I have an 04 Navigator with 195k miles on it. It was runnnig fine, no problems until the starter went out. I replaced the starter and flywheel (ok cool). I had an oil leak coming from the radiator (this metal tube that goes through the bottom of the radiotor that has the transmission fluid) and from oil pan. The oil leak was fixed, okay perfect. I got my car back and now it is acting funny. When I go into reverse, the car drops RPM's and like jerks?? It does not always turn off completely but it does every other time I got into reverse. I was told by that mecahinc that I should replace the IAC valve and I should be okay? I attempted cleaning it first with the throttle body cleaner and nothing. I cleaned the throttle body (to the best of my ability bc I was going based off what I saw online.) I was scared to put too much of that spray and it going into the throttle body but I know I definitly cleaned it. -should I replace the IAC valve ?? Its $30 on ebay and $60 at Orileys. The vehicle also like lags to shift when Im turning and gasing it at the same time, it also lags a bit when im merging onto the freeway. --- After what ive read, its either going to be that IAC valve or an air leak right?? Im not sure how to look for leaks! Im honestly gonig to replace the valve but I dont know what to do after that if it doesnt work so I wanted to come on here and see what other suggestions anyone may have! I checked the transmission fluid levels and the look okay?
Thank you in advance for taking the time in even reading my post!! I apprecate any and all information!!!! #Stayblessed
Seeing as how that thing is over two decades old it could be any of a number of things. If the problem started immediately after you worked on the vehicle first check to see what may have been damaged or disturbed in the process.
should I replace the IAC valve ?? Its $30 on ebay and $60 at Orileys.
Only replace it if it tests bad. If it does need replacement an OEM part is best. Aftermarket knockoffs frequently don't work properly.
Im not sure how to look for leaks!
You can do a physical examination for deteriorated vacuum hoses and seals, listen for air leaks, and/or use the carb cleaner method.
What troubleshooting have you done so far? Performed a diagnostic scan for codes and live data? What do your fuel trims look like? Did you check the usual suspects? (Filters, spark plugs, fuel pressure, etc.)
You can find a repair manual for that vehicle at the link below:
https://charm.li/Lincoln/2004/
