roberttran

Hey,
I am 99.999% sure that there is a crack somewhere on my exhaust system. Whenever the car has been driven for a certain amount, I can hear ticking from under the car. It persists when I turn the car off.
If there is a crack, whats the best way to find it? It sounds like its coming from around the left catalytic converter area. When I find it, is the only way to fix it welding? Could I use some epoxy like JB Weld? I have an arch welder and have some experience with it, could arch welding be used?

Thanks,
Robert

VVT-i

The leaks probably from you exhaust manifold. You will hear it clearer when first start in the morning. It's very tight spot to repair or weld.

steviej

iTrader: (1)

do you see any exhaust coming out from anywhere but the tailpipe? or can you smell a heavy odor of exhaust if you are up under the car near the cats?

I ask because some ticking is normal.....it is the heat shields expanding and contracting due to the heat.

steviej

roberttran

I usually have my car parked in the garage with the tail pipe pointing outside. When I turn the engine on, not soon after that I can smell some smelly exhaust standing towards the front of the car. I don't think everytime I turn my car on the wind blows exhaust into my garage. I will have to get underneath there this weekend to see if I actually see anything comeout

Thanks,
Robert

Lexmex

Look underneath your engine, right in the center and you will see an accordion looking piece. That should be exactly where the problem is coming from. These things crack easily and it happened with mine. I think the replacement was something like $250-$350 and it is a flexible mesh.

What did I do? I welded the sucker shut. I had to do it twice, but now it holds. The second time I had to get some extra metal to seal it as the original material is very thin.

If you let this go unchecked it won't cause a problem, but you will let too much air in to pass a state emissions test (if you use the tailpipe method as opposed to OBDII).

I would have said your fuel injectors, but since you mentioned the smell that should be it. Sometimes these hole are really tiny, so you should have someone else press the gas while you look with a flashlight

roberttran

thank!
I've seen that thing down there when I was underneath greasing the propeller shafts. I will definately look at that thing this weekend. What kind of welder did you use? How hot does that thing get, I was wondering if I could use solder and a torch.

-Robert

Lexmex

It was a propane torch. I would not use solder as it is too thin, much like the material the accordion piece is made of. What I did was take that little piece of metal that partially protects the accordion piece. I ripped that off and used it to cover the holes. I eventually had a to get a similar piece of metal to cover the top.

I found it useful to remove the whole section of pipe. Use just need a wrench and a little effort and you can get it off.

I wish I had a digital camera as it looks like a fat clump surrounding the affected area. Both Lexus dealers I used when I took a trip back to the U.S. in December thought it was ugly, but agreed it was entirely effective.

That piece does get hot. Both times I looked at it before giving it the torch, it was black around the holes.

roberttran

Did you have to replace the seals and nuts when you put it back?
I am looking at the repair manual and there are seals and nuts that they say are non reusable.

-Robert

Lexmex

No.

There was notproblem with either. I work with a mechanic who used to work on Lexus/Toyota before returning to Mexico (very unique for here), and we even checked to make sure no exhaust was venting from that section of pipe after putting it back in. I also ran it through and emissions pre-verification station here, and no problem.

damon

There are many post here on the procedure to replace cracked EGR pipes on particular Lexus models.

damon

roberttran

I just checked that supplement thing that has the warranty info.
It seems my powertrain is still underwarranty (^_^). doesn't that mean any cracks on any exhaust pipe is covered? It does say exhaust manifold is covered under that.
When I take it to the dealer, what should I say? Should I just say that my car ticks, I get ****ty gas mileage, and it all points to a crack somewhere?
I should be able to get them to do the work for me since my family owns 4 Lexi and 3 of them came from that dealership.

-Robert

cuttingedg

this is a very common problem with the lx470's.the exhaust manifolds tend to crack around the tubes that go against the heads.i've never repaired one, only replaced them.

cuttingedg

there is also a problem with the heat shields cracking on the front convertors.they need to be replaced and also there is an updated set of mesh washers you use.some ticking after truck is turned off is normal due to convertors and mufflers cooling down.