Exhaust manifold leak/tick
- Thread starter hamiltonj2w1
- Start date
fulltimervexplorer
New member
Im told if we do long tubes and delete the front cats we will have to run some type of spacer soif you dont install them there will alot wrong and the cel will be on.
I just recently got a 2005 v6 4th gen sr5 and on the test drive i noticed ticking under acceleration, Then on the drive home had the check engine light come on and I scanned it through the obd2 port and got a p2238 code which is a bank 1 o2 sensor. because of the code my vcs off and traction control off light is on. While having some other exhaust work done I asked the people at my local exhaust shop to look at it and they said I was leaking on both sides of the exhaust manifold. the previous owner had all of the exhaust parts replaced from the bank 1 cats to the resonator at the tailpipe. Does anyone know how to fix the leak and the p2238 code??
Auto Doctor
New member
Tundra manifolds on v8 4R
Hello all! New member to the forum but I've been using all this wonderful information to fix some 4Rs at my shop. Just bought a 7/10 rust mama for pretty cheap (2003 limited 4.7 4x4 grey in colour) and it has the dreaded tick from the manifolds. The flanges are all but dissolved and I'm 90% sure they wont be fixable. I've tried researching but to no avail. My question is has anyone put tundra manifolds on instead? Was able to look at the two engine bays side by side and they look identical aside from the attached cats. So if anyone has any input I would appreciate it! Thanks all
Hello all! New member to the forum but I've been using all this wonderful information to fix some 4Rs at my shop. Just bought a 7/10 rust mama for pretty cheap (2003 limited 4.7 4x4 grey in colour) and it has the dreaded tick from the manifolds. The flanges are all but dissolved and I'm 90% sure they wont be fixable. I've tried researching but to no avail. My question is has anyone put tundra manifolds on instead? Was able to look at the two engine bays side by side and they look identical aside from the attached cats. So if anyone has any input I would appreciate it! Thanks all
I've wondered this as well but my guess is the down tube / exit tubing is different and any modifications you'd have to make would end up causing more time/cost and therefore eat up any savings in buying the cheaper tundra manifolds.
Inv4drZm
Senior Member
Like mentioned above, Tundra manifolds/headers exit at a different position, and they use a 3 bolt pattern instead of our 2 bolts. A custom Y pipe will need fabricated, if the headers will even fit. The Tundra's steering rack is located behind the front axle so it has a way steeper steering shaft angle which means the Tundra headers could interfere with our steering shaft.
Auto Doctor
New member
Thanks for the responses guys. You are both correct with needing a custom exhaust. So with all this In mind I decided to see what I could do without replacing parts or costing too much. I was able to get through the fender wells and remove the heat shields to get a better look. 3 of the 8 I could see cracked, but the manifold gaskets looked in good shape. So I tried my luck smooshing a bunch of high temp exhaust paste between the tubes and the flanges. Let it sit for a hour or 2 and fired it up. No ticks! Dont know how permanent it will be but for a couple hours labor and a 10 dollar tube of shmuts, I'll do it 10 times! Hope this is helpful for someone and I dont get flamed too hard
Currently, Toyota only offers the 4Runner with a V6. But the 4th-gen 2003-2009 Toyota 4Runner also offered a V8. The 4th-gen Toyota 4Runner has had some notable issues, rusting frames being particularly egregious, but the later 2007-2009 models are just as off-road-capable as new 4Runners. YouTube team Throttle House called the 4th-gen 4Runner’s V8 one of Toyota’s most reliable engines—but is it really?
Why the 2003-2009 Toyota 4Runner V8 can be problematic
The 4th-gen 4Runner’s 4.7-liter V8 wasn’t a model-exclusive engine. According to Canadian Gearhead, the engine was also used in the Tundra, Land Cruiser, and Sequoia. And while it does a fairly sterling reputation, its one fault, as some Expedition Portal forum users put it, is cracking its exhaust manifold.
The issue, according to Canadian Gearhead and CarSpec, is with the 4.7-liter V8’s catalytic converters. Catalytic converters need to be warmed up properly in order to lower emissions. So, as Toyota 4Runner owner forum users explain, to help the V8 comply with emissions standards during cold starts, Toyota incorporated a secondary converter into the exhaust manifold.
