Engine Shuttering / Check Engine Blinking

[Hoos95]

I am experiencing engine shuddering usually on acceleration or uphill. Also, when I gun it (rarely) the car hesitates and the check engine light blinks rapidly. If it’s not caused by bad spark plugs/coil packs, could it be the torque converter in the transmission?

2007 EL Eddie Bauer approaching 350,000 miles

 

[1955moose]

You'll need to plug into data port and run codes. You most likely have a shorted out coil or sparkplug or 2. Don't drive it like this though. You'll burn out the catalytic converters.

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[Hoos95]

Update:

Had the spark plugs and coil packs replaced - no improvement. Idle is often rough too. Any suggestions as to what would cause this? I’m thinking of cleaning the MAF sensor and throttle body.

 

[Yupster Dog]

The Moose had a good idea to check the codes. check the fuel pressure at the fuel rail. If you want to get a @stamp11127 of approval around here you got to stop throwing parts at it and do some diagnostics. As you test, post the results here and Members can lead you in the right direction.

 

[drokmofo]

Sounds like what I just went thru. Take it to an exhaust shop and have backpressure tested. My wife had to drive ours while I was trying to diagnose it, (plugs, coils, trans fluid and filter) causing a cat converter to go bad. The shop I took it to did the backpressure test for free and $330 to replace drivers side cc. Dude said the cat looked like cottage cheese inside. Recommended I have fuel system checked due to strong fuel smell. I wish I had gone to exhaust shop sooner rather than later. But now I have new coils and plugs. Runs awesome again.

 

[Hoos95]

Sounds like what I just went thru. Take it to an exhaust shop and have backpressure tested. My wife had to drive ours while I was trying to diagnose it, (plugs, coils, trans fluid and filter) causing a cat converter to go bad. The shop I took it to did the backpressure test for free and $330 to replace drivers side cc. Dude said the cat looked like cottage cheese inside. Recommended I have fuel system checked due to strong fuel smell. I wish I had gone to exhaust shop sooner rather than later. But now I have new coils and plugs. Runs awesome again.

Thank you dromofo, I'll definitely consider that if I can't solve this soon.

 

[stamp11127]

Reminds me of a quote from the "Cool Hand Luke" movie. "What we've got here is failure to communicate. Some people you just cain't reach. And you get what we've got here today....."


What part is next?

 

[JExpedition07]

Sounds like what I just went thru. Take it to an exhaust shop and have backpressure tested. My wife had to drive ours while I was trying to diagnose it, (plugs, coils, trans fluid and filter) causing a cat converter to go bad. The shop I took it to did the backpressure test for free and $330 to replace drivers side cc. Dude said the cat looked like cottage cheese inside. Recommended I have fuel system checked due to strong fuel smell. I wish I had gone to exhaust shop sooner rather than later. But now I have new coils and plugs. Runs awesome again.

Must be nice to get a converter done for $300, here in NY it’s more like $2,000....

 

[Hoos95]

UPDATE #2:

Connected a scanner tool and nothing showed up. The Innova scanner detected nothing: no current or stored codes, and nothing with the Ford specified scan.

Cleaned the MAF sensor (dirty) and throttle body (heavy carbon build-up) - did not fix issue.

Going back to when the spark plugs were replaced, there was no improvement. A few hours passed and the engine drove really rough. Took it back to the mechanic who did the plugs and he said there was a bad fuel injector. He replaced it and the roughness of the engine improved, but was similar to before he replaced the plugs. Engine is still pretty rough with a rough idle and hesitation. After taking the car to replace the plugs and bad injector, driving it at highway speeds now feels extremely rough in terms of smoothness of ride, similar to over-inflated tires and a stiff suspension.

As of now, I'm planning to replace the remaining fuel injectors this weekend (and possibly fuel pressure test) and go from there.

Also: I had the catalytic converters replaced a while ago and the mechanic (different mechanic) made a poor connection from the new converter to the manifold, which has resulted over time into pretty loud and smelly exhaust leak - sounds like a go-kart. Is there a possibility that this exhaust leak is also causing the engine shuttering, etc. symptoms?

 

[Trainmaster]

While you're replacing stuff, don't forget the timing chains, guides, and that variable stuff. You may want to get some rockers and springs while you're doing that too. Then see how it runs. If that doesn't help, pull the heads and change the rings too.

 

[stamp11127]

Get somewhere that is away from traffic preferably that is going uphill. You want to load the engine. Place trans in low gear and run engine fast enough to cause the check engine light to come on. Hold it there running rough long enough to log a code.
Read code.

Effect of exhaust leak will show up in the fuel trims and O2 readings.

 

[1955moose]

In the words of my favorite Rooster, Fog horn, that boys busier than a centipede in a toe countin contest!

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[TobyU]

If your check engine light was flashing you had a solid miss and a code was stored.
If you didn't see the code, it got erased by someone somehow.
Never seen one flash light with no code stored.
Seen plenty that had a solid miss that took a long time to set a pending code or a hard code.

Misfire counts would have been high for a cyl too in test results.
You can cancel out cylinders with it running and missing to see which one makes the least difference when you unhook coil connector or inj connector.

 

[Hoos95]

UPDATE #3:

Replaced all fuel injectors and fuel filter. Engine performance has improved in terms of peppiness and response. Rough idle has improved as well. Overall the engine is running better.

Unfortunately the shuddering and transmission shifting remains the same - can’t complain with it having almost 350K miles.

Next steps are to connect a fuel pressure tester and eventually take it into an exhaust shop to fix the exhaust leak.

 

[along88]

This might sound stupid... If you haven't replaced air filter in a while I've read on other forums of that fixing this similar issue. Be an inexpensive possible fix. I say this because you hadn't listed that as something you've replaced( I think).

 

[Hoos95]

This might sound stupid... If you haven't replaced air filter in a while I've read on other forums of that fixing this similar issue. Be an inexpensive possible fix. I say this because you hadn't listed that as something you've replaced( I think).

I replaced the factory intake system with a K&N cold air intake a few years ago. The reusable filter was dirty, but I did clean it with K&N recommended products a couple weeks ago. Unfortunately, that didn’t solve anything.

Also, is it possible that a bad exhaust leak (from a bad connection for new cats) causes a rough idle or shuttering? If not, I’m close to confident that the transmission with 335K miles and original fluid/filter had a bad torque converter, etc.