I am searching for ideas/suggestions on how to troubleshoot a rough idle problem on my car. I have owned it since May 2011. It has 169K miles on it. I have installed a new distributor cap, rotor, plug wires, plugs, front engine mount, and air filter. This car runs well off idle and accelerates well. I have noticed that the rough idle is more noticeable when stopped in gear. I have also read many posts on the net where this is a common problem with these cars? This is my third Camry and first with this type of problem. The rear engine mount is next on my mind. When I first looked at the car to buy it, the upper "dogbone" mount was shot. The rubber was totally gone. I bought the car and replaced the front mount and it was shot as well (I mean completely worn out). Should I believe that my rear engine mount is probably shot too? The transmission mount too? I don't want to rebuild the whole car but would like to fix the rough idle if monetarily possible/feasible. Thanks for any help you may offer.:con fused:

 

The load of the trans is pulling down the idle RPM. The lower the idle RPM the more the engine shakes.

A worn out upper mount is extremely common, front less so. Rear less so the front.

Trans mount no.

Might attempt to inspect the rear mount or change it out but stop there on mounts.

Have you tried cleaning the throttle bore and IAC valve with throttle bore spray cleaner?

 

I changed the motor mount in the front but i am unaware of how to find the throttle bore. Can you give me directions?

 

Suggest a Google search on cleaning the IAC valve on a 5SFE engine for possible photos and video.

Follow the large air duct for the engine air intake. This goes from the air cleaner to a metal part on the engine. The part has a large pulley to which cables are attached. If the large duct is removed from this part inside is a flapper valve moved by the pulley. This valve is inside the throttle bore.

If you go this route use a throttle bore cleaner, not a brake cleaner (as often done). You want something safe for plastics.

 

1. read error codes
2. run 2 cans, consecutively, of Seafoam, through tankfuls of gas.
see what happens.

Your car has been running great for years, but recently it has developed a rough idle. The tachometer needle jumps erratically, and the engine surges and wanes. There are some definite causes for the rough idling, and the problems may be simple to repair. Not correcting this problem now may lead to serious engine damage later, leaving you stranded by the side of the road.

Vacuum Hoses

• A loose or broken vacuum hose causes rough idling, and is the easiest repair of all. This is a very common problem since hoses wear out over time. Look in your engine compartment, and examine the hoses carefully for any signs of abrasion, breaking or loosening. Replace any damaged or broken sections of hose, available at most autoparts stores, and your rough idling will more than likely disappear.
  
  

Clogged Filters

• Clogged filters are another common cause of rough idling. Inspect your air filter. If dirty, replace it. Also, a clogged fuel filter causes rough idling. It's hard to tell if a fuel filter is clogged or not, so a good rule of thumb is to change it at every general tune-up.
  
  

Electrical Components

• Bad spark plugs, bad spark plug wires and a bad distributor cap are other common causes of rough idling. If it has been a while since you changed these components, do so. Most auto service centers can do this for you if you need technical expertise.
  
  

Timing Belt

• A timing belt jumping a tooth is also a cause of rough idling. This throws off cam timing, setting in motion a series of events that prevent your engine from achieving proper timing. This is a more in-depth repair and, if needed, should be referred to a qualified auto mechanic.
  
  

 

The idle speed is 800 rpm in park. Is that what it should be? If it isn't, could you tell me how to adjust it? I looked at it today and don't see a stop screw like the carburetors had. Is it adjusted with the cable? Thanks!
Randy

 

What about the 2.2L engine's counter-balance? I've read where this is probably what the problem is causing the rough idle? The car starts and runs too good to be a timing belt problem. It's just the idle, in gear, that is excessively rough. I started to tackle removing the EGR in hopes that I could clean it to help the rough idle but gave up as I did not realize that it would be a fairly big job to get the EGR out. Can the EGR valve be cleaned? Thanks!
Randy

 

I routinely clean my EGrs. carb cleaner works well. careful with metal gasket, it's easy to bust. but EGRs usually get dirty towards quite advanced mileage, towards 200 000, or if cheap gas was used.
like toyomoho told you - your engine lacks load power. there can be multiple causes for that. READING ERROR CODES gives nice starting point.
your RPMs are most likely ECM controlled. It's fuel injected car, right? 750 sounds about right. it's not large block Chevy V-8 that purrs at 500 RPMs.

 

Idle speed is OK. There is no idle speed adjustment. The computer does this via the IAC valve.

The EGR valve can be cleaned but it should be fully closed at idle, unless open for some reason would not effect idle. If the valve is open too much at idle the engine will quit.