So I bought a used 2013 SHO with 130k on her, was running fine until now. Runs normal until you start to give it about half throttle to get moving and starts to shudder and then misfires on cylinder #2. I took out the plug in cylinder #2 and it looked fine, almost looks new other than a bit of carbon on the end of it (as to be expected). Did a test on the coil pack and its got voltage so I'm stumped. I don't think it's the transmission because it still does it in manual mode. It seems to quiver at about 2-3k RPM and then misfire when you give it a bit more gas. I've talked to multiple people about it and researched a few forums with the same keywords and most of them say dirty throttle body or nicked crank sensor. Any thoughts?
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Moved to a more appropriate section.
Did you check the plug gaps? Boosted engines are very sensitive to that. If the plugs had never been changed, this would be a good opportunity to do so. If the SHO sees all highway miles, you can get a lot of life out of the plugs, but really most should change them between 30-60K miles due to mixed or city driving.
What code did you get exactly? P0302 or something else?
What code did you get exactly? P0302 or something else?
luigisho
SHO Member
After checking the gap, swap the plug and coil from 2 to another cylinder and see if the misfire follows or stays at #2.
Thanks for the replies, I got a repetitive p0302 code from the misfire, then I had this code before this started happening p0430 (Catalyst System Efficiency below threshold (Bank 2) )
Also I will try regapping them to see if that might fix it.
Also I will try regapping them to see if that might fix it.
If I moved it and it did stay would that likely be an injector?
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luigisho
SHO Member
Maybe. What it factually does is eliminate the sparkplug and/or the coil as causing the misfire. You just have to get the easy stuff off the table first. This is easy, free, and accurate. If the miss follows to the swapped cylinder then you swap the coil back, leave the plug, and can narrow it even further to either coil or plug if necessary.
yaycandy
Aerospace Engineer
I was through this replacing part after part. Do a compression test before spending money on parts or tearing intake manifold off
You really never know the background of the engine and how long between oil changes. My cylinder 2 started the same way. I replaced part after part with it never clearing up. Compression test showed low compression in cylinder and i took it in to a trusted shop and they saw with a bore scope that the cylinder walls were butchered up. And when ford got back the engine to reman i requested to know what the cause of failure was and ford said it was from increased piston skirt wear from long oil periods.
Hope its not the same for you, hope i didnt scare you but compression test is easy and cheap and will let you know if its physical wear instead of just a fixable part or sensor
You can be searching and searching on here for weeks with a 15 page long thread when really a compression test will give you the better answer to know if the engine is good. If the engine is fine the fix can be pretty easy.
You really never know the background of the engine and how long between oil changes. My cylinder 2 started the same way. I replaced part after part with it never clearing up. Compression test showed low compression in cylinder and i took it in to a trusted shop and they saw with a bore scope that the cylinder walls were butchered up. And when ford got back the engine to reman i requested to know what the cause of failure was and ford said it was from increased piston skirt wear from long oil periods.
Hope its not the same for you, hope i didnt scare you but compression test is easy and cheap and will let you know if its physical wear instead of just a fixable part or sensor
You can be searching and searching on here for weeks with a 15 page long thread when really a compression test will give you the better answer to know if the engine is good. If the engine is fine the fix can be pretty easy.
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It probably is that because I keep getting low engine oil pressure lights coming on which I'm pretty sure is bad... I swapped coil packs and gapped the plugs and swapped the plugs and its still doing it. Haven't got the code read yet but I'm going to get it checked asap.
luigisho
SHO Member
Don't the codes tell you which cylinder is misfiring?
Yes it does but I haven't got the code ran since I switched coils and plugs on the cylinders so I wont know until then
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What fuel trims are you seeing? Major imbalances between bans 1 & 2?
Oxygen sensors do fail, I would check the bank 2 sensors first, and replace them as needed. Motorcraft brand is best.
Injectors can begin to leak over time. That is one reason why pulling all the plugs to compare is an important diagnostic step.
A compression test is a great idea.
Oxygen sensors do fail, I would check the bank 2 sensors first, and replace them as needed. Motorcraft brand is best.
Injectors can begin to leak over time. That is one reason why pulling all the plugs to compare is an important diagnostic step.
A compression test is a great idea.
Excuse my ignorance but I have no idea what you mean by fuel trim, also it stopped misfiring now and just jerks in 3rd through 6th gear when you go to get on it a little bit. Not when shifting through the gear but while in the gear. I wonder if that's the torque converter?
Whats weird to me is that it doesn't miss at all in first through second, you can pretty much floor it in those gears and it doesn't skip a beat. As soon as you get to third is when it starts to **** and act up.
Sorry I'm new to this sort of thing on these cars so I'm sorry if I don't understand some of these things.
Does the RPM gauge fluctuate without change in load? That would indicate a torque converter lockup issue.
You can check misfire counts by running Mode 6 Data functions, that would help correlate with it being an engine rather than a transmission issue.
The PCM continually adjusts fuel delivery based on feedback from the oxygen sensors, how much it adjusts is displayed as the amount the fuel is trimmed, either positive or negative. If the engine is running lean, it will add fuel, i.e. have a positive fuel trim. If the engine is running rich, it will reduce fuel, i.e. have a negative fuel trim. Usually on these engines, the trims are pretty close if everything is working properly.
Is your SHO tuned? If not, you can use Torque Pro or Forscan Lite with an OBD adapter to get at a lot of data that the PCM continually streams while in operation.
You can check misfire counts by running Mode 6 Data functions, that would help correlate with it being an engine rather than a transmission issue.
The PCM continually adjusts fuel delivery based on feedback from the oxygen sensors, how much it adjusts is displayed as the amount the fuel is trimmed, either positive or negative. If the engine is running lean, it will add fuel, i.e. have a positive fuel trim. If the engine is running rich, it will reduce fuel, i.e. have a negative fuel trim. Usually on these engines, the trims are pretty close if everything is working properly.
Is your SHO tuned? If not, you can use Torque Pro or Forscan Lite with an OBD adapter to get at a lot of data that the PCM continually streams while in operation.
Its stock as could be, and yes the RPMs bounce up and down with the same amount of throttle introduced. I'm thinking it's a torque converter because I noticed it jerks a tad bit more than usual when downshifting.
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Not sure it will resolve the issue, but if you have not performed a complete trans fluid exchange (4x drain/fill) you can try that. If the jerking continues, add a tube of Lubegard Shudder Fixx. If the jerking subsides after that, then odds are the TC is on its' way out.
https://smile.amazon.com/Lubegard-19610-Tranny-Instant-Shudder/dp/B0002JMLQU/
https://smile.amazon.com/Lubegard-19610-Tranny-Instant-Shudder/dp/B0002JMLQU/
luigisho
SHO Member
Still looking for error codes. Did you clear the old ones out before driving it again?
I never cleared them and it's not throwing anymore codes for some reason, I even tried to make it misfire again just to see if it switched cylinders.
I noticed that the shudder happened when I drove it when it was really cold out, not sure if that has anything to do with it but it didnt do it before that. Also what's weird is it didnt really progress and get worse it was fine one day and then shuddering hard the next.
I will do a complete transmission drain and fluid change and add some shudder fix, again thanks a lot for all the help.
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yaycandy
Aerospace Engineer
Like 37 degrees lol, not "really" cold but I dont think this car has seen past freezing hahaWhats considered “really cold” in Florida?
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