The cast iron exhaust manifold it a fairly reliable part that doesn’t break often, but when it does you can often repair it yourself. A crack in the manifold will cause excess noise and leak smelly exhaust fumes since the leaked fumes haven’t gone through the catalytic converter located after the manifold.
Cracking in the cast iron can occur from repeated heating and cooling of the metal from normal use of the pickup. A weak point in the casting can develop into a crack over time. If you know how to weld, you can repair it yourself very inexpensively or purchase a replacement.
Exhaust manifolds are not particularly expensive. Today we checked online and found several:
- Autoparts Warehouse lists one for $34.98
- Car Stuff lists one for $98.49 (you can see it pays to show around)
- Parts Train lists one for $39.96
Repairing the manifold yourself is fairly straight forward. You’ll need a socket wrench, sockets, breaker bar, grinder, cutting wheel and a welder. Start by removing the re-circulation tube and EGR valve. Then remove the manifold bolts, the manifold and the manifold gasket. Clean up around the crack with a grinder to find the extent of the crack. Now cut out the crack using your rotary cutter and fill in the cut using your welder. Grind off the excess welding material and you can re-install the manifold. Be sure to replace your gasket with a new one. Most gaskets are in the $6 – $12 range.
This video illustrates how the crack in the cast iron was cut out and then the cut was filled in using silver solder:
Repairing the manifold yourself costs about $12 for a new gasket and perhaps $2 for welding material. This compares with $35 -$100 (plus gasket costs) to buy a replacement. So if you have a couple hours available and know how to weld, doing it yourself can save you a lot of money.
Good luck with your repair!