Car takes a leak - Now with pictures!

51 plate 1.9 TDI 110 SE Toledo, ASV engine (I know, not a Leon, but close enough and there's more people in this section)

Got a puddle under the offside front corner of the car that isn't drying out and wasn't there the last time I drove it, on Friday. Coolant header tank is empty. Looking down the front of the engine bay I can see the undertray is wet, but there are no obvious leaks I can see - but of course I can't see much, it's dark and there's a lot of bits in the way. Ran the engine briefly, starts on second try, runs ok, no warning lights. Small drip from the undertray, which is worn and cracked on that side.

Obviously I've got a coolant leak, but where? No evidence of leaks in the top hose or at the thermostat housing. What I can see of the bottom hose looks dry too, but I can't see where it joins the radiator.

Of course it'll have to go up on axle stands at the weekend so I can get the undertray off and have a proper look, but I have no spare time until then and I'm worried about what I might find. I hope its the bottom hose, which won't be a big problem. Might be the radiator, which will be more painful. Anybody had this happen to them, or care to hazard a guess about what's most likely?

I'm also concerned that the header tank is empty but there's no warning light on the dash, so the level sensor is not indicating. Perhaps it needs the engine to be running for a few minutes before it will ping. I'm pretty certain this has just happpened and that I haven't been driving with no coolant in the car, but it is a bit worrying nevertheless.

Radiator removal Mk.2 Toledo/Mk.1 Leon

Ah well, at least it isn't raining. Undertray off, no leaking hoses. Drat.

Coolant warning did sound as I moved the car to a better spot for working on. At least it is working, and it gives me confidence that I haven't been driving round for hours with no coolant.

Bumper off - more fun than it should have been. The lovely plastic button retainers need levering with two flat-bladed screwdrivers if you don't have the special tool, and who outside a service center will.

There are five Torx screws that have to be taken out from each wheelarch liner, not four. These are T25, but the four Torx screws behind the black bump strips and the towing eye cover and its mate are T30. Why? 13mm bolts were taken off , but didn't need to be: the Torx screws are the only ones holding the bumper on.

Getting the bumper past the headlights requires a delicate touch of leverage with a plastic spatula to prise the bumper out just far enough to slip past the headlight. Nobody tells you that in the Golf manual (probably different for Golfs) or in the guides on here. I sense a rewrite coming up.

Bumper crossmember off next, more 13mm bolts and two nuts. Which are rusted and need penetrating oil.

Now I can see the radiator corner behind the a/c condenser, and its wet. Looks like it has simply sprung a leak. I didn't think that happened with modern components. Anyone had it happen to them? No damage marks, and its difficult to see how any road debris could get to it. Pictures to follow.

Now I need to work out how to get the radiator out without disturbing the a/c condensor. Seat seems to use a special tool to slide the whole carrier assembly out by a couple of inches or so. I don't have them, but I can get some long bolts or studding. What size, though? I'm guessing M10, but its a wild guess.

Hopefully with the whole front crossmember carrying the radiator and headlights slid out I can get to the mountings to dismount the radiator without disturbing anything else.

Anyone who's taken a radiator off got any helpful hints? And anyone know a good radiator repair service in North Kent - or should I take it back to my favourite VAG-independent, The Motorist Center in Hersden?

Brief update, pictures will follow - although I seem to be talking to myself mostly.

The leak is only slight, enough to cause a puddle after a few days. After chatting to my engineer friend ( about getting studding to work as a slider for the front frame) he recommended a sealant called K-Seal, which claims to fix small leaks in coolant systems, including head gaskets, and to work only at the leak, not gumming up pumps and thermostats (like Radweld or Bar's Leaks has a tendency to do). Safe to leave in the coolant and stays active if you get a new leak.

Big claims. Still, I'm taking a small risk (of gumming up the works) for a big gain (not dropping the radiator out). So I've tried it, and so far it has done the trick, stopping the leak. I'd only lost about 2 litres of coolant. However, time will tell, and I'll keep my eye on the coolant level and the temperature gauge to catch any leaks or gumming up.

Took the opportunity of having the front bits off to take a few photos, which I'll put up in a day or so. They may help with some of the questions I've seen on here recently, such as where are the horns, what does the bonnet lock look like, what does the side-mounted intercooler look like, where's the MAP sensor, the outside temperature sensor, and so on

Taking off the undertray showed me another reason why you should keep it, or replace it if it gets lost or damaged. The underside of the engine and engine bay was clean as a whistle, the bolts, fill and drain plugs and electrical connectors clean and free of corrosion and of course no impact damage. That's enough for me to want to keep it on there.

One big surprise was that I've got an oil temperature-and-level sensor in the sump! So there are pics of that in place too.

The studding? We found that the bolt thread was M8 coarse, fairly common thread, and a metre of studding and some nuts was less than three quid. To recap, the intention is to make two long bolts (maybe with sleeving over the studding) to screw into the lower chassis mounting holes for the front frame, to allow what SEAT calls the lock carrier (i.e. the front crossmember/frame that holds the radiator and a/c condenser, and the bonnet lock) to be slid forwards after all the other bolts have been removed, letting you get at the fans and fan shroud from the back to remove them, and the radiator mounts to hopefully slip the rad out without having to degas the a/c. This is apparently SEAT workshop practice.

