Exhaust Manifold Leak (2 Viewers)

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Nov 5, 2014
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Hi all,

I have the infamous ticking sound that indicates an exhaust manifold leak. The dealer replaced the left side manifold at 125k (now have 150k), so I am thinking the right side is leaking. That said, the dealer told me last year that both sides are leaking. Three questions.

1. I have searched for 30 minutes trying to find a write-up for how to tackle the right side. Can anyone point me in the right direction...I am certain there is one, I just can't seem to find it.

2. What is the best option in terms of parts at this point? DT? OEM? etc?

3. Assuming the Toyota tech was correct (I think he was BSing me) and the left side is also cracked, what are the odds I can get Toyota to replace at their cost? I think it is downright $hitty that they never recalled this problem, and I would be even more ticked if a 25k part is already leaking again.

I feel like we need a full out campaign to get Toyota to replace these crap parts at their cost. What a joke.

NicB
 
If by left you are meaning driver's side that was replaced and the passenger side is leaking you can do that one yourself fairly easy. DT headers have had issues with cracking in the past, haven't heard completely if that's worked out but I replace mine with a new one from Toyota. Toyota parts direct had them fairly reasonable.

Here is a decent link

DT Header Install Quick Overview
 
This may be a dumb question, but how about welding and grinding the cracked manifolds? I'm not sure how that would affect thermal expansion and likelihood for future problems, but it seems like a viable option if the OEM units fail so easily.

You can do that, mine lasted 3 months before it cracked again. I would just do it once rather than twice.
 
You can do that, mine lasted 3 months before it cracked again. I would just do it once rather than twice.

Yea, I am not going to go the weld route. Looks like I can pick up an OEM manifold for the RH side for about $250 online. Does anyone know if I will need the bolts as well?

Also, in the DIY Placemotorsports posted above, it references "throwing away" the heat shield in step 6. Does that literally mean throw away? I have some sort of loose heat shield that I am going to try and find today anyway. Between the heat shield rattle and the ticking, I'm going insane and my ride sounds ghetto even though it isn't.

Is this the correct part number? Exhaust Manifold - Toyota (17104-50121) | Titus-Will

Thanks!
 
I'm in the same boat as @NicB, my driver side is ticking but goes away after it's warmed up. I'm planning on fixing it in the future with new bolts and gaskets. I think the throw away was meant for people installing aftermarket headers, not replacing a stock one with a oem one.
 
I think there's several of us on here who have welded up our stock manifolds. I have done both sides and have had no issues since. I just bought eight or so new studs(same ones for into the cylinder heads and exhaust manifold to y-pipe- I think) a few nuts, new exhaust manifold gaskets, and collector gaskets. I had no issues with any of the studs coming out of the cylinder heads as many have. Mine is originally a southwestern vehicle. That being said I did have to drill out a couple of studs on the flange to the y-pipes and run new threads in before installing again. This is to be expected with any half a$$ engineered penny pinching item. How thin of metal is used on the factory exhaust manifolds is almost astonishing and a no brainer as to why almost every early 4.7l Toyota produced had/has this issue.

It's really not that hard, driverside is really time consuming to take out and reinstall without removing other stuff.
 
This may be a dumb question, but how about welding and grinding the cracked manifolds? I'm not sure how that would affect thermal expansion and likelihood for future problems, but it seems like a viable option if the OEM units fail so easily.

You can do that, mine lasted 3 months before it cracked again. I would just do it once rather than twice.
I read a very interesting post on welding these, wish I could find it?

It talked about the need to heat weld of pipe & mounting plate to very high heat. This condition metal to expand at same rate, is my limited understand.

I had a Dealer installed replacement exhaust manifold on a 01 LX470 go bad (crack). Neither Slee nor I had seen or heard of this every happening before.

I came up with two possibilities for this:

1) Lexus Dealer use old stock or didn't actually do the job. Neither was like as they are consider a good shop & job was in 2007, all new replacement stock was supposed to be good at that time.

2) PO drove with very lite foot, that I'm sure of. Never running engine at a prolonged high RPM to creating high temperatures.

