Crack in Exhaust Manifold...
 

Hey Everyone,

So I believe I have a crack in the Exhaust Manifold... When I rev the car I can hear a slight tick. I had taken it to a shop to do a muffler delete and said that there may be a leak or crack somewhere. The tech said it wasnt too bad but it may be something to keep an eye on. My question is, what would be the best route to go? Is this a common issue with the ISF? I was thinking if it was also possible if it may just be the gasket, which the tech also said it could be.

I have a 2008 model with about 113k miles on it. Any help would be appreciated!

Mine is an 08, and a similar issue was reported by the previous owner.. I saw on the service history that they found a leak in the exhaust manifold 'cracked flange'.

If they can confirm, then I guess its headers time?

I found a small crack in mine as well when I did my header install. Car had a 125k at the time

I have heard of multiple cases of this. I was hoping it wasnt legit. I guess it is. It would be a great reason to take the header plunge. I wonder about mine with all of the INSANE track work my car does, but she still only has 45k on her. Fingers crossed. Best of luck

Would a crack in the manifold produce a smell similar to one from the catalytic converter is removed? still trying to figure out where that smell is coming from before I get emission testing done

It's probably going to be a more common problem as these cars get older..

Here is my 2008 RH manifold w/117k miles daily driven, pipe cracked right off and remaining piece fused itself to the floating flange..

No leaks at the gaskets. They were clean.

The tricking sound for me was prominent on every first start.. The sound and leak is identified by the carbon black soot. Hidden by the manifold heat shield..!!

Pictures from my last visit to the dealership.

https://cimg2.ibsrv.net/gimg/www.clu...76372200e.jpeg


https://cimg3.ibsrv.net/gimg/www.clu...c96d6b67a.jpeg


https://cimg4.ibsrv.net/gimg/www.clu...26010d1f5.jpeg


https://cimg6.ibsrv.net/gimg/www.clu...a567559a8.jpeg

After a battle with Extended Warranty, they finally covered the new parts & labor.


Joe Z :)

After reading this thread I feel like I have something similar going on..

I get a slight egg smell when I go wot, it slowly dissipates as I continue driving.

Looks like I have a reason to buy an aftermarket header now..

The 4AG engines in the Mk1 MR2s had exhaust manifold issues as well. This would not be a first for Toyota at all. It makes me wonder about the random ticking noise problem...

I get the same thing too with a stock exhaust and as far as I know all four cats intact.

Apparently the rotten egg smell is normal. It's hydrogen sulfide which under cooler conditions in the cat will attach itself to the surface of it. Once you WOT you heat the material inside of the cat and it desorbs and exits out of the tail pipe in a fairly high concentration. After running hard for a bit it should go away.

"As the fuel burns, the organic sulfur compounds break down into simpler compounds. If the engine is running lean (more air than is needed to burn the fuel), the sulfur is likely to be SO2, or sulfur dioxide. The catalytic converter can change this into SO3 (sulfur trioxide), which then reacts with the catalyst to form sulfates on the catalyst. Over several minutes there is a build up of sulfates. If the engine suddenly starts to run rich (not enough air to burn all the fuel), such as when you stop at a red light, climb a steep hill, or brake hard to slow down, the chemistry changes. Now the sulfates are unstable and they react to form hydrogen sulfide, which is expelled from the exhaust pipe all at once. The high concentration is the reason for the bad smell! This effect is a common problem with new vehicles because the catalyst is working at a very high efficiency. However, as the catalyst gets older, the activity drops. Fortunately for us, one of the first reactions to be affected is the formation of hydrogen sulfide. So as the catalyst gets older, the smell will go away. It should also be noted that many catalysts never smell bad. One reason might be because the vehicle doesn't run lean for much of the time, or perhaps the catalyst has an extra component that reduces the production of hydrogen sulfide."

http://www.swri.org/10light/catalyst.htm

How easy is it to check and spot if there are cracks on the manifold? Do I need to remove everything just to check? I have an exhaust smell right when I fire up the engine that lingers.

Hmmm. I have had a tick since I got the car primarily before it's warmed up. The master tech at lexus just noted it as a minor exhaust leak. I had assumed that it was probably just a bad gasket, but maybe it's cracked. +1 on the above question. Is there any possible way without removing the manifold completely? At that point with labor I might as well install aftermarket headers.

You could always purchase a camera snake. They're fairly inexpensive these days and useful (though not easy to use depending on app) for a lot of different things.

I also have had the ticking since I had bought the car... Looks like many people have reported the issue. If its a small crack, would this issue be something that should be fixed/replaced right away? I have been driving with no issues for some time. But, like someone else had mentioned there are times I will get that rotten egg smell once every now and then when flooring the car.

And that's a normal smell for high efficiency catalytic converters. The chemical reactions ebb and flow with temperature increases and decreases.