2000 2.5 auto vibration at stop light

[351ranger]

I just bought this truck and it's got a vibration that I feel in the steering wheel and the floor while I'm in drive at a stop light. Its got 125000 miles but don't know much history on it. It's got an automatic trans. I just replaced the trans mount, I'm thinking about changing the engine mounts but I shook the engine and it seems like they are in good shape still and considering the milage I don't think they should be bad...any ideas? Is this maybe a spark plug problem? It runs great though which doesn't make sense to me, just vibrates a lot! Any help would be appreciated

 

[Mark_88]

Howdy,

Any idea what the idle RPM is at? It is not adjustable on these engines typically, but can creep higher with vacuum leaks and other issues.

Aside from that...could be something is touching the frame like part of the exhaust system...or it's held tight to the frame so not making noise but transferring vibration...

Most of the one's I've felt turned out to be noise related...like loose heat shields...but I usually hear them more than feel them.

 

[351ranger]

It idles at around 700 rpm. It's definitely not just noise I feel it through the steering wheel and floor. I'm leaning towards engine mounts. I failed to mention it was hit pretty hard in the front and I had to straighten the frame and put a new core support on so maybe in the wreck the mounts got ruined.

 

[tomw]

The idle @700 is a bit too low. I think I would remove the IAC and clean it, disconnect the battery, and see if the idle settings can be re-learned by the computer. In older models you could remove battery power, and then step on the brake pedal or turn on the headlights to drain the KAM (keep alive memory) quickly.
One way to discern if the IAC is functional is to load the engine, at idle, with A/C and power steering movement(doesn't have to be sweeping turns, just load), and the IAC should keep the idle steady as the loads are applied and removed. It should also bump the cold idle above 1000 rpms for a while until the engine is warmed up. If it doesn't do those, then it's likely not functioning well.
tom

 

[351ranger]

It does idle high on start up but then settles down. I sitting at the drive a little while ago and tried turning the wheels and no change in idle. I do feel this vibration while driving also. I thought maybe the driveshaft u joints were bad but then noticed it does it while in drive with the brake on. This is why I'm leaning towards engine mounts. I'm going to try to jack up the engine and see if the mounts have alot of movement in em.

 

[351ranger]

Well I happened to look at the plugs and that they are Motorcraft plugs and wires and that gap looks enormous so I'm guessing these are stock plugs and wires. Would this cause a vibration?

 

[351ranger]

Well, I got underneath and jacked the engine up and there is only about 1/4" or less of movement in the mounts when I jack it up until it doesn't go any farther. Not sure if a new mount would move that much? I'm think I'll do the plugs and wires soon to and see if that makes a difference.

 

[enjr44]

If the plugs look like the one in the picture, you need new ones for sure.

 

[351ranger]

If the plugs look like the one in the picture, you need new ones for sure.

I figured as much, do you think this would cause the vibration I'm feeling?

 

[enjr44]

Well, generally, increasing the gap a few thousands will smooth the idle and decrease highway mileage. But.... there is a limit. And, it is a waste spark system, so each time the coil fires it has to fire two plugs. So there is a limit!

Replace them with dual platinum or straight copper. Straight copper will not last as long as the dual platinum; but, will last just as long as single platinum.

 

[351ranger]

Ok thanks, I used to have a 2.3 ranger for a driver a few years back but never changed the plugs and don't remember having the vibration I'm feeling in this one. I did take out the iac and cleaned it but didn't notice much difference in anything. Also put a O2 sensor in because the check engine light came on and said it was that. Seems to run slightly smoother after the new O2 but maybe it's just in my head.

 

[Mark_88]

Seems like you are making some progress...I wanted to ask if you had someone available that can put the truck in gear and keep the brake on to create the same situation (at lights) so you can poke around under the hood.

Although I'd make sure they were not named as your beneficiary of an insurance policy and stuff like that...just in case...

 

[351ranger]

Doing plugs and wires this weekend. Hope it fixes all the vibration I'm feeling. It definitely better after putting the O2 in at least.