Does anyone know what may be causing a loud rattling noise under my truck (98' f150 sc, 48K miles) on the drivers side? I've checked the muffler, the firewall (above the muffler) and anything else I can see under there. Everything seems tight.

Help!!!! It's driving me nuts.

 

Does it do it when you rev it up? or only at idle? If it does at idle only, then you could have lost a catalytic converter. Just a thought......

 

It only does it when the truck is idling. Any slight increase is revs make it go away. I'll look into the CC possibility. Thanx.

 

I've always had problems with the stone guard that protects the CC, usually only spot welded in the four "corners". On my older cars I have bought clamps (the kind you turn a screw and it tightens) and placed three around that stone guard to keep it from rattling. Haven't had to do it on my truck, but just did it to my son's 92 Festiva recently...his type of music makes EVERYTHING rattle on that car!

 

check your Power steering line rattleing against the frame rail I have seen a few of these latley.

 

Check all those sheetmetal heat shields, i've had them crack, welds fail, and mounting bolts come loose. All will cause rattling.

 

mine sounded almost like an exhaust rattle.

Diagnosis?


Bad alternator. Mechanic put the stethescope on all the parts and sure enough... alternator.

Borrow someones stehescope and check for yourself. You would be amazed at what makes noise down there.

 

I found it! It's the exhaust connection that runs from the drivers side and connects to the one one the passenger side. Only does it when it's hot. Everything looks tight (hangers, bolts etc.). I tried to loosen and retighten everything but I couldn't break the bolts loose (didn't have any liquid wrench handy). I think I'm going to take it to a muffler shop.

 

Fixed! I took it to Ford and they tightened the exhaust. Only cost me $37. They did try to sell me Dampener (???) for $170, I declined and everything seems OK.

Thanks for the help all!