Should I DIY manifold/downpipe gaskets or not

This is probably a dumb question to ask, but anyway...

I have an exhaust leak somewhere on the drivers side. I understand manifold and flange gasket leaks are pretty common. I have on-hand a set of gaskets and a pair of spare exhaust manifolds. I have a decent selection of Sears hand tools and a few air tools. No lift, but I have ramps. Given how hard it is to access things on this motor and 20 years of being welded together, should I even bother attempting this in my home garage or should I just take it to a shop? (I'm just envisioning a snapped stud and a towing event!)

As long as you treat the bolts to a overnight soaking with a quality rust removal spray you should be just find.Remember to be patient and apply pressure gently to break the bolts loose.If you have a impact gun with a good trigger that allows you to regulate the torque application,that will work too.I worked as a motorcycle mechanic way back in the 70s and your best tool was a hand impact that you
used with a hammer,those aluminum bolts would rust in place almost overnight.

PS:there is no such thing as a dumb question unless you DONT ask it!

Before you tear into you car, check the rear exhaust manifold bolts. They are notorious for breaking and when they do it sounds like an exhaust leak.

Tom

If the shop breaks a stud/bolt, it is going to get expensive fast. Like Tom said, check the rear bolts. If they are broken, that is your exhaust leak, and it is going to be a PITA to fix. The manifolds are known to crack as well. WD 40, CRC, or any equivalent on the bolts at the base where it goes into the block will help. Sometimes tightening them a tiny bit helps break the bolts free (without breaking the bolts). Start in the back, so if you do break one, you can still drive it to a shop. Use grade 8 bolts to reassemble the manifold to the head.

Ok, thanks for the suggestions. What about the bolts that hold the flanges together? Those look even nastier than the manifold ones. Any different techniques to try there?

The flange bolts are  usually easier to get off than the manifold bolts. You have more room to work.

You guys may find this amusing. While attempting to diagnose an unrelated issue, I fired up the car stone cold with the hood up, and I heard the leak. I put my hand back by the firewall on the driver's side where the back bolt is, and sure enough that's where it's coming from. Shut the car off and got a wrench on it, and it turned really easily. I figured it was probably snapped off- but I kept and it and it eventually bottomed out. Tightened it up and no more leak!

I guess worrying about bolts being on too tight wasn't the problem. Turns out they're too loose.

AWESOME!

Update- I got the exhaust manifolds off without too much difficulty. On the passenger side I ended up sawing off the EGR pipe and all the studs snapped off the flange. (one was already broken, hence the exhaust leak)

I've tried heating the studs with a propane torch, applying candle wax and trying to wrench them off with no success. I'm guessing that maybe the propane just isn't hot enough, or I'm just doing it wrong. Thankfully I can get a new manifold for less than $50, but the stupid AIR hose fitting/adapter thing simply will not budge. The pipe itself can be moved, but the fitting just wants to round itself off even when using a flare wrench.

Also, thankfully, with use of an impact wrench the driver's side manifold flange nuts came off with no issues.

Do I just need more heat to get the other manifold fixed?

Dunno if you need emissions where you live, but why not buy a pair of headers and get some better sound and power. Gets rid of all that AIR pump crap too.

Hah, yeah can't do that until the car turns 30 and they don't care about emissions anymore. I've got a stud puller on the way.

awesome write up, i have the same issue i am hoping it is just the donut gasket . but thanks for the insight.