[rhodjamd]

I have a 2015 Explorer Limited with the 3.5 V6 (no turbos). When I drop the engine in neutral it surges down and up from 600 to 400 RPM. What causes this and what could be a potential repair? I have not thrown a code and do not see an impact while driving but get the feeling that it may be coming.

 

[elyk864]

Possible vacuum leak somewhere?

 

[rhodjamd]

Thanks...did check for that but no go...wouldn't a sensor pick that up?

 

[elyk864]

Thanks...did check for that but no go...wouldn't a sensor pick that up?

I'd check fuel pressure, the LPFP could be going out and fluctuating.

 

[joljol]

Yes, it could be a sensor (Air Mass Sens

 

[19Sport]

Idle Surge

I have a 2015 Explorer Limited with the 3.5 V6 (no turbos). When I drop the engine in neutral it surges down and up from 600 to 400 RPM. What causes this and what could be a potential repair? I have not thrown a code and do not see an impact while driving but get the feeling that it may be coming.

Had a similar situation with past 13' XLT Natural 3.5. Found residue accumulated on throat wall of throttle body, and edge of throttle plate, causing throttle plate to stick closed (rpm dip) then surge when it pops free and over-compensates. Dealer wanted to replace throttle body (read: $$$$!). I took a rag, lightly moistened with 2+2 gum cutter, wiped the throat and edge of the plate clean. Problem was resolved and did not return for the remainder of the time we owned it.

 

[19Sport]

Btw,

Had a similar situation with past 13' XLT Natural 3.5. Found residue accumulated on throat wall of throttle body, and edge of throttle plate, causing throttle plate to stick closed (rpm dip) then surge when it pops free and over-compensates. Dealer wanted to replace throttle body (read: $$$$!). I took a rag, lightly moistened with 2+2 gum cutter, wiped the throat and edge of the plate clean. Problem was resolved and did not return for the remainder of the time we owned it.

DO NOT SPRAY CLEANER INTO AIR INTAKE. This can damage sensors in the induction system! Lightly dampen a rag and wipe surfaces until clean ONLY.