expansion tank filling?

ok... been having a problem with overheating...

one serious boil where coolant was was spraying out of side of bonnet before i could get to emergency refuge area on motorway..

so new....

water pump,
another radiator that didnt have a leak,
serpentine belt,
belt tensioner,
viscous fan,
new stat, then stat removed and running without one now..

still doin it.. if i run with heaters on it dont overheat,, only ever gets warm under load up hill etc..

so...

head off, pressure tested and skimmed..

refitted, new head bolts etc,

new timing belt too, pully and tensioner..

still overheating under load if i dont have the cabin heaters on full..

got warm on way to work this morning, water had leaked past plug in top of radiator.. topped up,,

set off home... got warm again.. got home, no water in stat housing, expansion tank full to the top.. had to empty the expansion tank then refil the stat housing..

what is goin on.... i'm out of ideas, i've done everything...

Poor bleeding
faulty bypass valve maybe
whats rad like

bypass valve?

rad not leaking and i jet washed it before i fitted it... so its not clogged with mud or anything... i shined a torch through it to make sure it was clean...

http://www.landyzone.co.uk/lz/f8/300tdi-coolant-bypass-valve-122735.html pump expansion ejector

also a rad needs flow rate.

will get an ESR2348 tomorrow i hope....

its the correct radiator for the disco...

nick2303 said:

will get an ESR2348 tomorrow i hope....

its the correct radiator for the disco...

Click to expand...

Just make sure it isn't blocked or you may be getting localised boiling

i've flushed to coolant system with central heating de scaler/cleaner.... forget to put that on the list....

yu can use liquid dishwasher cleaner

Just change the whole bypass hose. i had similar symtoms once. Try removing the bypass hose from the thermostat housing and see whether the level in the reservoir goes down. If it does, the bypass hose, valve etc are most definitely at fault.

Ok...

Fitted new bypass thingy on way to work.. topped system up.. stat stayed full when I topped it up...

Some right crap came out of bypass hoses when I took old ones off...

Seemed better most of way to work... Got a little warmer though just before I came off motorway.. so I don't think it's completely cured ..

Tried to get a new top for expansion tank but out of stock.. getting one on my way home...

Anything else I need to try?

topped up maybe 300ml and set off home..

fine at 55... so floored to get it up to 65, temp started to rise again.. put cabin heatyers on hot an down it came...

got new expansion tank cap to put on... when its cooled enough to swop over i'll go for a spin...

new cap on... went for a spin... floored it to 65 and up goes the temp...

put the heaters on hot and down it came...

i'm stumped now... maybe new rad... its the only thing that aint new,,,

nick2303 said:

new cap on... went for a spin... floored it to 65 and up goes the temp...

put the heaters on hot and down it came...

i'm stumped now... maybe new rad... its the only thing that aint new,,,

Click to expand...

does rad core get hot all over ?

as far as i can feel...

got r lass to try rad, n she said it felt cooler in one spot but i couldnt feel it...

basics first.

when hot, feel all over the rad for hot/cold spots.

is the top host hot? are the pipes rock solid?

edit: i should have refreshed the thread

all hoses hot....

pipes solid...

How much coolant did it take after the flush ?

Should take 11ltrs

Did you fill from thermostat or expansion tank ?

Out of ideas, could be crub stuck to the rad, might need a soak to get it off

ive always filled expension tank to level..

then topped rad, then stat...

always worked fine before doin it that way...

Then stumped.

Could thermostat be buggered ?

running without one after i put a new one in an it still got hot...