Thread: My TD5 is overheating

thermostat ?

I was just about to say the same thing , have you tested the Thermostat Baz? Just put in inside Boiling water to see if it opens up etc?

Unfortunately it sounds like the headgasket.
Exhaust gases displacing the coolant.
Its very hard to get the die dests to pick up a posative exhaust gas in the coolant on a TD5 as they are a pretty clean engine.
If that top hose has plenty of pressure its the head gasket.
Goodluck
Andrew

this is going to kill off whats left of your coolant but Im guessing youve already done that so no loss.

turn the heater controls to max heat then remove the bleed screw from the top hose and using the garden hose in the top of the coolant tank start filling, if you dont get anything out of the bleed screw tightly wrap a rag around the hose and tape it in place in the top of the coolant tank. Turn the hose back on and you should at least hear air escaping from the bleeder and eventually get water out.

for filling and bleeding to the top hose it doesnt matter if the thermostat gets totally welded shut there is 2 paths for water to get into the engineand radiator from the tank and theres one on each side of the thermostat. however if the thermostat is stuffed you cant run the car as it will overheat and destroy itself.

once youve got water out of the bleeder turn off the hose and pull it out, then remove the plug from the front of the head that controls the injectors (search for oil in the injector harness you'll quickly find where and how to do this) top up the expansion tank till its got a miniscus then quickly put the lid back on it.

have someone crank the engine over while you watch the bleeder if it spurts at you at this point your in for head work. if you dont get spurting you might be ok BUT not for long, if youve been runnning it with low coolant you will have done damage to at least the head gasket and probabley the head.

(this test is to make sure that you havent hydrauliced the engine and if the engine wont turn over as easily as it usually does stop here, your head or gasket is skippy roseavelt)

IF you dont get the spurting after about 5 seconds of cranking reconnect the injector harness and fire it up if you still dont get spurting keep an eye on it and let it slowly rise to operating temperature (when you start gettting warmer air out of the vents) at high idle


one of 3 things will happen. you will get the spurting you will get bubbles coming out of the bleeder or you will get fluid focring out of the bleeder and bubbles up in the coolant tank till its empty.

If you get none of these, go buy a lottery ticket, then start looking for leaks from hoses/fixtures and then go and get the coolant professionally replaced with OAT and the system bled.

My moneys on it needing the head pulling off.

No leaks, no oil in the harness, lots of pressure once it starts to overheat.

Looks like i'll have to start eliminating things

Baz.

I am making an educated quess here.

You have coolant blowing out of the expansion tank, but not boiling hot.

Your motor is getting hot because it is blowing coolant out of the expansion tank.

You have had it tested for gas & the head gasket is not leaking.

OK.

I suspect you have a leak on the suction side of your water pump.
( Bottom hose, loose clamp, water pump seal, leaking bottom tank joint loose drain plug, leaking gasket )

The pump sucks cold air into the system.
The air gets hot quickly & expands, rises to the top of the motor, pushing coolant out in the process.
The engine slowly overheats due to loss of coolant.

Good Luck with it, Davy

I had this problem in my diesel courier turned out it was a cracked head

"I have had it pressure tested and gas tested, both negative"

If it was a cracked head it would test positive for gas I would think.