losing coolant

[frogface]

Hi everybody,new to this 406 ownership,but think it's a fantastic car for it's age.However just lately,it seems to be losing coolant,but can't see any leaks,not even with the engine running and pressurised. tried changing the expansion tank cap,but not made any difference.The car seems to run fine,but can be a bit of a bugger to start sometimes-i've got into the habit of warming up the glo plugs twice,then it starts up right away.
I am a fairly competent mechanic-I've been running a british motorbike for twenty some years!Thought it may be a blown head gasket,but the engine looks clean enough. must admit I've never actually heard the fans cut in yet! Any advice/help would be greatly appreciated thanks!

[teamster1975]

Have you gone around all the hoses to check for corrosion? The conrad fittings (especially on the bottom hose to rad union) are very prone to this; also check for leaks around the thermostat housing. If the system is watertight it's got to be the headgasket.
What bike do you ride frog?

[mjb]

Could be the radiator. I've had a swiss cheese one in the past which only started to visibly chuck steam out when it was getting through about 3 litres a day Use a high concentration of anti-freeze (strong red or orange coloured stuff is good for this) and look for stains on the radiator after a couple of days.

[frogface]

Thanks guys,will check those solutions out.My bikes are Triumph Bonneville T140 and Kawasaki Z1000 Lowrider,both great bikes!

[marco2002]

Hi
I have the same problem been losing a bit of coolant for a while now. Didn't think anything of it. About every 5-6 weeks the coolant level would drop by about 250ml for no apparent reason. This has started to happen a bit more regular now every week and the coolant low level light comes on as well.

Tracked it down to the radiator at the bottom there is a load of cheesy looking muck that mjb described. New Rad is about £80-£100.

I've just bought some stuff called K-seal which is a bit pricey retails at £9.00 apparently itsvery good at sealing leaks and its better than the radweld and bars stuff you can buywhich can block the pipes that run from the header tank sometimes so i went with this stuff as it sounds a bit safer.

I'm just about to put the stuff in this afternoon and and take a 40 mile round trip later on. I'll report back with the results later..........

[mjb]

Tracked it down to the radiator at the bottom there is a load of cheesy looking muck that mjb described. New Rad is about £80-£100.

Here's a couple of good 'dead radiator' pictures. Note how it's not too visible on the other picture - it can be hard to spot these things sometimes
viewtopic.php?f=2&t=5706

I've just bought some stuff called K-seal which is a bit pricey retails at £9.00 apparently itsvery good at sealing leaks and its better than the radweld and bars stuff you can buywhich can block the pipes that run from the header tank sometimes so i went with this stuff as it sounds a bit safer.

Radweld and K-seal are about the same. They do the job but they're NOT permanent fixes - if you change coolant you need to re-add the stuff, and it has a limited lifespan so after a few months you'll need to flush the coolant and re-add it anyway unless you want to knacker your engine

[Welly]

I must be missing something there m cos I can't see no radiators in that there fred you said.

[jasper5]

Whatever sealer you choose to use (Bars is the best), if you get it in liquid form, warm the plastic bottle that it comes in by running it under the hot tap for a while as the stuff is solid on the bottom of the bottle, shake it up and fit it into the top radiator hose....NOT the expansion tank.It won't get to the rad if you fit it into the expansion tank.

[mjb]

I must be missing something there m cos I can't see no radiators in that there fred you said.

unless I'm missing something...

[Welly]

unless I'm missing something...

What, like, that's an Air Con Condenser and not a water radiator!

[Doggy]

What, like, that's an Air Con Condenser and not a water radiator!

That's not an Air Con Condenser ....
That's THE Air Con Condenser, (least it would be if wot it didn't 'ave 'ole in it, like)

I'm getting so I can spot the right one at 30 paces, (may be getting obsessive)

[mjb]

unless I'm missing something...

What, like, that's an Air Con Condenser and not a water radiator!

Still, it does the job of showing what a radiator leak looks like A condenser is just a radiator for refrigerant after all