So I took the car apart this weekend to install my new exhaust. I ran into a strange, strange problem. I do not believe the exhaust has ever been touched, I am the second owner of the car.


I was able to get 3 nuts off between the two sides, the other 5 nuts presented me with a problem I have never experienced before in 20+ years of working on cars. The 3 nuts that came off fit the open end wrench perfectly tight like you expect.


The 5 remaining nuts were "off" regarding their size. 13mm open ends and box ends were significantly to big to the point where if I would have put any torque on the nuts, they would have quickly rounded. I tried 1/2" (it is a fraction smaller than 13mm) and that was also too big still to the point where I would have rounded them easily. I stepped down to 12mm and while the 6 point and open ends wouldn't fit on because it was to small, the 12 point probably could have been persuaded to go on.


I have never seen such a disparity in nut sizes....all of the nuts that were off size wise were the lower turbo to exhaust nuts.

I even tried 3 different brand open ends from craftsman to some off brand to snap on and they were all WAY to loose at both 13mm and 1/2".


Anyone else ever experienced this?? I figured the only thing that makes any sense is that with the heat cycling and the exposure to water from road spray etc, that the nuts changed some how.

 

Just did my exhaust this past weekend. It had been touched before and is a relatively low mileage car (<7k), but all the nuts were 1/2"...

Were the nuts corroded? It would explain why 1/2" was a bit loose...

 

They were corroded but not so much that I would expect a 1/2" to be so loose.

 

I replied on that other forum. Not much QC on the nuts IYAM.

 

Bump. I had the same problem with the lower and outer bolts on each side of the turbo. My car has only 16K on it, and it seemed like those bolts were just a bit corroded. The other ones were a standard 13mm, but the outer and lower bolt on each side was between a 1/2" and a 12mm. Neither size fit well, so I cut it off and pulled the studs out after I got the exhaust off.

Xander

 

I had the same problem with mine. Just keep soaking them and tap a smaller size wrench on. I had to use a vise grip on one it was so bad.
Good luck.

 

Major pain. Plus one on the soaking. You basically have to throw everything you can at it. I hope not but sometimes even a chisel. Email me or give me a call if I can help

 

Thanks for the input guys, I did actually PB blaster it about 3 full days spraying 3 times a day, and they did come out. After cutting the sides off the nut and chiseling off the ends, I was left with a damaged stud that I ran the die over it to clean up the treads and then 2 bolts on, and backed the inner one off and the stud came off easy.

X...

 

There is an inexpensive tool made for exactly for that purpose, it's called a nut extractor or damaged nut remover. A socket set of various sizes is only $20 or so. Spray the nut good and it should come right off with no drama, using a nut extractor.

 

I have the Irwin /vice grip ones, but I couldn't fit it on with the fat factory cats.

X...

 

Encountered this as well, that was when I used the $4 "nut *******"

 

I used the Irwin nut extractor. It worked well.

 

I bought that after seeing your posts, but mine kept slipping to the side and wouldn't cut the nut straight and parallel to the bolt. I guess I need more practice with it.

X...

 

Interesting problem, but anyone else ever had issues with o2 sensors? My shop had replaced several during the course of a couple of exhaust installs.

 

The first o2 I removed I broke, threads totally screwed. After that I have heated each o2-bung with a torch, and no issues so far (swapped exhaust several times).