Protecting the Radiator

[mstv]

A6 Saloon 40TDI Quattro MHEV 2023, two months from new. Stone impact on radiator caused coolant leak. Recovery to dealership, radiator replacement, £1256 evaporated! Looking at options to protect the radiator. There's so much cabling/tubing on the back of the grill, it would be hard to fit plastic or aluminium mesh flush behind it. Considering whether I could install something between the grill and the radiators that would retain airflow but increase the chance of any debris being deflected.

Planning to remove plastic trim between grill and radiator (slam panel?) with the bonnet release in the middle of it and take a good look inside, to see what could be done. Thinking about plastic honeycomb mesh as opposed to anything metal, to act as a net in the space. 

Before I start tinkering, has anyone already solved for this please and could advise? 

 

[Steve Q]

You could buy mesh from Halfords or similar and attach it on the back of the current grill if that makes sense. 

[Optimus]

I had to take a look at my front bumper and work out how unlucky that was.

Obviously not a coincidence that the new facelift has a slightly different design on the lower grille which may be an indication other than styling this might be a common an occurrence? 🤔

Mesh also known as chicken wire is a cheap popular way of preventing this but it’s tacky and rusts within a few months. 
 

may be worth looking into changing the grille for an aftermarket one which is honey comb shaped straight box section grills because of the geometry of projectiles tend to do a poor job at deflecting or taking impact. Stones rarely go straight, as much as people think they do, because they tend to be not round and when moving they spin around and go diagonally. Honey comb grills work best because they tend to have an imperfect shape hole with 9/10 times take the impact of the projectile forcing it to deflect up/down, left/right as opposed to ‘straight’. 

[JMKC82]

Hi,

Are you overthinking things, or unfortunately just unlucky on this occassion?  If it has happened multiple times or going to happening multiple times, then go ahead and fit a radiator guard.  I have one on my motorbike because it is fully exposed, but it is a standard item on motorbikes.

I would just chalk this down as an unfortunate incident than ruining a lovely NEW car, that could void the warranty with any aftermarket products.

Sorry, just my thought.

Joe

[mstv]

Could well be overthinking it, but there are signs of other impacts on the (aircon?) radiator too which is mounted in front of the coolant radiator. I would like to feel that I'd reduced the risk somehow. Thinking so far that some tough honeycomb plastic fixed inside the grill just to cover the bottom (area in red in the picture below) could retain all the airflow necessary but also deflect a lot of stones. On some earlier models, I've found reference to audi specific clip on covers fitted to the lower radiators to avoid damage... 

With new radiator showing at bottom:

The hole that caused the leak (circled in red)

Area of high risk:

There are three radiators in total, top down view:

[mstv]

Some tough plastic honeycomb cut exactly to fit inside the grill section. Tempted to do the next section up, but felt this was a balance of reducing risk on the bottom section of the grill without introducing any significant reduction in airflow and without spoiling the look too much.

[Steve Q]

Definitely worth adding it for protection. 

[Optimus]

I’d be interested in knowing where you sourced components and how you installed it?

[mstv]

Hi,

thanks for asking. Write up below assumes your starting with very limited knowledge I have, so apologies if you know all of this, thought I'd write it up for anyone to follow.

Uniwersal [sic] Honeycomb Black Plastic vent car tuning Grill Mesh 40x100 cm https://www.amazon.co.uk/dp/B01M035FL1

Cut a strip that was exactly 5.5cm high from the bottom edge using a Dremel or very fine saw. (Gave me excuse to buy a Dremel for about £50). Bottom edge of the sheet is already smooth, top edge was inline with one particular straight edge of honeycomb which made it easy to guide the cutting wheel along, though important to go slowly as one wrong cut and you'd have to start again. I can't remember the width, I measured along the open edge of the grill with a piece of string and left some extra - and then trimmed it afterwards to fit.

You'll find that the bottom section of the grill has a ridge which will retain the bottom edge of the panel you make, and that at 5.5cm the top edge will side just high enough inside the gap to push against the back of the open section. Once inside, it was just a matter of getting cable ties into the right places at the very top and bottom of each vertical support on the grill, and fastening them tight inside the space behind the grill and snipping the ends of the tie (leave a tail, in case of the need to tighten further). Be very careful to make sure what you snip!

Getting access to fit the grill was quite simple. Remove the bonnet opening lever by depressing the small rectangular indent in the top. I put something big and soft under each bonnet strut so it would stop the bonnet closing if I tried to close it without fitting this lever back again!

