Will a Leaky Radiator Fail a MOT?
 

Trying to get a consensus on this before I proceed. My car has had a radiator leak for about a year now. Nothing significant, but I need to top it up every few weeks. The leak is coming from the very top right corner of the radiator where different materials appear to join.

Now, my mind has been on other things not car related for pretty much of the last year, so things like fixing problems isn't high on my agenda, if even on the agenda. The problem is that the car is due a MOT next month, I need to get it ready and the radiator is my one concern.

I have looked through the entire MOT inspection manual and can't find anything in relation to coolant leaks. Added to that is being in NI were the MOT centres are government run, and may play to a different tune.

I see three options. Take it the way it is and see what happens. Put something like Radweld into it, and lastly, fit a new radiator. Obviously the new radiator is what I'd like to do, as I want to give the entire car an overhaul, but I don't want to fit a new radiator and then a bit down the line have to move/remove it to work on other parts of the engine bay (and potentially damage it).

Radweld or something similar would be the next port of call, but I've read others caution the use of these products. I don't know if there is reason to be wary of them or just that some people think it will damage or clog other parts of the coolant system.

Have you tried these guys Sean - they are radiator repair specialists, so might be able to repair your existing one?

https://www.brownlowradiators.com/product/radiators-2/

+++

A leaky radiator is not an MoT fail. Its very common for radiators of that age to be weeping slightly. As long as its not dripping hot coolant on the tester's head it'll be fine.

Please don't put rad weld in it. It will clog up other parts of the cooling system. It settles at the lowest point of the system - in the D2's case, that's the coolant drain ports on the side of the block, and the heater cores.

A new radiator can be fitted without pulling the whole front end off, but its not the easiest job as you have to disconnect the power steering cooler which is messy. Usually the mounting bolts are seized so make sure new mounts are ordered at the same time. Often the snap nuts on the radiator shrouds are also seized so replace those too. I would advocate a genuine radiator or a Valeo if you can find one. The fitment on the Nissens is terrible.

Radiator 4D0121251R
Upper mounting 441121273L
Lower mounting 441121273K
Snap nut N 90419002
Screw N 90543801
Also have 2 x M6 nuts and washers and 2x M8 nuts on hand so you can cut the old ones off.

:ROFL:

And this is the very opposite place to where I need it to be! :mad:

Is this the thinner radiator in front of the main radiator? If so, another reason for why I'd like to do this myself, as the last time a mechanic worked on the car, they damaged the top line of fins. No leaks thankfully. I won't really care if it takes two days for me to do it, so long as I don't break anything else in the process.

Doesn't the transmission oil flow through a pipe within the radiator as well (or is that something else)? If so, I also need to avoid too much loss, and then be able to top it up afterwards.

BTW Thanks for the shopping list of parts MJ. Best to have these now than having to chase them down later.

The thin radiator in front of the main one is the AC condenser. That swings out of the way to the passenger side. The PS cooler is the wiggly pipe in front of that.

Good point about the trans cooler - I forgot about that. The lines do indeed attach to the radiator, on the opposite side to the water hoses. You lose about 200ml taking the lines off - well within tolerance of the gearbox, but if you have the kit its prudent to check the level and top off if you can. Always replace the two o-rings on the ends of the lines, and make sure when they go back in they seat properly and aren't pinched. Lube them up with a bit of ATF and they should go in ok.

Trans cooler line o-ring N 90666001

A dremel with a tiny cutting disc is useful to cut the rusty nuts off the radiator mounts.

Would you have a link to the kit necessary to do that? Since I also have the S8, it might be a wise investment, and a lot easier than trying to pour oil uphill.

Sealey VS70095

Its discontinued now which is odd. Plenty on ebay though.

The car has to be level to fill the gearbox and you need good access underneath it so it really needs to be on a lift, but you also need to get to VCDS to monitor the gearbox temperature so it can't be all the way up in the air (unless you have a USB extension maybe?). I tend to do it about 4" up in the air so I can still see the laptop but there's room to work underneath. I don't think you would be successful trying to do it on axle stands.

That's got me thinking now - it might be possible to fashion a contrivance which would replace the oil in the radiator before you put the top line back on, then you don't need to mess around underneath. Hmm...

That's exactly what I did when replacing my radiator +++.
I put the bottom trans line on, then used a 20ml syringe (just because it was the size I had in the first aid kit) with a 6" piece of vac hose on the end to add some fresh ATF in the top hole until that was full and put the top line on. No worries!

We just used an infrared gun type thermometer and monitored the trans sump temp.
We weren't too critical about the process though...

Excellent :D That's exactly what I came up with while I couldn't sleep last night! Glad to know it works +++

I am having to replace my radiator and note that it can be done without the front end being removed, and as I have small hands I think that may be an advantage? :):

Is there fluid loss from the PS cooler? This being the messy bit?

I cannot find a genuine (local ish) and not a Valeo either. Have seen a few MAHLE units online, would these be a good bet?

Also as I will be doing this on the drive is it best to put the car up on ramps for the underneath work? Will it affect the 'syringe' technique when refilling the ATF?