Corrosion Protection for Exhaust Hangers

[JHZR2]

Hi,

I started hearing a jingle under my 91 318i at around 1900 RPM. Had a look, and the exhaust support for the cat converter was broken. The right resonance made it shake the right way to jungle metal on metal.

This isn't the first time that I've replaced this. The exhaust is, I guess, Stainless and is like new, but these hangers need to be replaced every couple years.

The issue is that it is metal on metal of the exhaust pipe, so though its about the lowest thing on the car and out in the air, heat could be an issue...

Any thoughts of how to better protect these? They only fail at the location where they are on the exhaust, the metal on the rest of the part is as thick as the new one, though surface corroded.

Also, any thoughts how to bond the two halves of the rubber mount? I bought the parts thinking the rubber was OK, and it wasn't when I took it apart. So I just need a week's long solution...

Thanks!

 

[spasm3]

Only thing i can think of is hit it with exhaust/ header paint before and after you install, not sure that will really help though. Wonder of you can use a muffler repair wrap, around the pipe before you install the bracket to prevent the metal to metal.

 

[CT8]

The heat speeds up the Rust. The hangers are mild steel.

 

[Bud_One]

Does plastidip make anything heat resistant ?

 

[ronbo]

CRC MARINE Corrosion Inhibitor, spray on new parts and will form a brown coating that will clear in a few days. Spray my parts a few days before installing.

Did it for some parts on my SUV in New York and still no rust after 3 years.

link: http://www.westmarine.com/buy/crc-marine--corrosion-inhibitor-10oz--279620

 

[JHZR2]

Originally Posted By: spasm3
Only thing i can think of is hit it with exhaust/ header paint before and after you install, not sure that will really help though. Wonder of you can use a muffler repair wrap, around the pipe before you install the bracket to prevent the metal to metal.


Good idea! I do have rock wool... Wonder if I can get some asbestos someplace

 

[JHZR2]

Originally Posted By: ronbo
CRC MARINE Corrosion Inhibitor, spray on new parts and will form a brown coating that will clear in a few days. Spray my parts a few days before installing.

link: http://www.westmarine.com/buy/crc-marine--corrosion-inhibitor-10oz--279620


Yeah I have that, but it will burn off the first time I cruise on the interstate...

 

[OVERKILL]

Get a local machine shop to clone them in aluminum or stainless?

 

[JHZR2]

I was thinking the exact same thing when impacting these off the car in 30 degree weather...

 

[OVERKILL]

THe ones on my M5 rotted off too. The replacements are the same material. I had a place cut me wheel spacers for the townie at a reasonable price, was thinking of getting them to clone in stainless for the next time around

The exhaust, like yours is mint. It is just the fasteners and hangers..... It is weird that they do this

 

[spasm3]

Perhaps buy this kit just for the pipe wrap. Spray pipe and hangers with the exhaust paint apply the wrap and hangers and spray again with paint. Worth a try for only $3.49.

http://www.oreillyauto.com/site/c/detail...4&ppt=C0022

http://www.permatex.com/products-2/produ...pair-kit-detail

 

[DuckRyder]

JET-HOT

 

[Nick1994]

Take it and get it powder-coated

 

[oldhp]

Paint spot on pipe and the hanger with hi-temp aluminum paint. Eastwood makes a great product.

Silver Hi-Temp Coating 11.75oz aerosol

Item #10396Z

 

[Olas]

I'd go with an inch of heat wrap to stop the metal to metal, and ditto n the stainless hangers

 

[HTSS_TR]

This is one of the thingies in a car that I don't worry about and have no idea how to prevent it from rusting out. Nothing under my cars has any severe rusty parts, very slight rusted parts are there especially for 21 years old LS400.

 

[Bandito440]

I think any protective paint would be rubbed off by the motion of the exhaust and damaged by heat and road grime.

So, two alternatives that I can think of.

1. Have the parts cloned in material to match the exhaust; stainless or aluminum.

2. Spray the existing parts with a coat of rust preventative every time you change the oil. That should extend their life anyhow. Krown, Fluid Film, WD-40 Specialist, etc.

 

[bullwinkle]

How about spraying the hangers with a couple coats of engine or high temperature paint?

 

[OVERKILL]

Originally Posted By: bullwinkle
How about spraying the hangers with a couple coats of engine or high temperature paint?


Might work. The issue on mine is they are right behind the cats, which may be the same case for the OP's. That means they get REALLY hot. The rest of my hangers (at the rear) look mint. It is just these two that catch the dead

 

[chrome]

Wonder how the ceramic coatings that people coat exhaust headers with will hold up in this application? Surely the headers will hit fairly high temperatures under high load conditions...