[sable_owner]

My vulcan's valvetrain is rattling at all rpm ranges but especially under load. I have tried different grades of fuel but no difference. Poured in injector cleaner..nothing. If I'm no mistaken, these engines have pedestal rockers. Could it be a sensor that has gone bad? If I have to take in on the warranty I will. Any ideas? Could I rest the computer?

Thanks in advance,
Mark

 

[sixfofalcon]

If it's rattling, something is definitely wrong, and resetting the computer isn't going to fix it. Are you certain it is coming from inside the engine? See if you can pinpoint the source of the noise (i.e. upper engine, lower engine, accessories, etc.) Could be a collapsed lifter, or any one of a hundred other things. Sounds like it's time to collect on your warranty.

 

[XLSuruaT]

Yeah, if it doesn't sound normal to you, take it in. Double check and make sure the engine has the correct amount of oil. Also, the rattle could be an exaust shield, thats what it ended up being on my car. Good luck.

 

[mikehawk]

Definitely check the exhaut. The y-pipes are notorious for leaks around the brackets. Also, I have a broken heat shield that made a nasty rattle/buzz, all I had to do was bend it a little so they wouldn't rub.

 

[mwt]

I claim no knowledge of knowing the specifics of the ECM but on my 94 that is exactly what what happened then it began starting hard and blowing black smoke.

The service engine light never came on but read that a throttle position sensor was out of range. replaced it with a junkyard unit and everything is still ok

just my two cents worth.

 

[mobiuslogic]

Yeah, I'm getting the same kind of rattle, with a few exceptions. Mine only happens after I've been cruising, even if after just a short distance. Then, as I press the gas, I get this rattle sound and if I leave the gas at this level, it will continue to rattle till the engine "wakes up" and the engine RPM and speed stays constant till the engine wakes up OR if when I get the rattle I go WOT the rattle will stop almost instantly as I hit WOT. So what's going on??? My only guess, it that TQ is not letting go soon enough (as going WOT would force a kickdown shift and instantly release the TQ). Any ideas guys as I would really rather it wasn't a valve or a lifter. But then again, it doesn't happen all the time.

-mobiuslogic

 

[greenstreak]

Where exactly is the heat shield that you guys have found rattling? I have the same problem, but can't seem to find it.

 

[majisto]

Sounds like the typical Vulcan ping to me...there is so much going on this subject. I myself get this pinging every once in a while, especially under load. Check the heat shields, clean the MAF...I'm too tired to give you all the suggestions I know, but if it sounds like a chain clattering inside your motor, you have pinging.

 

[mobiuslogic]

Yeah that is what it sounds like, but if that is the case then why does the engine RPMs not increase AT ALL and then once I hear the tranny downshift, it goes away? I think I'll go fill up on premium

and see if that's what fixes it, considering I'm on empty right now anyways, and if it is pinging, then that should fix it.

-mobiuslogic

 

[majisto]

Originally posted by mobiuslogic@Jan 1 2004, 04:28 PM
Yeah that is what it sounds like, but if that is the case then why does the engine RPMs not increase AT ALL and then once I hear the tranny downshift, it goes away?  I think I'll go fill up on premium 

 

  and see if that's what fixes it, considering I'm on empty right now anyways, and if it is pinging, then that should fix it.

-mobiuslogic

because your transmission is in OD and you are lugging the motor up a hill. Mine does the same thing. You can press the gas pedal and the RPM goes almost nowhere since it's in too tall of a gear to accelerate upwards. When you press the pedal closer to the floor, it will downshift into a shorter gear and the engine will make enough power to move you up. The Vulcan doesn't make THAT much torque. As well, the pinging pretty much goes away.

Btw, lugging the motor is a very bad thing to do, especially on a Duratec. Try to avoid doing this.

 

[gtx2000]

I got the same rattle and it is in the engine Not the heatshield. DOes everyone here have the 3.0 liter. I got the rattle right after i got my car back from the tranny shop. I think the problem lies in the distribitor. i replaced the Ign module and i just found out yesterday that the HALL EFFECT sensor in the distributor has prone to go bad. If you got the black style replace it with the Ign Module and this should fix it. The updated part is BLUE. I havent gotten to getting to the dealer to get one but i want to know if everyone posting for this noise has a distributor. Ill be trying this before this weekend and ill let you all know.

 

[mobiuslogic]

Originally posted by Majisto@Jan 1 2004, 04:39 PM
because your transmission is in OD and you are lugging the motor up a hill. Mine does the same thing. You can press the gas pedal and the RPM goes almost nowhere since it's in too tall of a gear to accelerate upwards. When you press the pedal closer to the floor, it will downshift into a shorter gear and the engine will make enough power to move you up. The Vulcan doesn't make THAT much torque. As well, the pinging pretty much goes away.

Btw, lugging the motor is a very bad thing to do, especially on a Duratec. Try to avoid doing this.

Now see that makes sense. What doesn't make sense now is that the instant the PCM reads increased TPS position (acceleration), it should disengage the TC lock-up to keep from lugging the motor and straining the torque converter clutches. However, when I go WOT, then it downshifts and automatically disengages the TC lock up. So now the real question is...."Why isn't the PCM correctly reading the TPS sensor, and if it is, why is it not disengaging the TC lock-up until a downshift?"

WOO HOO, 1 step closer to fixing the problem.

-mobiuslogic

 

[sable_owner]

I have tried premium gas and that did not work. The rattle is worse under engine load but it rattles at all driving ranges. mobiuslogic, the voltage output from the tps is what tells the pcm the throttle location. I know that mustangs prefer a .96-.99 v KOEO for the tps voltage output. The voltage tells the mustang eec when and how much fuel to add to the air mixture. The voltage increases, the fuel increases. Does ne body know the voltage spec for 2000 Vulcan motor? Maybe the voltage is out of spec.

 

[Bob Gervais]

Should be about the same as the Mustang. 1 V KOEO with the throttle closed.

 

[mobiuslogic]

Yeah, I'm running premium right now too and it's still doing the rattling deal under load. What does KOEO stand for?

-mobiuslogic

 

[sable_owner]

Key On Engine Off. To check tps voltage, stick a pin into the green wire and measure the voltage to the engine block. If it's not .96-.99 volts you can change this by loosening the tps screws and rotating in the proper direction to achieve the proper voltage. If you cannot attain the proper voltage, you can modify the tps by opening the holes up. Even if your not experiencing valve rattle, you will get better throttle response with little or no delay.

 

[majisto]

Where is the TPS on the Vulcan again?

 

[Bob Gervais]

Originally posted by Majisto@Jan 12 2004, 03:32 AM
Where is the TPS on the Vulcan again?

On the throttle body.

 

[majisto]

Originally posted by Bob Gervais+Jan 12 2004, 06:25 AM-->QUOTE (Bob Gervais @ Jan 12 2004, 06:25 AM)

<!--QuoteBegin-Majisto

@Jan 12 2004, 03:32 AM
Where is the TPS on the Vulcan again?

On the throttle body. [/b]

Makes sense...