Exhaust leak

[JimMadsen]

Greetings all, I have an exhaust leak from what appears to be the pipe behind (on the muffler side) of the Cat. How much work am I looking at to replace it? I am thinking it is bolt on at the cat, bolt on at the muffler and hangers keeping it in place. So it should be pretty straight forward. I do not have too much $ to sink into it at this point or I would replace the entire pipe and cat. I may replace the muffler at this time as well, not sure on that one.

 

So a couple questions, I found this one:

http://www.amazon.com/AP-Exhaust-Products-68386-Pipe/dp/B000CHHJ3M/ref=au_pf_ss_2?ie=UTF8&Make=Chevrolet|47&Model=Lumina|465&Year=1998|1998&carId=002&n=15684181&s=automotive

 

But the description only has this:

This product fits your 1998 Chevrolet Lumina

Engine: 3.1L V6 Gas OHV Distributorless Naturally Aspirated SFI Electronic FI MFI

Trim: Base

Fitment Notes: Rear Exhaust Pipe, SINGLE EXH, IF WELD ASSY, REPL ALL REQD PARTS

 

Here is the manufacturers site:

http://www.apexhaust.com/index.php/products/filter/pipe/C7

 

They appear to be US based so it should be decent quality and not chinese crap. A note on amazon, I have bought several various parts on amazon, from water pump to door handles. I have not had any problems with them, which is more than I can say with the brick and mortar stores around me.

 

Should I just go ahead and replace the pipe, or would the quick fixes with a sheet of aluminum and a hacksaw work as well.

 

Thanks for the help

[Schurkey]

Is the pipe perforated by rust, or is the leak at a joint?

 

I would have expected the pipe to be welded to the muffler. replacing just the pipe becomes trickier when it's a welded assembly. if you can't weld, you'll need a reducer or a band-clamp.

 

Consider a complete Treasure-yard exhaust from manifold to tailpipe.

[JimMadsen]

it appears to be rust. I have priced out a muffler and the cat back I believe is what the pipe is called for $110 for both. Add in the other parts such as hangers if needed, gaskets and such, I should be able to do it all for around 150. The welding if needed should be ok, I have a stick welder at work and while I have never welded before, I can learn or ask someone at work to weld it for me.

 

I can call my junkyard to see what it would run, but the only difference would be in the price. I would still have to do all of the actual work. So unless it really is a tresure for 50 bucks or so, might as well buy new and not have to worry about it.

[JimMadsen]

So I went ahead and did it, let me give a quick rundown on the replacement. I spent maybe 150 total for the parts and took me maybe 30 minutes of actual work.

 

I replaced everything from cat back including the hangers (not the posts on the car though)

 

Parts list:

resonator pipe (ap exhaust 68386), muffler (ap exhaust 700246), 4 rectangular hangers (ap exhaust 8202) and 2 circle ones (ap exhaust 8166), 2" clamp, exhaust sealant, gasket for resonator to cat. Got the last one at napa and it was the wrong size.

 

Tools used:

Liquid Wrench (penetrating oil), 5/8 deep socket, breaker bar, screwdriver, hanger removal tool (http://www.amazon.com/Lisle-38350-Exhaust-Removal-Pliers/dp/B0012S9A5U/ref=sr_1_1?ie=UTF8&qid=1366582999&sr=8-1&keywords=exhaust+hanger+tool) cheaper at rockauto... jack, jack stands.

 

Other items used: gloves, new pair of jeans.

 

The day before, I jacked the rear end up and placed the jackstands, I then heavily coated the bolts on the resonator to cat with the liquid wrench. Couple hours later, I added some more than again the next morning. Their are only 4 bolts to remove to replace the entire thing. The lower two bolts loosened without a problem using the breaker bar but the upper 2 were more difficult because of the angle. The lower bolts were left in, just very loose. The pipe is cut at the bottom so it can be lifted off these using them like pegs. I used the screwdriver to scrape some rust off around the bolt heads and sprayed them again.

 

After an hour, went back out and was able to remove the upper bolts. After that, I removed the hangers from the pipe and muffler and pulled the whole thing out. I had a golf ball sized hole in the pipe causing my problems. The hanger removal tool was bought on a whim when I got the hangers at rockauto. After all, no project should be done without buying a new tool. The ends of the prongs that the holders are attached to are heavily flaired to keep it in place, but they slipped right off using the tool. Took maybe 10 seconds each.

 

I then slid the new pipe into place and hooked it onto the lower bolts. I then hung it with one hanger at the muffler end to keep it in place. I have not yet put the muffler on. When I went to put the gasket in place that I got from napa, it was the wrong size. Just a tab bit too large. Well when I took the old one off, I saw that there was no gasket but rather red goop so I figured why not and used the exhaust sealant around the diameter of the connection. Tightened the bolts back up and the on to the back for the muffler.

 

Put the clamp on the pipe so you just have to slide it into place. The muffler tube fits over the pipe. I put the sealant inside the muffler pipe and on the outside of the resonator pipe. Slide the two together and hook the muffler hangers up. I found it easier to put the hangers on the new parts first then onto the pegs on the car. Tighten down the clamp and make sure all of the hangers are in place. After that I checked for leaks by starting the car and placing my gloved hand very briefly over the exhaust pipe and had my helper look at the joints to see if any exhaust is seen or smelled.

 

Then while picking up the jack to put it away, I spit my pants thus needing the new jeans.

 

Just a quick note, both the service manual (got a full set on ebay for $15) and the old muffler had a clamp. No welding at all.

Edited April 21, 2013 by JimMadsen