I have an Audi A4 1991 2.6 V6 model, with a overheating problem since they fitted a new radiator, it goes up to 90 deg but then after about 10 km it goes over to 100 to 110 deg. Could this be a faulty thermostat if so where is it located on this model engine

A failed thermostat stuck closed will cause overheating. Test that item by boiling it. Nearly all car thermostats will have opened fully at 100 deg C. There may also be a number stamped on it to indicate its opening temp. You can keep track with a kitchen thermometer with a range above boiling.

A blown head gasket will often cause very quick overheating, and you may also see white bubbles like dry ice in the radiator neck. There is a simple test for combustion gases in the coolant, which any competent mech can do for you. The kit can also be bought from Autozone etc.

https://www.youtube.com/watch?v=a3J00_e7fyo

It is possible that the water pump has corroded away internally and is not circulating water, but if the car has always had antifreeze added, that should not happen. My Camry V6 water pump was still good after 220000 km. If you do get in there, replace the timing belt while you are at it.

A faulty temp sender in the block may also cause overheating, but only because it does not start the radiator fans when it should. You would notice if they were not running when the engine got really hot.

Tailpipe drips don't tell you much, as there is always moisture in the exhaust gas.

Forenza 2004
this is a Suzuki, id sell it, and is not even real Suzuki its a badged
product. actual. Daewoo Lacetti
Daewoo can't sell cars here so suzuki tries and fails... amazing car.

p0217 means overheated.
and when overheated power is lost. stop that or burn up the engine.
do the service on engine, 60,000 miles. steps.
and a new thermostat. i bet yours is 10 years old,,huh and END of life.
non last over that.
id sell it. when fixed, Suzuki's are no good.

FSM data.
Trouble Code Conditions:
Engine is running. Engine coolant temperature is higher than 50 Deg C (122 deg F). Intake Air Temperature (IAT) is higher than 35 deg C (95 deg F). Engine soak time is higher than 360 minutes, or start-up coolant temperature is less than 45 deg C (113 deg F). Engine Coolant Temperature (ECT) sensor reading is greater than 107 deg C (224.6 deg F).
Possible Causes:

• Sensor ECT
• Circuit
• ECM

the fsm skips bad thermostat. odd that... huh"?
and dead cooling fans.
and clogged radiator.
etc.
the first step is to see if it really is overheated, with a IR pyro gun.
if not, the ECT is bad
if is overheated, then fix that, as the ECT didnt lie.

simple , the sensor lied, (nah) or did overheat.

or air pockets at the ECT, low coolant actual.

90 deg C is normal for a vehicle standing for some time. What does the temp read when the car is on the highway doing around 100 km/h.

Grant, you need to check if the pump is ok with your model engine, not just the car model number, these cars were fitted with at least four
different engine variants that i am aware of.
i don't think you should attempt to fit it if you don't know at least that much, sometimes the cambelt has to be removed first, thats a whole
different kind of level of experise required.
good luck

how about replacing the termstat and when you do this make sure you get all of the air out of the system. also make sure your fans are coming on when engine comes up to temp. if you turn on the a/c the fans or fan should automatically come on.

Follow the upper and lower radiator hoses to the engine block (upper first). At the end of one of these hoses, there will be a "bubble" housing attached to block -- thermostat is under that.

Charlie

I do,but no you dont

I had that same problem on a 1990 audi 90.

Turns out the radiator was leaking, so the coolant kept running out causing the temp light to go on. as a temporary fix, you can keep topping up the coolant, but otherwise you are going to need to get that radiator fixed. by the way, audi 90s have TWO radiators; in my case it was the smaller radiator that had gone. 

new radiator later, and it was fixed. unfortunatley, my temp gauge has never work...

Sounds like your thermostat may be sticking try recalibrating it or replacing it

First when it has cooled down, check the water level in the radiator. Then determine it overheats while idling, does the fan turn on?