2002 lincoln ls idiling strange. Rpms go up and down.
I'm not sure if it's the change in weather or if something is wrong with my car. I live in Florida so it's generally very hot. The past two mornings were about 50degrees and when I woke up and started my car it idled very strange. The rpms were going up and down while in park, it was making the car shake. While driving I took my foot of the gas peddle to coast and the car continued to drive at 25mph. While sitting at a red light it was idling so low I thought it was going to stall. Any suggestions? The check engine light is not on. i have a 2002 ls and the rpms dont go up and down but it idles while sitting and stalls out when it gets at about 45 mph. i have changed the spark plugs, wheel bearings, and checked the transmittion. still spending money to figure it out
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
There are a few reasons to limit RPM which can be a "Limp home" mode activating. But most show a code of some sort with a dash light. Another area is the automatic braking for the "Traction control" which in some models can also have a control to throttle the engine down to prevent wheel slippage.
Blocked catalytic converters can limit RPM by choking the exhaust flow. You have crankshaft and camshaft sensors which count the RPM and send signals to the brain and the fuelpump. Your crankshaft sensor regulates the fuel pressure and if it miscounts, the engine can be fuel starved.
Not all scanners are the same. One that reports fuel pressure while simultaneously reporting RPM would be something to know for fuel starvation.
You can kind of eliminate some possibilities by whether "Check engine" or "Traction control" warnings are on.
Did you purge the air out of the syst.? Also you replaced the fan but are they coming on? have you checked the fuses and relays? if all this is ok then is the computer comanding it on? Is the computer getting correct info from Eng coolant temp. snsr (ECT)
Vaccum leak. There are a bunch of little hoses in the engine compartment that give vaccum to various components, if one is leaking (dry rot and cracked) or got pulled off when someone replaced ... say an air filter or other service ... you will get this symptom.
A variety of sensors and the computer itself can also cause these problems ... if the component is not throwing an OBD II code, it WILL be costly (time AND $) to find the problem.
If you open the engine compartment and can detect a slight sucking sound from somewhere, that is a vaccum leak and may be your problem. You could have autozone or another nice parts store pull OBD II codes for free, but if the check engine light is not on, there may not be any codes to pull.