318i temperature

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parakeats
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Post Sat Oct 11, 2014 6:07 pm

Wasn't sure what to search for to find this answer, so here goes!

When driving normally, temperature is fine - middle of gauge. However, when I get to a big hill and put my foot down to maintain speed going up it (mainly on motorways) the temperature gauge reaches 3/4 and then the viscous fan cuts in and cools it down, never gone past 3/4 but is it meant to increase or should it stay at 1/2?

kinda just put it down to being 25 years old and as the fan cuts in it's not a problem <-- is this the case?

Another thing is after a drive and the temp gauge reading 1/2, if you park it up and leave it for a minute then turn the ignition on, the needle is then reading 3/4 or even above sometimes. When started this comes back down to 1/2 with water circulation and fan running.

I'm more worried about the second issue, is this something I should be worried about and investigating? or is that a normal occurrence?

Probably explained that terribly, but you might get the idea :P

Cheers
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blazed
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Post Sat Oct 11, 2014 6:12 pm

http://www.e30zone.net/e30zonewiki/index.php/Cooling

could be a couple of things, i had similar on a e36 and it was the thermostat but have a read of the wiki and see which one suits.
parakeats
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Post Sat Oct 11, 2014 6:20 pm

Have read through there, and it doesn't really sound like any of the problems listed, I'll go out and double check coolant levels oil colour but I'm 99% sure it's none of those.

Have kinda put it down to a hotspot just where the temperature sender is? which would explain getting hot after engine is off with no circulation?
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Brianmoooore
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Post Sat Oct 11, 2014 6:58 pm

It's normal for the temp. gauge on any car to read a little higher than normal when switched back on a minute or two after having been driven. This is known as heat soak, and is why whenever you pull into a motorway service station or a fuel station after a high speed run you should let the engine idle for a short while before switching off.
Your car, however, definitely has a cooling problem. Possibly a problem with the water pump (how long since it's been changed?), but equally likely a worn out and partly clogged radiator. They don't last forever, and should be considered a 100,000 mile service item.
parakeats
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Post Sat Oct 11, 2014 7:23 pm

Should this heat soak be as high as 3/4 or almost touching the red at times? No idea when it was last changed, had the car for 6 months, the cars only done 20k in the past 9 years it's at 95k now. I don't have the history with me (at my uni house) but I know it had a cambelt change about 18 months ago, would they look at the pump with that (have read it's easier while everything is off).

I probably wont get around to looking at it properly until i'm back home come December with all my tools and equipment. or do you recommend looking at it earlier? While running the car sits at 1/2 and only slowly increases to 3/4 in a queue when the viscous fan cuts in and brings it back down.

edit - on a 120 mile run from Bristol to Plymouth, the engine temperature didn't budge from 1/2 until i booted it up telegraph hill, so to me that would suggest pump and flow were fine? (but I'm really no expert, if there's way to check these without taking half of the system off I'll have a go) It doesn't seem to like extended foot flat (which only ever happen up hill, on flat I would be speeding, and that's bad 8))
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Brianmoooore
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Post Sat Oct 11, 2014 11:23 pm

If I didn't have the history of the car, I would definitely have changed the water pump at the same time as the cambelt, but if you had the job done by a garage, then they wouldn't have touched the pump without you asking. One pump is good for two cam belts IMO.
First thing to note is that the E30 does not have a linear temp. gauge. The bit in the centre is expanded, so as long as the needle is away from the red, it's not as hot as you may think.
E30s in general should have plenty of cooling capacity though, so Telegraph hill shouldn't really affect the needle by much, although IIRC, the needle goes up a bit on mine if I give it full throttle all the way up.
Have you had the centre kidney grill off and had a look at the front of the radiator, to see if it's partly blocked with debris?
parakeats
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Post Sat Oct 11, 2014 11:36 pm

the previous owner had the belt done not me so without looking myself I couldn't say :P I remember reading that about the pump somewhere... It doesn't worry me a massive amount as long as it doesn't actually overheat - I've got a good eye for temp gauge movements so should spot it in case it does happen... and who know, it might speed up my m52 conversion? :rolling:

That's helpful to know, I was thinking about getting one of those infra-red temp thingies, can get them pretty cheap off fleabay (not sure on the quality though...) any experience on these? seems like a useful thing to have lying around in the box!
I think last time I went up it it almost reached 3/4, then cooled off as soon as I wasn't on full throttle - just never experienced this on any of my past cars. Regards to looking at the rad, i'll pop my head in tomorrow and have a little look around, is it just blocked/bent fins i'm looking for?

Cheers