Taking the front bumper off - Toledo Mk.2

Sounds of desert wind - a vulture flaps slowly away from a cactus in the background - tumbleweed rolls across the field of view. Pull back to reveal - some idiot working on his car?



There are six plastic buttons holding the top of the bumper moulding to the bonnet lock carrier. The inner plug (a sort of plastic drawing pin) has to be prised up and removed using two small flat-bladed screwdirivers, then the outer part can be popped out of the hole. They work like little rawlplugs, the central pin expanding the outer fixing.

Now there are a bunch of T-25 Torx screws to remove. I found five screws in each arch liner - the top one being vertical and hard to spot.



Now you have to get the bump strips and the L-shaped towing eye cover sections off - I levered them up from the bottom carefully with a plastic spatula, to avoid scratching the paint. This reveals four T-30 screws.



You now have all the fasteners off, but the bumper is slotted into guides attached to each front wing and will not simply slide past the headlight. I had to lever the bumper moulding, very carefully, with a thin plastic spatula, to get it clear of the headlamp, at which point it can slide forward to free itself from the guide. Repeat on other side.

Catch the bumper and hold it with your knees while you disconnect the foglamp connectors (fsckng VAG electrical connectors) and remove the outside air temperature sensor. Bumper moulding can now be taken away to reveal the horror beneath !




The steel bumper is held on by six M13 bolts and two nuts.



The intercooler, horns and outside air temperature sensor can all be seen in the photo.


Now, I didn't go any further in, but the next stage would be to fit two long bolts into the lowest bolt positions , undo the four bolts holding the lock carrier to the wings and slide it forwards along the long bolts. This gets you access to the back of the radiator, the fans,the fan shroud, radiator mountings and hoses. The bolt thread is M8 coarse, and I bought some studding to make my own fittings for the next time I need to do this.

Now I can see the leak, and its a pitiful little thing.



So much so that I decided to fix it with a sealant, K-Seal, recommended by an engineering friend. One small bottle of K-Seal and two litres of 50% mixed G-12 coolant later, the leak seems to have stopped.

What you can see with the bumper and undertray off

With the undertray off, one thing you can see is that the underside of the engine, the nuts and bolts, electrical connectors and so on, are clean and free of corrosion. This on its own is a good reason to keep the undertray, or replace it if it gets damaged.

I found that there is an oil level-and-temperature sensor in the sump, which I was not expecting. This is what it looks like, looking forward, with the a/c compressor visible at the front of the engine.



Looking towards the back of the car, the dogbone mount and gearbox drain plug can be seen.



Pull back a bit, and the gearbox filler plug is visible, with the starter motor above it.



Crawling out from under the car, we can see the horns on the nearside.



The lock, complete with microswitch.



and on the offside, the intercooler.



Getting closer, the Manifold Abosolute Pressure (MAP) and inlet air temperature sensor location can be seen (two sensors in the single housing) with the washer bottle level sensor behind.

CupraTim, The K-seal stopped the leak for the remainder of the life of the car, and was a viable alternative to replacing the radiator, a job that would have taken a lot of work. It caused no problems with the cooling system during the 18 months it was in the car and I would do the same again if I had another small leak like this.

I would *not* use Radweld, Bars Leaks or any of the other wonder potions.

(The car was written off by a WhiteVanMan turning right, across my bows, leaving me no room to stop. His mind must have been elsewhere, Australia perhaps?)

Dan1720v, your comment is the kind of unreasoning blind prejudice not usually seen here. Can you say why you find K-seal so horrible? I had it on recommendation from a friend who is active in the kit-car community, where older engines and cooling systems with leaks are a little more common.

tonycane, the location of the leak was behind the ducting for the intercooler so I doubt very much if anything had hit it. Apart from the leaking corner,the radiator was fine. Bear in mind that the radiator you can see in the pictures is the refrigerant condensor from the air cooling system, the engine coolant radiator is behind it.

In your other recent threads you've reported that you're not loosing coolant, but earlier that you were. If you are loosing coolant, there are no obvious puddles and your radiator hoses are rock hard then I'd suspect head gasket failure.

Your situation is different to mine, I had an obvious puddle on the floor and on taking the bumper off could see a leak in the corner of the radiator. I don't think you've found a leak yet, have you?

K-seal worked for my radiator leak. It claims to be able to deal with head gasket problems as well. It's probably your best bet short of taking the engine apart.

White bubbles in the expansion tank? Doesn't sound normal, but hard to say without actually seeing what's happening. I didn't get any.

I'd expect that sort of mess from Radweld or Bar's Leaks but K-seal are adamant that their product seals holes to atmosphere or cylinders of up to 0.7mm and no larger.

It worked for me and caused no problems with heater or water pump, but I never took the system apart to look at the insides. The coolant header tank stayed the same colour and had no deposits on it.

However, if you've had real-world experience that was different, I'll take it into account. Did the customers say it was K-seal, or just a sealant of some kind?