Q Where can I source a replacement exhaust?
Living by the sea in West Sussex, I am well aware that high winds and salt spray can cause more than average corrosion on vehicles. I recently had to get my local garage to look at the exhaust system on my 2015 Sunlight based on a Fiat Ducato.
It looks like the muffler is made up of laminations, and the outer layer was coming away (and dragging on the ground). The garage was able to get underneath and remove the loose layer, but said that, as the exhaust wasn’t standard, we would have trouble finding a replacement if more corrosion forced us to get a new one.
I was surprised about it being a ‘speciality’ exhaust. I would assume there must be lots of older motorhomes that require replacement exhausts, so do you know of a motorhome exhaust supplier? Presumably, I should check out my local Fiat commercial vehicle garage.
Also, is there a type of bandage that I could fit around the exhaust that would prolong its lifespan?
The second question relates to overall corrosion. Can you recommend anti-corrosion sprays or pastes that I can apply under my ’van that will eliminate, or minimise, any rust from building up?
While applying anything you suggest, I will also take the opportunity of ensuring all loose wires are securely fixed as a way of eliminating any fox damage!
Bob Dargan A Let’s deal with the underbody protection first. Traditionally, the go-to product was Waxoyl, but I have been reading that Dinitrol is easier to apply and is better. I suspect these things are quite subjective.
I have always been concerned about sealing in things that would last longer if they were left in free air, to dry out. Corrosion is like an open wound and it will spread more quickly and penetrate deeper if the (often) moist metalwork is encased in something else.
On the whole, I would say that corrosion needs to be repaired, cut out, sanded back to bare metal and prepared and painted before covering the affected area with any other kind of sealant. The chemical treatments are really only any good at protecting and preventing. Not fixing.
If you have a body repairer nearby, I would recommend getting advice from the very person that you might have to ask to repair things later on!
The exhaust is a bit of a mystery. Your vehicle is converted
from a van and there would be very little point in the converter using any other exhaust system than standard, unless that is, they have needed to reroute the system to provide underfloor storage or tanks to be fitted.
The most common thing I saw when working on Fiat motorhomes was that some of the continental conversions (even those that were right-hand drive, had exhausts that exited on the wrong side of the vehicle. Maybe that is what the garage was thinking during the inspection?
Yours being a Euro 5 with a DPF, it should have the tailpipe coming out of the driver’s side; about 12 to 18 inches in front of the rear tyre. The tailpipe is clamped to the rear of the DPF. The DPF is pretty large and is suspended right of centre up to just under the driver’s door.
Replacing this with anything else other than standard will have been far too costly and difficult for the converter. I doubt very much that it did this. The next part is the downpipe from the engine, which contains a catalytic converter. There are only three parts to the system and there are pipes for sensors and the sensors themselves.
I did have one or two Euro 3 vans that arrived with an exhaust exiting from the passenger side. I never got to the bottom of how or why this happened at the factory, but I suspect the wrong parts turned up on the production line and they were fitted anyway. Left-hand drive vehicles have the exhaust exit this way, and I have seen European-built motorhomes with this arrangement.
Prior to Euro 5, the exhaust system was fairly straightforward and spare parts were available from a number of suppliers. The option of having a custom system made from stainless steel was also possible and would have been much more durable. It is not a cheap option, but if you are keeping motorhomes for a long time, it is worth it.
Where the outer skin has been removed from the exhaust, presumably the DPF, there may be some merit in getting the surface rubbed down and applying some very high temperature paint to it, but the DPF can get very hot indeed, sometimes 400˚C and not many paints can cope with that.
And your suggestion of ‘bandaging’ it? While the DPF is carrying out a regeneration, it is desirable to have insulation and the quicker it gets to the optimum temperature the better but the rest of the time it is better to be cooler. I don’t think that a jacket would be a good idea.
With all this in mind, I would suggest that you get in touch with the converter and ask whether it used the original exhaust system, or if it modified it. We would be far happier to know for sure, I think you would agree?
Nick Fisher