Acura World banner

1 - 2 of 2 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hello
My 00 Acura RL starts and runs at a normal rpm but when it is cold outside and the car gets to operating temperature if you put the car in neutral or Park the rpms will jump up to 2000 rpms and if you tap the accelerator will go from 1000-1500 rpm. When it is hot outside it does not fluctuate at all, all summer it idled normal both at start up and at operating temp. At about 50F outside it starts to show these symptoms but sometimes the idle smoothes out after 2 minutes. It seems the colder it gets (now 5F) the higher the rpms will go and I haven't noticed it stopping yet but I will check. At current temps the idle goes from 2200 rpms to fluctuating without me touching the gas pedal. When I first had it checked at a shop it had IAC codes (will have to check) and both IAC valves have been replaced with OEM new. Coolant flushed and new radiator cap. What else can it be?
 

·
Registered
Joined
·
4,812 Posts
It could be a low coolant issue, or a bubble of air trapped around the thermo water (TW) sensor.

Make sure that the thermo water sensor, located on the thermostat neck (at the terminus of the upper radiator hose on the engine) is plugged in securely. With a cool engine, remove the radiator cap and see if the coolant is up to the very top of the radiator. Start the engine with the cap off, and allow it to run for about 30 seconds. Watch for bubbles coming up from the coolant. Replace the cap before shutting the engine off, and see if it improves.

If you do see bubbles come up, it will be an air pocket releasing inside around that TW sensor, which can sometimes only work itself out with the coolant flowing and the radiator depressurized. This can cause a choppy idle, and choppiness in the lower RPM range.
 
1 - 2 of 2 Posts
Top