Mechanics

TICKING NOISE AND RPMS GO UP 200-300 WHILE IDLING AND HESITATION @ 30MPH WHEN ACCELERATING

1999 Ford Explorer • 145,000 miles

I have a 99 Ford Explorer XLT AWD with 145,000 miles, well taken care of by previous owner. The problems I have noticed are (1) when idling, you will hear a "tick" noise and the RPMs go up like 200-300 RPMs briefly and then back to where it was before. It does this rhythmatically. I had a visual inspection done at a dealership after purchasing it and they said it was nothing.? And (2) when accelerating, I feel hesitation @ 30mph as if it lags/drags a bit before speeding up. I thought maybe spark plugs/wires but was told probably not. I had the transmission looked at and they couldn't find anything wrong. I made them stop looking when they offered to go in and try filing parts/pieces if needed and seeing if that fixed the issue. I said no because if they don't know what's wrong and they are a transmission repair shop, then I prefer they left it alone. I also should mention I have a delivery route I do 7 days a week with constant stopping and going @ 10 - 60mph.
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Norestrictions08
March 11, 2012.



Have the idle air control valve, EGR valve and the TPS and MAF sensors checked/tested

Rasmataz
Mar 11, 2012.
If the ticking noise is from the engine, I would suspect the valve lifters.

As to the erratic idling, it seems the idleing system is not very stable and I would suggest cleaning the throttle body and IAC and retest.

KHLow2008
Mar 11, 2012.
Thanks I will have those checked. I also noticed yesterday that when I had the heat and fans OFF the revving and ticking noise wasn't happening anymore. I will try again to see if the two are directly related. Would that be normal when using the heat or fans?
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Tiny
Norestrictions08
Mar 12, 2012.
The revving could be related. Check the coolant level. As to the ticking noise, it wuould depend on what ius causing it, can be the cooling fans emitting the noise, indicating the motor is failing.

KHLow2008
Mar 12, 2012.

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