Car gets hot in slow traffic but fine when moving at a steady speed, why ?

FastLife91

Torque Junkie
Points
57
Location
England
Car
Ford Focus mk2
I've had my current car ( 57 plate vauxhall vectra 1.9 CDTI) for 1 month. I've noticed that when in slow moving traffic such as rush hour , overall any real slow moving causes this problem.
problem is the temp gauge goes to half way and stays there for a few minutes, then it goes about 1 - 2 mm above half way and strays there for a while before dropping below half way again.
however when driving at a steady speed the temp gauge stays way below half way.

I've been told on owners forum by someone saying this is normal on these car's, however somebody else said it is not normal.

questions please can you answer each one.

1 - is it safe for the temp gauge to go about 1 - 2 mm above half way ?
2- what could the causes be ?


thanks
 

TCJBOLDIE

Moderator
Staff member
Points
697
Location
Brisbane
Car
2011 Honda FN2
- Fan belt slipping
- partly blocked radiator from the accumulation of bugs etc
- Thermostat not opening fully
- radiator may need cleaning internally
 

obi_waynne

Administrator
Staff member
Moderator
Points
1,157
Location
Deal, Kent UK
Car
A3 1.4 TFSI 150 COD
This is quite normal - you only have to be concerned if the temp gets near the red.

In traffic the air is not pushed through the radiator so it is not as effective at cooling. At some point the fan will kick in to pull air through the radiator but this is usually just over half way on most cars.

If the fan doesn't kick in, then get the fan sorted, it could be a bad switch, poor earth or bad thermostat.
 

FastLife91

Torque Junkie
Points
57
Location
England
Car
Ford Focus mk2
- Fan belt slipping
- partly blocked radiator from the accumulation of bugs etc
- Thermostat not opening fully
- radiator may need cleaning internally
1. The fan belt looks fairly new, the previous owners didn't recall it having been replaced but car is at 139,300 miles and for the belt to look that good it must have been replaced at some point.

2. I do question the radiator, also there are quite a lot of missing fins, some rows even have almost no fins.

3. I am suspecting the thermostat as a possibility

4. when the temp gauge goes above half way by approx. 1-2 mm does this mean the engine is in danger ?


ty
 

FastLife91

Torque Junkie
Points
57
Location
England
Car
Ford Focus mk2
This is quite normal - you only have to be concerned if the temp gets near the red.

In traffic the air is not pushed through the radiator so it is not as effective at cooling. At some point the fan will kick in to pull air through the radiator but this is usually just over half way on most cars.

If the fan doesn't kick in, then get the fan sorted, it could be a bad switch, poor earth or bad thermostat.

hi

on my previous cars the temp gauge never went above half way unless there was a problem. I have noticed on my previous car/s I could usually hear the cooling fan come on while sitting in the car, however I do not hear the cooling fan on this car even when the engine temp gauge is at or above half way by 1-2 mm.

Also noticed many missing fins on the radiator, some rows are almost empty without fins, is that a possible problem ??
 

Yugguy

Torque King
Points
507
Location
Rugby (expat Preston lad)
Car
Merc C220Cdi Elegan
You worry too much fella.

A slight movement is perfectly normal especially in hot weather. If it was to be ranging between say 1/4 and 3/4 on the dial while driving then that's an issue.
 

TCJBOLDIE

Moderator
Staff member
Points
697
Location
Brisbane
Car
2011 Honda FN2
You checked the belt and it "looks fairly new" but did you check the tension to see if it has worn or stretched and may need adjusting tighter to remove the chance that it may be slipping ??
 

thexav

Pro Tuner
Staff member
Points
387
Car
2002 Clio 172
It sounds quite normal to me as well. Just make sure it doesn't get into the red.

You could add some coolant booster (like water wetter) to aid the cooling.
 

ViFeiler

Full member
Points
28
Location
SG
Car
MB Kompressor
Some have said this is normal. However, Have you checked your coolant level? If it's low it could cause that problem. Another possibility is the radiator could be plugged and is restricting the flow of the coolant. One thing more, it might be a thermostat problem.
 

FastLife91

Torque Junkie
Points
57
Location
England
Car
Ford Focus mk2
Some have said this is normal. However, Have you checked your coolant level? If it's low it could cause that problem. Another possibility is the radiator could be plugged and is restricting the flow of the coolant. One thing more, it might be a thermostat problem.

hi.

Yes coolant is fine but it does look as though it's dropped a few cm's from the bottle over past few months.

I am wondering about the thermostat, though when not in slow traffic the temp seems fine
 
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