Exhaust/welding shop

[sherv]

Hi guys,


Just wondering if you guys know a shop for welding, exhaust modifications that does good work. Wanting to take my cats out :D

Instead of making two threads, if you know a mechanic that's good and knows M's pretty well please let me know.

Thanks for your help!

Shervin

[Bruno]

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For ur 1st question any exhaust shop in sharjah can help u out.

For ur 2nd question it depends on the mechanical issues that u have.

[G37Sam]

Cat delete isn't exactly rocket science, I'd take it to Fox exhaust, they took good care of me when I went to resonate my pipes

[sherv]

thanks for your responses, bruno, I like to deal with one mechanic that is good with M engines, I don't want to keep going to different mechanics, at moment I just want to get it checked out as I have some small clicking noises.

And for the welding, of course taking out cat is not rocket science, but there's a night and day difference between a good welding job and a bad welding job.

[SSense]

at moment I just want to get it checked out as I have some small clicking noises.

Clicking noises are not always a small issue :nono:

[sherv]

yea of course, I think it's most likely vanos, or vanos shaft, or loose cam shafts.

[SSense]

Post some pics of your car sherv :)

[G37Sam]

And for the welding, of course taking out cat is not rocket science, but there's a night and day difference between a good welding job and a bad welding job.

True, but what's the worst that can happen from a bad welding job that's the thing?

You're not welding your engine head or a crank shaft, it's just a lame ole pipe in your exhaust system

[Ayham]

yea of course, I think it's most likely vanos, or vanos shaft, or loose cam shafts.

Camshafts don't get loose...

True, but what's the worst that can happen from a bad welding job that's the thing?

You're not welding your engine head or a crank shaft, it's just a lame ole pipe in your exhaust system

Whoa!

1) Exhaust leak ==> Messed up O2 sensor readings ===> Messed up MAF readings and AFR (Air/Fuel Ratio) ===> No power.

2) Most certainly damaging temperature sensor(s) and O2 sensors. Each at around AED800.

3) Moist/water induced internal rust ===> spreading into adjacent exhaust sections.

I'd take any welding job very seriously. And I'd check my resonators job site Sam. :)

[G37Sam]

Camshafts don't get loose...




Whoa!

1) Exhaust leak ==> Messed up O2 sensor readings ===> Messed up MAF readings and AFR (Air/Fuel Ratio) ===> No power.

2) Most certainly damaging temperature sensor(s) and O2 sensors. Each at around AED800.

3) Moist/water induced internal rust ===> spreading into adjacent exhaust sections.

I'd take any welding job very seriously. And I'd check my resonators job site Sam. :)

Hahaha man you're looking at the extreme of the extreme.

1) I don't know about the M5s but in my G, there are two O2 sensors on each side, one in the headers (which also measures EGT I believe) and one in the cats, the moment the one in the cats starts reading similar flow numbers to that in the headers (detects that the cat isn't working due to them being deleted basically) it will trip your Service Engine Soon light. A simple O2 bung can fix that.

2) How can the sensor be damaged from a leak in the exhaust pipe? Only way to damage it would be to physically drop it or damage the tip of the sensor I believe, please correct me if I'm wrong.

3) How can moist/rust be induced in a pipe who's temperature is in the hundreds of degrees? Unless that thing was soaked in water for a few days lol Even then, exhaust gasses will be forcing anything that gets in the way out.

The techs @ Fox exhaust know what they're doing, I've seen them work on a Cayenne Turbo while waiting to get my G on the lift and their work is quite professional and besides, I ordered my cat deletes (aka test pipes) from the US. I just didn't like the way they sounded which was I had resonators fitted into them. It sure isn't a bad idea to go to ADNOC oil change and give it a quick look from below :)

[G37Sam]

I wrote a review a while back when I had my pipes resonated, have a look and feel free to comment honeslty :)



What we did was cut around 10" length from the test pipes and weld custom resonators in. The resonators were basically uniformly perforated pipes with Rockwool wrapped around them.

That also meant that the O2 bung had to be moved down along the length of the test pipe since it had to be removed from the way. Here are pix of the resonator fabricated by them





Final product being let to cool off after all the welding work

[Ayham]

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My points come from long years of ownership and working on BMWs. Sensors damage and rust mitigation come from leaking humidity through less than perfect welding jobs. Can show you a current example whenever.

So, obviously, parking at night in such weather we have now will speed the process. And sensors can be damaged by the fine amount of seeping air through pores and seams. Proper companies examine their welds with X Ray, this is the scale of imperfection that can lead to the outcomes I mentioned earlier. I didn't say anything about any specific shop, my remarks are general :)

[Ayham]

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Great discussion bro

I'll go through ur procedure in the morning...

[Bruno]

didn't one of the M3 owners damage 2 o2 sensors and the temp sensor from water leak due to a crappy welding job?

[sherv]

everything is well said!! Where is fox located and their contact # please??

Any good recommendations for mechanic for the M's, this clicking is really starting to bother me now, want to get it checked out asap.