Diesel back box, exhaust.

firefrost · 12th August 2012, 19:18

corrosion has caused a hole to appear on the underside of the back box.
2005 saloon. The hole is on the rearmost panel of the box and the double skin can be seen through it. No exhaust leakage yet so I would like to carry out a repair if possible. What I would like to do is remove any further corroded material from this underside rear panel, expose the double skin and paint it with some preservative that can withstand exhaust temperatures.
Can someone suggest a suitable paint etc for this?
I would buy a new OE box but it seems they are no longer available and I don't want to go stainless yet. Many thanks. Firefrost.

sworks · 12th August 2012, 19:21

A non gen one is around the £80 mark and it goes all the way to the front. You also do away with the corroded rear strap which is about £30 on it's own. Only downside is that the box sits a little lower

firefrost · 12th August 2012, 19:43

Yes, I know replacements are available but the original was a well engineered unit and it may be that the double skin could last quite some time if protected. cheers.

wuzerk · 13th August 2012, 09:23

Paint for the exhaust manifolds is available so it should be suitable for the exhaust system? I believe it is rated up to 600 degrees C!

T16 · 13th August 2012, 09:29

The Diesel exhausts barely get warm, I wouldnt worry too much.

Arctic · 13th August 2012, 09:35

I am sure i read on here some time back that the rear part is available ?

The double skin helps protect the back box, my outer skin as been like this now for two years and its still going strong.

the middle piece is also very robust so if the back box can be obtained the pipe can be cut so back box can be fitted

Hengist · 13th August 2012, 12:40

The outer skin of our back box looked scabby for a couple of years but seemed OK - till I noticed that it had actually developed a couple of little holes on the top too, where you can't see it.

I noticed this after putting a plastic cup in the boot on that side, which proceeded to melt. The boot floor was geting cooked by a jet of exhaust gas, obviously.

So would be worth checking the top of the box too. I replaced ours with a stainless Powerflow - got the front flexi and decat done at the same time for £280 all told.

firefrost · 13th August 2012, 19:02

Wuzerk, That type of paint I think is mainly for appearance. I'm looking for something like underseal but able to tolerate temperature. I would like to paint the outside of the inner skin.
T16, I will check the inner skin temperature tomorrow after a run but I think it will get hot.
Arctic, The one you show is,I think, from 'Mr Exhaust' and is for a 1.8. If anyone knows where to get the original diesel back box could you please advise.
Hengist, I'm sure in my case it is only the bottom rearmost panel of the box that is corroded on the outer skin,but I will observe this with the engine running. The car has only done 33,000 miles and always garaged.
Thanks for all comments and any others welcome. firefrost.

Thanks to all for your comments, any others welcome,

12th August 2012, 19:18	#1
firefrost Avid contributor rover 75 cdti 54 auto Join Date: Jul 2008 Location: South Lanarkshire Posts: 103 Thanks: 1 Thanked 4 Times in 4 Posts	Diesel back box, exhaust. corrosion has caused a hole to appear on the underside of the back box. 2005 saloon. The hole is on the rearmost panel of the box and the double skin can be seen through it. No exhaust leakage yet so I would like to carry out a repair if possible. What I would like to do is remove any further corroded material from this underside rear panel, expose the double skin and paint it with some preservative that can withstand exhaust temperatures. Can someone suggest a suitable paint etc for this? I would buy a new OE box but it seems they are no longer available and I don't want to go stainless yet. Many thanks. Firefrost.

12th August 2012, 19:21	#2
sworks Been absent for a while… Rover 75 Tourer, Classic mini Cooper S, Abarth 595 competizione, MG TF and a Hyundai Tucson PHEV Join Date: Feb 2007 Location: Cumbria Posts: 13,065 Thanks: 1,033 Thanked 1,686 Times in 1,040 Posts	A non gen one is around the £80 mark and it goes all the way to the front. You also do away with the corroded rear strap which is about £30 on it's own. Only downside is that the box sits a little lower __________________ ................................................. 'Marmite' Possibly one of the most famous 75 tourers produced! left the production line as the last of only Three Rover 75 tourers produced in Trophy Yellow. 48 hours later Longbridge closed. The last sold ordered 75 Tourer. Paid for by the Phoenix Four and handed over by John Towers to the Warwickshire Northampton Air ambulance service as a Rapid Response vehicle

13th August 2012, 09:23	#4
wuzerk Passed Away Rover 75 CDT 03 auto Conn. SE Join Date: May 2009 Location: London Posts: 2,885 Thanks: 104 Thanked 254 Times in 204 Posts	Exhaust paint Paint for the exhaust manifolds is available so it should be suitable for the exhaust system? I believe it is rated up to 600 degrees C!

13th August 2012, 09:35	#6
Arctic Give to Learn Freelander 2 Join Date: Aug 2010 Location: West Midlands Posts: 18,717 Thanks: 1,155 Thanked 6,407 Times in 3,874 Posts	I am sure i read on here some time back that the rear part is available ? The double skin helps protect the back box, my outer skin as been like this now for two years and its still going strong. the middle piece is also very robust so if the back box can be obtained the pipe can be cut so back box can be fitted __________________ Arctic Givology Learn to Give Everything is Achievable ad altiora tendo. Check out our Nano meet dates http://www.midlandsnanomeets.co.uk/ http://www.the75andztclub.co.uk/index.php?thepage=howto " You do the work , we supply the expertise " Last edited by Arctic; 12th February 2018 at 09:38..

12th August 2012, 19:43	#3
firefrost Avid contributor rover 75 cdti 54 auto Join Date: Jul 2008 Location: South Lanarkshire Posts: 103 Thanks: 1 Thanked 4 Times in 4 Posts	Yes, I know replacements are available but the original was a well engineered unit and it may be that the double skin could last quite some time if protected. cheers.

13th August 2012, 09:29	#5
T16 I really should get out more....... ZT CDTi 135, ZT260SE Join Date: Feb 2011 Location: Dundee Posts: 2,877 Thanks: 10 Thanked 331 Times in 213 Posts	The Diesel exhausts barely get warm, I wouldnt worry too much.

13th August 2012, 12:40	#7
Hengist Avid contributor MG ZT CDTi Join Date: Mar 2008 Location: New Deer Posts: 225 Thanks: 0 Thanked 20 Times in 2 Posts	The outer skin of our back box looked scabby for a couple of years but seemed OK - till I noticed that it had actually developed a couple of little holes on the top too, where you can't see it. I noticed this after putting a plastic cup in the boot on that side, which proceeded to melt. The boot floor was geting cooked by a jet of exhaust gas, obviously. So would be worth checking the top of the box too. I replaced ours with a stainless Powerflow - got the front flexi and decat done at the same time for £280 all told.

13th August 2012, 19:02	#8
firefrost Avid contributor rover 75 cdti 54 auto Join Date: Jul 2008 Location: South Lanarkshire Posts: 103 Thanks: 1 Thanked 4 Times in 4 Posts	Wuzerk, That type of paint I think is mainly for appearance. I'm looking for something like underseal but able to tolerate temperature. I would like to paint the outside of the inner skin. T16, I will check the inner skin temperature tomorrow after a run but I think it will get hot. Arctic, The one you show is,I think, from 'Mr Exhaust' and is for a 1.8. If anyone knows where to get the original diesel back box could you please advise. Hengist, I'm sure in my case it is only the bottom rearmost panel of the box that is corroded on the outer skin,but I will observe this with the engine running. The car has only done 33,000 miles and always garaged. Thanks for all comments and any others welcome. firefrost. Thanks to all for your comments, any others welcome,