanic never had opportunity to learn but i am a technical very accurate person. I know i am capable of doing the work myself. Just dont have too much experience on cars. .. im a master carpenter by trade..i restore homes not cars ...i would love to take care/baby and restore this car as much as possible. Just dont know where to start...any tips..advice? Might it be the codes that i have making the car slow down rough? If i clear these codes will this problem still exist?
This problem happened after i changed the oil n filter i used 10-30 high mileage synthetic(autozone rep recommended that one) then after 2 weeks i took car to oil change place and they said u need thicker oil and they put 10-40 high mileage synthetic. Now the problem exists but it comes n goes...i always warm car up for 15 minutes .. the guy at oil change said its probably a sensor problem he also brought to my attention i need to replace my motor mount..might it be the spark plugs or oxygen sensor or solenoid or rocker arm..oil pressure switch? Diagnosing a car feels like detective work and honestly i dont know where to start.....Any words of wisdom or guidance will be greatly appreciated ! Will ship bottle of wine! to whoever can help me figure out this problem.
03-28-2015, 09:35 PM
#2
Moderator
First of all... Never.. ever use 10W on a J Series unless you live behind an active volcano. Second never use 10W anything on a J Series.
Go back to 5W-30 and never use "high mileage" gimmicks... Mobil 1 Extended Performance is a popular choice in the forum.
Now your problem.. Sounds like rough idle? I would guess the IACV is acting up? try this: With the car on neutral and engine running, Disconnect the IACV. The engine should now drop to -750rpm almost stalling (BUT NOT STALL). If the RPMs remain the same or the rpms shoot high you have a bad IACV. Disconnecting the IACV should always make the engine drop RPMs to -750 any other behavior is a malfunctioning IACV.
Once the IACV is ruled out we can diagnose your other issues.
Go back to 5W-30 and never use "high mileage" gimmicks... Mobil 1 Extended Performance is a popular choice in the forum.
Now your problem.. Sounds like rough idle? I would guess the IACV is acting up? try this: With the car on neutral and engine running, Disconnect the IACV. The engine should now drop to -750rpm almost stalling (BUT NOT STALL). If the RPMs remain the same or the rpms shoot high you have a bad IACV. Disconnecting the IACV should always make the engine drop RPMs to -750 any other behavior is a malfunctioning IACV.
Once the IACV is ruled out we can diagnose your other issues.
The following 2 users liked this post by Skirmich:
edsandler2145 (03-29-2015),
thelastaspec (03-28-2015)
03-29-2015, 10:36 AM
#4
lets go with the basic things we all need:
remove intake manifold to clean egr passages inside it, also service TB and IACV (idle air control) inside bottom of TB
2-3 hours DIY at a casual pace
remove a front spark plug and ck for wear, may be original to the car!! or have normal max miles on plugs,,after 60-70kmiles they are ready for new
May even have WRONG plugs such as bosch - a favorite of quick lube and tune places.
WRONG for the TL!!
8 dollar each NGK are what you need
after that- O2 sensors do wear out and give the bank 1 code- front O2-pre cat sensor is the one to fail from use.
DENSO is the preferred/original brand of O2 and total plug and play- sold everywhere
Seafoam is your new friend too, use twice thru gas tank at 1 can to just under half tank, repeat in a tank or two= another 1 can to just under half tank
If you were a car person I would say use vac port method for faster diagnosis/cleaning, BUT the 2 can method is better overall
(seen on sale at walmart for 7 bucks= good price)
Codes are CLUES not a diagnosis in themself
remove intake manifold to clean egr passages inside it, also service TB and IACV (idle air control) inside bottom of TB
2-3 hours DIY at a casual pace
remove a front spark plug and ck for wear, may be original to the car!! or have normal max miles on plugs,,after 60-70kmiles they are ready for new
May even have WRONG plugs such as bosch - a favorite of quick lube and tune places.
WRONG for the TL!!
8 dollar each NGK are what you need
after that- O2 sensors do wear out and give the bank 1 code- front O2-pre cat sensor is the one to fail from use.
