I recently had my motor replaced with an FQR. The install went great and the motor runs strong. The only problem is now when either it is warming up or cooling down some of the sounds coming from underneath are loud! I'm not talking the normal cracking and popping, I'm talking something is POPPING underneath. It is loud enough that if you are standing next to it you jump!

I'm sure it is just the exhaust but it has to be in a bind somewhere. Should I undo all of the exhaust bolts and then reassemble. That sounds like a pain. I orginally thought the bind would work its way out but its been 1,200 miles now.

Help!

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'97 F150 Lariat, Flareside, white/sliver, SC, ORP, 5.4 (FQR), Mods: 305/70/16 GY ATS, AR Baja wheels, dual exhaust, Smittybilt Nerf Bars, Edelbrock IAS Shocks, K&N Filter and Carbon Fiber Bug Gaurd. Rigged the fog lights too.

 

You have a warranty with FQR!!!
Take it back and tell them to fix it or at least write it up so you have a record of the complant.

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97, 4.6, 3.55LS, Dk red 265/75/16, Leer cap, Rhino bed, rose wood dash kit, CD player, High performance cross drilled rotors

 

Yea, I know. It's just such a pain to have them wrench on it. You know, drop it off the night before so it can be cold when they start it etc. etc.

I would rather fix it myself if I can.

 

I remember a post similar to this where everyone was discussing that the new aluminum things were stretching into initial shape. This was causing this noise and it went away after enough heating up and cooling down cycles. It was developing memory. It may be normal.

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97 F-150 SC Lariat, Styleside, White over gold, 4.6L (Windsor) automatic, 3.55 rear end, electronic 4X4, w/ every option of Lariat and ORP packages except the 17" wheels and the 4X4 decals, MOD so far= K&N air box mod, Gibson Super Truck, clear Bugflector II, Leer TSC 600 hard cover, Bridgestone Dueler OWL ATP 265/75 R-16's, TrailMaster VVS shocks, Smittybilt step bars, "White-white" head lamps.

 

KKIRT1, i too am getting very loud pops with the new engine installed it is as loud as you described, i will have them look at it when i take the truck back in to see why it would be so much different than before, i could understand a little better if they also replaced the exhaust or cats.

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97 F-150,XLT,4X4,Supercab,bright Red,5.4,3.55 LS,LT265/75/16 Bridgestone Dueller A/T tires,Downey SST soft tonneau cover,56,000 miles, FQR MOTOR.

 

Kcdan: When are you taking it back? Let me know what they say - thanks!

I have more than 2,000 miles and I'm getting the popping as much if not more than before. I crawled under it tonight after driving it for a few miles and messed with the exhaust pipes (insulated gloves.) I duplicated the noise by pulling on the pipes.

Why can't I get away from startup noises?

 

I get some real loud cracking and popping under my truck as well. One thing I did notice, but wasn't this sound was when I parked after having the A/C on, the condenser drips right on to the exhaust on the passenger side of the engine making for some 'strange sounds from under the hood...'

cd

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Silver 99 F150 XLT 4x2 Sport Extended Cab with Flare Sides...
Mods: K&N Air Filter, Tinted Side Windows, Reese Class 3, Airbox Mod's, Fiberglass Tonneau Cover, Alpine Deck & Subwoofer Processor, Zapco AG350 Amp, JL 10W0 (times 3) & 1 Farad Cap
Coming soon: Flowmaster 40 Series Catback System (Orderred), Spray-On Bed Liner