Thread: High TD5 coolant temps after recent work

2000 TD5 Disco 280k

Just wondering if I can get some ideas about cause of recent high coolant temp that set off my Nanocom alarm (96 degrees) after idling for 15 minutes, multiple bleeds and a leisurely drive of less than 3 klms. Previous highest coolant temps around 92 deg. Block temp as per TM2 engine watchdog/coolant alarm around 91 deg after very prompt shutdown. It seemed like the temp went up in a linear or normal manner however the cooling system (t'stats or fan) not kicking as it usually does at the low 90's.

Recent changes:

1. Water pump replaced

2. Coolant rail crack repaired - Possibly original thermostat spent approx 1 week without coolant after it drained due to crack.I have read that old t'stats can cease up if left out of coolant.

3. 4 bolts at rear of fan removed to assist access to bottom of fan shroud (and of course replaced). At this time movement of 1-2mm of the fan assembly noted with annoyance as this bearing replaced just earlier this year. Mate who helped with work thought viscous fan okay other than movement (I don't get what is normal with viscous fans so I can't help).

Things I noticed following high coolant temp:

1. Another bleed got some more air out and coolant burnt my fingers

2. Top hose hot and not hard

3. No visible leaks/loss of coolant from hoses

After returning 1.5 hours later got car back home with coolant temp of 85 deg and block temp of 80 deg. Noted that heater now working fine (no heat when left home). Let idle in driveway for a further ten mins where coolant temp rose slowly to 91 deg. At that point got frustrated as prior to recent events idling like this would give coolant temps of around 89 deg.

Any ideas re t'stat vs viscous fan? Or other?

Update: Recent issues tentatively attributed to forgetting to reinstall the top radiator shroud/guard and residual air in system.

Issues seems to be resolved now with about 350 k travelled, no further coolant temps => 96 deg and nil loss of coolant. Nonetheless, when I have a chance will take to rad guy for rad flush.