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So about a year ago I developed a dreaded mysterious rattle. It was clearly coming from the front end around the engine compartment. I could tell that it was something vibrating and it annoyed me but not enough to REALLY investigate it. Figured I'd get to it when I had the time. That's why it's been 1+ years. The rattle would only happen when starting from a stop...so under load (I have a manual), or when idling, or when driving slow, like in a driveway, after disengaging the clutch (pushing pedal in). And even at those times not always. Over time I would check this or that to see if it was loose and could'nt find anything like a cat cover being loose. Fast forward to about two weeks ago. I notice another different rattle developed. So today while changing my oil I decided to investigate more thoroughly. Checked everything underneath that I could. Did a Google search for F150 rattle and pulled up a million things of course. In one thread I noticed someone mention that it was the engine brackets used to hoist the engine out of the bay. So I decided to check them.
Drivers side bracket made a "twang" vibration when I plucked on it. Decided to try and tighten it down. It was already basically as tight as could be. Checked the passenger side one and noticed that one of the threads that goes into the engine that the bracket gets bolted to was missing. The other nut was tight and flush. Thought to myself "that seems odd, what could've happened to that thread?'. So I decided to just roll the dice and remove both brackets. The bracket with the missing thread and nut was a little tough to get out. The nut that was there was pretty hard to turn. Took like 3 minutes to unscrew it with a ratchet. The nuts on the other bracket came off easy. When I took the bracket off of the drivers side (the one that twanged) I found out why it was twanging. The bracket had somehow cracked and sheared itself off. It was still being held in place by the other nut and thread but it seems very strange that it broke. I have literally never touched these brackets and I've been the only owner of the truck...bought new from dealer.
Question: Anyone have any ideas on how that bracket cracked on its own? And any ideas on what may have happened to the threads and nut for the other bracket? Seems odd.
Oh, and btw, drove it around a bunch and all rattles are gone. Quiet as could be. Changing from Motorcraft partial synthetic to Mobil 1 full synthetic seems to have made her a bit quieter too. But that could be my imagination
in the first photo is that the exhaust manifold ? Bolts rot out due to heat / cool in that area... nothing to do with the bracket... you could get an exhaust leak at the flange without the bolt installed.
It is the exhaust manifold. Didn't think of it at the time but I guess those nuts were holding that pipe of the exhaust to the manifold. You think I could get a replacement "thread bolt" (not sure what theyre called) to put in that spot where the one was missing? Seems like a random thing to find at an autozone or someplace. Cant tighten another nut on without the threads to tighten it on to. Did'nt think about that coming loose but I'll put the 3 nuts I have back on the three threads that are there at least
Did a search and see that I can indeed buy a manifold bolt from O'reilly's. Now I'm concerned that maybe the bolt somehow broke and half of it is still in there. I hope that is not the case
Went out and checked this morning and sure enough that bolt is sheared off and still attaching the exhaust to the manifold. It seems that the manifold bolts that had the brackets on them have two sets of nuts....one to hold the bracket on and one keeping the exhaust secure to the manifold. The bolt sheared off at outer edge of the nut securing it and still seems to be tightly secured although not visible. You can see the nut still there in the top picture. If I take off that nut would I be able to change out the bolt with a new threaded exhaust manifold bolt?
That studded bolt has two sets of threads. One that secures exhaust manifold to cylinder head and the stud portion for the bracket. Those brackets are only used for engine removal and installation. If it were me, I would leave the brackets off and not disturb the remains of the bolt. It's possible it could break off in the cylinder head when you try to remove it.
You got lucky finding that rattle, but the reason you did is you actually looked for it. I agree, leave the brackets off and don't mess with the studs.
