overheating

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mattyray
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Thu Jul 17, 2008 12:39 am

my 320i's overheating temp g going up 2 red regardless! no sign of water leaks but water is brown colour? lots of strange gurggling nosies coming from the pipes around the rad, when i squeezed the large pipe coming out of bottom of rad which was cool? (others red hot) it seemed like it was pushing air around making lots of nosies?

do i have air lock? water not circulating? or sumit more serious? cheers!!!
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Thu Jul 17, 2008 1:10 am

Maybe the thermostat has gone and its closed i am not completely sure i need to look at the engine bay as it is not fully blueprinted in my mind as yet, i am sure some of the clued up lads will be along soon to help you out mate. 8)
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Supafly
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Thu Jul 17, 2008 1:35 am

If the water is brown coloured then its very likely that the cooling system has been neglected.

First few things I would do is, see if the viscous fan is working, then do a thorough coolant flush and refill with the correct coolant mix and pull the thermostat out and put a new one in. If you search for coolant flush and viscous fan I'm sure you'll find all the info you need on how to do it. Make sure you flush the block out too, a 19mm bolt on the side of the block if I remember correctly.

If you need any more help then post up, there are lots of knowledgeable and very helpful people here.
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mattyray
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Thu Jul 17, 2008 2:01 pm

cheers bro! spoke to my mechanic mate today and he,s coming over to have a look on saturday, problem could be a few things i just hope it aint the head gasket or worse!!!!!!!!!!!!!

Yeah the viscous fan is working! and the thermostat i didnt think that affected the actual engine temp it just makes the temp gage go up and down? which it is doing but what do i know lol, once again just praying it aint a head problem.

just to add there,s no mayo on oil filler cap and no smoke coming off exhaust.
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mattyray
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Thu Jul 17, 2008 2:05 pm

also it had new water pump and coolant few months ago when i had cam belt done.
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Thu Jul 17, 2008 2:52 pm

Thermostat affects the temp of the engine. It opens to let colder water from the rad circulate round the block once the coolant reaches a certain temp (depending on the particular thermostat in use). If the coolant is below that temperature it stays closed to avoid the engine running cold.
Blue temp sensor feeds engine temp information to the ECU for fuelling.
Brown temp sensor sends temperature information to the gauge on the dash - I think this is the bit you're getting confused with above.
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mattyray
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Thu Jul 17, 2008 2:57 pm

thanks morat! its good to learn and very interseting!
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mattyray
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Thu Jul 17, 2008 4:51 pm

right went out for a drive round block and temp gauge was going str8 up to red again after only after 5 mins! came back in and read somemore about leaving heaters on full blast so took it round block again trying this and it made a big differance it took a lot longer for gague to go up and it settled just past the half way mark what does this mean :?
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Supafly
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Thu Jul 17, 2008 6:26 pm

All this means is that your heater matrix is doing its job. Basically taking the heat from the coolant and transferring it into the air which gets blown into the car.

If its had a recent water pump and coolant change then I'd bet it hasn't been fully flushed, if your coolant has turned brown. Unless someones used red coolant which tends to look brown in an old expansion tank... take some out to see if its actually brown/rusty or just red.

How do you know that the viscous is ok even when they're shot they still spin around. An old test I know of is to let the engine get warm then using a lightly rolled up newspaper try to stop the fan. if it stops then your fan clutch is knackered. if it starts to shred the newspaper then its good.
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Bobbydoughnut
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Thu Jul 17, 2008 10:35 pm

Cold bottom pipe means no circulation through the radiator, gurgling noises is the too high water pressure on the output side of the pump but there's no flow to release it, were the hot pipes really pressurised, hard to press? When you refill an E30 with water, you need to have the heater on full hot and fan on high, that opens the heater matrix valves and allows any air to be circulated out. Does it stay ok at half now even with the heater off?
The brown water (could it be orangey pink?) is down to years of either not changing the coolant mix regularily or the wrong type of coolant mix 2 start with. Needs a good flush out with a hose if it's rust brown water as Matt say to clear it all out and get the proper coolant mix for it, especially as it is a mixed metal engine....
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mattyray
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Fri Jul 18, 2008 2:15 pm

right fan is shot stops easily with newspaper! so that needs sorting cud this be the solution?? but wouldnt explane the noises and cold bottom pipe???????????

to answer bobby water is defo browny colour, hot pipes are hard to sqeeze, and when i turn heater off temp gague rises heading for the red.
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Sat Jul 26, 2008 10:06 pm

it could also be airlocked so try squeezing all of the hoses with the bleedscrew (on the thermostat) removed completly removed and add water to it then start the engine and squeeze them again then leave them until you see water coming out of the bleedscrew (or a bubble then the water) coming out of the bleedscrew hole.
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mattyray
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Sun Jul 27, 2008 7:48 pm

turned out i had shot thermostat replaced now and its fine! :D
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Brianmoooore
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Sun Jul 27, 2008 8:47 pm

mattyray wrote:right fan is shot stops easily with newspaper! so that needs sorting cud this be the solution??
Fan lock up is triggered by the heat from the radiator, and since there was no circulation through the rad., the viscous coupling is possibly (probably?) O.K.
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mattyray
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Mon Jul 28, 2008 11:22 pm

thanks m8 will check it out tomorrow cheers!
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