Strange sounds engine area ????

[dvieira]

Hi...



last wednesday driving home from L. A. , on Hwy 5,

this strange noise started coming from the engine compartment, while still in L. A. and i was giving it some fuel the noise sounded

like either a combination of a miss [gas enginenoise] exhaust leak, and sometimes like a rattling spray can of paint that you shake first, stopped at a rest stop, checked out the engine compartment, found no cracks in manifold, no wet leaks of any kind, everything looked good, gave the engine a couple power

boosts in neutral, no strange sound at all, just in drive under

power to get up to speed, then a slight sound under cruise control.

this is driving me nuts, maybe the vacuum pump, i don't know, i'm guessing here.

thanks for any suggestions,



the truck drives good otherwise, no other problems.

again thank you

dave

 

[MidwestMotorman]

cruise tap

The throttle pedal can make some noise while the cruise is working, but it would not make any noise while you have your foot on it. You can set the cruise and hold your foot to the side of the pedal to see if it goes away.

 

[Shooter]

KDP

 

[Steve Campbell]

Could it be...

that water line to the heater (why would he be using the heater this time of year in LA) that has been the source of mysterious sounds for a few posters here?

 

[cwsoules]

Our strange noise turned out to be caused by loose exhaust header bolts. One of the #6 cylinder bolts was finger tight and several others were not tight. When I tightened them the noise went away. It had been most prominent when the exhaust brake was on. Since then I've started checking with a torque wrench set to 32 ft-lbs.

 

[Steve Campbell]

You might want to...

have the exhaust manifold surfaced. The heating and cooling with the bolts loose, and now doing it all over with them tight... puts a lot of strange stress on the casting. It may never crack, but the resurfacing colud save you some larger dollars down the road.

 

[dvieira]

Found the problem !!!

Hi...



As cwsoles mentioned above, bottom exhaust manifold bolt

on #6 cylinder was loose, could turn it with my finger's, tighten

check all other's they were all tight, test drive, awwww

what a feeling of no more unknown noise, happy, now just

waiting for the KDP device to get here so Brandon of Modesto

can get my dowel pin squared away.



thanks all for for your comments



daveOo.