[Jimmy Limache]

18-year-old 147 2.0 – the "translucent" plastic radiator overflow tank is brown enough that I can't get an external sight-reading on the water level. Anyone else experience this problem, and is simply removing the tank and cleaning it (from the inside) the best solution?

 

[David C]

Best solution is to buy a new tank.

 

[mikesalfa]

I periodically clean my tank by removing and spraying standard automotive degreaser in there with some water and giving it a good shake and a rinse out.
I've cleaned mine out 2 times in the last 4 years over about 12,000 kms. It also helps that I bought a new tank at that 4 year mark. So I would get a new tank, and then periodically clean it out every now and then. They are cheap and easy enough to come by for most of the 147 and 156 models.

Because the tanks are divided into compartments you can't just stick a bottle brush in there to get everywhere, you can only physically access a couple of small portions.

When you remove it there will be a date stamp on the bottom. It could be it's original which may be showing signs of cracking on the underside or the top edge near the bonnet shut line.

 

[ceecao]

If it's tank dirt only you can unmount and clean. If engine radiator, heater radiator, oil radiator and main coolant hoses are old it's internal contamination, you should do a coolant flush and after then you can clean or put new tank.

 

[johnlear]

Just to note that this is not an overflow tank, it is an expansion tank. Overflow and expansion tanks may look similar, but work in quite different ways.

Regards,
John.

 

[Negativvv]

They get dirty over time. I've replaced mine twice in just under 9 years of ownership... Although the second time I replaced it was because it cracked and was slowly evaporating coolant.

 

[Jimmy Limache]

Thanks for all that! A new tank's cheap enough, but the shipping to Chile ups that considerably – I'll give cleaning the old one a go first (using mikesalfa's spray degreaser procedure).
The tank's brown enough to merit before and after photos.

 

[Negativvv]

If you can get one more tank then you can keep one cleaned up and the other in the car.

Although as above be warned. I had an OEM tank but after about 6 years it cracked and started leaking coolant.

 

[halftone]

Are you using antifreeze? OAT type is required and is very good at preventing corrosion when used at 50% dilution with de-ionised water. My expansion tank is still like new after 6 years in my ownership, and 2 antifreeze changes when radiator replaced and cambelt + waterpump changed x2. It is a JTDM but that shouldn't matter.​

Every other car I've owned has used the old inorganic-buffered glycol type, which is shorter life and had cooling systems full of rust. NB you mustn't mix old type with OAT, the system needs drain and flush first.

 

[Jimmy Limache]

I've had the car for six months. From what I've seen, the maintenance has been economy-class in recent years.

 

[halftone]

Ah. Then after you've sorted the coolant... it's likely the brake/clutch fluid is also old, brown with water and crud. Bad for braking and corrosion in slave cylinders, which you really don't want in a petrol 147 which has a concentric clutch slave cylinder. That needs the gearbox out to replace!

 

[Jimmy Limache]

Got it clean enough to read with spray degreaser and a good strong well-nozzled garden hose.