Change in Exhaust Note

Hey all, just curious if anyone has an opinion on my situation.

I'm in the middle of a road trip from Pittsburgh, PA to British Columbia and back. Just this morning while climbing one of the many mountain highways in the Rockies my exhaust suddenly got louder. It's not extremely louder but the note has definitely changed. It's only really noticeable under load and not while cruising under light throttle.

Obviously it points to an exhaust leak but I spent some time under the truck and can see no obvious sign of a leak. I felt around all the joints and the muffler seams with the engine running and felt nothing. No black soot anywhere I can see. I can't really hear any "putting" sound at idle, just the normal ticking of the valve train. The truck doesn't feel any different driving, no loss of power or anything. No check engine lights.

Is it possible that some of the fiberglass in the muffler has burnt out thus making it louder? The truck is a 2014 with about 35,000 miles.

Ultimately I don't think it's a huge problem since it still drives the same, just wanting a second opinion or some advice on things to look out for.

Thanks for reading!

 

Has your cat already been replaced under the recall?

 

No sir, I don't recall ever doing that one. Have they been known to blow out?

 

My apologies, it's not a 'recall' but a special service campaign. Worth looking up on Toyota's website to see if you are included.

https://www.tacomaworld.com/threads...vice-campaign-2010-2014-4-cyl-tacomas.399785/

 

I checked the my Toyota page and the only service advisory is the one about the tire capacity sticker. I ignored that one since I'm not on stock tires anymore. Is there a time limit on special service campaigns?

 

Dunno. You may not be part of it if truck is not on the list. Could have only been certain production numbers and yours was correct from the get go.

I suppose it's worth a call to your dealer and ask about it.

If you have no performance issues and no CELs (or pending CELs) related to the exhaust stream, you're probably fine to continue this trip.

 

May be the cat blowing out, hard to see that happening in a 2014 model but I guess that's what the special service campaign is for. The noise problem could be one of the baffles or internal chambers blowing out of the muffler, but again on a 2014? Possible but not likely. I'm pretty sure these mufflers don't have fiberglass or any other packing material. Auto mufflers typically have internal chambers of specific size and shape to counteract the exhaust noises from the engine it's spec'd for. That's why you can install a brand new muffler, and it will sound awful if it's the wrong brand new muffler.

 

Thanks for the help guys. I checked what exhaust manifold bolts I could easily reach and they were all still tight. I guess I won't worry about it til I can get home and do a thorough inspection.

 

I would advise you to really keep an eye and "ear" on it.

My 2014 RC truck got a funny sounding exhaust leak at about 30K or so, When under load like on a downshift and then it got to where it had no power at all.

Cat was stopped up, which meant the engine was torquing so much the engine was twisting the spring loaded flange of the exhaust manifold donut gasket open.

Thing is it happened so quickly.

Covered under the 8yr/80K converter warranty.

 

Thanks man!

 

Well, I can report some good news and bad news. Good news is I found the problem. Bad news is that my LC header is effed. Some pics to explain...

Here's the header after 2 years. Now I did have it wrapped in fiberglass header wrap because I thought it would lessen under hood temps and I liked the look. I didn't think I'd have to worry about corrosion because the tubes are stainless. They appear to have corroded slightly anyway. Also I'd like to say that I really wish LCE would use stainless for all the parts, flanges included.



Here's where my leak was. The area where the four pipes converge was completely rotted away. Makes me wonder, is this really stainless?



The darkness allows the light to come through.



Some more close ups...



I'm gonna try and call or email LC and see if there's anything they can do about it.

I think I can fix it by cutting off the collector and trying to patch up the hole and welding the collector back on. My only concern is getting a decent weld to the crusty nastiness in there.

Any thoughts fellas?

 

Wow. Please keep us posted. I just purchased an LCE header, but haven't installed it yet.

 

Please keep us posted, was looking into purchasing one of these. Definitely looks like a quality issue, I don't think rust or corrosion is to blame entirely, those welds do not look very good on the inside of the collector. It's possible whoever made it made a second pass and welded partially on top of some slag which would explain why it blew out.

 

That's very possible. That said, I wouldn't have any qualms about buying the part. In my case the header wrap probably screwed me over. If I could do it over I would not use the wrap but I would probably send it out for a better ceramic coating, both for corrosion protection and heat mitigation. Been looking at these guys but haven't gotten an estimate yet. https://www.jet-hot.com/ I think with some of their coatings they can even do the inside of the pipes, and it's supposed to last a very long time. LC's "ceramic coating" has pretty much all worn away on my header.

My best guess as to why it corroded is that maybe it's possible that because of the insulation of the wrapping on the collector, that portion of pipe got to the point of being red hot causing the stainless to oxidize. If you've ever TIG welded stainless it's a very common problem that the backside of your joint, if it becomes sufficiently hot, can become gray and crusty if not properly shielded by gas.

I did contact LC and I'm pleased to report that they said if I'm willing to pay shipping to and from their shop they would do everything they could to repair it. It means a lot to me that the company stands behind their work and I greatly appreciate that.

I still gotta get a shipping estimate though. I'm expecting it to be kinda pricey so I'm leaning toward just fixing it myself. When I start the repair process I'll include some pics.

Also I'd like to add that since I'm driving around on the stock manifold again I can tell the difference in performance. It's not a huge difference but I've noticed two things. On the OEM manifold I'm spending more time at a higher rpm before shifting. And when travelling on the highway on a gentle incline, it's more difficult to accelerate. There's a hill on a highway I travel frequently and usually I can slowly accelerate up it in 4th gear with the LCE header. On the stock part acceleration in noticeably more labored in 4th gear.

 

That's great news - glad it's working out and glad to hear they'll stand behind their product

 

Header wrap is a often blamed cause of pipe damage. Iirc more than 1 company puts a 'void if wrapped' note in their warranty.

 

Yeah, I can definitely see that being a warranty buster.

 

Decided to start a new thread to chronical the repair.

https://www.tacomaworld.com/threads/lce-header-rust-out-and-repair-attempt.515108/