karcher man

All sorted - fitted new stat, blew through rad to make sure it was clear, refiled with fresh coolant solution, slowly with engine running, left cap off and brought up to temperature. Heaters blowing warm (getting excited by this point) put rad cap on and drove to fill up with fuel, heater still nice and hot temp indication showing 90, filled up fuel tank and drove back, approx 7 miles on open county roads 70 mph ish. All now appears ok, temp ok and heater hot. Original fault: heater cold, apparent overheating and erratic temp gauge. Cause - Rear heater matrix partially blocked and stat u/s, air lock caused by poor circulation due to blocked rear heater. Fix - Loop out rear heater on pipes under passanger side rear door, ensured main rad and pipework clear, fit new stat, refill with coolant solution. Refilling the coolant: start engine and intoduce coolant slowly to correct level, leave cap off and run engine to normal temprature, fit cap. check coolant leve after a short test drive. i hope this helps someone, sorry for hijacking the thread. it may help when trouble shooting any system to make a list of all the componets, and test each one logically ticking them off the ist, you will eventuall find the fault. Just stop and think about it lol. Thanks for the advice too, its amazing what power an open forum gives, and knowledge is power! cheers Lee

Hi, Yes i had cold air in both heaters before the matrix change, The booster pump appears to be working correctly. i did remove the pipes from the rear heater and loop it out of the system it is worth noting it was extremely difficult to blow through the rear matrix hence the reason for leaving it out of the system. It did warm breifley, so took it for a spin 50mph on open roads, now its blowing cold again, the thermostat has also been removed but i read on another post this may affect the front heater circuit, so ive got a new one to put in tonight, im also going to check the radiator tonight to make sure its clear. If the rad is clear I suppose this leaves either the water pump is faulty, or head gasket however there is no water in the oil, no oil in the water and there are no bubbles in the header tank. the prvious owner had the garage put k seal in the water to try to cure the leaking heater matrix, so maybe this has clogged up the system. As the car is due a timing belt change anway, im going to put a new water pump on it. Ill report back with the findings, i guess with faults like this its just a process of eliminatation.

Im a newbie on this forum, I too am having the fault exactly as you describe, electric pump is running, but cold air ony from the heater. Did this last step sort your probem out? im going to try it tomrrow and see what happens, incidentaly i have just renewed the front heater matrix because the pipes where split, leaking water into the drivers footwell, dash out job but not really all that difficult - just time consuming.