engine running rough pls help - Toyota Nation Forum : Toyota Car and Truck Forums

shloho · 03-27-2010, 10:55 PM

Please help,

I own a 2002 Camry 4 cylinder that has been running rough lately. I think it's been since I got an oil change. The guy inspected the carbon filter and air filter but didn't replace them. I am going to do that as well as change the spark plugs and wires. It runs rough at all times. No check engine light as of yet.
Any suggestions?

Thanks,
Sean

Redline_Me · 03-28-2010, 12:40 AM

What oil did they put in there and also, how much oil? Maybe they put the wrong grad or not enough.

***judge34411*** · 03-28-2010, 01:10 AM

Quote:

Originally Posted by shloho

Please help,

I own a 2002 Camry 4 cylinder that has been running rough lately. I think it's been since I got an oil change. The guy inspected the carbon filter and air filter but didn't replace them. I am going to do that as well as change the spark plugs and wires. It runs rough at all times. No check engine light as of yet.
Any suggestions?

Thanks,
Sean

Has it been getting worse over time or all of a sudden? No check engine light? OBDII readings are always the best. Clean throttle body fuel filter change, plugs and such. But one at a time. Doubt oil change was the deal.

If he did not change them they prob okay.

shloho · 03-28-2010, 06:08 AM

Quote:

Originally Posted by judge34411

Has it been getting worse over time or all of a sudden? No check engine light? OBDII readings are always the best. Clean throttle body fuel filter change, plugs and such. But one at a time. Doubt oil change was the deal.

If he did not change them they prob okay.

no check engine light. It got bad all of a sudden. I bought this car used at 22,000 miles. It's now at 90 K miles and I have never done any sort of tune up. Just change oil (mostly on time), flush oil, change other fluids, brakes, serpentine belt, battery, and thats it. I'll do all of the above... Can you sepcify what else to do?
Thanks
Sean

shloho · 03-28-2010, 06:09 AM

Quote:

Originally Posted by Redline_Me

What oil did they put in there and also, how much oil? Maybe they put the wrong grad or not enough.

I don't know the answer to either question. I could go back and find out. I never paid much attention to it. I went to the local Shell station. I have never had a problem before...

shloho · 03-28-2010, 10:17 AM

The noise is coming from the exhaust manifold... I changed spark plugs and air filter so far. No change. Not sure if there's a pcv valve.......

The7 · 03-28-2010, 10:57 AM

What is the idle rpm when normal?
What is the idle rpm when running rough?

Redline_Me · 03-28-2010, 11:00 AM

Quote:

Originally Posted by shloho

I don't know the answer to either question. I could go back and find out. I never paid much attention to it. I went to the local Shell station. I have never had a problem before...

Believe it or not, they forgot to put the oil cap on my dads 2003 Camry once and it ran like shit.

shloho · 03-28-2010, 01:20 PM

Quote:

Originally Posted by The7

What is the idle rpm when normal?
What is the idle rpm when running rough?

Right now its running about 400 rpm on idle. If I recall correctly the normal idle rpm is about 750 +- 50. So definitely running slow and rough.

shloho · 03-29-2010, 07:31 AM

Quote:

Originally Posted by Redline_Me

Believe it or not, they forgot to put the oil cap on my dads 2003 Camry once and it ran like shit.

Oil cap is on fine.

Thanks

The7 · 03-29-2010, 08:17 AM

Quote:

Originally Posted by shloho

Right now its running about 400 rpm on idle. If I recall correctly the normal idle rpm is about 750 +- 50. So definitely running slow and rough.

Does it run smooth when you apply gas?

BlackCamSe · 03-29-2010, 08:21 AM

disconnect the battery for about a half hour, then plug it back in and try it. That should reset the ECU

Redline_Me · 03-29-2010, 08:22 AM

Wish it was that simple right.

See if removing the air filter improves you rpm speed. You just have to diagnose and eliminate everything that would cause low idle speed.

shloho · 03-29-2010, 08:40 AM

Quote:

Originally Posted by The7

Does it run smooth when you apply gas?

The car runs fine still. It's this thrumming noise that I hear both at idle and when applying gas. Its most pronounced when at 60 mph.

The7 · 03-29-2010, 08:50 AM

Quote:

Originally Posted by shloho

Please help,

I own a 2002 Camry 4 cylinder that has been running rough lately. I think it's been since I got an oil change. The guy inspected the carbon filter and air filter but didn't replace them. I am going to do that as well as change the spark plugs and wires. It runs rough at all times. No check engine light as of yet.
Any suggestions?

Thanks,
Sean

Did the guy unhook any of the connections (hoses and/or wires) during the inspection and forget to hook them back properly?

2002 Camry uses mechanical linkage (mechanical cable) for throttle and has an idle assisted throttle (IAT) unit for idle speed compensation . The IAT is electro-mechanically controlled by the ECU to compensate the idle rpm at start and at low engine temperature before the car is fully warmed up.
If the wire connection to the IAT is unplugged (or the IAT is malfunctional), the idle speed will be very rough and low, especially at low temperature.