overheating 156

[baldy1926]

my 156 started to over heat yesterday in traffic-what are the likely causes of this-what should i be looking for?

[V6Alfisti]

Is the fan kicking in? (thats the first check)

If so, then the likely cause is the thermostat.

[wrinx]

If the fans are working the radiator could need changing. Faulty thermostats usually stick open causing cool running, not hot.

Another possibility is the water pump but that's rare and usually affects running temps, not when in traffic.

Check your fans and radiator....

wrinx

[mph147]

Have a look at this.

http://www.alfaowner.com/Forum/engines-ts-jts-jtd-...

Should do the job

[bint]

mph147 said:

Have a look at this.

http://www.alfaowner.com/Forum/engines-ts-jts-jtd-...

Should do the job

What about a V6? Is the thermostat in a similar place?

I know mine needs changing and I haven't gotten around to booting up the CD manual I have and that how to guide is great!

[Avocet]

I have a feeling the 156 has a two speed fan switch. A mate of mine had a 2 litre t'spark and complained that it would run hot - hotter than usual, and then the temperature would suddenly drop back to normal. It turned out that only his high speed part of the fan switch was working. The low speed part was corroded up. There was a resistor somehwere near the top left had (as you sit in the car) corner of the radiator (I vaguely remember).

[mph147]

V6 is totally different and have absolutely no idea,

Sorry.

[exgtt]

Avocet said:

I have a feeling the 156 has a two speed fan switch. A mate of mine had a 2 litre t'spark and complained that it would run hot - hotter than usual, and then the temperature would suddenly drop back to normal. It turned out that only his high speed part of the fan switch was working. The low speed part was corroded up. There was a resistor somehwere near the top left had (as you sit in the car) corner of the radiator (I vaguely remember).

The above is correct, first slow fan should start at 90 degrees and the second faster fan kick in at around 92 degrees. You can test the slow fan by turning on the air con - this will activate the slow fan.

When you say overheating, by how much? My V6 will creep to 93 and the fast fan will bring it down to 90 in slow moving traffic. It's normal especially given the hot weather and the fan will be on and off pretty much all the time when not going above 25 mph. Not sure about twin sparks or diesels though - the V6 is much fuller under the bonnet than the twinnys. This fluctuation in hot weather is normal on a V6.

If it's overheating (above 95) when stationary or slow moving and you have no water leaks then my moneys on the rad - they have a useful life of 6years or 90k (in my experience) and look perfectly fine until you take em out and they fall to bits! When my rad was foook3d it got hot whilst thrashing @ speed aswel.

Another possibility is the waterpump especially on the V6 but a knackered rad is much more common and cheaper to sort!

Edited by exgtt on Sunday 11th May 00:42

Edited by exgtt on Sunday 11th May 00:47

[baldy1926]

the temp guage was hit the end stop the traffic was heavy it did drop back slighty when in free traffic then it started to steam!!!.its not been used for a couple of weeks but it did a 250mile run the other week no prob.this time i did put the air con on as well-i dont know if that will effect it.dont know weather to just replace the themostat or do the rad as well

[Mave]

My £££ would be on the radiator. Even if it was OK a few weeks ago, a combination of hot weather and using the aircon is probably enough to tip it over the edge

[Wombat Rick]

baldy1926 said:

the temp guage was hit the end stop

Geez!! Get it sorted quick or you'll be looking at head gaskets and all sorts of other trouble before you know it!! As mentioned check the fans and the radiator as soon as poss!!

[baldy1926]

not used it since it was only about 1 or 2 miles at the most with the high temp so hopefully it should be ok