S2 4.2 Cooling

[robertmurrell]

Hello,
I have a problem with my E.
The engine has been rebuilt, all the cooling jackets were flushed and cleaned by me so I know they are clean, the head is very clean inside.
It has a new water pump, the timing is fine, it has a new thermostat, it has new leads, plugs and electronic ignition with new distributor geometry dash scratch
It has newer type fans on the radiator not them crappy originals.
The car runs fine (and on keeps cool when pushed hard) even when on a very hot day as I have had in Europe recently, but when in slow moving city traffic it gets very hot, like near the red hot. The fans work.
The only thing I have not done is change the radiator, but it does look clean inside from what I can see.
Would a new aluminium type stop this, or do I just have to avoid town traffic.
What I do notice is that oil pressured drops too at low revs when it gets CITY hot so the engine is actually very hot and not just the temp gauge.

[DWW]

I would check whether the fan is pulling cold air in rather than pushing hot air out the front, in which case the polarity of the fan wires needs reversing.

[chrisfell]

As Danny said, I had just this problem and it was that the fan was wired to push rather than pull air through the radiator. At a standstill it worked, but driving slowly in traffic the air coming through the nose stopped the fan pushing enough air through the radiator to cool the engine.

Simple to check, also simple to correct.

[malcolm]

When you say oil pressure drops, how low do you mean?

[mgcjag]

What fans are you useing....in front of the radiator or between radiator and engine...the later is the way to go with a correct cowl fitted to the radiator..
Steve

[MSM]

The fact that you say it keeps cool when pushed hard eliminates the radiator as a problem.

As has been suggested already check the airflow direction, if the fans are on the engine side of the radiator, where they should be, see if a piece of paper stcks to the radiator air inlet face when the fans are running. That shows the fans are sucking.

How does the cooling perform if you leave the car ticking over on your drive? If the fans cycle on and off when it gets hot that is what should happen but it sounds as if it does not happen in city traffic which could indicate wrong airflow direction.

Report back.