Club 80-90 Forums

Hi My T25 1998 diesel engine keeps over heating over small distances but not when running stationaryfor 45 mins to bleed system. The engine bay pipes get hot along with the radiator. I have changed thermostat and water pump. Also pipes which have burst. I am awaiting a new oil cooler to be delivered. There don’t appear to be airlocks as no bubbles on radiator bleed screw. No water appears in the oil. Any suggestions please.

Head gasket?

order a "sniff" test

The rad could be partially blocked perhaps.. if it isn't new... If pipes have burst due to pressure rather than age could be a head gasket issue

Yeh was hoping it wasn’t the head gasket as out of my league to fix. I think it probably is though. Will flush the radiator after. Getting fed up of draining and filling coolant now.

it'll be the HG

It's not a huge job really, it just feels like it when you haven't done one before, and can feel quite overwhelming.. it's not..

Happy to give pointers/help if possible

and while you're there you can do the waterpump, timing belt and tensioner.. win win..

dont guess , test to determine the problem

is the heater getting hot?

is the cooling fan kicking in?

how are you bleeding the air out

why did you change the water pump/ oil cooler /thermostat and hose?

The burst pipes suggests pressurisation of the coolant system, i.e. head gasket failure, but if that was the case then you'd also expect to see gas in the coolant header tank displacing most of the coolant into the reserve tank behind the number plate, and the OP hasn't reported this kind of coolant displacement or the low coolant warnings you'd get, assuming the header tank sensor is good. You'd also expect this to show up to a lesser extent if the van was sat idling for 45 minutes. A sniff test as suggested above would resolve whether there are combustion products getting in to the coolant system.

Thanks all for the points and tips. I replaced water pump belt as it was squealing and slack as not driving the alternator effectively. The water pump as there was a leak from it. The oil cooler as there appeared to be smoke or bad seal. Going to get the pressure tested. Then flush the radiator next.

grahamwise4 wrote: ↑20 Jun 2025, 07:38

davidoft1 wrote: ↑18 Jun 2025, 00:11 dont guess , test to determine the problem

is the heater getting hot? Yes

is the cooling fan kicking in? No

how are you bleeding the air out through the nut top left of radiator.

why did you change the water pump/ oil cooler /thermostat and hose?

If your fans not kicking in either there’s an issue with the fan or an air lock