Cars overheating, worried

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Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
Posts: 36

  Z3 roadster 1.9i

Cars overheating, worried

Post by Wanting Z3 »

Bought the car a couple of weeks ago. Drove 120 miles back home no problems. Been on short 15 minute drive since again no problems. The gauge has never gone past 1/2 when hot.

Today after 15 mins I noticed irratic temps and it went right into the red!

I noticed fans weren't running at all. There doesn't seem to be any fluid leaks.

I let the car cool and limped home with temp guage moving from just over 1/2 to red.

Help!!
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Robert T
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Joined: Mon 12 Jun, 2006 10:35
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  Z3 roadster 1.9
Location: Cheshire

Re: Cars overheating, worried

Post by Robert T »

What kind of fan does you car have? Viscous coupled or electric? If it is viscous, the fan should run all the time, if electric, it will be static.

If the fan is not working at all, then provided you are driving at a reasonable speed, you should have sufficient air coming through the radiator not to need a fan. If you remain stationary for any length of time, then the temperature will climb rapidly. Note that on some (most, possibly all) Z3s the temp gauge is "buffered" meaning that it will sit dead centre for a range of temperatures and only move towards the red when the temperature gets higher than the normal operating range - this means you can't see the temperature creeping up until it exceeds what is considered to be normal.

For a viscous coupled fan, I can only see it being the viscous coupling or possibly the waterpump. IIRC the same belt that drives the fan also serves the alternator, so you'd have a flat battery pretty quickly.

For an electric fan, check the fuses, thermostat and possibly the fan itself.

I note that you said "fans" and not "fan", so does you car have aircon?

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
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  Z3 roadster 1.9i

Re: Cars overheating, worried

Post by Wanting Z3 »

Yep it's got AC
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Robert T
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  Z3 roadster 1.9
Location: Cheshire

Re: Cars overheating, worried

Post by Robert T »

I'm not 100% familiar with the facelift 1.9, particularly w.r.t. aircon, but I believe you will have two electric fans on that - one for the aircon and one for that car. If the aircon works, then running the aircon should activate the aircon fan which will pass some additional air through the radiator. However you need to find the problem with the other fan, so start with fuses and work from there.

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
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  Z3 roadster 1.9i

Re: Cars overheating, worried

Post by Wanting Z3 »

Many thanks for help my friend. Will update once its back from garage
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Southernboy
Joined: Thu 07 Oct, 2010 12:39
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  Z3 roadster 3.0i
Location: Johannesburg

Re: Cars overheating, worried

Post by Southernboy »

I expect you did check the coolant level to ensure it wasn't running low. If it is, top it up and check it again within a day or two...if it has dropped significantly, you have a leak. Leaks may not be apparent as wet areas...the water / coolant may be escaping as steam while driving, and when it's hot, it will be under pressure in the system. The "leak" may simply be a hose clamp which isn't tightened down sufficiently, and allowing steam to escape at the connecting point.
Oh, and if you are ever driving along, and the temp guage gets dangerously high, turn the heater on fully, with the fan on high...this will dissipate some of the heat from the water / coolant...put the roof down if it's too uncomfortable inside the car...The water / coolant is what passes through the heater matrix to create the heat in your car, so by turning it up fully, you use the heater fan to draw loads of heat out of the system...it may just save your motor... :wink:
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Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
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  Z3 roadster 1.9i

Re: Cars overheating, worried

Post by Wanting Z3 »

OMG I've just checked the coolant and its took a litre. The bottle is stained so it looked like it was full from the outside.

I'm hoping its just this. Will get the garage to check hoses.

Amazing advice thanks
geminimustang
Joined: Mon 11 Jun, 2012 21:06
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  Z3 roadster 1.9
Location: Wirral

Re: Cars overheating, worried

Post by geminimustang »

A car doesn't just lose a litre, take a refill and be ok.Something is causing the loss but if it was a hose, I'd expect to see fluid on the floor or at least a wet spot in the engine compartment.I'll watch this thread with interest.
gookah
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  Z3 roadster 2.8

Re: Cars overheating, worried

Post by gookah »

My wife's did the same, unfortunately it was the head gasket, rear head bolt snapped M43 1.9 engine...
Lets hope yours is not as drastic, and maybe just the plastic elbow at the back of the engine..
Pull the dipstick and see if the level has risen, or looks milky
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Jonco
Joined: Sat 04 Jun, 2011 07:24
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  Z3 roadster 1.9
Location: Cheshire

Re: Cars overheating, worried

Post by Jonco »

geminimustang wrote:............... but if it was a hose, I'd expect to see fluid on the floor or at least a wet spot in the engine compartment.I'll watch this thread with interest.
I'm also looking for a coolant loss at the moment but it does not leak when cold so no pools on floor or in engine well. As a Southernboy says it can be escaping as steam when under pressure - if so, you should eventually notice white salt deposits around any leakage point. Mines going up on the ramp tomorrow to check rad drain plug.