DENSO is the preferred/original brand of O2 and total plug and play- sold everywhere
Seafoam is your new friend too, use twice thru gas tank at 1 can to just under half tank, repeat in a tank or two= another 1 can to just under half tank
If you were a car person I would say use vac port method for faster diagnosis/cleaning, BUT the 2 can method is better overall
(seen on sale at walmart for 7 bucks= good price)
Codes are CLUES not a diagnosis in themself
03-29-2015, 10:43 AM
#6
10w-30 or 10-40 oil is allowed per owner book, Our mega moderator has run straight 40 with no problems!
the first number is oil viscosity at 32F, so its for the initial start up temp and immediate oil flow due to thinner action of the 0, 5 or 10-
high mileage oils have extra stuff for leaking seals, not a real problem we have~
Use what's on sale and don't worry about it, synth, plain, mixed, Use different one each time if you like, Just don't mix brands together in one change, may have conflicts
If you have to add oil between 7500 mile changes- something is wrong!!
the first number is oil viscosity at 32F, so its for the initial start up temp and immediate oil flow due to thinner action of the 0, 5 or 10-
high mileage oils have extra stuff for leaking seals, not a real problem we have~
Use what's on sale and don't worry about it, synth, plain, mixed, Use different one each time if you like, Just don't mix brands together in one change, may have conflicts
If you have to add oil between 7500 mile changes- something is wrong!!
03-29-2015, 10:47 AM
#7
good plan now would be: take a 3 ounce sample of ATF and send to Blackstone Labs with 20 dollars for a mass spectrograph test and human interpretation plus comparison to every sample of same fluid they have ever tested
If anything is wrong like clutch material clogging torque convertor- that test will let you know now!
look them up online, used for various fluids and vehicles by many ziners
If anything is wrong like clutch material clogging torque convertor- that test will let you know now!
look them up online, used for various fluids and vehicles by many ziners
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03-29-2015, 01:32 PM
#8
Moderator
10w-30 or 10-40 oil is allowed per owner book, Our mega moderator has run straight 40 with no problems!
the first number is oil viscosity at 32F, so its for the initial start up temp and immediate oil flow due to thinner action of the 0, 5 or 10-
high mileage oils have extra stuff for leaking seals, not a real problem we have~
Use what's on sale and don't worry about it, synth, plain, mixed, Use different one each time if you like, Just don't mix brands together in one change, may have conflicts
If you have to add oil between 7500 mile changes- something is wrong!!
the first number is oil viscosity at 32F, so its for the initial start up temp and immediate oil flow due to thinner action of the 0, 5 or 10-
high mileage oils have extra stuff for leaking seals, not a real problem we have~
Use what's on sale and don't worry about it, synth, plain, mixed, Use different one each time if you like, Just don't mix brands together in one change, may have conflicts
If you have to add oil between 7500 mile changes- something is wrong!!
More oil viscosity = Lower MPGs, Slower reeving engine.
Why is the main question? why use 10W-30/40 at all? 5W-30 has proven to protect even in the long haul and racing.
03-29-2015, 02:16 PM
#9
This is really good info, thanks guys. I'll be using 5W from now on.
My maintenance light just came on after about 6000 miles (or so, could be more than that). I checked the oil on a warm engine and it read above the lower dot so it looks like my rings and seals are still good at 160K.
My maintenance light just came on after about 6000 miles (or so, could be more than that). I checked the oil on a warm engine and it read above the lower dot so it looks like my rings and seals are still good at 160K.
03-30-2015, 12:01 PM
#10
Mait light means approx. 6500 milkes have passed since the light was reset
has no connection to actual oil condition
It starts blinking at startup- eventually getting to Full ON all the time when it hits 7500
You reset using the 2 trip buttons- see DIY section
I use 5-30, my point was only that the use of 10-whatever was not behind Op problems with running
ck the oil cold and at full mark, it holds just under 5 per book but many of us- at our own risk- put in 5, buying it by the jug, and it barely uses any during the 7500 miles
you will be safe with 5 until next change
Think about 1/2 can seafoam in the oil for 30 minute drive before change
cleans out years of crud from oil passages and ports
has no connection to actual oil condition
It starts blinking at startup- eventually getting to Full ON all the time when it hits 7500
You reset using the 2 trip buttons- see DIY section
I use 5-30, my point was only that the use of 10-whatever was not behind Op problems with running
ck the oil cold and at full mark, it holds just under 5 per book but many of us- at our own risk- put in 5, buying it by the jug, and it barely uses any during the 7500 miles
you will be safe with 5 until next change
Think about 1/2 can seafoam in the oil for 30 minute drive before change
cleans out years of crud from oil passages and ports
03-30-2015, 12:02 PM
#11
160kmiles- these engines are barely broken in!
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