Ristin

My father in law has a California emissions 2002 Civic with 330,000 miles. The exhaust manifold has a 4" crack in the manifold just to the drivers side of the sensor. Did some searching and have a couple questions regarding what I read.
Welding-Cheapest option, will it hold? Since the crack is right up front and easily accessible, do I need to remove the manifold to weld on it? Neighbor has a MIG welder but would welding cause any issues with the car electrical?

Replacement manifolds with cat- Rockauto has the manifold for about $370 legal in California. I was looking on Ebay and the see units for $180 but not legal in CA, however in the pictures the units look identical. Anyone know why? Is there an actual difference in the parts or are the Ebay sellers not recognized by C.A.R.B.?

scooty

Weld it. It will hold up fine. I would remove the manifold from the car to weld it. There might be other cracks you can't see yet.

Ristin

Thanks. My worry about trying to remove is causing more damage like a bolt breaking off in the head. My in-laws would be making a 3 hour drive to our house for a visit and we would attempt to fix at that time. If we cause more damage they would really be up a creek...
He's been driving it like this for a long time and the car seems to run OK, he puts 750 miles a week on it.
They are on a tight budget so I don't want to create a bigger hardship for them. Even though the car runs and drives good at 330,000 miles if he has to spend a bunch of money he would rather put the money towards a newer car.

BlueEM2

iTrader: (1)

Don't worry too much about a bolt breaking off in the head. When I removed my manifold I had to cut 2 of the studs. Once the manifold is out you simply weld a nut onto the broken section of the stud and remove it like a regular bolt. Sometimes there is enough thread left sticking out to just simply attach 2 nuts together and remove the stud that way.

foedoemoehoe

you could "weld" it with a mig welder but as far as I know they are all made of cast ,if it is the stock manifold. When you weld cast with a regular mig welder it may apear that it has been welded but it will break very quickly , you can weld cast but there is a prosses that requires cleaning, preheating and special types of welding rods , witch can be done by a shop or well eqquiped neighbour but probably would be more expensive than a new one..

If you did break a stud and wanted to weld a nut on to it and extract it that way it will work great but I will caution you that you could cause electrical problems but more likely cause arking between enternal parts witch could mess them up bad ( ive herd or valves and oil pumps being fused together)
soo just a word of caution make sure that the ground clamp is as close as possbible to the place you are welding and you will be fine with doing that.

HTH

BlueEM2

iTrader: (1)

Never thought of that... most of the time I just tighten two nuts on it and release it that way.

maxtierney

iTrader: (5)

Soak your nut/stud threads with PB Blaster. I usually do this a few times during the week, while the engine is warm (not hot, let it cool a bit), overnight. By the time I work on my car on Saturday, everything loosens up like butter. Never had any problems removing the nuts or bolts.

Ristin

Thanks for the replies. I looked closer when the engine was cool and discovered the crack runs around the back as well. The manifold will have to come off. I just hope it doesn't come off in two pieces.

scooty

Incorrect. Stock manifolds are made of stamped steel. Mig welds will hold up perfectly fine.

Ristin

Some pics. I ran my finger under the heat shield at the top and could feel the crack on the back side also.

Ristin

Pulled the manifold off Saturday. Took my Dremel with a small bit and V'ed out the crack then had my buddy mig weld it. Re-installed with the old gasket (forgot to order a new one) and bolted back together. Sounds good, no more exhaust tick; 600 miles so far and weld is holding. My father in law is very happy.

Sorry no pics. It was bloomin hot and I just wanted to get it done.

Thanks!

BTW, car has 337,000 miles and still going strong.