td5 cold radiator.

Hi all, just bought my first td5 discovery, always had 200 or 300 but this was so cheap it had to be bought. Its showing 216000 with a decent history and plenty of evidence that its been maintained using genuine lr parts so not been scrimped on maintenance wise. However it has a strange cooling fault in that the system is building up pressure but the temp stays at halfway and heaters are working fine. i've tested for compression gasses in coolant and thats coming back ok so unlikely to point to headgasket but the major pointer is that the radiator is stone cold apart from an inch or so across from where top hose would enter. Water pump seems ok as if you remove bleed screw on top hose and start engine it literally pumps jets of water over a foot high from hose. Is it possible that this could be a simple thermostat issue or is it likely to be radiator or some other issue. Any advice or help would be greatly appreciated as i know nothing about td5's

I had the same thing on my 300tdi so i changed the radiator for a new 1.
If the thermostat is opening the top hose will get hot but if your radiator is blocked it will stop the coolant flow.
You could try reverse flushing the radiator.

Daz

cheers daz i think i,ll back flush rad anyway, as regard to top hose being hot, looking at the position of the stat i believe that the top hose would be hot anyway as the stat on the td5 is at the bottom of the radiator its attached inline on the bottom hose. I think that stat not opening would stop flow through rad but would be nice if someone can confirm my thinkin.

Ah right i see! Not had a td5
SORRY

Daz

no need to be sorry mate, your answer was good old common sense which seems to me got thrown out the window with the td5, i've never seen a stat at the bottom of the rad before

Seems like a blocked stat to me.

i'm going to pick up a stat 2moro, is there a way to see if old one is working, kettle trick etc as it looks on pics like a sealed unit

Sealed it is, i dunno how to check it apart from the system which is under 1,4 Bar pressure when it's hot. It's not so expensive so put a new one then bleed the system well: pull up the tank and lift it above the level of the bleed hole, fill it with coolant untill a steady flow comes out, put the tank back, fit partially the bleed screw, start the engine and wait untill no bublles are showing there. Tighten the tank's cap well otherwise u might get overpressure/overheating.

cheers sierrafery i'm gonna try and find time to swap stat today or 2moro. i didn't realise they were under so much pressure when operating, i'll let you know how i get on.

quick update, fitted new thermostat (what a bugger of a job that is!!) bled up with header tank lifted above engine and all seems spot on rad getting hot, heaters hot and temp fine, just a pesky drip of water from somewhere around fuel heater to investigate but did'nt notice till nearly dark so i'll sort that 2moro. many thanks sierrafery your bleed up instructions made for a very easy job.

It's actually a fuel cooler! At the pressures the fuel system works at, the overflow which goes back to the tank would be way too hot, so the returning fuel is cooled to engine coolant temps to lower it before sending it back via the fuel filter to the tank.

Cheers!

Unfortunately that fuel cooler is quite expensive but also quite common to leak

sierrafery said:

Unfortunately that fuel cooler is quite expensive but also quite common to leak

Click to expand...

And here i was thinkin you were helpful and friendly, why did you have to spoil it with the word "expensive"

haven't looked properly yet but whats cooler made from?

u better think i'm mean than have a shock if u'll have to buy one to replace yours

gregomega said:

haven't looked properly yet but whats cooler made from?

Click to expand...

Not from inoxidable steel i'm affraid...cos it rusts
Fuel cooler
The fuel cooler is located on the right hand side of the engine and is attached to the inlet manifold. The cooler is cylindrical in design and has a coolant feed connection at its forward end. A 'T' connection at the rear of the cooler provides a connection for the coolant return from the heater matrix and coolant return from the fuel cooler.
The 'T' connection houses a thermostat which opens at approximately 82C. This prevents the cooler operating in cold climates. Two quick release couplings on the cooler allow for the connection of the fuel feed from the pressure regulator and return to the fuel tank. A counter flow system is used within the cooler. Fuel flows around a coolant jacket within the cooler and flows from the back to the front of the cooler. As the hot fuel cools travelling slowly forwards it meets progressively colder coolant travelling in the opposite direction maintaining a
differential cooling effect.

But to see that i'm friendly i tell u that u have the chance to fix it cheaper if u are lucky > www.discovery2.co.uk - Leaking Fuel Cooler Fix

It seems you may not be so mean afterall! many thanks i shall report back on my findings tomorrow

well had a good look and can't find any water drip at all. took for a drive got nice and warm parked on dry drive and no sign of any leak. And someone has already done the cooler o ring repair as its fitted with a jubilee clip, so thanks sierrafery. I shall monitor it over next few weeks, wondering if i'd just disturbed some trapped antifreeze that had spilt while previously bleeding system afterall i only found drips on floor below fuel cooler area, i never actually saw it dripping. so i'll keep my fingers crossed!

Are u sure the drips are not from the aircon drain?