So question is; can we produce with prolonged high RPM (+4,500) driving, the kind of heat required to condition the metal as a welder does?

If the answer is yes, this could explain why some exhaust manifolds didn't fail.


Yea, I am not going to go the weld route. Looks like I can pick up an OEM manifold for the RH side for about $250 online. Does anyone know if I will need the bolts as well?

Also, in the DIY Placemotorsports posted above, it references "throwing away" the heat shield in step 6. Does that literally mean throw away? I have some sort of loose heat shield that I am going to try and find today anyway. Between the heat shield rattle and the ticking, I'm going insane and my ride sounds ghetto even though it isn't.

Is this the correct part number? Exhaust Manifold - Toyota (17104-50121) | Titus-Will

Thanks!
You'll soon know if you need new studs & nut, as they may snap during removal. I'd just count on replacing, if they snap on install it will be PITA to redo.
 
What are the negatives of having a cracked header? I have a cousin that may have one, but didn't want to ruffle his feathers and mention it. Is it a big deal?
 
What are the negatives of having a cracked header? I have a cousin that may have one, but didn't want to ruffle his feathers and mention it. Is it a big deal?

Noise is the main issue. If the leak is big enough you can get untreated exhaust into the passenger cabin. And if the leak is big enough it will trick the oxygen sensors into thinking the engine is running to lean, they will then rich the fuel mixture reducing MPG and fouling spark plugs sooner than later and possibly clogging the catylitic convtors.
 
For poops and giggles has anyone tried this stuff to fix their manifold leak?

FiberFix
 
Just picked up a new to me 100, just curios if this is the sound most experience with the manifold leak?


 
Yup, that is the sound. Stops ticking on my 2000 in under a minute, so I've never been too worried about it.
 
Thread revival and an informal introduction.

Just picked up my first LX470 this last Wednesday. Been handling some minor maintenance and now it's come time to do the manifold. My PS manifold has a leak. Where are you guys purchasing replacement parts. The link in this thread was a dead end, but I'm assuming it's "online Toyota parts." Any help is appreciated.

Thank you,

Luis Jr
 
Thread revival and an informal introduction.

Just picked up my first LX470 this last Wednesday. Been handling some minor maintenance and now it's come time to do the manifold. My PS manifold has a leak. Where are you guys purchasing replacement parts. The link in this thread was a dead end, but I'm assuming it's "online Toyota parts." Any help is appreciated.

Thank you,

Luis Jr


I got mine from Camelback Toyota- Camelback Toyota Parts - Genuine OEM Parts - Free Shipping

I think I was all-in under $300 for the DS manifold, new gasket, and new studs and nuts.
 
I've had this tick for over 2 years now, i have the tools and knowledge to replace it but i'm just too lazy, maybe one day when i'm bored i'll tackle the job. Looking at my rusted manifold bolts doesn't really excite me either.
 
I have a ticking noise, but I can only hear it when I have the windows down. I stopped by my mechanic to get his opinion, and he believes it is the exhaust manifold. We didn’t spend time trying to determine which side. I figured I’d just replace both anyway, since I have 197k miles (assuming they are original).

Is brand new the only option I should consider, if I want to replace them?

I’ve found a pair (driver and passenger side), from a wrecked car, but I don’t have physical access to them to visually inspect them myself. I’ve asked for photos and a guarantee they are not cracked. They are asking for $125 each which seems like a good price, if they actually are in good condition.

McGeorge Toyota has them for about $220 each, brand new.

They are also from a 2000 LC, so I’m not sure if they are compatible with a 2003 LC either.

What do you guys think? I’m considering doing this work myself. My goal is to learn while maintaining as much of my LC myself as possible. I would like to have this truck for many years to come.

My mechanic said he recently spent about 15 hours replacing the manifolds (@ $100 / hour) on another vehicle, because of having many issues getting all the bolts out. He also seemed somewhat reluctant to even take on the job.
 
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@Slashzero if they are from a 2000, they could possibly be cracked and cause ticking also. I believe the years affected are 2000-2003. DT Headers is your after market option. last I checked, they were about $900, and just as much to install. but you will get some performance gains?
 

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