e34 530 thermostat
 

Hi

I'm not a mechanice but...

i've done this job before on nearly every car i've ever had. Just
tried replacing a thermostat to my 1989 530. I bought the new unit
from GSF but it's made in Brazil. water heats up and overflows from
the expansion tank, steam hisses out from the bleeder bolt but no
circulation, nothing hot from the heater and a temperature needle that
stays well and truly in the blue. Took the thermostat back out and
turned it around (was no thermostat in when i bought it) and still no
joy. took out it and tried it 'the right' way (double checked with a
parts schematic at http://rust.mine.nu/bmw/carselect.do) but this time
tried to position it differently to the first time. Still no joy.

2 questions, then:

how likely is it that it's a dud or even wrong part?

how likely is it that i'm doing something well wrong.

by the way, i now need a new thermostat housing cos the damned thing
got a crack in it when i was getting myself all the way back to square
one!

sorry for going on.

tia

mojo

On Sat, 02 Oct 2004 14:14:39 -0700, mojo wrote:

> Hi
>
> I'm not a mechanice but...
>
> i've done this job before on nearly every car i've ever had. Just tried
> replacing a thermostat to my 1989 530. I bought the new unit from GSF but
> it's made in Brazil. water heats up and overflows from the expansion tank,
> steam hisses out from the bleeder bolt but no circulation, nothing hot
> from the heater and a temperature needle that stays well and truly in the
> blue. Took the thermostat back out and turned it around (was no thermostat
> in when i bought it) and still no joy. took out it and tried it 'the
> right' way (double checked with a parts schematic at
> http://rust.mine.nu/bmw/carselect.do) but this time tried to position it
> differently to the first time. Still no joy.
>
It is easy enough to find out if the new stat is operating. Place it and
a thermometer in a pot with enough water to cover the stat. Slowly heat
the pot and watch to see what the temperature is when it opens.

From your description it sounds like the engine is over heating and
there's little or no circulation of coolant (does the radiator get hot?).
While that could be a thermostat problem it could also be that the water
pump isn't working. I think you have one with a plastic impeller and they
are known to fail. You can, without pulling the pump, determine if that's
the case or if it is a bad stat by simply leaving the stat out. If the
engine then runs cold it's the stat. Otherwise it's the pump.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

Thanks for that, Jim. forgot about the thermostat experiment in a saucepan
of water trick - will do in the morning. the engine and circulation was fine
before i tried installing a new thermostat. as i said earlier, the car came
without a thermostat fitted. at present, no thermostat and circulation ok.

thanks again

mojo


"Jim Levie" > wrote in message
...
> On Sat, 02 Oct 2004 14:14:39 -0700, mojo wrote:
>
> >
> It is easy enough to find out if the new stat is operating. Place it and
> a thermometer in a pot with enough water to cover the stat. Slowly heat
> the pot and watch to see what the temperature is when it opens.
>
> From your description it sounds like the engine is over heating and
> there's little or no circulation of coolant (does the radiator get hot?).
> While that could be a thermostat problem it could also be that the water
> pump isn't working. I think you have one with a plastic impeller and they
> are known to fail. You can, without pulling the pump, determine if that's
> the case or if it is a bad stat by simply leaving the stat out. If the
> engine then runs cold it's the stat. Otherwise it's the pump.
>
> --
> The instructions said to use Windows 98 or better, so I installed RedHat.
>

"mojohotmail" > wrote in message
.uk...
> Thanks for that, Jim. forgot about the thermostat experiment in a saucepan
> of water trick - will do in the morning. the engine and circulation was
> fine
> before i tried installing a new thermostat. as i said earlier, the car
> came
> without a thermostat fitted. at present, no thermostat and circulation ok.

....which would make me nervous. Why had the t-stat been removed? Somebody
was apparently attempting to circumvent some sort of cooling system
problem...

How do you know the coolant circulation is adequate? Without a thermostat
the wide open path may allow enough coolant flow (even with a bad pump?) to
keep the temps down and allow the hoses to get hot. While it is not rocket
science, I would believe there is more to the problem than just the -stat.

Also, when you do put the new -stat in, there should be a small hole on the
upper part of the large disc. It may have a little poppet in the hole or
may just be a hole. This is there to allow the air trapped behind the -stat
to pass when you are filling the system. If you trap air in there it may
boil over due to the uneven cooling.

-Fred W

thanks Fred

a bit more info in order to contextualise things.

i took the old therm out a while ago because it got knackered. it got
knackered because i poured some 'rad-weld' type stuff in to stop the rad
from leaking. subsequently changed the rad but couldn't get hold of a therm
for love nor money until yesterday.

btw, tried the thermostat in hot water routine. opened up but only when
close to boiling point. will see if there's a different type available that
opens a bit sooner.

thanks again for taking the time

mojo

"Fred W." <Fred.Wills@'remove this to reply to' myrealbox.com> wrote in
message ...
>
> "mojohotmail" > wrote in message
> .uk...
> > Thanks for that, Jim. forgot about the thermostat experiment in a
saucepan
> > of water trick - will do in the morning. the engine and circulation was
> > fine
> > before i tried installing a new thermostat. as i said earlier, the car
> > came
> > without a thermostat fitted. at present, no thermostat and circulation
ok.
>
> ...which would make me nervous. Why had the t-stat been removed?
Somebody
> was apparently attempting to circumvent some sort of cooling system
> problem...
>
> How do you know the coolant circulation is adequate? Without a thermostat
> the wide open path may allow enough coolant flow (even with a bad pump?)
to
> keep the temps down and allow the hoses to get hot. While it is not
rocket
> science, I would believe there is more to the problem than just the -stat.
>
> Also, when you do put the new -stat in, there should be a small hole on
the
> upper part of the large disc. It may have a little poppet in the hole or
> may just be a hole. This is there to allow the air trapped behind
the -stat
> to pass when you are filling the system. If you trap air in there it may
> boil over due to the uneven cooling.
>
> -Fred W
>
>

On Sun, 03 Oct 2004 19:46:46 +0000, mojohotmail wrote:

> thanks Fred
>
> a bit more info in order to contextualise things.
>
> i took the old therm out a while ago because it got knackered. it got
> knackered because i poured some 'rad-weld' type stuff in to stop the rad
> from leaking. subsequently changed the rad but couldn't get hold of a
> therm for love nor money until yesterday.
>
Hmm, with your having used "some 'rad-weld' type stuff" I think I'd go for
a full cooling system flush at this point.

> btw, tried the thermostat in hot water routine. opened up but only when
> close to boiling point. will see if there's a different type available
> that opens a bit sooner.
>
Close to boiling doesn't really say a whole lot. The stat for your car
could be a 71C, 75C, or 80C unit. That means that they be fully open at
those temperatures, which are pretty close to boiling. To be a valid test
you need to measure the temperature when the stat just reaches the full
open position.

--
The instructions said to use Windows 98 or better, so I installed RedHat.