Quieter and Quieter

[Panther]

I've got one for you guys.....why would my exaust be getting quieter and quieter(making less and less noise). I installed a new remanufactured engine(4.0) from pep boys(pro-built). It has 600 miles on it now. The exaust is a new flow master 40 series with new cat. my old 4.0 rumbled nicely with this exaust, this engine rumbled nicely for about 200 miles now it is getting progressivly quieter with less rumble. I have a 94 ranger stx super 4wd auto. the tranny is also new from transmission exchange, a heavy duty utility a4ld with a low stall torque convertor. I don't know if it matters but the long block came with after market heads(non-oem)supposedly the same specs but after market...Thanks for any help

 

[Wicked_Sludge]

with so much having been changed, its hard to tell what could be causing it. how old is the exhaust system? its possible that it'd just getting quieter as it breaks in. have you noticed any reduction in power along with the change in note?

 

[Panther]

I haven't noticed any power loss and the exaust system is about 4 months old. I will run a compression test on all cylinders in the next couple of days..seeings how the engine is new should I retorque the heads to factory specs??

 

[rickcdewitt]

not a bad idea it just depends on if you want the hassle of removing the pass side valve cover

 

[Wicked_Sludge]

heads that use "torque to yeild" bolts generally dont require re-torqing.

 

[Panther]

How can you tell if they are torque to yield head bolts and does it matter if the heads are after market??

 

[Wicked_Sludge]

they are...its all ford's used on all their motors for a long time now.

 

[Panther]

Thanks for your time and the 411 wicked_sledge.....How are you with the auto trans(a4ld)..???

 

[Wicked_Sludge]

auto trans isnt my strong suite. only advise i can offer is check fluid level/condition and change the filter

 

[Original_Ranger84]

I would say its because there is probably a layer of soot or somthing that built up in the muffler and pipe, even though it probably isn't alot I think that it would act sort of like the hush mat in the interior and dampen the sound waves coming out the pipe.

 

[RangerHunter66]

hey this is a bit off topic but u said ur 4.0L rumbled nicely.... can u elaborate a bit im bout to buy an exhaust for my truck (same as yours) but i just want to make sure i make the right choice and what did u do bout an intake?