Overheats Alfa 145 1.6 boxer

[pawelk]

Good day!
I am from Belarus. Sorry for my English.
My car: Alfa Romeo 145 1.6 boxer, 1996 year
I have a problem. In traffic jams the temperature gets above 100 degrees.
Today, drove through the city, arrived at the parking lot, took a look at what is the temperature of the fan. They are included at this temperature:
b9fea72dfc93.jpg
Included, with just seconds on the 30-40 seems to be on the second speed. Temperature, respectively, not fallen and remains at the same testimony, and they are off and on again after a minute or two.
Unscrewed the cork coolant reservoir, there is quiet, no boiling.
Already replaced the coolant sensor (black, single-contact). 2 years ago shot and completely washed the inside of the radiator. Replaced the resistor first gear. Nothing helps. The next week I will change the thermostat. What else advise? Why not include the first fan speed? How to check the resistor first speed multimeter? Thank you for your advice

[Ralf S.]

Hi Pawelk..

Yes, your English is shocking!

But it's not a problem. Can you confirm:

1) When you drive the car normally, the temperature is okay (78-80C)?

>>If yes, the thermostat, radiator and water pump are okay

2) When you sit in the traffic.. the temperature rises to >100C ?
Does the fan come on? The fan should activate around 90C.

>>It sounds as if the fan is not working for some reason.

3) The heater works okay... the coolant level does not drop and there is no air in the radiator?

>>If yes, then the head gaskets are okay.

Be careful when you open the coolant reservoir when the engine is hot (or even warm). And don't drive the car with the temperature so high.. you will damage the head gasket.


If the problem is the fan isn't working... check the plug on the back of the radiator. Is there a good connection.. (clean and tight)? When the temperature is >90C is there a current at the plug? If you can find a current there.. then the problem is the fan itself.

If there is no current, then the problem could be somewhere else. I think the 145 fan is controlled by the ECU.. but I think that should be okay.. it's more likely to be a fan relay or fuse problem.


Ralf S.

[pawelk]

Thank you for your answer!
1. When driving the temperature 85-90. But if you stop for 3-5 minutes - rises.
Keep going - the temperature is about 100 degrees and does not fall below.
If you stand for 20-30 minutes, the temperature is 80-90
2. If you stand the temperature is> 100. The fan is activated when the temperature both in the photo above. At the fastest speed. Works 30-40 seconds and shuts down
3. The heater works fine. The fluid level is not falling. Oil in the fluid not there. The radiator is completely hot.
4. Checked and cleaned all relays and fuses.

Fan works, but only at a very fast speed. Changed the resistor first gear, but it did not help.

[Ralf S.]

So.. the fan's "slow" speed isn't working. The car heats up until it gets to >100C.. which activates the "high" speed for 30-40 seconds.. then when the fan should switch back to the "slow" speed, it doesn't.. it turns off completely.

Everything else sounds normal and okay.

I'm not sure where the fan is controlled.. but assuming the ECU knows the correct temperature and is sending the correct signals (probably it is.. since the high speed fan is fine) then somewhere there is something which should be switching the slow speed.. but isn't.

I'm sorry I don't know where to check.. Hopefully someone who has fixed the same problem will know and give you some advice soon.

Otherwise you can also try Alfa Romeo 145 - 146 Forum (Powered by Invision Power Board) There's people who wear anoraks and who know everything about 145s on there.


Ralf S.

[pawelk]

Ralf S. Thank you for your help!

[Major_Day]

I think the boxer engines only have a single speed fan, which cuts in at 92 deg. and cuts out again at 87 deg.
I would check the radiator temp. sensor, since the fan seems to be working, but coming on at a higher temp. than it should
It could also be a faulty gauge or engine temp. sensor

http://www.alfa145.com/upload/Alfa14...t%20Aircon.PDF

Page 2 and page 30

[lovely146]

hello everyone im havin a problem with my 146 t-spark 1.6 and the temp just goes up... im sure the problem is the waterpump but does anyone know were i can find it and how to remove it?
thanx

[Ralf S.]

Are you sure it's the water pump and not a knackered head gasket or blocked radiator or a defective thermostat?

Water pumps very rarely fail compared to other problems... What symptoms do you get?

But to answer the question: The water pump is behind the cam belt (beneath the camshaft pulleys) which all lives behind that plastic cover on the left of the engine. You have to remove the cam-belt to change the pump (it is driven by the cam-belt) so if you do have to change the pump, fit a new belt and a new tensioner at the same time.


