Z

ZEK

New Member
Hi chaps,

Just bought a 95 54k mile 300tdi, long story short it overheated on way home the M25, not badly but gauge was to the far right) but the coolant was boiling and seeping from the expansion tank (I think a few litres were lost)

Got it towed home and today I flushed / checked the cooling system and everything seems ok (w pump, hoses, tstat).

Anyway the problem now is a hesitation to start and then once it does (usually 3 4 seconds) it runs for 2 mins getting rougher and rougher until it dies, then it will not run for more that a few seconds until it cools down (30 mins later).

Does this sound like a head gasket issue? I do not have any smoke or contamination in the filler or dipstick. What confuses me is the why it starts but only runs for 2 minutes. Could the overheating also have caused a fuelling issue?

Any help would be great, I am a newbie to land rovers and diesels but not afraid to tackle myself as I consider myself a competent DIYer.

Cheers - hope I can get this sorted before winter sets in :).
 
cheers will take a look now :(, it was actually perfect before this overheating I drove it for a week and 400 miles before taking it home (was on holiday) and it always started instantly and had plenty of power. I know the previous owner and it is has never been messed with.
 
could be a coincidence that when it overheated something else might have gone that has nothing to do with it overheating, so I would start checking all the possibles causes that would make it die after 2min..

air intake, fuel filter, is diesel getting to the injectors?, lift pump working? etc...
 
Thanks for the replies, I changed the fuel filter put some more fuel in and she started straight away and runs fine.

The next issue is the cooling system - it seems that coolant is not circulating though the system properly (top hose feels cold and soft).

I have bled the system 4 or 5 times but get no hot air in the cabin and the water seems to sit there - I am suspecting head gasket but will check the water pump tomorrow to rule that out.

There are occasional bubbles in the expansion tank, mainly when first opening the cap - seems to settle down after that.
 
Top hose won't get hot until the coolant is up to temperature and the thermostat opens allowing coolant to flow through the radiator where it is cooled before flowing out the bottom. This means that this might not be a problem unless you mean it NEVER gets hot in which case I would suspect a dicky thermostat. When sitting stationary with no load it is quite possible that the engine could run for half an hour or more and still not get hot enough to open the thermostat so that alone doesn't indicate a fault.

Is the thermostat housing hot to the touch?

The heater is on the closed side of the system and gets its coolant direct from the jacket so that should warm up quite quickley so that does indicate a problem.
If you are certain that you have bled through correctly then yes there is a problem somewhere and if you boiled then the head and/or gasket are the most likely culprits along with the pump.
 
Ok, good to learn new stuff :), the thermostat is new and housing gets pretty hot, I will measure it with a laser thermometer today to see exactly how hot.

I am now going to take it for a short drive and see if it unlocks any air in the system, and also top up the heater matrix via the hose.
 
There is a plastic bung on the thermostat housing which the system needs to be bled through. These bungs can break so advice is to replace it with a brass house radiator bleed valve.
 
Noted, already replaced with brass caps as a plasic one sheered off on the m25 :).

Took the belt off and the water pump pulley had no play and turned fine.

Went for a drive and the heater started working, but the temp needle quickly rose into the red so went staight home. Opened the bonnet and all the hoses seem hot/warm but only the top section of the rad is warm. Took the expansion cap off to see if I could see any bubbles, the water did burst out at first but just a spalsh and the level was ok. After a while the level built up and it started overflowing lots of coolant.

The pump seems ok, and I can't locate any leaks in the system and it held slight pressure overnight - so the only other cause than the HG could be a blockage? I did flush the rad and water seems to circulate ok.
 
Last edited:
If only the top half of the rad is getting hot, that sounds like the rad's had it.

Rad should be hot all over.
 
the water pump impellor might have snapped off,seen it before with the same symptoms your 300 has.
 
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