Technical Overheating TD100

[franglais]

i was on my way home, a 40 minute journey and had done about 20 minutes with the air-con running, when i noticed the temperature gauge had almost reached the red (since the previous owner had changed the instrument cluster, the gauge has never been right, the cooling fans kick in at half way and normal operating temperature is a quarter) so very seriously hot. i pulled over and switch off, opened the bonnet and found the expansion cap pressure release howling.

as the video (currently uploading) shows, i released the pressure slowly (i didn't fancy an old pipe bursting to add to my woes) and the water boiled in the engine and eventually settled down, i saw that the water level was very very low, just a small amount was left in the expansion tank.

this poses the question, "where has the cooling liquid gone?" and there aren't many nice answer to that question are there?

 

[franglais]

 

[varesecrazy]

favourite would be a slow coolant leak - Radiator being #1

always the possibility of Head Gasket issues.., normally associated with "MAYO" - white creamy gunk in oil filler car region.

all I can suggest is refill to correct level,
beware of air-locks..,

then use gently for a few hours.. reguarly keeping an eye on levels.

diesel motors are pretty tough .. the heat itself wouldn't necessarily kill it,
Charlie

 

[Neverth]

When the engine is running, does water flow from that little tube on top? That one comes from the thermostat housing and there should always be flow when the engine is up to temperature (and even when not as the tube is just before themostat to provide flow for it).

No flow -> low coolant/airlock/waterpump broken.

Stuck themostat is easy to check as the hose after themostat is hot feed for the radiator. Cold hose/rad -> stuck themostat.
But that might also be waterpump/airlock.

 

[franglais]

Hello, thanks for the replies, good news, no mayo on oil filler cap when i checked this morning, the ambient was about 17celcius, so hopefully that reduces the problem to a leak somewhere (please dont be heater matrix).
i refilled to the min line with water this morning before braving the issue and taking my car for a day out in Nantes. i knew the pump was alright, because like Neveth said, there was coolant flowing into the expansion tank, so i topped up (i didn't bleed the system, as i couldn't find the valve anywhere, its supposed to be on the top of the radiator no?) and set off, watching the needle every 500 metres for the fisrt 10km, i had no problems and the needle stayed around a quarter and never went above a half the whole day, so very good.
what i did notice, when i had my nose under the bonnet this morning, is that when running (up to temperature, thermostat open), the pipes to and from the radiator are under quite a lot of pressure, and sqeezing them fully is impossible, could this indicate a blockage in the system? i think i will drain the system and flush through with the hose pipe, even if there is no blockage, it can't hurt to change the fluid, i have no idea when it was last done.

 

[djwpk]

A new radiator shouldn't spring the bank....

 

[franglais]

well after the work i did today, it's definately a head gasket problem
i started the day with a bleed (after finally finding the screws under the air intake cowl) and straight away the level in the header tank sank to the very bottom, and even dissapeared, i had to add a little fluid before any water came out the bleed holes, so the radiator was very empty. I went to the shops, got myself a bottle of rad cleaning fluid, and tried to put it in before i set off home, but the level in the expansion tank had reached such a high that i could not open the cap, without water coming out, occasionally, a bubble of air would release itself and the level would sink a little. when i got home, i re-bled the radiator, and the same thing happened, loads of air came out and the level in the expansion tank dropped right down. i ran through the cleaning fluid and went through the draining and refilling process with water for a rince, slowly filling the system until water came out the bleed holes, then plugging them and filling up to the level, ran the motor till the cooling fan came on, same thing, rad full of air, no space in the expansion tank.
there is a lot of compression going into the cooling system.
this would also explain the occasional lumpy start, with puffs of white smoke, despite being in the middle of summer.
there is going to be a thread about this new adventure soon, i can't afford to change cars right now, so the DIY option is the only option, i will have to speak to the neighbours about borrowing/renting a spot in his big garage, and sort out some alternative means of transport for a week or so.

 

[varesecrazy]

that's not the best of news,

keep us informed,
make sure you can get all the torque values for the things disturbed before you start,

charlie