However, according to Tundra World and Expedition Portal forum users, this design forced engineers to make the metal there thin. Thus, as the metal heats and cools, it expands and shrinks, eventually cracking. This causes a leak and catalytic converter failure, causing, as many forum users and CarComplaints reports have cited, a horrible sulfur smell.
How often does this happen?
Although this doesn’t happen to every single Toyota 4Runner with a V8, Consumer Reports claimed this was a fairly common problem. Canadian Gearhead even said that there are “two different types of Toyota 4.7s: the ones that already have cracked manifolds, and the ones that are about to have cracked manifolds.” One owner reporting to CR even went so far as to call it a defect.
CarComplaints notes that the issue was enough of a problem for Toyota to issue an official technical service bulletin. The Toyota 4Runner’s V8 was enough of a hassle that the automaker stopped offering it in the 5th-gen SUV. And none of the other trucks or SUVs that had the 4.7-liter V8 offer it in the US today.
Can the Toyota 4Runner’s V8 problems be fixed?
Part of the Toyota TSBs appears to have been, according to Toyota 4Runner owner forum users, simply replacing the cracked manifolds with OEM ones. However, while the parts did fit, they had the same design flaw. Eventually, they’d crack again. This is also the most expensive solution, as many Toyota 4Runners with V8s are out of warranty.
It is possible for a skilled mechanic to simply weld the crack shut. However, it appears that this is, at best, a temporary fix. The weld fixes the crack, but it doesn’t fix the problem with the metal itself.
There is another solution, though. It is possible to fit aftermarket exhaust manifolds/headers to the 4.7-liter V8. Commonly-recommended brands are Doug Thorley, Pacesetter, and Dorman. Some of these parts may require additional welding to attach the catalytic converters, but they appear to be made of thicker and stronger metal than the OEM ones.
However, these parts are not 50-state emissions-legal. Especially if you live in California, this solution may not be feasible. That being said, it does appear that Dorman, at least, offers CARB-compliant aftermarket Toyota 4Runner V8 exhaust manifolds.
One additional caveat about aftermarket exhaust manifolds: according to Expedition Portal owner forum users, Toyota modified the manifold design for the 2005 and 2006 model years. Make sure, if you’re going to install an aftermarket unit, that it will fit your engine.
Video for a cheap fix> https://youtu.be/96cpY2vb_n0
Why the 2003-2009 Toyota 4Runner V8 can be problematic
The 4th-gen 4Runner’s 4.7-liter V8 wasn’t a model-exclusive engine. According to Canadian Gearhead, the engine was also used in the Tundra, Land Cruiser, and Sequoia. And while it does a fairly sterling reputation, its one fault, as some Expedition Portal forum users put it, is cracking its exhaust manifold.
The issue, according to Canadian Gearhead and CarSpec, is with the 4.7-liter V8’s catalytic converters. Catalytic converters need to be warmed up properly in order to lower emissions. So, as Toyota 4Runner owner forum users explain, to help the V8 comply with emissions standards during cold starts, Toyota incorporated a secondary converter into the exhaust manifold.
However, according to Tundra World and Expedition Portal forum users, this design forced engineers to make the metal there thin. Thus, as the metal heats and cools, it expands and shrinks, eventually cracking. This causes a leak and catalytic converter failure, causing, as many forum users and CarComplaints reports have cited, a horrible sulfur smell.
How often does this happen?
Although this doesn’t happen to every single Toyota 4Runner with a V8, Consumer Reports claimed this was a fairly common problem. Canadian Gearhead even said that there are “two different types of Toyota 4.7s: the ones that already have cracked manifolds, and the ones that are about to have cracked manifolds.” One owner reporting to CR even went so far as to call it a defect.
CarComplaints notes that the issue was enough of a problem for Toyota to issue an official technical service bulletin. The Toyota 4Runner’s V8 was enough of a hassle that the automaker stopped offering it in the 5th-gen SUV. And none of the other trucks or SUVs that had the 4.7-liter V8 offer it in the US today.
Can the Toyota 4Runner’s V8 problems be fixed?
