03 mk4 vw golf 1.6 petrol 143000kms new tbelt and water pump and thermostat fitted 12 months ago. Fans running full time when engine is running. Overheats when engine is running at low speed ok at high rev. Waterpump or thermostat??

2.0L liter? must be MARK IV in UK???? petrol right? not 2.0 TDI

ours is USA only 1.8L I4, here. +2.5 and 2.8
or 1.8L is belted cams.

In UK the belt is 120km /5year rated. at VW


the manual said for p0322 , the 2 sensors read wrong
that means it is out of time.
and fully normal this old. ignored for 20years, 2002 to 2023?


if the cam belt is bad
1000 new cam and crank sensors will never ever fix the car.
see?
with a water pump too see how it runs off the same cam belt>
do the full kit.

see this for fast example, and real, belt, I'd buy gates belts.or DAyco.

https://www.ebay.co.uk/itm/VW-GOLF-MK4-2-0-GTi-8V-TIMING-CAM-BELT-KIT-WATER-PUMP-TENSIONER-NEW-/271021267537

Time for a service as the transmission fluid will only leak out when there is an issue. I suspect the clutches are worn out or the pump is faulty.

not an auto matic fault

engine checks to make
soft hoses
clogged radiator ..try a flush
thermostat
thermatic fan temp switch
thermatic fans might be spinning too slow
water pump worn


or a head gasket .?

My first question is make model and year.
Second, are you saying the engine is boiling over into the overflow tank and onto the ground ? Is the tank about half full when the engine is cold ?
Have you run the engine with the thermostat removed to test ?
Usually when you can hear the coolant moving around, you have air in the system and it is not full of liquid coolant.

Is the cooling fan coming on and working? If not the fuse, or relay may be bad. Did you bleed all air from the system after the service, and did you replace the thermostat? If the thermostat was not replaced then replace it. If all this checks ok, then either the water pump has failed or the interior or exterior of the radiator is clogged. Use only G12 coolant in your VW.

get a new coolant temperature sensor.

the orginal black ones are faulty.

make sure it is the green topped one.

also do a normal tune up with spark plugs, clean the maf, maybe replace coils packs.

There is a part between the air intake manifold and the air box on your engine, it's usually black on a golf, will look like a 15cm tube around 80-90mm in diameter with a plugged wire leading into it, this is your MAF sensor or MASS AIR FLOW sensor and if dirty / faulty can cause an incorrect temp reading from the air intake and cause rough engine starting, this is a very common problem on mk4 golfs... the part is apparently cleanable, with isoprop alcohol, or I assume white spirit. the actual sensor needs to be removed from its housing for cleaning, and as always treat carefully... the part replacement, depending on where you go can be around $50 - $100 used or even new.... part number off the existing one on your car, try ebay as you can do well for price :) could be fouled spark plugs from rich fuel mix on bad airtemp sensor, could be a million things but the MAF sensor is one of the golden oldies I'd be checking first :) Goodluck, Chas

there is a strong possibility that the impellers on the waterpump are broken!!!!. they are made out of plastic and are notorious for breaking. ck this first have seen it countless times. make sure new waterpump has metal impellers.

Replace thermostats.

Wait, your water pump is leaking? if so, that is your problem. Water pumps will slowly leak coolant if their about to go. The thermostat can get stuck open or closed. I'm not sure where it is located in a VW Golf 1997, but it is most-likely a pain to get to it should be done professionally.