Hi Team-bhpians, would like to share my recent experience of overheating issue with my Spark Vehicle. The car does about 500-800 kms a month in recent times and it's a 2008 Model car. The car has been well maintained with timely service at Service center.
To the uninitiated, Chevy spark has a Temp gauge in the instrument cluster and for the past 1 week for so, it was giving me a low read-out about a quarter readout (less than 1/2 in the gauge which is normal temp). I ignored this thinking this might be due to the cold weather which Mumbai was experiencing.
During a recent commute to my Office in Thane which is about 8 kms from my home, encountered a traffic jam, due to a overturning of Truck in a flyover. I took the service road and traffic was bumper to bumper. Suddenly i saw white smoke coming from the car bonnet, and managed to pull over nearby.
Opening the car hood, saw coolant gushing out of the coolant tank. After waiting for sometime, opened the tank cap and saw coolant gone. Temp Gauge had touched the normal mark by now. So called up my known mechanic and he asked me to check the FAN is working or not. Entered a bottle of veedol coolant from nearby store and started the engine after cooling down. Fan was not working.
Since the chevy SC was nearby (SC Auto), called them and reported the issue- they instructed me to drive slowly and get the car to the station. The advisor informed me that Fan was working and the problem is something else, so they would need to keep the car.
Went to SC auto next day and wanted to validate the issue. So the advisor started the engine and warmed it up. And the same thing happened after 10 min- coolant gushing from radiator cap. So car was switched off. He called the technician with Scan tool and advosr told they have done the following checks: -
1. Checking Fan with Scan Tool ( they showed me with Fan working at both speeds -high/ low
2. Checking faulty radiator cap
3. Thermostat
4. Coolant Leakage checks
5. Coolant pump
Finally he told me that the Engine head Gasket had failed, and I am looking at an engine overhaul with a verbal estimate of 60K!
So I called up Anis Bhai of Unicool Auto :-
(I've been going to him for my car AC servicing / Repairs and know him since last 3 years
He asked me a few questions when I told him about the situation
1. Is the fan working with AC on?
2. At what temperature is the Fan activated
3. When the heating issue happened - had you switched on AC?
On switching the Ac, saw fan was working and finally he told me that if it is a head gasket issue, then the same issue would happen.
Suprisingly the remaining coolant was ok ( i had topped it up again) with the AC on. So he told me to come to his workshop, and he doubted that it is an engine gasket issue
Arrived at Unicool Aircon at about 3 PM. All this time I was driving with AC switched on
Following STEPS performed at Unicool :-
STEP1 -
1.checked the temperature with scanner and same thing happened, all coolant started throwing out and no trouble code while at it, recorded reading at the point - 82C
STEP2:-
Water Pump was checked - if it was functioning properly
STEP3:-
Radiator was removed- it was badly chocked- pics attached here, muddy deposits came out. Radiator was sent for cleaning.
Even after radiator cleaning Problem persisted!
STEP 4:-
So Water reading in coolant tank was checked after same issue re-occured! and reading showed 98.7 C! So Same car at same time showed temperature difference
So the Problem is analysed to Temperature sensor issue-
Temperature sensor replaced! and problem got resolved!
So why did the scan tool not detect issue?
It was explained that change in Temp sensor resistance was the reason and due to this scan tool could not detect it ! and it takes the feed from ECU. There was no open or short circuit of temp sensor.
Pics attached