A visit to the Polo underworld
Posted: Sat Sep 30, 2017 4:52 pm
As hinted at toward the end of my thread about removing the headlights and other front lighting assemblies, I put my 2017 6C Match Edition 1.2 up on ramps this morning and got underneath, to suss things out as regards the exterior of floorpan.
The box-section hole I'd talked about turned out not to be a hole at all. Instead, it was a small, deep depression in an expansive plastic covering that ran along just about the entire length of the middle section of the car's underside, either side of the exhaust pipe, as it were. That said, the large cover had, here and there, quite a number of holes and slits in it.
The cover is functional, just that; a cover that protects wires, cables, and plastic tubings that pass underneath the vehicle, from roughly the front to the back. So the fact that the cover had all kinds of holes and purpose-made slits in it did not affect, as far as I could tell, the basic weathertightness of the floorpan or would have had any appreciable effect on roadnoise. The cover doesn't form part of what I'd term a 'box-section'. I could see that underneath the cover, the usual floorpan underseal had been used. Although I spotted some installed blanking grommets just inboard of the sills, at their ends, I couldn't see any obviously-missing grommets.
One thing that didn't look quite right to me, however, was that this large cover had two 'tongues' near to its forward end (situated just forward of the left-to-right steel crossbrace) and these tongues looked as though they were designed to tuck in to the underbelly of the tunnel. But they'd both been left out, drooping down a bit. It doesn't look quite right, but perhaps this has been intentional, to allow the maximum airflow toward, and waterflow away from, the floorpan. On the other hand, these tongues, which each measure about 15cm x 15cm, will act as water scoops in the event that the car is ever driven through deep water, eg. through a ford, or just along a flooded road. The plastic wasn't totally rigid and I wondered if it'd be possible for me to retrospectively tuck them in, but I could see that various intricate fasteners would need to be undone in order to flex the tongues sufficiently to do that. So I left them as they were.
With the car reversed on to the ramps, I could take a look at the rear section of the underside. There, it was not a pretty sight. It appeared that someone on the production line had started to apply a pinkish-brown underseal to the boot underside (essentially, the exterior of the wheel-well) but had abandoned it some way through, leaving most of it untreated. Furthermore, something had clearly gone wrong with the applicator, with the result that a diluted residue of the pinkish underseal had got sprayed (that's to say, mis-sprayed) over virtually the whole of the rear underside - so, over the exhaust boxes and pipes, over the rear axle/subframe, over exposed parts of plastic fuel lines, exposed brake lines, the coilsprings, the dampers, and so forth. It'd all dried on as thousands of powdery, pink spots.
Now, I didn't want to take any remote chance of this residual stuff having any detrimental effects on any of the paintwork of those aforementioned components, either in the medium term or long term, so I spent half an hour or so with a rag, cleaning it all off. It now looks much better. It'd gone all over the part of the bumper that tucks under the rear of the car too. Actually there, I found a small, broken, plastic fastener, whose function was probably to stop the bumper vibrating against the underside. I've had to fix that temporarily with a standard rubber grommet.
Turning my attention to the rearward parts of the sills, it was obvious that the sills had been wax-treated internally. Although a couple of the bigger holes in and around the sills had been stoppered with blanking grommets, there was still one hole, about 1cm diam, on both sides, that'd been left unstoppered. These two holes were probably where the tubes for the wax had been fed in, while the car was on the production line. Again, whether these were intentionally left open is impossible to say, but certainly if you were to drive the car through 6 inches or so of water, quite a lot of water would get into the sills. This all begs the question as to whether it's best for sills and box-sections to always be left vented, or whether they should be fully stoppered. On my old Golf, I made sure that all such holes were plugged, and that car's bodywork is still fine after some 23 years! If anyone's got any special thoughts on this, I'm all ears.
As regards those pinkish spots or splashes of what I presume to have been dilute wheel-well underseal, I'd noticed a couple of weeks ago when I was underneath the car emptying out some excess engine oil, that a good deal of the front subframe had acquired these spots. At the time, I couldn't figure out what they were. At one point, I presumed they were just mud splashes. But of course now I know.
It rather looks as though, in hopefully an isolated instance, the standard of production-line workmanship had slipped, and that my Polo kinda ended up as a less-desirable B grade. I've nonetheless managed to clean 85% of the 'splashwork' off. Come the Spring, I'll get underneath again and treat the bare areas, and the subframes in particular, to some good old waxoyl.
Whether the VW dealer who acquired and sold me the car knew about the state of the underside is unknown. I have to say that I've always been quite cynical about car dealers and their so-called pre-delivery checks. I just don't think they do them at all thoroughly enough; I think they probably just glance at a few things under the bonnet, ensure the washer fluid's topped up, kick the tyres, and that's about it. The dealer probably assumes that if there's anything amiss underneath the car, the customer's never going to bother to look there, in any event.
But there's obviously a lesson here, not to assume that everything on handover is, in fact, 100% okay. Alright, you might say that, in this particular case, the degradation was primarily aesthetic. Certainly, topside, everything looked immaculate. Nevertheless, finding out what the true state of your vehicle is, both top and bottom, could have some longterm implications in terms of safety and longevity. My adage has always been, "know your car".
