Overheating When Stuck In Traffic

[bmw323inewbie]

So , i've had this since I bought my E36 323i (96) 8 months ago now.
When driving on open road, not a care in the world, soon as I hit a traffic jam, I sit and sweat, fearing the heat needle rising towards redline.

I have bled the radiator and topped up and all good, but today I drive 300 miles or so , stuck in traffic twice, 2nd time was near red lining it and had to do something, wasn't worth pulling over because 5 mile tailback (M25),so I had to absolutely cane it , I was stuck in middle lane , and slip road to my left onto M4 doing 40mph, I love that 6 cyclinder beauty
anyway soon as I hit speed, nearing 40mph, goes straight back to the middle bar = ok.

so, i reckon viscous coupling or fan clutch ?
Anyone had this and know. ? I think knowing the problem/potential solution before you go into the garage is a good thing to avoid being stung, as I found with my last experience. ....

thanks in advance.

[abemcclellan]

i'm guessing its the fan clutch or the thermostat. if your fan is spinning very weak, then you might need a new one. yeah i'd check the waterpump too.

[locutuz]

Fan clutch yeah maybe.. park it and let it warm up in your driveway and see if the fan ever engages.. if not, fan clutch is cheap.. or go electric convert for about the same price (maybe cheaper) and gain HP @ the same time.

Another option might be your water pump.. they have notorious failure rates, not positive that effects your '96 but I think that's within the years of the plastic impellor blades that *always* break and require replacement.. maybe just one or two of them shaved off, and it's unable to pump enough water at low rpm. If you replace it, be sure to get a replacement that does not have plastic impellors.

- Nate ('95 M3)

[BimmerDan]

thermostatic switch - possibilty, iv had this exact same problem in a previous car of mine and have you checked/seen that the fan is working?
theres my 2 pence!

[bitcore]

I doubt it's the water pump, they tend to fail catistrophically and the engine will severely overheat withen 5 minutes of idle if not shut off.

[supark]

Sounds like it might be your thermostat - swap it out - it's a cheap part and an easy diy.

[mmclaren]

I had the exact same problem, was the fan clutch, the reason out of town it doesnt heat up is since you have a high air flow going through and in town well not a high air flow, hope that helps

[bitcore]

OH YAH:
BTW: I think it's your thermostat as well.

[mmclaren]

and with the fan clutch replacement, just do the mod of taking it out all together to increase hp

[bmw323inewbie]

Cool thanks got the input and ideas guys, appreciate it.

I think from what i've seen thermostatic switch ; fan doesn't run on idle....so I might try fixing that and if still wonky take it to the garage.

also Bimmerdan, i'm in Surrey any garages you recommend in the south ? I bought mine from Riverbourne in Caterham and they seem quite good...

[schilke]

IF viscous fan is not moving @ idle and you can plainly see it's pulley spinning, then you really better get it fixed.

Waterpump failures tend to overheat @ speed and not at idle or traffic (assuming everything else is working properly)

Thermostats can fail in all sorts of ways, so I agree with bitcore, change your thermostat as well as your fan clutch.

[BimmerDan]

bmw323inewbie - you got mail!

[bmw323inewbie]

answer on this = new fan & water pump (leaking apparently)