Overheating and need some help...

Hi Guys,

I need some help. I have a 110 300TDi M Plate. Since buying it I have had no problems relating to the engine, however a trip on the Motorway (which it has done numerous times before) led to it overheating. I cooled it down and crawled to the services on the hard shoulder, there I filled it again with water, which I then did numerous times to get it home, each time I checked there was no water.

It has sat a few days - I have just topped it up and ran the engine, seemed ok, tried to look at the thermostat but the bottom bolt is seized. I took it for a run and it seemed ok, cracked the filler tank lid but there seems to be a lot of back pressure there and the water seems to 'chug' out of there.

Any ideas guys? could it be the thermostat, water pump - I cant see any obvious leaks and the tank had retained water. I took the bung out above the thermostat and tried flicking it back and forth and poured boiling water in incase it was seized and took it for another run but the temp gauge rose and there is a whistling/humming noise coming from the header tank cap.

Any help greatly appreciated!

Water must be going somewhere. If you cannot see where it is going then it must be going out the exhaust.

Gmacz said:

Water must be going somewhere. If you cannot see where it is going then it must be going out the exhaust.

Click to expand...

Or into the heater box and evaporating.

Hi,

Make sure you bleed it properly.

Check everywhere to see if you can find any leaks.

Can you feel the heater pipes , are they getting hot?

Have you checked the oil on the dipstick and the oil filler cap to see if there is any evidence.

Can you put a long screwdriver to the pump housing and hear if it is turning or not?

Also, change your thermostat and the radiator plugs for brass items if the y are still plastic.

Cheers

P gasket is always a favourite, difficult to see as it leaks slow down the block and the heat dries the coolant out before it can drip on the floor.

"there I filled it again with water, which I then did numerous times to get it home, each time I checked there was no water."
This sounds like a serious water leak, park it up and let it run up to temp and see where it is leaking.
Radiator pressure tester might get it.
Is it smoking from the back when hot.

For a long time I was losing coolant but only when it was being used, basically when the system was under pressure. Never found it for a long time just kept the system topped up, as time went on longer motorway drives or real hot weather would have the gauge creeping up, but there was never an obvious leak. Only when it started losing a significant amount of coolant (quickly emptying the expansion tank) did I find that the radiator itself had started leaking, even when sat on the drive. Replaced the radiator, flushed everything through and it's absolutely fine now.

Seems that it was only leaking from the rad when under pressure and thus hot, as well as the viscous fan behind it meant that any evidence was quickly evaporated.

So you'v put another DUFF rad in that's leaking when it's hot ?

Of course not Might've misread the summary...

Edit help?

Right Stags lets start wot to do next shall we ?
Header tank top off !
Rad bung out !
FILL rad thru bung hole ! Stick bung back in !
FILL header tank ! stick top back on !
TOP hose should be SOFT ish to squeeze !
Start motor up ! & keep squeezing top hose ! IF it goes HARD BEFORE it gets hot it's your H/G
If It dunt then it could be your H/T top ! when did you last change it ?
you haven't got the STUPID cover on top of the head have you ?

Magicgrotto said:

Right Tom lets start wot to do next shall we ?
Header tank top off !
Rad bung out !
FILL rad thru bung hole ! Stick bung back in !
FILL header tank ! stick top back on !
TOP hose should be SOFT ish to squeeze !
Start motor up ! & keep squeezing top hose ! IF it goes HARD BEFORE it gets hot it's your H/G
If It dunt then it could be your H/T top ! when did you last change it ?
you haven't got the STUPID cover on top of the head have you ?

Click to expand...

I would suggest you forget the thermostat bung out and refit once fluid comes out when you fill the header tank.

Cheers

Time to take a snooooooze mi thinks neilly LOL

Can't say I understand your reaction. My cooling system is running perfectly, I was merely describing the issue I had regarding overheating/losing coolant somewhat similar to the OP, re; no obvious leaks.

Magicgrotto said:

Time to take a snooooooze mi thinks neilly LOL

Click to expand...

well I am not reading you a goodnight story......LOL.

Cheers

SORRY tom thought it was you !ooooooooooops

Edit button is ACE !

Ahaha makes sense all round now

Magicgrotto said:

Edit button is ACE !

Click to expand...

Then edit your bleeding procedure to be correct, you muppet......

Cheers

neilly said:

Then edit your bleeding procedure to be correct,

Click to expand...

NOPE

Buy UV Leak Detection dye. It will show up very clearly any leak areas.