M50 cooling issue..

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daimlerman
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Post Fri Apr 17, 2009 1:51 pm

Had an issue with the 'folly' going to work last night.Hit 5000rpm in third winkeye and this was followed by a sudden rise of the temp gauge...followed by a small bang and a cloud of steam...upon investigation I found that the top hose had blown off.Re-fitted,begged water from a nearby house and continued to work.Finished work this morning and bled and filled the system before leaving,but I had to stop and fill up two or three times on the way home,fortunate that the dykes are full this week...
This morning I have investigated further and it seems that water is not circulating,I fitted a new 'stat the other week so feel that the water pump must be suspect.Radiator passes the hosepipe test,top hose gets warm but the bottom one does'nt,sqeesing the bottom hose forces water out off the bleed point.Now as the incident started with a hose blowing off,no circulation(heater is cold)does anyone agree with me,or any other suggestions?
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320Touring
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Post Fri Apr 17, 2009 2:06 pm

Heater blowing cold suggests an Air lock.

Rad hose blowing off suggests a pressure increase..

M50 Thermostat housings are not great re thermostats jamming etc. Best advice is a front end stripdown and investigation

Much like I'm doing to the 320 this weekend :cry:
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http://www.e30zone.net/modules.php?name ... 81#2766881
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abelai
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Post Fri Apr 17, 2009 2:46 pm

Might have the old plastic impeller water pump.
If I can't fix it I'll f**k it up so bad nobody can!!
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Brianmoooore
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Post Fri Apr 17, 2009 2:53 pm

abelai wrote:Might have the old plastic impeller water pump.
Absolutely essential to check for these when doing a M50 conversion!
Has the pressure cap been replaced under the recall, if applicable?
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monkey
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Post Fri Apr 17, 2009 2:54 pm

abelai wrote:Might have the old plastic impeller water pump.
thats wot it sounds like mine fell off the back of the pump
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daimlerman
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Post Fri Apr 17, 2009 2:56 pm

I am using the M50 rad.,Brian,what am I looking for ref pressure cap,please?
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leeparkes
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Post Fri Apr 17, 2009 3:51 pm

daimlerman wrote:I am using the M50 rad.,Brian,what am I looking for ref pressure cap,please?
It should have '140' stamped under the cap on the yellow bit.
Cypriotgeeza wrote:I done both my mates in my old 318is
felt so proud,even tried it with a E30 325i and got put in my place.. :o:
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daimlerman
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Post Fri Apr 17, 2009 5:56 pm

All those who agreed with me that the waterpump was chief suspect form an orderly queue at Mr Moooore's desk to collect your coconut...and the zoner who mentioned the plastic impeller gets two coconuts..waterpump came out in two bits,the plastic impeller had seperated from the drive shaft.Thanks also for the mention of pressure cap,mine has a black inside and was marked '200'...just so happens that I have a spare M40 pattern radiator 'in stock' with the correct yellow watsit and marked '140'.
So 'folly' can go to the meet tonight afterall!
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abelai
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Post Sat Apr 18, 2009 1:05 am

I think my m52b25 (323i) runs a rad cap of 200 same with my friends m50b20 (520i) only e30's that use the lower 140 which does bring the question of what to do when you put an m50/52 in the e30, 140 cap safer for heat exchanger or 200 cap correct for coolant system?

I am amazed to be honest there are any m50s with plastic impellers still out there as it is such a common failure.
If I can't fix it I'll f**k it up so bad nobody can!!
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bss325i
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Post Sat Apr 18, 2009 1:32 am

Do BMW sell water pumps with metal impellers for M50/52/54?
http://www.bmrperformance.co.uk

BMW and MINI specialist - Gatwick
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blingsta
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Post Sat Apr 18, 2009 1:38 am

copy parts from euro's etc are solid, unlike the bmw plastic pumps... i had to change soooo many of these a few years back while i was working at a garage, common fault with the m50's !!!
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abelai
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Post Sat Apr 18, 2009 1:38 am

yes, you can't buy the plastic one anymore m52/54 only came with metal ones.
If I can't fix it I'll f**k it up so bad nobody can!!
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daimlerman
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Post Sat Apr 18, 2009 1:22 pm

My all steel waterpump came from GSF for £40 or so,they also list the plastic type somewhat cheaper.My local dealer would have needed to order a pump....
Strange about the pressure cap issue,I am right in thinking that E30 was modded because the heaters were spaying hot coolant onto legs in the l/h footwell? Cannot think of a sound reason why E34 would need to run at a higher pressure.
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Brianmoooore
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Post Sat Apr 18, 2009 2:54 pm

The coolant cap recall applied over the whole BMW range, not just E30s, but I'm fairly sure it only applied to those cars using the 1.4 bar pressure cap.
The problem was with the excess pressure valve not opening, and bursting the cooling system.
If the electric heater valve failed, it would dump superheated coolant over the legs of anyone in the LH front seat, hence the safety recall.
I had the valve blow apart on one E30 while I was working on the electrics in the glovebox area, which was not a pleasant experience! Sure enough, it still had the original cap fitted.
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capri_rob
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Post Sat Apr 18, 2009 3:00 pm

Just had the pump replaced on my E36 M52 under warranty - the one they took out was all metal.
Image

e30topless said : Proper BMW's have 4 headlights, last of the run was the E30 and E34/E32 anything after that is just complete shite
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DanThe
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Post Sat Apr 18, 2009 10:29 pm

abelai wrote:yes, you can't buy the plastic one anymore m52/54 only came with metal ones.
M52 and M54 had plastic impellers, maybe not all but ive taken plenty out, ive a 2003 M54 that had a plastic pump. Nothing wrong with it so its going back in
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