Small Amount Of Gunky Residue On Radiator Cap - How Do I Find Where Its Coming From?

[Penfold]

Hi,

Just noticed that I have a small amount of brown residue on the bottom of radiator cap on R33 GTR. It's not like a complete chocolate milkshake gunky mess when the head gasket fails however (I've had that already). I'm wondering what the easiest testing procedure would be for myself before I get mechanic to check it out later. I could flush & have radiator pressure tested but wondering if this is the best idea. I wiped it off with finger today but it builds up over a period of months so I could take a photo when it builds up again.

Cheers,

Geoff

[DLOOOK]

How long has it been since you've driven your car? Do you drive short distances? My mate had some milky residue under his rad cap in his Supra. Only ended up being cos he rarely drives his car and for the fact that his work is only 4mins away.

[Penfold]

Yeh tend to really only drive 4 mins or so to work - that could be it.

[l0WRB]

give me the keys geofff ill drive it hard n fast hahahah should fix ur problem

[THENIG]

Careful with radiator flush, it might just dislodge all the crap in your engine and dump it in your radiator. Found that out the hard way, blocked a brand new alloy radiator after the 25 conversion, no water going through the centre of the radiator prevented viscous centre of clutch fan from locking and pulling air through the already blocked radiator. Needless to say had a few scary moments when the temp needle kept rising. Got it all sorted out before anything went pop luckily.

My advice, if you have to use radiator flush to get rid of the gunk, make sure you get your radiator flow tested after to make sure it aint blocked, if its a standard radiator then its easy for a rad. specialist to take the plastic end caps off and clean it properly, if you have an alloy radiator then it maybe a bit more difficult to clean, most radiator places will be able to help you out though.