BMW E39 540i sport, cracked bumper (fixable?)

[The Stiglet]

(I've just put this in the General BMW forum but this is probably the better area - can you help please?)

Hi Guys,

I don't understand what's going on. I took my car to a BMW dealer in London about 6 weeks ago to get them to replace a parking sensor in the rear bumper (was a bumper off job as the sensor was body coloured) but when I went to pick up my car I noticed the rear bumper was cracked right underneath the number plate. It looked as though it was a stress fracture caused by them having problems getting the bumper off - there was no damage that showed abrasion or impact and I categorically did not drive in there with the bumper in that state. To cut a long story short, they admitted they had some problems getting the bumper off but the damage must have occurred in the past and been patched over. (I still am not sure about this). The manager didn't want all the fuss of me kicking up st with any further letters and emails and kindly offered to have it fixed, not replaced, at their bodywork department free of charge.

All good and the results were superb - perfect in fact. I was chuffed.

However, just used the car today to pick up something at work and as soon as I walked round the back after parking in the office car park, I did the 'look over the shoulder' and noticed the bloody crack was back!!!! It was not there when I had left home 15 minutes before and I know this for certain because I had opened the boot and couldn't have missed it.

My question is, what's going on?! Did they do a bad repair? Again, there is no sign of damage from another vehicle. What should I do about getting it fixed and how much ££ should it cost? It certainly looks rubbish and will give me hell in resale if I try to sell. I paid top dollar in October last year for it and don't want to take that sort of hit because of a cracked bumper. VERY annoying.

Thanks in advance.
Stiggy

Original crack (fixed by BMW):






Cracks today (different but same starting point):

[Anatol]

Repairing a split usually requires it being welded, usually with reinforcement - either with mesh or staples melted into the plastic, fibre-reinforced backing or filler, or there are some 2k adhesives that you use at the split, and through drill holes either side to 'suture'.

If the weld isn't strong enough, or wasn't done, then the panel flexes too much at the damage point, and the filler cracks and the repair fails. And looks just like your photos.

Have you taken it back and asked the repairers for their opinion?

[The Stiglet]

Anatol said:

Repairing a split usually requires it being welded, usually with reinforcement - either with mesh or staples melted into the plastic, fibre-reinforced backing or filler, or there are some 2k adhesives that you use at the split, and through drill holes either side to 'suture'.

If the weld isn't strong enough, or wasn't done, then the panel flexes too much at the damage point, and the filler cracks and the repair fails. And looks just like your photos.

Have you taken it back and asked the repairers for their opinion?

Thanks Anatol, appreciate the feedback. I haven't taken it back yet because they aren't open at the weekend but will make sure I get it over there next week. I read on the BMW website that approved bodyshops supply a 2 year warranty on parts fixed - I wonder if this applies to work on my bumper?

[Vette]

If they have any self respect, they should repair it under warranty. Looks like they need training! Any competent SMART repairer would have been able to produce a flawless repair.

Cheers
David
SMART Repairer - Cornwall

[dentmanwarren]

The first picture shows that the crack is new not an old one opened up, if it had been patched up before it would have been filled and there wouldn't be any fresh black plastic showing as is the case in that picture.

I suspect they were to lazy to remove the bumper completely and separate it from the carrier, they've probably tried to get at the sensor by stretching the bumper cover out of the way and consequently have caused it to split.

Tell them you'd like the bumper cover replaced not patched, it can be welded, stapled, glued or splinted and then filled but because it starts at the edge it's always going to be a weak spot and unless they can assure you it won't open up again you're going to be going back again and again to have it repatched at their expense, it's more economical for them in the long term to just replace the cover.

I see also some damage to the paintwork on the panel above that doesn't look like it was there in the first picture, possibly mini grinder marks or it's been caught with sanding paper while repairing the bumper.

Edited by dentmanwarren on Sunday 22 May 21:55