Too hot?

Kulwinder · February 08, 2015, 07:53:22 PM

Hi guys, today Sunday was a nice day. 25degree in Melbourne. We went upto Belgrave for a drive. That had been nice drive. But one thing I noticed that the temperature gauge was showing too hot. Over 90.!!
When I was on the way back through traffic lights. It was staying above 90 as picture. And used to come down upto 90. And on freeway. It was staying far less than 90. Is this normal.? Coolant level is ok. But I have no idea when last owner changed coolant. Will a coolant change work?

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colcol · February 08, 2015, 08:46:51 PM

Find out when the last coolant was done, but as you say, no idea when the coolant was changed, so i would have it changed, as bad old coolant turns into acid and rusts everything.
The coolant is usually red or pink, not green or blue, check your owners manual for the correct coolant.
The coolant temperature should take 5 - 10 minutes to get to 90c and should stay there without dropping back, in traffic or a hard run up a hill it will get to about 100c, but once you get going and get a bit of airflow through the bonnet, it will drop back to 90c.
156 twin sparks and JTS's have a bad reputation for failed thermostats, they usually run too cold, but they can sometimes run too hot, i am on my FOURTH thermostat, Colin.

Kulwinder · February 08, 2015, 08:52:36 PM

You are right Colin. I start my car in morning for work, let it run for 2-3 minutes as its really too early to let it run for a while. I start driving slowly. I reach work with in 15 min. And it doesn't hit 90. I mean I reach at work before it hits 90. And while normal driving it stays just under 90. But today there was a big variation.
So where should I start? Changing coolant first? Or thermostat?

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Stuart Thomson · February 08, 2015, 09:21:38 PM

Is the car a V6? Regardless, the water pump impeller may be plastic, if so they can spin on the shaft at high engine revs, hence not much cooling, at idle they work fine. Common problem with the V6 cars, not sure about 4Cyl cars.

Cheers
Stuart

colcol · February 08, 2015, 09:39:59 PM

I know from past posts that yours is a JTS, i would replace the coolant, as its not that hard to do, and old coolant will damage your metal parts with corrosion.
While you have your coolant drained out, remove the thermostat and check it that its not open, which would cause the car to run cold.
Put the thermostat in hot water with a temperature thermometer in the hot water and check to see when the valve in it opens, the opening temperature is stamped on the thermostat body.
If it is more than 3 years old, then it most likely on the way out.
There are youtube video's on checking thermostats, Colin.

Craig_m67 · February 08, 2015, 11:01:46 PM

Can you find any indication (service history, etc.) that the thermostat has been replaced during the cars lifetime?

No. Replace the thermostat
Yes. Replace the thermostat

Is there any coolant in the expansion tank?

colcol · February 09, 2015, 12:00:31 AM

If there is no coolant or low coolant in the expansion tank, check for leaks, the first place to look is the coolant transfer pipe on the top of the motor, check for coolant traces, it usually leaks where it meets the cylinder head, Colin.

Kulwinder · February 09, 2015, 04:09:04 AM

It's 4 Cylinder JTS. And coolant level is ok. This is second time I have seen this. Once when I was bringing this home after buying. And yesterday. Other than that I have driven it to Geelong, great ocean road trip, Dandenong etc. Always show normal. Is there any screw type drain under radiator like some cars or need to pull bottom hose like Commodores.? Is that a job can be done at home. I normally work on my Grandeur at home, but never opened a screw of this Alfa. I hope it's a easy job.?

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bazzbazz · February 09, 2015, 04:42:18 AM

WAIT!

Before you do ANYTHING, check to make sure your radiator fans are coming on!!

"When I was on the way back through traffic lights. It was staying above 90 as picture"
Sometimes this is an indication that your fans are not coming on as they should to assist in stop start traffic & driving. Once you have verified the fans are functioning or not, THEN change the coolant, even of the fans ARE faulty & have to be fixed, change the coolant anyway, as it sounds like its way over due for it

Baz

colcol · February 09, 2015, 08:55:40 PM

I had a similar problem with mine when i first had it, the coolant was a bit rusty, and there was corrosion on the coolant temperature sensor and it wasn't reading correctly, just had to take it out and clean it as the corrosion was insulating the sensor from the coolant, Colin.

Kulwinder · February 10, 2015, 03:55:04 PM

Where is coolant temperature sensor is located, Colin?
And how to drain coolant. There is a big plastic cover underneath the car. Can't see. Is there any drain plug/screw under radiator? Or do I need to pull bottom hose off?
And also it takes red coolant. Can I use any red coolant from super cheap or is there special recommendation?
I want to try this job at home.

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colcol · February 10, 2015, 08:46:23 PM

Take the good advice of bazzbazz and see if thermo fans are switching on when car is hot, i check mine everynight, when i drive up the hill into the shed i hear them switch on, i take it for granted that they work.
Do a Google of coolant temperature sender on 156 JTS, from [poor] memory it is on thermostat housing.
You have to take off undertray to do any work on these cars, such as oil and coolant change.
This is a Fiat motor, so there is no drain plug to drain water, [unlike the good boxer motor!], just undo the bottom and top hoses and drain out the old coolant.
Make an executive decision about how dirty it is and consider putting a cleaner through it.
Have the heater on flat out so the heater valve is open and the heater coolant will drain as well*.
* May not have heater valve, but have vacumn doors to switch heater on and off, have heater on anyway.
Check on Nulon/Repco/Penrite/Castrol/Valvoline/Mobil websites for the correct coolant, from memory it is OAT type coolant, it is usually pink or red, blue is mostly for Japanese cars and green is the older type cars, it is the same coolant used in GEN 3 Chevrolet motors.
Have a big drain pan to try and catch the coolant, have fun, Colin.

Neil Choi · February 10, 2015, 09:26:45 PM

Coolant temp sender is usually screwed onto the thermostat. Just look for some connector on the thermostat housing, and a hex fitting. Can't be too difficult to find.

colcol · February 10, 2015, 10:17:09 PM

You are right Neil, done it about 6 years ago, can't remember if it was the temperature sensor or cold start sensor, the 156 thermostats that are cheap have no new sensor installed, the expensive thermostats have a new sensor installed.
Should be held in by velcro strips or wing nuts the thermostats fail so often, Colin.

Kulwinder · February 19, 2015, 07:58:07 AM

I took my car to Alfa Men in Braybrook. Machanic checked my car. I plugged his computer in and tried find any code. No code. Then he checked the temperature. At what temperature fan was coming on.
Fan was coming on at 97 degrees. And cooling down to 90 degrees. He said its fine. Normal. My gauge is showing little bit over. But how about your cars. Doing same??