07 Lariat 5.4L Knocking/Idling issue

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11-12-2016, 08:33 PM
camijack63

07 Lariat 5.4L Knocking/Idling issue

I'm brand new to the forum and need some help. I purchased an 07 Triton 5.4L Lariat Quad Cab with a little over 125K miles on it about 3 weeks ago. I absolutely love the truck and have noticed an idling/knocking issue after it warms up. I've done some research and have read EVERY post on several forums about this issue. I'm in the Boise area and do mostly city driving and not very far at that. The issue seems to happen when the truck is warm and I've driving on the highway. I take the offramp and come to a stop sign/light. The engine rpm drops, the knocking starts and the idle goes. It doesn't happen in city driving, it only seems to happen after its been warmed up for awhile. I noticed today at 65mph its running about 2000 rpm and when idling, its running about 650 rpm.

Since its a new (to me) truck, I've had it to the shop where front brakes/rotor, serpentine belt, plugs (all new), boots were replaced. MAF sensor and throttle body were cleaned along with an oil change ( Motorcraft SB 5w20, Motorcraft FL820S Filter). The truck runs great to/from work but once it warms up and I go a distance longer than it seems like 20-30 miles and slow down the knocking/idling issue start. The engine even died at a light and I had to start the truck again. Once I got going, everything was fine. As I said, I've read many forums on this issue and all I seem to read is "have you tried this, have you tried that". "try this, try that". There has to be ONE person out there who has had this issue and was able to solve it. If your one of those people and happen to be in the Boise area, thats even better. I dont have a problem fixing what is wrong, but nailing it down to what is wrong seems to be the problem. BTW, Check engine light was on prior to the major tune up. Light is now off and never came back on during todays incident. Mechanic mentioned one of the banks on the Catalytic convertor but I haven't done anything with that....yet. I've also read about the VCT solenoids, cam phasers etc but would rather have a direction to tell my mechanic to go.....Thanks all
11-14-2016, 01:24 AM
RhinoZ24

Scan the truck again, just because the engine light isn't on doesn't mean there isn't a pending code that hasn't thrown it on yet. If its a catalytic converter, one of them could be clogged and once the truck warms up it could be causing the issues you listed. Scan the truck again. Also change your fuel filter, clogged fuel filters can suffocate an engine, and for $20-$30 it's worth it and probably necessary if you haven't done so already
05-07-2018, 10:20 PM
Donpauli2

Quote:

Originally Posted by camijack63

I'm brand new to the forum and need some help. I purchased an 07 Triton 5.4L Lariat Quad Cab with a little over 125K miles on it about 3 weeks ago. I absolutely love the truck and have noticed an idling/knocking issue after it warms up. I've done some research and have read EVERY post on several forums about this issue. I'm in the Boise area and do mostly city driving and not very far at that. The issue seems to happen when the truck is warm and I've driving on the highway. I take the offramp and come to a stop sign/light. The engine rpm drops, the knocking starts and the idle goes. It doesn't happen in city driving, it only seems to happen after its been warmed up for awhile. I noticed today at 65mph its running about 2000 rpm and when idling, its running about 650 rpm.

Since its a new (to me) truck, I've had it to the shop where front brakes/rotor, serpentine belt, plugs (all new), boots were replaced. MAF sensor and throttle body were cleaned along with an oil change ( Motorcraft SB 5w20, Motorcraft FL820S Filter). The truck runs great to/from work but once it warms up and I go a distance longer than it seems like 20-30 miles and slow down the knocking/idling issue start. The engine even died at a light and I had to start the truck again. Once I got going, everything was fine. As I said, I've read many forums on this issue and all I seem to read is "have you tried this, have you tried that". "try this, try that". There has to be ONE person out there who has had this issue and was able to solve it. If your one of those people and happen to be in the Boise area, thats even better. I dont have a problem fixing what is wrong, but nailing it down to what is wrong seems to be the problem. BTW, Check engine light was on prior to the major tune up. Light is now off and never came back on during todays incident. Mechanic mentioned one of the banks on the Catalytic convertor but I haven't done anything with that....yet. I've also read about the VCT solenoids, cam phasers etc but would rather have a direction to tell my mechanic to go.....Thanks all

The direction to go is with new VCT solenoids, a timing chain and guided , chain tensioner and a new “ Melling” brand high volume oil pump. You may need to toss a couple phasers in also. Either the VCT solinoids are not releasing oil pressure to the phasers or the phasers ( one or both ) are staying advanced when idling. The other stuff I suggested due to mileage and typical problem areas

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