Fluctuating RPM when starting the car

[Tash Oh]

I own a 2016 manual GT with 3k miles on it. Today I noticed that when I turned on the car the rpm went to about 700 and then slowly went up to 1.4k ish and then kept fluctuating until the engine warmed up and went down to 620 where it stayed steadily. After I warmed up the car and got the cylinder head temp to about 190 I turned off the car and turned it back on. Same thing happened except now the rpm went to 700 and then fluctuated between 600 and 800. It is the first time this kind of issue has occurred, never had any other issues and no new parts have been installed. Engine is bone stock and there shouldn't be any reason for this to happen. If it doesnt go away on its own, I will be taking it to Ford tomorrow. If anyone has any helpful info please feel free to share.

Sponsored

 

[Mustang_Lou]

Almost seems like a vacuum issue ... was going to ask if you installed anything in the intake system but it seems not. Maybe check all connections from the air box to the throttle body and make sure they're tight. Otherwise, dealer as you say.

 

[Tash Oh]

Yes I don't see it being anything else other than a loose connection or a bad wire somewhere. I will update after I visit Ford today.

 

[Boggus]

I have the same issue. Cold start and the RPM's fluctuate up and down before it finally settles. Almost sounds like a cam

 

[Tash Oh]

Exactly haha its like a messed up cam. Anyways I took it to my local ford and they basically told me to fuck off (told me to wait a month for an appointment). Got an appointment at Galpin for next week so we will see whats up then. I asked one of the mechanics who happened to pass by and he told me its bc of the exhaust:shrug:

 

[TungstenGT]

Sub

 

[Boggus]

Well I don't have exhaust, blows that theory

 

[Tash Oh]

Yea I didn't really buy that either since I've had my exhausts on for 3 months and this just started happening yesterday

 

[astolt12]

Mine does the same thing; but sometimes it doesnt. Range from 900-1400.

Been doing it for a while; figure its something with how the H02S' heatup/work.

 

[VinnAY]

Has everything to do with Emissions on a cold start, it's normal. Stop over analyzing every little thing.

Sponsored