'97 Mountaineer won't start, big problem | Ford Explorer Forums - Serious Explorations

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'97 Mountaineer won't start, big problem


August 29, 2009
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City, State
Santa Ana, CA
Year, Model & Trim Level
'97 Mountaineer
Hi, first post, long time lurker I hope someone can help. 97 Mountaneer 5.0 130K. Replaced radiator and water outlet, dropped bolt couldn't find. Started engine, it ran, idled then CLUNK and it died. Missing bolt got jammed between cutout in crank balancer and block. Got it out weeks later with mirror and magnet. Engine turned over. It's been sitting for 8 weeks. Today I finished the water outlet (had to get a part for a '99, the '97 part everyone sells is wrong) Engine cranks but won't start. I've read a lot of posts and am at a loss:

Fuel pump makes normal sound when you turn the key. Check engine light is on when the key is turned on and goes out when it's cranking. ODB2 scanner shows no codes and communicates normally. It seems to fire weakly occasionally and after cranking several times there's a gasoline smell. No physical damage to crank sensor or cam position sensor or wiring. Before all this it ran fine, just had a radiator leak. I unplugged the cam sensor, cranked it and there was no change in sound and no codes. I can't get to the crank sensor without a lot of trouble and can't tell where the wires from there go.

Any ideas out there?

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I'd be willing to bet that the crank sensor got damaged. It may appear fine but I suspect it is not.

^ thats a possibility.

Also check your fuel inertia switch. If you dont know how theres a vid in the link in my signature.

not the fuel inertia switch

I wish it were that easy, I checked anyway and the switch is ok. Thanks for posting your video links though.

Wouldn't a bad cam or crank position sensor throw a code when cranking? I've got no codes.

Any other ideas?

Checked everything carefully, replaced crankshaft position sensor, no change.
Replaced cam position sensor, no change. It turns over, sounds like it's very weak firing occasionally, has backfired a little. Sounds to me like a 66 GTO I had when the nylon timing gear disintegrated. Could I have broken a gear or a timing chain? No internal grinding noises. It was running fine til jammed bolt stopped it. With cam positon sensor off, metal disc is rotating when cranked, so that's not broken. I'm out of ideas...

Anything else to test?

Does anyone have any other ideas of something to test. Again my 97 mountaineer 5.0 cranks but wont start, sounds like it's firing very weekly if at all, smells of gas after cranking. No codes, check engine light on with key and off while cranking. Replaced Crank Position Sensor and Cam Position Sensor.

Engine ran after installing radiator but loose bolt fell into slot in crank balancer, jamming into block and stopping engine immediately (from slow idle)

What could break? Timing chain or gears? Could timing chain skip or timing gear shear off pin?

If I take it to a shop, it sounds like big $$$ to fix so I might have to junk it. I'd appreciate some advice.

Have you checked for spark at the plugs? Also, try squirting some ether into the intake to see if it will fire for a few seconds.

well one of the "simple tests" that will quickly tell if your "mechanicals" are "sound" after your "episode with bolt" is a compression test.

Any chance the magnetic pickup/tone ring on the harmonic balance got damaged?

Thanks for replying

The ring with teeth that the crank position sensor uses wasn't damaged. That was one of the first things I checked. I'll pull a couple of plugs and do a compression test. From the cranking sound I think it has compression but I should check, maybe tonight. I'll check the spark too while the plugs are out.

Update: still won't start

Checked the spark: OK Checked the compression in one cylinder: OK, disconnected the battery to zero the computer, no change. It cranks and fires weekly, coughing with light backfires as if it's completely out of time. Below is a picture of the trigger wheel. Does anyone know if the missing tooth is in the right place relative to the harmonic balancer? Is there any way it could have rotated and thrown the timing off?

I really appreciate the help and advice you guys give here to help us backyard mechanics get out of trouble.


As it turns out the harmonic balancer was to blame. The back side of it where the keyway is was shattered and it rotated about 90 degrees on the crankshaft. $80 to fix but months of being dead in the driveway.

As it turns out the harmonic balancer was to blame. The back side of it where the keyway is was shattered and it rotated about 90 degrees on the crankshaft. $80 to fix but months of being dead in the driveway.

Afterthought. Like a good belch, I guess one should have immediately thought, WTH could that bolt have caused to go out of whack right there where it was jammed?

Glad you finally found it without tearing the engine apart! imp

Yeah, I should have trusted my instinct. Now I've got the famous "chirp" problem to track down. I've read the posts and am nervous about changing the synchronizer but it's got to happen. Thanks for the reply!