Heater core _ Over Heats!!

2002-landrover-Freelander

hey i have a question, i just have to be sure...
i've just replaced my waterpump and thermostat, and radiator...
After i;ve changed the water pump the car sounded good... then i noticed that the hoses build up pressure, kinda like a block in the system, hence i flushed it, and still over heats about 8miins holding accelerator on 1200rpm,,,, i noticed that the heatercore hoses are cool, not hot like the lower radiator hose, and the upper radiator hose is somewhat cool not hot... the car also doesnt have heat... but blows... and at this point itsappears to overheat. I also noticed that the hoses directly behind the KV6 are hot on the one leading to motor and cool on top going to heatercore....

p.s. the very frist day after the latest fix (waterpump) the vents blew smoke,,,, indication of heater core prob..... but after a camshaft cap replace, it stopped... now just over heats (no heat) please help.....

(seriously dont wanna do a heater core if not nessasary....

Sounds like an air lock in the system somewhere. Try draining again then refil a little then start engine and put heater on hot and blower on full, leave engine on tickover, then continue to refill until system filled.

Link the two heater hoses together to rule out the matrix. Sounds like really bad airlock or head gasket

hey thanks for the advice... by the way what do mean link the heatercore hoses together... to rule out matrix??

rmg24pro said:

hey thanks for the advice... by the way what do mean link the heatercore hoses together... to rule out matrix??

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DD means, remove the two rubber hoses that go into the heater matrix and join then together with a small lenth of pipe of the same bore diameter. A piece of copper pipe should do the trick, this will eliminate the heater matrix.

Wot he said^^^

Diesel Do said:

Wot he said^^^

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I understood yus the first time DD.:doh:

ok by linking the hoses together, the car shouldnt overheat? correct? I'd just wont have heat,,

rmg24pro said:

ok by linking the hoses together, the car shouldnt overheat? correct? I'd just wont have heat,,

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not necessarily ,it wont have a heater ,if your heater goes cold you either have a combustion gas leak ie head gasket or just not enough coolant for whatever reason

It was just a suggestion that would rule out your heater concerns completely. From your description my first thought would be head gasket! Why did you do all the other work? Have you run it with the header tank cap off? Does it just chuck water out? Does it blow bubbles? Sniff the fumes from the tank, does it smell of exhaust gas?

What engine have you got diesel or petrol. Was it over heating before you changed the water pump, rad, and stat. Is there a gray like gunge on the oil filler cap.

Just trying to help but need more information.

EDIT: Just found out you have the KV6 engine.

If the hoses are going hard before the engine is at running temp there is a very good chance a HG has failed. Why did you change the pump and stat? The KV6 needs to be properly filled with water and bled as much as possible before the engine is started. If you start the engine before it's filled completely there is a very good chance of cooking the rear HG!!

yea sorry it took so long to reply, but im going to check if spark plugs, to see which head i might need to replace.... Hey is it common to mill a head before replacing the gaskets?

oh and to answer perious question, i changed the therm and waterpump beacuse thier seemed to be no circulation through the system, when the car gets at normal temp. Hence, once at NORM TEMP, if i press the accelerator down for some time the coolant hoses are tight as if its gunna pop, via no room to move... :[

The KV6 doesn't generally blow HG's unless it's been run with an airlock for any length of time. If the system has been completely bleed using the air bleed screw in the heater pipe, it should finish bleeding in use. It's common for the bottom rad hose to feel cold even when the gauge shows normal temp. The gauge is calibrated to show normal engine temp when the engine is between 75° and 115°C so the only way to measure the engine temp accuately is using the OBD live data. Normal thermostat controlled running is around 100°C but rad is so good at removing heat and with such a small amount of hot water leaving the engine to be cooled it gives the impression the stat is'nt working. The stat should be fully open at 106°C but in this cold weather you'll struggle to get it that hot. Unless the head is damaged around the fire ring or it's warped I'd not mill it.

Nodge68 said:

The KV6 doesn't generally blow HG's unless it's been run with an airlock for any length of time. .

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bollix

The Mad Hat Man said:

bollix

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And you are basing that on a bad experience with yours I've run and rebuilt lots of KV6s in lots of different vehicles. They are good engines if looked after. The most likely cause of HGF is a localized overheat due to an airlock. This normaly starts at the thermostat or top hose O ring, this allows the water level to drop. Result = airlock which = a failed HG. Normally the rear one

Nodge68 said:

And you are basing that on a bad experience with yours I've run and rebuilt lots of KV6s in lots of different vehicles. They are good engines if looked after. The most likely cause of HGF is a localized overheat due to an airlock. This normaly starts at the thermostat or top hose O ring, this allows the water level to drop. Result = airlock which = a failed HG. Normally the rear one

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No
I am basing it on the experience of many peeps on here over the last 6 years!

Most of which are good Engineers with an understanding of how cars work. Have maintained their cars well, looked after them and have still had major, if not catestrophic failures.
the KV6 is a poor design, poorly executed.

The Mad Hat Man said:

No
I am basing it on the experience of many peeps on here over the last 6 years!

Most of which are good Engineers with an understanding of how cars work. Have maintained their cars well, looked after them and have still had major, if not catestrophic failures.
the KV6 is a poor design, poorly executed.

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The earlier KV6s were not good. After the 98/99 redesign the reliability improved massively!! It ended up as Powertrain's most reliable engine besides new engines will have problems. The KV6 is no less reliable than the other petrol engines fitted into landrovers. The engine design is'nt any different the lots of modern engines. You should see some of the French rubbish I rebuild on a daily basis!!

ok checked the spraks and thier clean... I'm stubbed... i have no heat, and the car overheats,,, it builds excessive pressure when i rev the motor for some time... would a bad radiator cause "no heat" or is it clearly my thermostat or heatercore,,, ??? :?

i taken the radiator upper hose off a while back and ran water trough the top radiator hose and water comes out the bottom, same vice versa,,,,, so the radiator cant be clogged... but im still wondering if its bad... the therm was recently changed.... and i'm not sure if that would cause no heat, please helppppp