Another TD Coolant Mystery

[Lewis 325]

(I read the thread on the previous forum but I'm pretty sure that this problem wasn't covered)

Problem: Engine gets hot, cooling system doesn't

Loss of coolant: No
Water / Oil / Water Mix: No
Does heater get hot: No

Undoing the header tank cap a day after running the car, there would be a rush of air (in or out, I'm not sure which)

1. Disconnected top hose from thermostat housing with engine warm and running, hot water dribbled out rather than flowed out

Replaced water pump and thermostat - no change, except the cold air escape seems less

2. Removed cylinder head (head gasket was in a horrible state, with a small escape path between waterway and one bore, the gasket was soggy where it covers all the waterways with the small water holes clogged up)

Replaced head gasket - no change

Any Ideas? :banghead:

[Strandy]

try running without the thermostat for a while - it not unknown for a new one to be faulty.

also, you say cooling system doesn't get hot - do you mean the whole system or just the radiator? If the rad remains cool or cold but the engine gets hot then the rad might well be blocked.

It also possible that the waterways in the block are just clogged up - in which case I would expect the rad to be too

Just a few thoughts... hope you manage to sort it.

Cheers
Phil

[Lewis 325]

Thanks Phil. The thermostat would certainly be a cheap / easy test and it might at least let some water round the system (i.e. enough for short journeys in the meantime even if it doesn't fix it). Not even the heater gets hot so I don't think the rad's blocked. Looked at it today and there's a sort of oil-cooler affair that's plumbed into the heater circuit, might try checking that....

[Lewis 325]

...well the oil cooler was a blind alley. However, I poured some radflush into the head via the top heater hose and ran the engine for a while, followed by flushing with a hosepipe from the bottom hose, the temperature sender and then both heater hoses. There's now a little flow, sufficient to warm the heater and keep the temp at about half. The thermostat definitely opens (the temp gauge goes down when it does) and the rad's getting warm. Still not sure of the root cause (blockage / airlock?) but I'll persevere with the radflush and pray it's not a bodged core plug moving around in the block!!