Overheating

H

hcbothmann

New Member
Messages
9
Reaction score
0
Location
Denmark
I am hoping someone in the forum can shed light on a heating issue I have with my 1971 BMW 3.0 CSI. Here is a bit of background.

The car has not had an overheating issue for years, but suddenly began overheating (temperature gauge int or a fraction under the red area). The water in the hoses between waterpump and radiator goes very hot within 3-5 minutes of driving.

To begin with, I tried fault finding and initially replaced the water pump, thermostat housing (not original – see picture) and thermostat. This did not solve the issue. Upon inspection by a BMW specialist the verdict was a broken head gasket causing the heating problem. That was replaced and it seems to have partially solved the issue, but the temperature gauge is still too high.

The following has been carried out to address the overheating problem:

1. New thermostat housing
2. New thermostat (80 degrees)
3. New thermostat cap on coolant reservoir (100 degrees)
4. New water pump. Make: Temot Spare part no. 11 51 1 263 934.
5. New cylinder head gasket
6. New coolant
7. New upgraded radiator installed (bigger dimension for greater water flow)
8. New radiator/water rubber hoses
9. Kenlowe fan mounted to new radiator (however, not connected yet)

All parts have been purchased from Walloth & Nesch in Germany who (as many of you likely know) carry solid quality spares.

Thanks in advance for any tips on solving this issue. If anything needs clarifying, I will happily respond to the best of my knowledge.

/Hans Christian

BMW 3.0 CSI 1971
 

Attachments

  • Waterpump - pic 1.jpg
    Waterpump - pic 1.jpg
    82.8 KB · Views: 169
  • Waterpump - pic 2.jpg
    Waterpump - pic 2.jpg
    91.8 KB · Views: 335
Was the air properly bled out of the cooling system via the bleed screw?

Is your fan clutch engaging properly?
 
Thanks, Stevehose,

- Yes, I believe it was bled properly. Will double check though.
- Fan clutch does engage properly.
 
Since you have the later model water divider, you need the thermostat that fits that specific item. If not the thermostat may not open, worth a look.

Also, your rad cap is 1 Bar, not 100 degrees.
 
check that the thermostat is installed in the correct orientation, if it is reversed it won't open.
 
9. Kenlowe fan mounted to new radiator (however, not connected yet)
Click to expand...
attachment.php







Since the headgasket was replaced, one has to ask, did that improve the cooling issues, at least for a short term? I ask wondering if the headgasket issue was a cause of the overheating or a byproduct?

You mention that your fan clutch engages properly and your attachment clearly shows a mechanical fan clutch. However, you also mention the existence of a non-operational electric fan in front of the radiator. Although this should not be a significant impediment to radiator air flow, especially with a larger radiator, it is nonetheless a restriction (unless it is functioning or freely rotating) and could impact the radiator's effectiveness. In other words, consider making it functional - or delete it.

I will assume from your narrative that you eliminated the possibility of a faulty temperature gauge. The gauge is notorious for acting up.

Like others have suggested, I would also want to test the thermostat for proper temperature operation and orientation. Can you actually observe coolant moving though the reservoir?
 
I was chasing a similar issue, until I traced it to my gauge. When it runs hot try tapping the gauge with your finger. If it falls down to normal you should be fine.

Also similar to you, mine was actually running warm and had a faulty gauge. It was a frustrating process until I got it all sorted.
 
Fire the person or shop that installed your tstat.

Obviously incompetent.
You may have to replace the head gasket and radiator now.

Buy a laser pointer pyrometer and let us know when you have it in hand.

I won't help you though if you continue to work with the same shop.

Where are you located?
 
As Chris referenced it's not the water pump part # that is

Important, it's the tstat part # that matters.
The next time someone gets near your car with a tube of black RTV and starts gooping up your coolant system- run like hell.
 
You must log in or register to reply here.
Back
Top