Exhaust noise when cold.

[93MTXSHO_STUD]

When I start my car in the morning and start driving I hear well it sounds like a dirt bike coming out of my exhaust pipe. Someone told me that it could be my lifters, but I have no idea. Also when idle I here a noise coming from my engine, more of a rattlin noise, kinda faint, but if you turn off the radio you can hear it. I was wondering if you guys had any suggestions on what this might be? My SHO has around 120K on it, the 60k service has been done to it.

 

[DHMag]

93MTXSHO_STUD:
When I start my car in the morning and start driving I hear well it sounds like a dirt bike coming out of my exhaust pipe. Someone told me that it could be my lifters, but I have no idea. Also when idle I here a noise coming from my engine, more of a rattlin noise, kinda faint, but if you turn off the radio you can hear it. I was wondering if you guys had any suggestions on what this might be? My SHO has around 120K on it, the 60k service has been done to it.

no lifters on this DOHC engine. your SHO sounds like a dirt bike when cold ? Rasp.

 

[Chris Benvie]

welp, since there are no lifter on the SHO it could possibly an exhaust last week or maybe the previous owner hollowed out the cats.

Either way please read www.shotimes.com to get some more knowledge on the SHO.

 

[Ishodu]

Next time try posting topics like this on in the maintenance section.
The noise you are hearing in the exhaust in the morning is the excess of unburnt fuel burning in the exhaust from the computer adding it to help warm up the engine.
The noise in the motor could be a valve shim out of spec, a loose timing chain or a bad rod bearing you will have to find out the area the noise is coming from.

 

[sideSHO]

My 91 made a noise like that last summer.Turns out it was a heat sheild that covered the cat.I guess after all those thousands of times warming up and coolingdown the tack welds stressed out and broke.This cuased the rasp sound.Just crawl under and see if their loose.If so take em off. thumb

 

[yamahaSHO]

I am not sure what kind of sound you are describing.

The sound out of your exhaust could just be rasp. When the motor is warming up, it will inject more fuel to aid in warm up. The fuel will not completely burn in the combustion chamber, thus burning in you exhaust giving you rasp.

The sound from you motor, I would have to agree with a valve(s) out of spec or timing chain... you also could just be hearing the injectors firing.

<small>[ March 28, 2004, 04:34 PM: Message edited by: yamahaSHO ]</small>

 

[DHMag]

yamahaSHO:
I am not sure what kind of sound you are describing.

The sound out of your exhaust could just be rasp. When the motor is warming up, it will inject more fuel to aid in warm up. The fuel will not completely burn in the combustion chamber, thus burning in you exhaust giving you rasp.

The sound from you motor, I would have to agree with a valve(s) out of spec or timing chain... you also could just be hearing the injectors firing.

but the injectors have a distinct patterned sound to them.