I also agree with GOOKAH that you should also eliminate the head gasket as the cause. Check your oil filler cap or dipstick for signs of emulsification and any oil gain. If ok that's a huge relief.
swamper
Joined: Thu 13 May, 2010 17:14
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  M roadster S50
Location: Mossley

Re: Cars overheating, worried

Post by swamper »

check the bottom of the radiator......had me baffled for ages on my 1.9....it pooled in the rear of the bumper....no leaks on the floor and loosing very little but enough for it to keep dropping the level every time i drove it but didn't leak when cold
the badness makes me do it...!

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BIG DAVE
Joined: Sun 15 Aug, 2010 20:17
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  Z3 roadster 1.9i
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Re: Cars overheating, worried

Post by BIG DAVE »

my 1.9 done the same this time last year found radiator was partly blocked hot and cold areas on rad. put hand on rad at various points to see if any cooler areas be carefull its hot, does it cool down with heater at full blast try that i replaced rad problem solved but bleeding system a pain in the neck someone mentioned plastic elbow at back of block mine is leaking there at moment new elbow being fitted today so have a look at this area its very difficult so see drips down back onto gearbox hope you get to bottom if problem soon
bigD
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jont
Joined: Tue 18 Oct, 2005 10:54
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  Z3 roadster 1.9
Location: Brisbane

Re: Cars overheating, worried

Post by jont »

Check the radiator fan thermal switch it is located on the top left of the radiator
the electric fan should kick in when the temp goes past the centre of your gauge if not the switch is RS easy to replace.

Johnt
Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
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  Z3 roadster 1.9i

Re: Cars overheating, worried

Post by Wanting Z3 »

The oil is clean as a whistle. The only other thing I noticed was I accidentally switched the A/C switch on. Might just be a coincidence.
Jonco
Joined: Sat 04 Jun, 2011 07:24
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  Z3 roadster 1.9
Location: Cheshire

Re: Cars overheating, worried

Post by Jonco »

Jonco wrote:
I'm also looking for a coolant loss at the moment but it does not leak when cold so no pools on floor or in engine well. As a Southernboy says it can be escaping as steam when under pressure - if so, you should eventually notice white salt deposits around any leakage point. Mines going up on the ramp tomorrow to check rad drain plug.
Had mine up on ramp - drain plug was ok - but leak is from expansion tank bottom joint when under pressure. White tell-tale deposits when cold. :head:
To radweld or replace - that is the question. :cry:
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
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  Z3 roadster 1.9

Re: Cars overheating, worried

Post by BladeRunner919 »

Jonco wrote:
Had mine up on ramp - drain plug was ok - but leak is from expansion tank bottom joint when under pressure. White tell-tale deposits when cold. :head:
To radweld or replace - that is the question. :cry:
Replace. The radiators are cheap enough that they're not worth messing about with:

http://www.carparts4less.co.uk/cp4l/c/B ... 097&000261
Wanting Z3
Joined: Sun 28 Apr, 2013 19:57
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  Z3 roadster 1.9i

Re: Cars overheating, worried

Post by Wanting Z3 »

Guys turns out its the radiator that has a slight leak. £220 supplied and fitted by local garage. Going to replace the thermostat at the same time as a precaution.
geminimustang
Joined: Mon 11 Jun, 2012 21:06
Posts: 487

  Z3 roadster 1.9
Location: Wirral

Re: Cars overheating, worried

Post by geminimustang »

[/quote]

Had mine up on ramp - drain plug was ok - but leak is from expansion tank bottom joint when under pressure. White tell-tale deposits when cold. :head:
To radweld or replace - that is the question. :cry:[/quote]
Colin,replace radiator,radweld waste of money imho.
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