Z3 Heater or is it just me.

[Andy-M]

Being the first winter with the Z not sure if this is normal. Notice a couple of times but not taken much notice but the heater takes ages to warm up. I mean like 8-9 miles worth. Once its warm its quite toasty. But with this damp weather it takes ages to demist.
Replaced thermostat and anti freeze couple months back and got rid of all the air locks but may check again. The temperature gauge goes up to half way in about a mile. But the heater doesn't keep up.
Anyone had problems with heater valves or matrixes. There get to that age were matrixes tend to get blocked. Or maybe heater valves not opening fully restricting the flow.

 

[Jack Ratt]

Mine is exactly the same. I thought it was because it's now an old car.

 

[Shelly]

Our Z3 was the same too

 

[Dickymint]

Just so you know its NOT normal, My Z3 heats up within a mile or so and its so hot it will melt ya legs

 

[jonco]

Agree with @Dickymint but there was a very long thread on this over 12 months ago. Title was something like `Brrr - it's cold in here' - can't find it at the moment and you would need an hour or so to read it all.

Edit - you can temporarily by-pass heater valve to check/eliminate that.

 

[Andy-M]

you can temporarily by-pass heater valve to check/eliminate that.


Thats a good idea.

 

[andyglym]

Mines similar in that I get good heat only when it's at max heat setting and driving. Even a slight click down and it goes tepid, also when at idle speed. Thermostat operates as it should but I'm getting the water pump, coolant and thermostat changed next week (unsure of the water pump age so a precaution). Let's see if this does the trick, if not I'll have to delve deeper.

 

[t-tony]

Mines similar in that I get good heat only when it's at max heat setting and driving. Even a slight click down and it goes tepid, also when at idle speed. Thermostat operates as it should but I'm getting the water pump, coolant and thermostat changed next week (unsure of the water pump age so a precaution). Let's see if this does the trick, if not I'll have to delve deeper.

While you have got the cooling system empty Andy, I would flush through the heater box with your garden hose as a precautionary measure. Nothing to loose.

Tony.

 

[Kit]

Also agree with @Dickymint warm after a mile and lovely and hot by 2 seats take a few mins to burn your bum then down to warm setting.

 

[5harp3y]

My 2.8 is warm within a couple of miles and heated seat takes same time.

the smaller engines should take longer to warm up

 

[Antm72]

My 2.8 is toasty very quickly and as mentioned almost too hot if its blowing on the hands!
If the gauge shows hot its usually hot to be honest i only noticed it as cool when the stat failed and it showed cool on the dash too.

 

[Grumps]

Mines warm really quickly and is proper roasty if you turn it to hot.

 

[andyglym]

While you have got the cooling system empty Andy, I would flush through the heater box with your garden hose as a precautionary measure. Nothing to loose.

Tony.

When I got her speeds 1, 2 & 3 didn't work though was fixed when I picted her up. All speeds still work ok but as above, only toasty when driving.

 

[Synclare]

Mines only a 1.9 eight valve M43 engine but after a couple of miles its chucking out warmth, cranked up fully it really belts the heat out, did wonder when I first had it if it was running too hot such was the heat!

 

[Tracy Dee]

Mine gets toasty real quick once engine is normal temp its roasting hot have to turn it down. 1.9 16 v

 

[zedonist]

If speeds 1, 2 and 3 do not work but 4 does, it will be the thermal fuse. If it is slow to heat up, it is either a blocked matrix or a sticking heater valve, this is what we found out over the last winter period, hope it helps...

 

[Andy-M]

Well looks like i have a problem with either heater control valve or matrix. This weekend i think i will see if I can bypass the valve and see what happens.
Thanks all for your imput guys and girls.

 

[Sam Schwartz]

I'm a little late to the party, but if anyone found the right answer, please share. My heater heats fast and is quite hot, except when I stop for a light and am at idle, then it cools almost immediately. If I let it idle for 10 minutes without the heater on and the fan on high, it will over heat.
With the heater on or off, it will overheat without the fan on high. Past experience tells me the possibility of a damaged/worn water pump are at least 90%. I have had a few vehicles in the past with the same symptoms, both were water pumps. Any input?

 

[Althulas]

Hi @Sam Schwartz it sounds like a stuck or sticking thermostat. I would replace and while your there replace the water pump, belts, pulleys and flush the radiator at the same time to refresh all the system. You will find a guide in the knowledge base https://zroadster.org/articles/bmw-z3-m52tu-thermostat-replacement-by-mike-fishwick.64/

 

[Sam Schwartz]

Hi @Sam Schwartz it sounds like a stuck or sticking thermostat. I would replace and while your there replace the water pump, belts, pulleys and flush the radiator at the same time to refresh all the system. You will find a guide in the knowledge base

New fan clutch, thermostat, radiator, cap, manifolds, hoses. idler pulleys, and belts.... not much left.... at 200,000 miles, I probably should replace the water pump anyway, I don't believe this year had an electric water pump for the heater, but not sure. That would not affect the overheating with the heater fan off at idle, but not overheating with it on. I think the pressure needed to open the heater valve thingy just isn't enough with a worn water pump at idle... I am guessing the water flow with a worn pump needs more RPM than idle to circulate the coolant properly, except maybe with the additional cooling form the heater fan. For the $50. I ordered one tonight and we'll find out in a few days... I will keep you posted. Thanks for the quick response.