Ralf S.

[pawelk]

Installed a new radiator. Replace the sensor in the radiator. In the photo the old sensor. Now at a temperature of 90-95 degrees. If reaches 100, then falls rapidly. I hope the repair is completed.
IMG_3756_resize.JPG

[Ralf S.]

That sounds how it should work..


Ralf S.

[pawelk]

Did not help. Today went to town and after 20 minutes the temperature was slightly above 100 degrees and lit lightbulb.
Fans are switched on the first speed (I think this is first rate, because if the air conditioner, the rate is much higher) when the needle is almost 100 degrees. They work no more than 10 seconds on and off. The temperature remains almost there.
I do not know what to do. Change the thermostat? Sensors?
Maybe my computer is an error on a faulty sensor in the radiator and it does not work correctly. May need to somehow reset the error? Remembers whether in my car computer information about the sensor in the radiator?

[Ralf S.]

Hmmm........

It could be the thermostat after all.

I'm not 100% familiar with the Boxer engine but (this is just my theory) you could get these symptoms if the thermostat is not opening 100%.. If it's mostly closed, then not enough hot water is going into the radiator.

If the engine temperature sender is on the engine block but the fan is only activated by the sender on the radiatore, then if the thermostat is not open enough the engine will get hot. You will see a high temperature on the gauge.... but the fan doesn't come on soon enough or stay on for very long because actually the water in the radiator is not really hot like the water trapped in the engine block.

When the water in the radiatore does become really hot (when the car is standing) then it's never *very* hot... so it doesn't take much time for the fan to cool it down again.

You can test this before you change the thermostat. Is the radiatore hot to touch or just warm when the engine is at 100C? What about the hose out from the thermostat..? Does it get very hot or just warm? When the engine is that hot, it should be almost impossible to touch the hoses.. so if you can hold it in your hand, it could be that the thermostat is not opening enough.. so the hot hot water is staying inside the engine block, not getting quick enough into the radiator.

Ralf S.

[Major_Day]

Forget about the gauge for a moment and do as Ralf suggests, check by hand the temp. at the bottom of the radiator,top and bottom hoses,and expansion bottle, if they are indeed at 100 deg. they will be too hot to touch, although in your first post you said that you had removed the expansion cap, but the water wasn't boiling (which it should be if the gauge reading is correct)
If they aren't that hot, it could be a faulty temp. sender (engine block) or gauge
The stat is easy to check just by feel, run the engine from cold for 10-15 mins.,and wait on it heating up to 92+ deg., if and when the stat opens you can check the temp. of the outlet pipe (top hose) from the stat. to see if it goes from warm to hot.
Boxer stats normally fail in the open position,but it looks more like this one has failed in the closed position, but if this was the case i would also expect the water to be boiling in the expansion bottle, since it is not circulating through the rad.

edit: had a few mins. to spare so i nipped out to the car park to have a quick look at my Boxer's plumbing, their is an expansion or bypass hose leading from the stat. back to the top of the expansion bottle, so that if the stat. was closed or partially closed, the 100 deg. water should feed back through that hose into the bottle, so you would certainly see and hear it bubbling back into the bottle.

[pawelk]

When the car is cold, the liquid in the tank is less. When the machine is hot - the liquid becomes greater. Fluid in the reservoir is reduced only after the machine is long and cool completely.
The upper hose from the radiator warms up gradually, after a 90-degree hose gets hot. Lower too hot. Radiator is hot and top and bottom.
From the hose, which in the figure, the fluid flows only after the start the car. When a hot car from this hose is not flowing liquid.
8df26ad19655.jpg

I tried to disable the sensor (black, 2 pins). Started the car. On the dashboard there was light injection. sensor is connected - is gone. It turns out that the sensor is working?
2.jpg

Today, drove around the city. After 10-15 minutes the temperature was 90 degrees. Came to the garage. Been there for 10 minutes. Went home and the temperature rose to 98-99 and kept for 5-10 minutes. Then he dropped to 93-95 degrees. Arrived at the parking lot. Stood. The temperature again was 98-99 degrees. Fans are switched on the first speed at 98-99 degrees. Work less than 10 seconds on and off. The temperature does not fall.
Fans should join at 92 degrees?
I think that the computer has a bug on the faulty sensor. Can this be? How to reset the error? Or does it just goes away after replacing the sensor?