The box-section hole I'd talked about turned out not to be a hole at all. Instead, it was a small, deep depression in an expansive plastic covering that ran along just about the entire length of the middle section of the car's underside, either side of the exhaust pipe, as it were. That said, the large cover had, here and there, quite a number of holes and slits in it.
The cover is functional, just that; a cover that protects wires, cables, and plastic tubings that pass underneath the vehicle, from roughly the front to the back. So the fact that the cover had all kinds of holes and purpose-made slits in it did not affect, as far as I could tell, the basic weathertightness of the floorpan or would have had any appreciable effect on roadnoise. The cover doesn't form part of what I'd term a 'box-section'. I could see that underneath the cover, the usual floorpan underseal had been used. Although I spotted some installed blanking grommets just inboard of the sills, at their ends, I couldn't see any obviously-missing grommets.
One thing that didn't look quite right to me, however, was that this large cover had two 'tongues' near to its forward end (situated just forward of the left-to-right steel crossbrace) and these tongues looked as though they were designed to tuck in to the underbelly of the tunnel. But they'd both been left out, drooping down a bit. It doesn't look quite right, but perhaps this has been intentional, to allow the maximum airflow toward, and waterflow away from, the floorpan. On the other hand, these tongues, which each measure about 15cm x 15cm, will act as water scoops in the event that the car is ever driven through deep water, eg. through a ford, or just along a flooded road. The plastic wasn't totally rigid and I wondered if it'd be possible for me to retrospectively tuck them in, but I could see that various intricate fasteners would need to be undone in order to flex the tongues sufficiently to do that. So I left them as they were.
With the car reversed on to the ramps, I could take a look at the rear section of the underside. There, it was not a pretty sight. It appeared that someone on the production line had started to apply a pinkish-brown underseal to the boot underside (essentially, the exterior of the wheel-well) but had abandoned it some way through, leaving most of it untreated. Furthermore, something had clearly gone wrong with the applicator, with the result that a diluted residue of the pinkish underseal had got sprayed (that's to say, mis-sprayed) over virtually the whole of the rear underside - so, over the exhaust boxes and pipes, over the rear axle/subframe, over exposed parts of plastic fuel lines, exposed brake lines, the coilsprings, the dampers, and so forth. It'd all dried on as thousands of powdery, pink spots.
Now, I didn't want to take any remote chance of this residual stuff having any detrimental effects on any of the paintwork of those aforementioned components, either in the medium term or long term, so I spent half an hour or so with a rag, cleaning it all off. It now looks much better. It'd gone all over the part of the bumper that tucks under the rear of the car too. Actually there, I found a small, broken, plastic fastener, whose function was probably to stop the bumper vibrating against the underside. I've had to fix that temporarily with a standard rubber grommet.
Turning my attention to the rearward parts of the sills, it was obvious that the sills had been wax-treated internally. Although a couple of the bigger holes in and around the sills had been stoppered with blanking grommets, there was still one hole, about 1cm diam, on both sides, that'd been left unstoppered. These two holes were probably where the tubes for the wax had been fed in, while the car was on the production line. Again, whether these were intentionally left open is impossible to say, but certainly if you were to drive the car through 6 inches or so of water, quite a lot of water would get into the sills. This all begs the question as to whether it's best for sills and box-sections to always be left vented, or whether they should be fully stoppered. On my old Golf, I made sure that all such holes were plugged, and that car's bodywork is still fine after some 23 years! If anyone's got any special thoughts on this, I'm all ears.
As regards those pinkish spots or splashes of what I presume to have been dilute wheel-well underseal, I'd noticed a couple of weeks ago when I was underneath the car emptying out some excess engine oil, that a good deal of the front subframe had acquired these spots. At the time, I couldn't figure out what they were. At one point, I presumed they were just mud splashes. But of course now I know.
It rather looks as though, in hopefully an isolated instance, the standard of production-line workmanship had slipped, and that my Polo kinda ended up as a less-desirable B grade. I've nonetheless managed to clean 85% of the 'splashwork' off. Come the Spring, I'll get underneath again and treat the bare areas, and the subframes in particular, to some good old waxoyl.
Whether the VW dealer who acquired and sold me the car knew about the state of the underside is unknown. I have to say that I've always been quite cynical about car dealers and their so-called pre-delivery checks. I just don't think they do them at all thoroughly enough; I think they probably just glance at a few things under the bonnet, ensure the washer fluid's topped up, kick the tyres, and that's about it. The dealer probably assumes that if there's anything amiss underneath the car, the customer's never going to bother to look there, in any event.
But there's obviously a lesson here, not to assume that everything on handover is, in fact, 100% okay. Alright, you might say that, in this particular case, the degradation was primarily aesthetic. Certainly, topside, everything looked immaculate. Nevertheless, finding out what the true state of your vehicle is, both top and bottom, could have some longterm implications in terms of safety and longevity. My adage has always been, "know your car".