Undo the 5 x TORX30 screws and washers holding the plastic slam panel in place, and then pull it gently upwards at the bottom side where it clips into the top of the grill. It pulls off quite easily. Then also remove the 2 x TORX 30 screws holding on the plastic air scoop on the left hand side. This gives you full access to the space between the radiators and the grill. Depending on spec there will be various cables to be careful of - the park distance sensors, the radar for the adaptive cruise control, the ambient temperature sensor, etc. Any of that lot getting unplugged or disturbed is a trip to the dealership.

For the first go, with my slightly longer piece of trim, I had a spare bit left over which is how I worked out that the 6cm I thought I'd measured was better at 5.5cm. At the passenger side there was a cable at the very end of that bottom grill section which I had to be careful of, so slide the panel in between the cable and the inside of the grill section.  There is a cable running all the way along the top of that lowest section which is why I couldn't cut a large piece and fit it flush behind the whole lot. However, I think this gave a better fit. You could do the upper section between PDC sensors and the number plate section of the grill, with another section of the mesh, but I chose not to at this stage.

Once the section was the right length, with about half a cm on either side to spare, it is just a case of cable tying on to the upright pieces in that section of the grill. Get someone to help spot when you're poking the cable tie out from inside so that you get exactly to the edge of the upright, then poke back in exactly on the other side of the upright but make sure you also go into another segment of the honeycomb on the way back in. Then, carefully reach both arms in to the space to pull tight and snip off the ends of the cable ties. 

The edges of the new panel are not secured, so I need to see if a motorway journey results in them being pushed backwards at all. That could be a problem so if it does happen, I might have to find a solution for it in case it fouls any cables. At the moment though hoping not to. Will test tomorrow!

[Steve Q]

On 8/13/2023 at 8:41 PM, mstv said:

Hi,

thanks for asking. Write up below assumes your starting with very limited knowledge I have, so apologies if you know all of this, thought I'd write it up for anyone to follow.

Uniwersal [sic] Honeycomb Black Plastic vent car tuning Grill Mesh 40x100 cm https://www.amazon.co.uk/dp/B01M035FL1

Cut a strip that was exactly 5.5cm high from the bottom edge using a Dremel or very fine saw. (Gave me excuse to buy a Dremel for about £50). Bottom edge of the sheet is already smooth, top edge was inline with one particular straight edge of honeycomb which made it easy to guide the cutting wheel along, though important to go slowly as one wrong cut and you'd have to start again. I can't remember the width, I measured along the open edge of the grill with a piece of string and left some extra - and then trimmed it afterwards to fit.

You'll find that the bottom section of the grill has a ridge which will retain the bottom edge of the panel you make, and that at 5.5cm the top edge will side just high enough inside the gap to push against the back of the open section. Once inside, it was just a matter of getting cable ties into the right places at the very top and bottom of each vertical support on the grill, and fastening them tight inside the space behind the grill and snipping the ends of the tie (leave a tail, in case of the need to tighten further). Be very careful to make sure what you snip!

Getting access to fit the grill was quite simple. Remove the bonnet opening lever by depressing the small rectangular indent in the top. I put something big and soft under each bonnet strut so it would stop the bonnet closing if I tried to close it without fitting this lever back again!

Undo the 5 x TORX30 screws and washers holding the plastic slam panel in place, and then pull it gently upwards at the bottom side where it clips into the top of the grill. It pulls off quite easily. Then also remove the 2 x TORX 30 screws holding on the plastic air scoop on the left hand side. This gives you full access to the space between the radiators and the grill. Depending on spec there will be various cables to be careful of - the park distance sensors, the radar for the adaptive cruise control, the ambient temperature sensor, etc. Any of that lot getting unplugged or disturbed is a trip to the dealership.

For the first go, with my slightly longer piece of trim, I had a spare bit left over which is how I worked out that the 6cm I thought I'd measured was better at 5.5cm. At the passenger side there was a cable at the very end of that bottom grill section which I had to be careful of, so slide the panel in between the cable and the inside of the grill section.  There is a cable running all the way along the top of that lowest section which is why I couldn't cut a large piece and fit it flush behind the whole lot. However, I think this gave a better fit. You could do the upper section between PDC sensors and the number plate section of the grill, with another section of the mesh, but I chose not to at this stage.

Once the section was the right length, with about half a cm on either side to spare, it is just a case of cable tying on to the upright pieces in that section of the grill. Get someone to help spot when you're poking the cable tie out from inside so that you get exactly to the edge of the upright, then poke back in exactly on the other side of the upright but make sure you also go into another segment of the honeycomb on the way back in. Then, carefully reach both arms in to the space to pull tight and snip off the ends of the cable ties. 

The edges of the new panel are not secured, so I need to see if a motorway journey results in them being pushed backwards at all. That could be a problem so if it does happen, I might have to find a solution for it in case it fouls any cables. At the moment though hoping not to. Will test tomorrow!

Great walk through 👍