2001 Toytoa Corolla , I Feel The Engine Is Not Smooth
by kulkarni_ash, July 26, 2006
kulkarni_ash
Hi
i have a 2001 toyotta corolla with about 125,000 miles on it...
i have changes the O2 and MAF sensor and spark plugs recently.
i got a check engine light again with P0420 code,
and some how i feel that the engine is not running smoth, i feel that it is making more noise when running about about 65 miles, i can hear it inside when driving, before i would never hear the engine ,
it sounds like it is a bit ruff and not very smooth
what may be the reason, what is the fix to get it run smoth again
Ashish
Bikeman982
Hi
i have a 2001 toyotta corolla with about 125,000 miles on it...
i have changes the O2 and MAF sensor and spark plugs recently.
i got a check engine light again with P0420 code,
and some how i feel that the engine is not running smoth, i feel that it is making more noise when running about about 65 miles, i can hear it inside when driving, before i would never hear the engine ,
it sounds like it is a bit ruff and not very smooth
what may be the reason, what is the fix to get it run smoth again
You can always do the basic checks of fluid, timing and spark plugs.
Hi
i have a 2001 toyotta corolla with about 125,000 miles on it...
i have changes the O2 and MAF sensor and spark plugs recently.
i got a check engine light again with P0420 code,
and some how i feel that the engine is not running smoth, i feel that it is making more noise when running about about 65 miles, i can hear it inside when driving, before i would never hear the engine ,
it sounds like it is a bit ruff and not very smooth
what may be the reason, what is the fix to get it run smoth again
You can always do the basic checks of fluid, timing and spark plugs.
You have to be a little more descriptive.
What does the noise sound like? Rumbling? Clatter? Screeching? Is it "exactly" at 65 mph or around that area (make a note of this). A 0420 is emissions related and you'll have to check the function of the rear O2 sensor. If I recall, you only changed the front (before cat)... this one will not trip your code.
A malfunctioning rear-O2 sensor or cat should not affect the normal operation of the engine.
Take it to another shop. Tell them what has been done already and get a second opinion.
I agree with ouroboros - need a bit more information.
You mentioned you changed out the front O2 sensor, MAF sensor, and spark plugs - did you do the work yourself or did a shop/dealership do the work for you? In either case, did you use OEM parts or universal aftermarket? What made you change those particular components - was there a previous CEL that indicated a problem? If so do you have that particular code?
P0420 code (Catalyst System Efficiency Below Threshold) is related to the rear O2 sensor reading the catalytic converter not doing as good a job as it should be doing. But that is not 100% guarantee that is the problem - it could have been triggered from a bad sensor elsewhere or misfire, bad ignition timing ,etc.
I usually try and hold off on swapping any parts as long as possible, until I fully diagnose the initial problem - many times swapping replacement parts will obscure the original problem or make it much more difficult to diagnose.
Bikeman982
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
Just as an aside, this is another reason why I'm sold on syn. When I came off the Pennzoil I was using (crap in my opinion), and switched to Mobil 1 the first 2 oil changes that I performed resulted in alot of dissolved sludge coming out of the drain hole... after that, clean clean clean... just normal particulates one would expect. I suspect that the 1ZZ is sludge-prone when using regular dino and extended changes (particularily with stop & go driving). Its plausible that this sludge could gunk up the timing chain tensioner amongst other things... maybe if K-A did a couple engine flushes his problem might disappear.
Bikeman982
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
Just as an aside, this is another reason why I'm sold on syn. When I came off the Pennzoil I was using (crap in my opinion), and switched to Mobil 1 the first 2 oil changes that I performed resulted in alot of dissolved sludge coming out of the drain hole... after that, clean clean clean... just normal particulates one would expect. I suspect that the 1ZZ is sludge-prone when using regular dino and extended changes (particularily with stop & go driving). Its plausible that this sludge could gunk up the timing chain tensioner amongst other things... maybe if K-A did a couple engine flushes his problem might disappear.
So you suggest as a solution to switch oil to Mobil 1 synthetic and give that a chance to help his engine?
That certainly could not hurt to give it a try.
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
The emissions seem to be a trouble spot for many cars and diagnosing the correct source of the problem can be difficult. Usually it ends up being something requiring cleaning or a new sensor to read everything right.
I agree but his symptoms suggest that something other than a bad rear O2 sensor is at play here. A defective rear O2 sensor shouldn't affect the driveability of the car as (I seem to recall, correct me if I'm wrong) it isn't tied into the ECM, just required for California regulations regarding proper cat function. I also suspect timing issues with the car, the sound he's describing could be related to a loose timing chain (chattering) via bad guides, bad tensioner, stretched chain... these might also trip a P0420 by altering the timing chair and messing with VVT function.
So far, I've only heard ticking from a very cold engine start... someone said that it was related to hydraulic valve adjusters (when cold).
Just as an aside, this is another reason why I'm sold on syn. When I came off the Pennzoil I was using (crap in my opinion), and switched to Mobil 1 the first 2 oil changes that I performed resulted in alot of dissolved sludge coming out of the drain hole... after that, clean clean clean... just normal particulates one would expect. I suspect that the 1ZZ is sludge-prone when using regular dino and extended changes (particularily with stop & go driving). Its plausible that this sludge could gunk up the timing chain tensioner amongst other things... maybe if K-A did a couple engine flushes his problem might disappear.
So you suggest as a solution to switch oil to Mobil 1 synthetic and give that a chance to help his engine?
That certainly could not hurt to give it a try.
My suggestion would be to switch to Mobil 1 and shorten his change intervals then see what happens. This car has over 100 k miles on it so plenty of time to sludge up. If he has a mechanic friend I would also suggest taking off the valve cover and examining the underside of it. Often times you can find tell-tale signs of sludge here as its deposited by the timing chain. If there's an excess amount of sludge perhaps its better idea to do a quick flush as well to make sure the oil galleries aren't clogged up and the engine is oil starved... although, I'm sure alot of sludge was in my engine and the Mobil 1 switch appeared to "gently clean" the gunk out over a period of 3 oil changes.
