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Discussion Starter #1
Replacing my undertray soon and new fixings can someone advise are the fixings pressed in. Thanx
 

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By "new fixings" do you mean the bolts or the captive nuts?
 

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Yep, the fixings along the front edge are all Torx socket M6 bolts into captive nuts, the two on the side are M6 bolts into plastic nuts on the little side covers that form part of the wheel arch lining, the rear two are M6 bolts into captive nuts in the subframe.

I lost the two rear fixings so dropped a bolt down through the subframe held with a locking nut, then offered up the aluminium undertray with a penny washer and fixing nut. The ally undertray doesn't have the side fixings.

Good luck

Pub
 

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The fixings are Rivnuts - a collapsible threaded tube with a collar, that installs like a Pop rivet. Getting old ones out requires drilling or cutting away the outside collar, then pushing the remains through and out of the hole.

New ones are inserted into the hole and crushed into position using a special tool. £15 tools that resemble Pop rivet guns aren't really up to it. http://www.ebay.co.uk/itm/Rivnut-Ri...it-car-rivet-nut-special-insert-/380904779400 are good.

You want M6 Rivnuts with (IIRC) an OD of 10mm. Zinc plated steel are better than alloy, which tend to slacken off with time and rotate uselessly when you try and undo the seized bolt. Getting those out is then absolutely no fun, so the previous owner resorted to trashing the undertray by ripping it off.

Moral: Alway use Copaslip on stainless undertray bolts. And the Polish copy undertrays are pretty good, same material and quality as OE. They do lack the quilted soundproofing of the originals, but since that just soaks up water and is a great source of rust and sagging, that's no bad thing.
 

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Discussion Starter #5
Undertray

Thanks much clearer now it's the sub frame ones that I've lost ordered all the fixings from flee bay. AA guy did a temp with locking wire.
 

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Bin it. Not needed.
I'm not getting mine replaced either on my theory that not having one will help with the engine bay temps on my V6 with the original cats in the manifolds.

It gets massively hot in there and I worry about the ecu and head gasket getting too hot as it is. I can only come to the conclusion that having a plastic/metal tray underneath the engine will not help it in cooling down after a long run compared to leaving it open.

I'm probably wrong no doubt but there you go!
 

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I'm probably wrong no doubt but there you go!
Heat does tend to go up, so probably!

It may help, but I would't run mine without an undertray. It keeps so much muck & rubbish away from the engine. Sump may run hotter though.
 

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Heat does tend to go up, so probably!

It may help, but I would't run mine without an undertray. It keeps so much muck & rubbish away from the engine. Sump may run hotter though.
See, told u !

I also leave the bonnet up for a bit when I pull up after a long drive, that and pulling out of junctions at a steady pace just in case the diff explodes when on full lock!

God this forum has made me paranoid :biglaugh:
 
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I just got bored of putting it back. I'm currently without the engine cover, top turbo cowling and the panel that covers the obd port. Locking wheel nuts have gone in the bin too. Don't think I will be entering this months detailing comp.
 

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I like to hear the scrapey-scrape noises as I pass over each of the 15,000 road humps LB Ealing installed to ruin every single non-bus-route road. Frankly they could have saved billions by just leaving them as muddy cart tracks, because it seems most people have gone and bought ridiculous 3Litre 4x4's just to take their kids to school at more than 3mph.
 

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I like to hear the scrapey-scrape noises as I pass over each of the 15,000 road humps LB Ealing installed to ruin every single non-bus-route road.
I like knowing it's there keeping my oil cooler unions in their preferred moist/humid conditions... Combine that with the heat cycling, and they rust through double quick ;)
 

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I like to hear the scrapey-scrape noises as I pass over each of the 15,000 road humps LB Ealing installed to ruin every single non-bus-route road. Frankly they could have saved billions by just leaving them as muddy cart tracks, because it seems most people have gone and bought ridiculous 3Litre 4x4's just to take their kids to school at more than 3mph.

Same here ... prefer to know when I do hear a scraping sound it is my alloy undertray and not my aluminium sump!

It has saved my sump from two potential failures :censored:: one a kerb that was deeper than I thought (in the dark, exiting MK Bowl car park - ie the field across the road) and a large delivery trolley caster wheel (sitting in the road again in the dark). It was easier to knock out the dents in the tray than replacing the sump ... probably twice!


I don't find my TS overheats because of it .. it does keep it a lot cleaner though.
 
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