Hi,

I've had a few problems with my engine undertray coming loose, been fixed up a couple of times. This latest time was a bit more serious. The side bits, reading around other threads, appears they might be the splash guards or something...the bits that attach directly to the chassis. Well one of these had come loose too. My mechanic fixed it back up with a temporay repair. However he told us that the fixings to the chassis have been badly damaged...and from what he says sounds like he means on the chassis side.

I was wondering if anyone else might be able to confirm or deny the potential fatal nature of this damage? Our mechanic seemed to suggest that he didn't think it was worth spending much on a repair as it wouldn't last and the car should be replaced. I can think of two instances which may have caused damage, both within the last 6 months. The first was a sad moment when a deer ran out in front of me, and although I slowed a lot, I still clipped it. The only damage I found was the headlight washer cover was missing and a small crack to the inside of the grill area. The instance was when I hit a massive pot hole in the dark. It damaged my alloy on the inside rim (tyre was fine, but my boss tells me used to happen a lot when he worked for Subaru Rally team). Both these things happened to the front left, the same side upon which the undertay has come loose.

At 143,000 miles and several repairs recently, this is beginning to feel a bit like a money pit.

Thanks

Might not be much help but my m8's a mechanic looking after taxis, all he does is drill a few holes in the undertray and uses cable ties to keep them on. In over 6 years of doing this he hasn't had a undertray come loose after his bodge err repair lol.

I wouldn't worry about it, unless you regularly travel at speeds in excess of 110mph. I do and find it makes the front end more stabble but if you don't then just remove the lot but when fitted it also may give you more mpg.

All mine have come off and no issues here

I really wouldn't worry about an undertray mate, every single Volkswagen group car with these on tends to the lose them at the first sign of a scrape.

If you really really want to keep it then do what Raf's said, make some holes and cable tie it up where you can. I really wouldn't worry as i say.

I gave up replacing the screws and clips holding the front/central deflector on. The things either just came loose and fell out, or corroded so badly that they just crumbled away. I now use small zip ties through the existing mounting holes to hold it on. Much more secure and reliable.

I had to replace a smashed side engine splash guard before too, the ones you're talking about. It shattered after driving through a snow drift, and ended up rubbing on the driveshaft. The things that hold them up are just two small coarsely threaded studs that protrude from the underside of the chassis legs, and you push these sort of star washers over them to hold the guard up. You'd be hard pushed to damage those studs, as they are well hidden behind other things (drivers side is behind the boost pipe, passenger side is next to the gearbox end). Unless they have corroded badly. More likely is that the guards are so badly damaged that they can no longer be properly secured.

The guards are there to reduce noise, improve aerodynamics, protect the engine compartment, control air flow through the engine compartment etc. I'm sure you will be able to replace the guards and get them fixed back on properly, if not then try a new mechanic! As Si says, you can even run with no guards and it's not the end of the day. Definitely no reason to give up on the car!

Driving around Wiltshire at night is like being on safari though! I've slaughtered a staggering number of critters on the 'shires roads over the years. Been through a couple of badgers, which were explosive, and my Volvo ate a few pheasants. The Skoda's lipped bumper seems good at taking the heads off rabbits actually....

The side pieces are held on by a screw or bolt at the rear, they slot into the metal bar at the bottom of the lock carrier at the front and there are two push on washers that grip studs in the chassis.

If the studs have lost their thread, the washers that hold up the side piece no longer grip. A good bodge is to put the original washer on the stud. Then put an ordinary washer below that and squeeze it with a pair of molegrips until it deforms and bites into the stud.

If it's the one on the driver's side, then it needs to be done, as it can touch the v-belt if loose. It also provides splash protection for the v-belt.

When the side pieces are secure, the undertray will be secure too. If necessary, use a few more u-nuts.

Rip them off and run without them, been running without mine for three years with no problems after the snow ripped off the engine one and wrecked the side one's.

The undertray on the diesels is different to the vrs, it covers a lot more of the underside of car, presumably for soundproofing in part.

As rbaldwin pointed out the side piece on the drivers side protects the aux belt.

Thanks for the reply.

It's not the undertray i am worried about (yes it is the diesel), its the potential damage to the chassis that i am a little concerned about. don't know what is, but wondered what might have caused it and how serious it might be or become. I've also got the Emissions light coming on intermittantly, which i've read about elsewhere on this site and realise might never actually go away!!. I'm doing about 25K a year on A roads mostly (fun driving ina great car!!), and what with the poor condition of most of those roads (what has happened to that roundabout in Marlborough and why do they do nothing about it!!) avoiding lumps and bumps is not easy if I need to look after the car a bit more, and I do have to accept that it won't last forever...not with my milleage.

Thanks anyway!

TB

The screws and clips are quite cheap from dealer . I replaced all my clips on MK4 Golf for less than a £5 ( some years back).The side panels are held on by large "star" washers which again should be quite cheap . The panels and tray do keep most of the muck and rain out of the engine compartment. It all depends on how long you intend to keep your car. I "waxoled" the undertray clips on our new Octavia within the first few days of ownership to stop them corroding.

I've got a 2004 diesel octavia and the undertray has cracked so it makes a really impressive rattle as you drive along. I can get hold of a new undertray relatively cheaply but can't find out anything about the fitting. Is this something that needs a ramp / pit to fit or is it a D.I.Y. job? I can get to the fixings at the front of the undertray relatively easily but if there are any at the back I would have no chance of reaching them.  

You'll need to get under the car as the fixings stretch back to the sump area. Definitely a diy job as long as you can get under the car safely, like ramps or axle stands. You can get the fitting kits on ebay for about £8 I recommend renewing whatever clips and torx screws you can (including side trays) as they do suffer under there. May as well while you're there.

Thank-you very much. I'll see if I can get hold of the bits now

A follow up question! Now I've actually got the car up on some ramps (and having already got the under tray panel of course!) I find it's actually one of the side panels that has torn. These seem to go much further up into the engine bay and without taking everything apart I can't find out how they are fitted in place. Are these also D.I.Y. replacable or is that a garage job?

Diy replaceable

Mounted to the chassis legs iirc with nuts

Relatively straight forward to replace just need to jack it way up

Yeah you should see 2 threaded studs pointing down, push the tray up onto them, you use these disc things from the fitting kit (can't remember the name for them) or a large washer with a nut would probably do it.

Thank-you very much again! Back to the ordering - I should have just got the whole package in the first place!