Engine noise on start up that goes away after driving

I have a 2007 Prerunner TRD V6 with 40,000 miles on it. Tuesday it started making a sound similar to that of those little civics with the crazy exhaust on them. It sounds kinda like an exhaust leak but it goes away after driving it on the highway at normal speeds. If I park it for any length of time (10-15 minutes) the sound comes back. I'm taking it to the dealer this morning but I'd appreciate any input I can get from you guys. What could it be and why does it go away after driving.

 

just throwing spaghetti at the wall here, but it could be a small exhaust leak that shuts after everything expands once it gets hot enough... my boss had the same problem on his audi and it was doing exactly what you are describing.

 

I'm at the dealership right now waiting to hear the news nice been waiting for an hour so far so I hope that means they're being thorough. What you say makes perfect sense mechanically and I hope it's just that simple. I can't afford to be without my truck for any length of time.

 

The dealer checked the exhaust and found that one of the wlds coming from the catalytic converter came apart. It's not a covered issue. This is a "Toyota certified" vehicle that supposedly goes through this huge check list and they're saying that they wouldn't have looked at a rusty corroded weld as a possible fix before certifying. To replace the part is $1200 minimum. F that s**t I'm gonna put muffler patch tape on it until I can weld the seam myself. Gotta say that I might have wasted my money for the wrap warranty. I don't understand why, with normal driving, no beach or saltwater, that this could happen in less than two years of me driving it. I just feel that this should have been found prior. I'm a navy mechanic and I'm trained to spot potential wear and tear issues why aren't ase certified mechanics that work for a major dealership?

 

that does suck at 1200 you could probably go to a junk yard and find one. one the bright side at least it wasn't anything major.

 

If it's the catalytic converter itself it should be covered under warranty until 8 years/80k (federal emissions control regs), assuming it wasn't damaged in an accident, etc.

 

The catalytic converter is fine the break is about two feet down the pipe that comes directly off of the cc. I wrapped the seam with high heat muffler repair tape and for now atleast I don't sound like a civic going down the road. My bro inlaw is a welder so I'm gonna see if he can maybe weld the seam later.

 

You should be able to fix that yourself for next to nothing. Go to a muffler shop and have them throw a weld on it, or simply replace the tailpipe. That's why muffler shops exist. Typical dealer BS. This reinforces my decision to pass on the extended warranty.

RZ Rob

 

NO... check first.... isn't the catalytic converter and even where the break is, part of the "emissions equipment" that (by federal law) is unconditionally warranted for at least 50,000 miles? Might be even more than 50K now.

Be sure and look into that!

 

Where would I go to find that out?

 

I put some muffler tape on for now and it's quiet. The part that came apart is on the pipe that comes off the header and goes through the catalytic converter not just the tailpipe.

 

o2, cat, and mufflers are 8/80,000 miles.

i'll check with the warranty clerk monday and see what the actual pipes are covered for

 

Thank you. Do you work for a Toyota dealership?