Exhaust Leak from manifold

[sarsman45]

My girlfriends 07 Corolla LE has seems to have an exhaust leak from the manifold (smells when you turn on the fan when you start the car) and you can totally feel/smell the exhaust from behind the engine when you open the bonnet.

Questions:

1) How hard is it to pinpoint the source of the leak from either the manifold itself or the manifold gasket?

2) How hard is it to take the manifold off? Does it entail a lift and drop of the exhaust pipe to get to it?

3) Would it be easier to take it to a shop to get it done? I'm all for DIY, but some things would better be done by someone who knows what's what.




Service History on car: Unknown. She got it second hand, her dad does the oil, had a new ECU implant when it died on her, and I changed the tranny fluid (never had a change for 120,000 miles and came up black as night).

[invader]

The manifold flange gasket (donut) is probably burnt out. You can upgrade to a Fel-Pro # 61106. It has a solid soft metal core where it usually wears out. You can reach down and feel any leak around it if you check when starting the car cold, as it gets hot there very quickly... It's replaced by unbolting the downpipe at the manifold outlet from under the car with ratchet and extension. Rock Auto also has replacement bolts (2) and springs (2) for much less than dealership.

http://www.rockauto.com/catalog/x,ca...,parttype,5836



On this borrowed shaowq's photo, you can see one of the manifold flange bolt and spring where a strip of the firewall's insulating material was ripped during installation of his header, then burnt on the hot flange...

[sarsman45]

Originally Posted by invader

The manifold flange gasket (dunut) is probably burnt out. You can upgrade to a Fel-Pro # 61106. It has a solid soft metal core where it usually wears out. You can reach down and feel any leak around it if you check when starting the car cold, as it gets hot there very quickly... It's replaced by unbolting the downpipe at the manifold outlet from under the car with ratchet and extension. Rock Auto also has replacement bolts (2) and springs (2) for much less than dealership.

http://www.rockauto.com/catalog/x,ca...,parttype,5836



On this borrowed shaowq's photo, you can see one of the manifold flange bolt and spring where a strip of the firewall's insulating material was ripped during installation of his header, then burnt on the hot flange...

I see a TRD STRUT BAR!!!

I'll check when I get another set of hands so I dont burn myself. It's the Converter/Pipe Gasket according to the manual right? And if I do disconnect the manifold to the pipe, (1) would it be easy to get to the gasket without taking off the pipe or header and (2) do I need to change the springs and bolts with it?

[sarsman45]

Pinpointed it. Exhaust was coming from the manifold engine area. Hopefully a blown gasket. I'm guessing I need to take off the heat shield and take off the manifold entirely to reach the gasket itself?

And do I need to get new bolts/springs for the flange connection also?

[invader]

Manifold to engine head gasket is steel. Maybe you just need to tighten any loose manifold mount nuts. I think the heat shield has to be removed for access. There is also a supporting nut to remove under the manifold, if you remove manifold.
Only the 2 flange bolts have to be removed to replace the converter/pipe gasket (donut). I recommend replacing those 2 bolts. Springs should still be good. Rock Auto has the Fel Pro gasket as well. Try just tightening the nuts first, and see if it's the manifold that's leaking from a failed weld or crack.

[Josh.Chaos]

Thats exactly where mine was leaking too. luckily mine was under warranty so it was a free replacement. That area is pretty easy to access. I undid mine to put on my new exhaust pieces. All I used was a jack and some jack stands... The bolts are a pita though. Mine were pretty hard to get off. I made sure the exhaust was cold and then used some anti-sieze on it... anyway, good luck...

[sarsman45]

Ack! Looks like someone's been under the hood before I have. Some of the manifold bolts have been stripped so badly, they're almost round. Guess I need to head to the dealership (needed to anyways to verify the TSB notice for the stupid ECM)

[sarsman45]

So I went to the dealership and they said the manifold was cracked. How credible is this? I trust the dealership to know what they are doing, but i know that they also need to make some money. ~a $700 job.

Also, is it hard to get stripped bolts off? If I can get the nuts out, I can do a lil DIY

[invader]

Manifold could possibly be cracked. Easier to determine with heat shield off, but should still be obvious by feel and sound when engine is running. A bolt extractor tool may be needed to remove damaged flange bolts... I can sell you my original exhaust manifold if you need one. There's about 20000 miles on it.

[sarsman45]

Got the manifold and seals/gaskets replaced yesterday. Worked wonders with fuel and power. BUT...


Exhaust is leaking from the engine bay again. I'm suspecting the cat. is blocked (actually banking on it). With the mileage on it (124,000), should I consider it a loss since the cat is like 800 to replace or get someone to cut it off and replace with 3rd party?

[AlanLe]

I have a cat for the Corolla (sawzalled off) and exhaust manifold if you want to throw me a few bucks and shipping. If you dont live somewhere where there are emissions you could always just get a straight pipe welded in its place for cheap.

[sarsman45]

Naw its all good. Dealer didnt install a seal right so leaked. Thanks though!