[Major_Day]

Looks like the thermostat is working, because both the top and bottom of the radiator are hot, and the bypass hose only flows water when cold ie:when the stat is still closed.
The sensor seems to be working but could be sending an incorrect reading to the gauge.
Replace the sensor.
The temp. sending unit is directly under nearside air intakes, just behind the alternator. (coloured blue?)

http://i303.photobucket.com/albums/n.../Photo0110.jpg

Edit: According to the manual their is another sensor which controls the high temp. warning light, im not quite sure where this is located (possibly just behind the dipstick), but its supposed to come on at 117 deg. and go off at 100 deg.

[pawelk]

I have this sensor looks like a photo. I changed it last fall.

1.png

[Major_Day]

That looks like the high temp. warning light sensor.

Look here:

ICP-WTS3128,Water Temperature Sensor,Temperature Sensor,ALFA ROMEO 33 1.4 i.e. (907.A3A, 907.A3B),ALFA ROMEO 33 1.4 i.e. (907.A3A, 907.A3B),ALFA ROMEO 33 1.4 i.e. (907.A3A, 907.A3B),ALFA ROMEO 33 1.4 i.e. (907.A3A, 907.A3B),ALFA ROMEO 33 1.4 i.e. (90

The one in my pic. looks like this:

http://www.probedistributors.co.uk/P...CP-WTS3128.JPG

http://www.alfaowner.com/Forum/attac...1&d=1307196578

http://www.alfaowner.com/Forum/attac...1&d=1307196578

[pawelk]

Found today thermometer. Measured the temperature of the coolant tank. On the dashboard shows about 85 degrees, and in the tank shows 70-72 degrees. The engine temperature is certainly higher. Prompt, which will be approximately the difference in temperature in the engine and the coolant tank. If the tank 70 degrees, approximately how many degrees will be performed in the engine?

[Ralf S.]

I'm not sure.. but the tank is just a reservoir. It's not "active" in the cooling system.. it's just where coolant goes while the engine doesn't need it.

I'll have to measure mine when I get the chance.. but it might be a distraction that doesn't prove anything.

Did you replace the sensor S7 in Major Day's post? I think that's the one that could be causing you problems.


Ralf S.

[pawelk]

I have this sensor looks like this:
http://www.alfaowner.com/Forum/attac...-6-boxer-1.png
I replaced it with a new

[Ralf S.]

It's a pity my beast isn't a Boxer engine.. I can't go to look what it looks like.

But Major Day thinks that you replaced the high temperature warning light sensor - it just makes the light on the gauge come on, if the temperature gets too high.

The sensor you should change is the water temperature sensor.

It lives at the back of the engine... and is usually blue.

http://i303.photobucket.com/albums/n.../Photo0110.jpg



Ralf S.

[pawelk]

I have 3 sensors. In the radiator and 2 on the motor. This sensor I have not.
Replace the thermostat. 15-20 minutes passed through the city, the temperature of 98-100 and did not fall. Fans are switched on for 3-5 seconds (at a temperature of 100 degrees) in the interval 20-25 seconds. I think my dashboard is not properly displays the temperature. Will replace the sensor again.

[GTV-TB]

You should have three sensors on the engine, one for engine management (blue circle), one for temp gauge (yellow circle) and one for overheating light (red circle), the sensors for engine management and tempgauge is in contact with the coolant but the sensor for overheating light is not, placement of the sensors may differ a bit either left or right intake runners, you have also a sensor on the radiator that controls radiator cooling fan.

Is your coolant boiling? the sensor for overheating light is triggered of the radiated heat from the exhaust system on the 145 as the engine in the picture belongs to when car is stationary with engine running, but I can remove the cap from coolant tank and there is not any tendency for that coolant will boil.

[pawelk]

I see myself only 2 sensors on the engine.
the first sensor is:
1.jpg
It is as follows:
2.jpg
The second is:
3.jpg
It is as follows:
4.jpg

[GTV-TB]

Originally Posted by pawelk

I see myself only 2 sensors on the engine.
the first sensor is:
Attachment 120863
It is as follows:
Attachment 120864
The second is:
Attachment 120865
It is as follows:
Attachment 120866

Hi

First sensor - temp gauge
Second sensor - engine management

The third one (overheating light) should be there somewhere take a look at the area around the tube for the dipstick.