Hello, not sure why it's taken me so long to join this community as I bought my 1999 TD5 110 Defender last August on 84k miles. I use it for my landscaping business so need it to be a daily driver. I'm quickly realising this is not as straight forward as I thought! Since last August it's had a new fuel pump, fuel filter, starter motor, & just recently rad & intercooler. New rad because I was visibly loosing coolant but no overheating. Since the new rad & intercooler (fitted by back street garage) Ive had pressure in the expansion tank when cold. I bought a new cap but still pressurized. I then realized the bottom hose & rad were cold after a good run, the heater was just warm & the temp gauge wasn't TDC as it had been previously. I took it back to garage & they bled the system & did an inconclusive head test. After this I've had no pressure in the expansion tank when cold but bottom hose & rad still cold after a good run. Garage has now replaced the thermostat which has made no difference. They suspect cracked head but not a bad one as power is good, starts fine, no emulsified oil, coolant dosent seem to have oil on surface & no white smoke. Advised if it was a HG it would have blown by now. So of course I'm wondering if this could be anything else before the head has to come off?? ......also whether steel seal or simular is worth a go if as suspected it's a crack in its infancy?? Any advice would be appreciated...although I got a B grade in MVS (motor vehicle studies) I'm no spanner warrior!! Thanks.