I have a 1973 350 and it has exhaust manifold leaks. How hard is it to change the gaskets and what dangers may I encounter in the process?
Also what does the leaks cause other than a loud pinging noise...performance and idle problems...?

 

Its a piece of cake if your bolts come out without any problems. Due to all the heat the studs and bolts are prone to snapping on their removal. If you can get past all of that, a simple loosening of the bolts to slide the exhaust manifold back enough to remove the old gasket and replace it should be problem free. If you have A/C the passenger side may pose as a small problem. Just spray WD-40 or some rust removing agent like PB-Blaster a week before or a day before depending on how much of a chance you'd like to take. The process isn't so bad unless you break the flange outlet like I did...a story behind that though. I'm a complete newbie at the mechanics of a car and removing the exhaust manifolds to replace the gaskets was my first project on the car. If I can do it anyone can. I did rip the stuffings out of the heat shield on the driver's side exhaust manifold as well. Just pray the bolts don't snap and you'll be leak free in know time. Also exhaust leaks have been known to create a lean problem. It got so bad my 79 would stutter and shake real bad between 5-15 mphs like it had a heck of a time pulling its own weight. It was worse when it was cold outside. Idle was bad, performance was going down the tubes, and bad gas mileage erupted. Another big problem could be fire. The exhaust is extremely hot and could burn spark plug wires or start a fire. I'd get it fixed as soon as possible. Good luck and if you have anymore problems I'm more than sure the expert Vette guys on this forum will come to your aid.

 

Really straightforward - like Phoenix mentions so long as the bolts are OK.

Even if you get them off, if you're not sure how old they are, don't take a chance and replace them. If they've been subjected to excessive heat from a manifold leak they are probably brittle and are going to give you problems, it's just a matter of time.

So, to be safe get a good set of new bolts, and don't forget to put a dab of anti-sieze on there so know you won't have another problem!

Good luck!

Also -- not sure what "pinging" sound you're referring to. Are you sure you may not have another issue?

 

Now back to reality. The car is a 73 with what is more than likely the original exhaust manifold gaskets on it. This car is almost 30 years old so lets get ready for the pain. The chance that you will snap a bolt off in the head is very good. If you have a source of heat I would get it ready as the hot wrench makes the removal process that much more likely to be successful. The guys are absolutly correct in the lubricant dept. If you could spray all the bolts everyday for a week prior to the day of removal would be a great Idea. and if you do go the heat way have a hose around that you can get to readily safety counts here. good luck :smash: :yesnod: :cool: :seeya

 

May the Corvette Gods be with you on this one. All advise above is great, but just be ready for lots of cussing. The heat shields can be a pain... just label everything and keep each side organized, for I haven't seen any good diagrams of how to reinstall. I am now in the process of pulling my heads, cause one son-of-a- beach exhaust stud broke off. If you have access to a torch, heat em, let cool a bit then squirt with penatrating oil. Heat em again, oil, cool. Doing this three or four times will help. The stud on drivers side was over torqued by BUBBA, and it snapped on me.... bummer...Good Luck!!