Part of the Toyota TSBs appears to have been, according to Toyota 4Runner owner forum users, simply replacing the cracked manifolds with OEM ones. However, while the parts did fit, they had the same design flaw. Eventually, they’d crack again. This is also the most expensive solution, as many Toyota 4Runners with V8s are out of warranty.
It is possible for a skilled mechanic to simply weld the crack shut. However, it appears that this is, at best, a temporary fix. The weld fixes the crack, but it doesn’t fix the problem with the metal itself.
There is another solution, though. It is possible to fit aftermarket exhaust manifolds/headers to the 4.7-liter V8. Commonly-recommended brands are Doug Thorley, Pacesetter, and Dorman. Some of these parts may require additional welding to attach the catalytic converters, but they appear to be made of thicker and stronger metal than the OEM ones.
However, these parts are not 50-state emissions-legal. Especially if you live in California, this solution may not be feasible. That being said, it does appear that Dorman, at least, offers CARB-compliant aftermarket Toyota 4Runner V8 exhaust manifolds.
One additional caveat about aftermarket exhaust manifolds: according to Expedition Portal owner forum users, Toyota modified the manifold design for the 2005 and 2006 model years. Make sure, if you’re going to install an aftermarket unit, that it will fit your engine.
Video for a cheap fix> https://youtu.be/96cpY2vb_n0
Latest Update on 4th Gen V8 Exhaust Manifold Leak Situation
Hey All,
I know this is an old thread, but I'm sure people are still dealing with the 4th Gen V8 exhaust manifold leak...and suddenly, I find myself dealing with it myself.
For the last 7 years, I've had a well maintained, three owner (including me) V8 Sport Edition that has given me almost no problems in the 90k miles I've driven it. The truck now has 216K on the clock. A friend of mine that wants to buy it took it to a well regarded local shop that diagnosed it with a manifold leak. I've not heard the tell-tale ticking noise, nor anything else, so was surprised by the diagnosis. Of course they wanted $3500 to replace the manifolds with new (an still defective) OEM parts, claiming that aftermarket headers are not available. Well having read the previous 17 pages of this (and other) thread, I know that's clearly not the case.
What's the latest "best solution" for this problem? I understand the metal is thin at the flange where the normally crack, but are they weldable? How many hours does it really take to R&R, knowing it's generally a PITA? Has anyone used muffler paste or furnace cement?
Mostly...should I even bother? OTOH this is a clean, rust free Colorado truck with 216K on it that looks badass, rides beautifully, burns literally no oil, passes CO emissions like new and everything works -that I would never sell if I didn't now need a PU. OTOH, the fix is a significant chunk of the value of the truck...a truck I am selling.
So the question is, has anyone actually experienced any engine damage because of these cracked manifolds? I understand significant manifold leaks can burn exhaust valves over time, but that experience varies by vehicle...is this really a problem for the V8 4Runner, or just an annoyance?
Hey All,
I know this is an old thread, but I'm sure people are still dealing with the 4th Gen V8 exhaust manifold leak...and suddenly, I find myself dealing with it myself.
For the last 7 years, I've had a well maintained, three owner (including me) V8 Sport Edition that has given me almost no problems in the 90k miles I've driven it. The truck now has 216K on the clock. A friend of mine that wants to buy it took it to a well regarded local shop that diagnosed it with a manifold leak. I've not heard the tell-tale ticking noise, nor anything else, so was surprised by the diagnosis. Of course they wanted $3500 to replace the manifolds with new (an still defective) OEM parts, claiming that aftermarket headers are not available. Well having read the previous 17 pages of this (and other) thread, I know that's clearly not the case.
What's the latest "best solution" for this problem? I understand the metal is thin at the flange where the normally crack, but are they weldable? How many hours does it really take to R&R, knowing it's generally a PITA? Has anyone used muffler paste or furnace cement?
Mostly...should I even bother? OTOH this is a clean, rust free Colorado truck with 216K on it that looks badass, rides beautifully, burns literally no oil, passes CO emissions like new and everything works -that I would never sell if I didn't now need a PU. OTOH, the fix is a significant chunk of the value of the truck...a truck I am selling.
So the question is, has anyone actually experienced any engine damage because of these cracked manifolds? I understand significant manifold leaks can burn exhaust valves over time, but that experience varies by vehicle...is this really a problem for the V8 4Runner, or just an annoyance?
