5.4L 3V Intermittent Shaking on Highway
02-06-2019, 03:32 PM
#1
Junior Member
Thread Starter
5.4L 3V Intermittent Shaking on Highway
Hey all,
I've got a 2005 F-150 with the 5.4L 3V with about 83k miles on it. The truck seems to run fine driving around town, however it recently started shaking intermittently at highway speeds. Sometimes the truck will run smooth with cruise control set at 70mph for an hour plus, other times it will shake until I let off the throttle completely. Additionally, on several occasions when I was merging onto the highway the truck would begin violently shaking and the check engine light would flash at me for a few moments. Each time this happened I quickly plugged in my handheld tuner to check for a code, but no codes are present. My mechanic suggested that it may be the cam phasers failing and advised I have them replaced. Since this is a relatively expensive repair, I wanted to make sure this is actually the cause before getting it done. If anyone has any ideas what this may be I would appreciate hearing your feedback.
I've got a 2005 F-150 with the 5.4L 3V with about 83k miles on it. The truck seems to run fine driving around town, however it recently started shaking intermittently at highway speeds. Sometimes the truck will run smooth with cruise control set at 70mph for an hour plus, other times it will shake until I let off the throttle completely. Additionally, on several occasions when I was merging onto the highway the truck would begin violently shaking and the check engine light would flash at me for a few moments. Each time this happened I quickly plugged in my handheld tuner to check for a code, but no codes are present. My mechanic suggested that it may be the cam phasers failing and advised I have them replaced. Since this is a relatively expensive repair, I wanted to make sure this is actually the cause before getting it done. If anyone has any ideas what this may be I would appreciate hearing your feedback.
02-06-2019, 03:37 PM
#2
Hey all,
I've got a 2005 F-150 with the 5.4L 3V with about 83k miles on it. The truck seems to run fine driving around town, however it recently started shaking intermittently at highway speeds. Sometimes the truck will run smooth with cruise control set at 70mph for an hour plus, other times it will shake until I let off the throttle completely. Additionally, on several occasions when I was merging onto the highway the truck would begin violently shaking and the check engine light would flash at me for a few moments. Each time this happened I quickly plugged in my handheld tuner to check for a code, but no codes are present. My mechanic suggested that it may be the cam phasers failing and advised I have them replaced. Since this is a relatively expensive repair, I wanted to make sure this is actually the cause before getting it done. If anyone has any ideas what this may be I would appreciate hearing your feedback.
I've got a 2005 F-150 with the 5.4L 3V with about 83k miles on it. The truck seems to run fine driving around town, however it recently started shaking intermittently at highway speeds. Sometimes the truck will run smooth with cruise control set at 70mph for an hour plus, other times it will shake until I let off the throttle completely. Additionally, on several occasions when I was merging onto the highway the truck would begin violently shaking and the check engine light would flash at me for a few moments. Each time this happened I quickly plugged in my handheld tuner to check for a code, but no codes are present. My mechanic suggested that it may be the cam phasers failing and advised I have them replaced. Since this is a relatively expensive repair, I wanted to make sure this is actually the cause before getting it done. If anyone has any ideas what this may be I would appreciate hearing your feedback.
02-06-2019, 03:58 PM
#3
Junior Member
Thread Starter
Previous owner told me the spark plugs were replaced once already but I'm not sure how long ago that was. I suspected spark plugs initially but the issues only seem to arise on the highway which seemed odd to me.
02-07-2019, 06:36 AM
#4
Mark
iTrader: (1)
A flashing CEL is a classic sign of a mis-fire condition. install a fresh set of motorcraft SP546 plugs and new boots and springs. Hopefully the PO didn’t lie to you about having changed the plugs or you will have some fun getting the OEM plugs out.
02-07-2019, 07:49 AM
#5
Senior Member
I'd replace the plugs. That's what my truck used to do before I replaced the plugs. It would miss when I let off the throttle a little bit. Eventually it will get worse.
02-07-2019, 10:02 AM
#6
Member
Sounds like a classic misfire; mine did this horrifically without throwing a code. Plugs/boots/coils.
02-07-2019, 10:09 AM
#7
Mark
iTrader: (1)
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02-07-2019, 11:01 AM
#8
Junior Member
Thread Starter
Thanks for all the replies. I will try new spark plugs and boots to see if that fixes the misfire. I found the Motorcraft SP546 plugs online, does any know what boots I should purchase? Thanks!
02-07-2019, 11:04 AM
#9
Member
Most certainly and I'd agree, I just pointed out most common misfire culprits... at this point, if its a coil problem, it'd be due to age. Check plugs/boots/springs first (cheaper than a set of COPs). My truck lost its first coil at 100k (when the plugs were first done), and it's 3rd by 140, so I went and replaced all 8.
02-07-2019, 11:15 AM
#10
Mark
iTrader: (1)