Subframe Corrosion

Hi all.

First proper look at new toy today. Remove silly plastic under engine cover --- oh dear, oh dear ! Why do they fit this wet retaining, s**t, c**p piece of tat ?????????

Passenger side, just ahead of lower arm front bush bracket; ominous bulging on bottom of subframe. Out with the needle scaler; rapid revealing of rusted through subframe --- hole about the size of a £2 (half crown in proper money) piece, right the way through both bottom layers of the frame. Trapped damp and grime has obviously wreaked the inevitable consequence. Feel through the hole and it's smooth and good on the vertical surfaces.

So, if in the interests of originality you persevere with this Heath Robinson bottom cover, make absolutely sure you have removed it and checked for trapped damp, mud etc. The other part of the equation to me, is why, having produced a truly great vehicle in most respects (and virtually unique in the case of the estate), you then go and compromise bits of it --- front subframe, rear 'axle', fuel tank support, spare wheel carrier, by using the cheapest, most badly prepared junk paint you can find ???????????

To be fair, I'm sure it's not just Citroen, but that doesn't make it any less frustrating. Sad thing is, I bet it's just the same on the C6 somewhere. Some accountant will have worked out that they can save a Franc or two by easing back on the spec and hey presto ---- rust. So, if we're not getting washed away tomorrow, it's out with the welding kit. The good news is that the tyre wear looks absolutely even (pretty much better than any of my previous XMs), so clearly no key dimensions have altered.

Mike.

Hi all.

Further prepping has revealed further nasties. If I manage to upload it, please feel free to sympathise with photo --- then make sure you catch your own before it gets to this !
For reference, this shot is after removal of the reinforcing plate that is spot welded in this location. I think the fact it is spotted on is also part of the issue; if it once rots through, then moisture gets between the two layers and goes to work. An unpleasant giveaway is if the bottom plate is bellied out anywhere --- a sure sign of rust between the two.

Mike.

This post has been edited by onthecut on June 20, 2007 10:40 am

Oooh Mike, that's fairly bad.

Reinforces the time I spend underneath mine with corrosion sprayer in hand at every opportunity.

Oh dear, your engine obviously doesn't leak enough oil!

Peter.N.

Hi all.

B****y Sod's Law to a tee. Everything else on the new toy seems A1. Low (relatively) warranted miles, everything working, sheaf of bills showing replaced belt tensioners, belts etc. etc. If only just one garage could have been forgetful and left this bottom cover off. Instead of being out with smug grin, stuck upside down with facefuls of crud. Grrrrrrrrrrrrrrr.
Should add incidentally, since last owner was on the forum and may still be, I'm absolutely not moaning about the buy. This is a genuinely unseeable fault and the cover clearly hasn't been off in some time. I'm quite delighted with the other 99.9% of the car.

Mike.

Oh dear Mike I have a funny feeling I've seen something like that rather close to home as I removed the cover from mine recently (it was falling off actually ). Will investigate further tomorrow.

Hi Mike,

I have the ominous bulge on mine too at exactly the location you describe. I replaced my rads last week and when the old ones were out I took the opportunity to attack every exposed part of rust metal at the front of the car with a rotary wire brush on my angle grinder (superb tool). I hit the bit you're talking about and knocked off a lot of rust. I thought I'd got through to something solid and covered it in Waxoyl. You've now got me thinking. I can see it back on the ramps at the weekend for a nosey.

cheers

noz

Hi all.

Maybe instead of the alternative models sections, we should have a depressed, or therapy section ??
Noz, Demag -- I hope you don't find the same. Obviously there is a lot of chance with this -- the other side of the frame in the same spot is A1, as is the frame on my hatch. With the benefit of hindsight, I would suggest you consider drilling test holes in the areas you suspect; a 2 or 3mm hole should easily suffice. If it's a false alarm, you'll go through two layers of clean steel; if you've got a problem, you'll see the red / brown layer inbetween. Again, with hindsight, if you wind up having to remove the bottom plate, as I did, I would look at picking out the spotwelds and taking them out with a spotweld cutter. I did mine the butchers way, with a cold chisel, which is both hard work and distorts the remaining surface.
Don't forget there's a shedload of pipes running up the backside of this frame -- could make for a very interesting welding experience and very prolonged job if you do!
Hope you're both lucky.

Mike.

Hi All

I was going to keep the pair of sub frames from the scrap 2.5 with the intention of clean up/repair then rust proof and work through all the cars doing a component swap while SORN. I had only looked at the rear sub frame so far and was surprised how good it was. The engine and a little bit of chassis is still stood on the front one but the bits that show (rad area) seem pretty rusty.
From Mikes experience it seems it will become an important issue for long term preservation. Are Mk1's suffering similar problems with rust subframes and was it only 2.5's that got the moisture trapping "cardboard" undertray.

Regards

XMexc

The box section above the rear suspension and the one behind it is showing signs of rust on both of mine, but only at present around edge of the pre formed holes, not serious yet, but I have given the inside of both of them a good soaking with oil as a preventative measure and its seeping nicely out of the seams. The front of the green one is sound, probably due to the abundance of oil and LHM leaking onto it, but the red one has a new, dry engine, so in view of what has been said I think I had better have a look.

Peter.N.

Sorry to confirm mine looks much like yours Mike, only on the one side and I haven't knocked it through yet. So its still intact (ish)

JEEEESUS and I cut a BLOODY good subframe up to get an engine out WITHOUT a hoist!!!


OUCH!!!

Regards
citroenxm

Hi Citroenxm.

I'll pretend I didn't see that !!!!!!!!!!!

Mike.

Onthecut!

Tell me about it!! I Never thought for a moment a subframe would rot like that!! I'll keep the next one I Get, well actually, I know were theres a 24v S1 subframe that I need to collect if the bare unit is any good??

Regards
citroenxm