2005 New Crankshaft Pulley Problems
 

Hi everyone, I'm in a pickle!

I have the original-style crankshaft pulley/harmonic damper on my 4.0L and it's beginning to wobble (the rubber is going to fail). I know this is a known issue for these original pulleys.

I went to Ford to ask about a new pulley and was told they were backordered with no promise date. So I went to the local parts store and bought an aftermarket one (a Dorman, but there wasn't any choice). The parts-store guy checked his computer for fitment and picked it from the back himself. BUT! after I installed the new one (with a new bolt), I started getting misfires at high rpms. I actually didn't even suspect the pulley might be wrong because it's such a precise fit onto the crankshaft snout (and keyed too). I researched for hours and ended up thinking there's a crankshaft relearn procedure Ford needs to do. So I take it down to the dealer and they tell me "Nope! No such procedure for your car. Everything's fine with the pulley and sensor and it's actually your plugs/wires/coil that need to change."

I was suspicious, but apparently also dumb. I agreed to that fix and $800 in parts and labour later they give my car back "fixed." I didn't even make it home before the misfires came back! To the dealer's credit, they took the car back and actually checked the damned crankshaft sensor and pulley like I asked (instead of just taking the codes [P030X] as gospel) and confirmed that the sensor something about the pulley was wrong and reinstalled the old one all for free. No more misfires!

But now I'm back where I started. Now Ford says they can get an OEM pulley from Detroit for about $400, but because it's spec'd for '07-'10 4.0L cars and not specifically for '05 cars, they won't guarantee it will work and say they can't accept a return on it if it doesn't. I can't afford to gamble $400 right now on another pulley (especially when I can't return the $200 Dorman pulley yet because of provincial Covid lockdown! Ugh!). Can anyone give me any insight here?

• Does the newer-style OEM pulley actually for-sure work on an '05?
• What about that Dorman pulley? Was it just a bad casting or something (I know the company's reputation)? Were there different pulleys for different models using the 4.0L block?
• I know some people recommend an underdrive pulley, but is that a good choice for a daily driver when reliability is first concern?

I want to move on finding a good solution before the original pulley fails on me and I'm totally up a creek. This is my only car.

Thanks so much!

Dorman is known to be crap on most any part they offer. Only good for an emergency until you can get a real replacement or in this case, not even that.

Go here and buy any other brand
https://www.rockauto.com/en/catalog/...+balancer,5512

Looks like there is a blank spot on the wheel of the balancer. I'd compare between the OEM and the Dorman in relation to the keyway, If the Dorman (or any aftermarket) has that blank spot on the gear in a different position, that will cause misfires. That is how the PCM knows where TDC is on Piston 1.

Thanks for your advice and heads-up about rockauto. What an awesome site. I've never actually tried them before.

I'm going to take a shot with one that looks very much like mine. At least rockauto has a return policy.

I’ve bought from rock auto since 2004 for many, many vehicles. Only got a wrong part once and it was easy to return.

does the dorman one you have match your old one?

No, it has a slightly different design. The original, and the new one I've ordered, have grooves cast into the shaft of the pulley. The Dorman has a raised, narrow "cage" of metal going around in a ring.
If you look at the Rock Auto options, you can see the "cage" type on the first three and the "grooves' type on the bottom option.

Could be just a ****ty product from Dorman, I guess. I ordered the bottom option (Dayco) to keep things as similar to stock as possible.

ohh yah, I see the difference. That narrow cage is probably not properly aligning with the crank angle sensor so the signal is weak or lends itself to interference from the weakness.

let us know how it goes with the new one once you get it.

Well, I put the new pulley on and changed the crank seal while I was at it. Now the problem is back again!

It's a misfire situation that starts at higher rpms. You could start and drive the car for a while without any problems if you keep out of the throttle, but try to rev up to 3500+ and it seems for a moment like the engine can't rev further, then it starts misfiring. I believe the last time it would randomly start misfiring at lower rpms too. I haven't driven with the new pulley long enough to see if that still happens.
The CEL light flashes and I basically have to pull over until it either self-corrects or I restart the engine. The engine codes are P030X (it seems random which cylinders).
The car has all new plugs, all new wires, and a new coil, installed by Ford, so it's not an ignition problem.

It was the same problem before with the Dorman pulley, so now I think it's fairly clear that the pulley isn't actually the problem--what are the odds that two completely different pulleys just happen to both be bad? Especially since this isn't a common problem in the forums.

Ford, when they had the car, checked the crank position sensor and said it's okay but I am now suspecting maybe it's not. It's one thing I haven't changed or touched. BUT that doesn't explain why the car ran fine with its original pulley in!
Also, the crankshaft sensor isn't throwing any codes.

The common thread here is new pulley, and the engine not being able to time spark correctly at high rpm. I wonder: if there's a slight variation in the offset of the gap on the reluctor wheel on the new pulley vs the old one, could that different signal be enough to mess up the computer's attempts to time spark? It seems far-fetched. Which makes me think about that sensor again.

I really need help here. I could put on the old pulley again, but it's a time-bomb with that failing rubber.

Another thought: maybe I should disconnect the battery for half an hour and force the computer to reset?

Well, weirdly enough that reset seems to have worked! I'm not going to call this a victory yet, but I couldn't get the problem to reoccur.

Perhaps it was some kind of engine computer issue, where the different pulley's slightly different signal was conflicting with the computer's expectations.

Was the problem fixed for good?