Technical Engine undertray

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Technical Engine undertray

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They keep the engine clean and have to be removed for any work under the engine. The chimney nuts corrode badly and seize the bolts. New nuts are easy to find on eBay and antiseize paste should keep them going ok.
 
They keep the engine clean

If you powertrain is prone to dropping the odd spot of oil, they help keep your driveway clean, too.

Oil can be difficult to get off concrete or block paving, and will permanently destroy asphalt.

An undertray is a lot cheaper than a new driveway.

The small additional effort at service time is, IMO, well worth it to have the benefits of an undertray. As Dave says, greasing the securing fixings will prevent corrosion and ensure it's easy to remove.

I had one on my Renault 5 (they came with the car when they were new), and it was still going strong when I sold it 13 years and 220,000 miles later. Dealers couldn't be bothered with them, and many got chucked away at the first service.
 
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a lot of cars have a large one front to back to help with the turbulence under the car


my 2011 has a small one around the NS suspension arm which wasn't on my 05 and 06


I would guess its designed around the air flow coming in through the grill and build up when stationary

be interesting to see which models, year, country, engine, fuel and aircon had them fitted as standard

how much lower is it than the exhaust. I can hit the exhaust quite easy as it is ?
 
i have caught it a few times on a stock 100hp, so it does tsit pretty low at its lowest point.

does a good job protecting stuff though. i have replaced the bolts with stainless steel to stop the rust demons!!!
 
On my Fiat Coupe I have one, it’s a standard item that comes with the car. Anyone who is in the know, it’s a nightmare to remove and reattach after an oil and filter carnage. Any one who is unfamiliar where the oil filter is on a Coupe should look it up :D A job that’s easy enough, but takes ages to do. :bang: Ah the joys
 
I've been quite used to dealing with similar undertrays on the VAG stuff I mess about with and although the 1.9 PD tdi engines have alloy sumps my old old VE engined Cordoba had a steel sump not unlike the one on the Panda. I ran that car out to 19 years old and the sump was just like new! also, as they claim, ancillaries, exhaust, (especially the flex joint) etc seemed to keep much cleaner and rust less quickly.

I'm going to have a look into these Panda Nut - didn't even know you could get one for the Panda, so thanks very much.
 
I took mine off the 100HP because one of the bolts sheared off. Ive just had another look, the bolts at the back (under subframe) need to be drilled out. I can get to it, but dont fancy hot drillings in my face.

Stainless bolts are ok, but use lots of anti seize because they will cause the carbon steel to rust and that can quickly cause trouble. If you have chimney bolts try to find stainless versions.

How about Dzus fasteners? Just a thought.
 
Yes indeed the bolts and attachments do rust and if not looked after can be a pain to remove. The way the Coupe undertray is designed, some use cable ties at the front of the tray.
Dzus fasteners might have their place but I'm not so sure how they might survive the salt and crud being thrown up on an under car application Dave? I've mostly seen them used for panel fixing like bonnets and inspection covers. I suspect the wee spring wire would corrode away? Fair bit of installation needed too?

As most of the family can't afford to buy new cars I spend my time trying to make older ones last. So corroded fixings are a constant challenge. I've not experimented too much with stainless fixings but do find stainless self tappers with a large diameter plastic/nylon washer work well on a lot of the VAG stuff because they are often screwed into a plastic female fitting so no interaction results. I've used cable ties too but they offend my sense of the "aesthetic"
 
Ps to my last post. I find speed nuts very useful where undertrays are fitted to body panels and I use them quite a lot:https://uk.rs-online.com/web/p/capt...3Yo61MiXnOdOn013pJBoCGGEQAvD_BwE&gclsrc=aw.ds Interestingly I haven't noticed much in the way of corrosion problems using them with stainless self tappers?

I have purchased these nuts and Allen bolts to match in stainless steel, I have yet to go under the Coupe to do the deed, the weather at the moment here is wet and windy...:mad:
 
I had a lot of stainless fasteners on the bike usually into aluminium** but some were into carbon steel. It was a great demonstration of the galvanic effect (aluminium and stainless are at opposite ends of the table) Aluminium oxide has at least 2x the volume of the base metal so an untreated bolt will quickly jam solid. Carbon steel does the same though not quite as fast. However, the clearance between threads is small so very little carp will seize it up. Stainless has poor shear strength so you can quickly run into nasty problems.

A really good anti seize paste is a must-have. I use Action Can CS-90. It's a stiff brown paste not at all like ordinary copper grease that can be brushed on. Use it all the way up and don't leave any bare patches.

** The bike side cases are aluminium sheet with stainless rivets. I put them away for the winter only to find (following Spring) the alloy had a white fuzz and minor pitting about 20mm radius around every rivet. The metal was clean but I had not sprayed it with a preservative like ACF-50. It was quite a job to clean them up.
 
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My brother recently bough a 2004 1.2 Dynamic. It's more basic than the later models (no aircon) and plain looking seats. I think an under tray is very unlikely to have been standard fit. You could make one from laminated sign board. Its a plastic board skinned with aluminium. It's not cheap but local council highways departments will have old signs made from the stuff and sports club (e.g Rugby) sponsors use it.

The rear bumper hangs down like a slow plough. A sheet under the rear axle would no doubt improve fuel consumption though I've not tried to fit anything to my car. It could be a nightmare.
 
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I think an under tray is very unlikely to have been standard fit. You could make one from laminated sign board. Its a plastic board skinned with aluminium. It's not cheap but local council highways departments will have old signs made from the stuff and sports club (e.g Rugby) sponsors use it.

The rear bumper hangs down like a slow plough. A sheet under the rear axle would no doubt improve fuel consumption though I've not tried to fit anything to my car. It could be a nightmare.

My youngest boy has his own sign writing business and he uses that boarding a lot on shop fronts, pretty tough stuff and seems to come in different quality grades? There's always off cuts lying around his workshop but he seems to use them on other smaller jobs. Very rare to see any in his scrap bin. Here's a video of him doing one of the customer loan cars for AVW our local Audi VAG specialist, the very same people who did Twinkle's cam belt the other day: https://www.youtube.com/watch?v=w61Sg4A6egI. I hope I'm not breaking any rules posting this link? If so please do tell and I'll not do it again. Wrapping and sign writing vehicles is his favourite thing, and he does a lot of the local tradesmens vans. Nice repeat business for him as trade vans don't last all that long so they seem to regularly replace them.
 
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