Vitz 2003 - Strange Overheat Scenario - Need Advice/Help

[venomdesire]

Dear All, Need your help.

I have a Vitz 2003. There is a strange overheating scenario.

1. During Normal Driving (With or Without AC - Single / Two persons on board) : Car Behaves Normal

2. During Fast Driving (High RPMs) and more than 2 people on board : Car starts to overheat. The Red Overheat light starts flashing. If i quickly get to Low rpms and start driving slow, it goes away, otherwise it eventually causes heatup and the water in radiator/reservior boils and evaporate.

On highway this phenomenon even observed on 60km/h speed.

Quite an annoying issue, need a fix.

Already got the Radiator checked, its rust free.

Car is Vitz 2003
Milage : 100k KM
Driven on : CNG+Petrol

[venomdesire]

Can it be anything related to a Tune-up? Tappets? Spark-Plugs? Mixture Settings? Head-Bolts (Maybe loose), Radiator Cap?

P.S Already checked & replaced Thermostat Valve.

[hash4u]

Check cap
Check for leaks
Fan speed
Water body
Timing if advance
If all ruled out gasket

[margallar]

^ this

[mehran]

I faced a similar problem but not the same. Car would overheat if driven a bit hard or stopped in jams. Radiator was fine, thermostat valve removed, fan on auto. Found out that water pump's blades had corroded and water was not circulating as required. It was circulating but at a lower flow rate than required.

I would suggest that you check if water is flowing by opening the cap of the radiator and observing the water movement. To confirm you can have the water pump opened and physically check the impeller blades for corrosion. I hope this fault diagnosis can solve your heating problem.

[capsat]

visit your mechanic ask him to check the engine main pulley. The balancer (2nd pulley with aircon /belt) pulley rubber insulation must be having hair line fractures slowing down the water pump. read this &this

[venomdesire]

@hash4u & @margallar

I have already Checked for Leaks, apparently No Leak Found anywhere.
Fan Speed - The fan is running at more or less the same speed as ever. I can judge this by the gush of wind i get in my face whenever the Fan starts and ive opened the hood !
Waterbody - I believe this is the impeller pump? Right?
Timing - The timing was calibrated 2 years ago when i installed CNG in it. I have not tuned/tweaked anything since the past two years, and only giving the car timely oil change & filter changes.

Is there any way to be sure about Gasket?

Check cap
Check for leaks
Fan speed
Water body
Timing if advance
If all ruled out gasket

[venomdesire]

@mehran

I have checked the Radiator water flow just now. Seems fine. When i open the Cover and peek inside, i can see a stream of water travelling at a pretty good speed.

Another thing to consider, that i have this car since around 2.5 years, and ever since the water/coolant has been rust free. Can the impeller blades on my Water circulation pump still deteriorate over time ? Is there a general life cycle for the watr pump, after which is will require replacement??

I faced a similar problem but not the same. Car would overheat if driven a bit hard or stopped in jams. Radiator was fine, thermostat valve removed, fan on auto. Found out that water pump's blades had corroded and water was not circulating as required. It was circulating but at a lower flow rate than required.

I would suggest that you check if water is flowing by opening the cap of the radiator and observing the water movement. To confirm you can have the water pump opened and physically check the impeller blades for corrosion. I hope this fault diagnosis can solve your heating problem.

[venomdesire]

@capsat Thanks for the perspective. I have already gone through the Water Circulation Test. It seems okay

However can you please help me understand how the Outer-Pulley (which connects to Air-Con Compressor) would have an impact on the Engine Itself.

i.e. If the pulley rubbers are worn out / cracked, this would result in slippage of the belt, this would cause efficiency/speed loss to the compressor itself , right ? Not to the engine?

Or is it so that The work/cracked pulley will also effect its own driving shaft and cause restrain to engine shaft rotation? Please correct me if i am wrong.

visit your mechanic ask him to check the engine main pulley. The balancer (2nd pulley with aircon /belt) pulley rubber insulation must be having hair line fractures slowing down the water pump. read this &this

[venomdesire]

P.S: My mechanic is pretty much an *** ! Thats why i dont get any tunings etc done and only go for oil changes etc.

WHen i mentioned this to my mechanic he was all up for opening up the engine & checking gasket, valves and what not. (Probably to make some hefty sum of money).

The next question i would be asking is a reliable mechanic in Karachi !

visit your mechanic ask him to check the engine main pulley. The balancer (2nd pulley with aircon /belt) pulley rubber insulation must be having hair line fractures slowing down the water pump. read this &this

[capsat]

check the thread

the outter pulley drive the aircon compressor which need torque the cracked pulley causes slow down of compressor causing compressor head pressure to increase & engine fail to compensate required compressor rpm, HVAC guys are more versed with it, my sohrab cycle does not have ac its a pedal power

[capsat]

@SER_GTR whats your catch on this heat up issue ! Gotcha !

[mehran]

@venomdesire

The original pump on my Honda Civic 1995 lasted from May 95 till Nov 2009, 14 years! But my car was driven till 2006 in Rawalpindi and then moved to Karachi. Once this pump corroded I bought an exact physical duplicate pump which looked exactly the same from a parts shop in Saddar, Karachi for Rs 3500. The shop keeper said this is genuine whereas all the other pumps were below Rs 2000 in price and looked shiny but with plastic impellers. Anyhow, the 'genuine' pump only lasted 2 years before its impellers corroded completely. I used coolant and normal water in the radiator. I replaced it with the shiny type. Sold my faithful car shortly after that.

The lesson I learnt was that unless you are 100% sure that the replacement part is genuine, then the water pump will probably corrode in about 2~3 years. Plus I used normal water which probably accelerated the corrosion. I would still suggest that you may check the water pump if you are not sure when it was changed. And before that check also the condition of the thermostat valve. Hope this helps.

[venomdesire]

Guys, checked everything .... all seems to be in order (i didn't get the head opened yet).... remaining all seems fine.
@mehran Bro I usually get such parts from fresh-imported half-cuts ! To ensure 100% originality.

[Xulfiqar]

@venomdesire

The original pump on my Honda Civic 1995 lasted from May 95 till Nov 2009, 14 years! But my car was driven till 2006 in Rawalpindi and then moved to Karachi. Once this pump corroded I bought an exact physical duplicate pump which looked exactly the same from a parts shop in Saddar, Karachi for Rs 3500. The shop keeper said this is genuine whereas all the other pumps were below Rs 2000 in price and looked shiny but with plastic impellers. Anyhow, the 'genuine' pump only lasted 2 years before its impellers corroded completely. I used coolant and normal water in the radiator. I replaced it with the shiny type. Sold my faithful car shortly after that.

The lesson I learnt was that unless you are 100% sure that the replacement part is genuine, then the water pump will probably corrode in about 2~3 years. Plus I used normal water which probably accelerated the corrosion. I would still suggest that you may check the water pump if you are not sure when it was changed. And before that check also the condition of the thermostat valve. Hope this helps.

a bit from experience.

If you dont remove all the air from your old honda engine, the water pump impeller can corrode from cavitation, This is accelerated if your coolant does not have good cavitation protection in it. Meaning if you use oldschool green silicated coolant then change it every 2 years at max.

[Xulfiqar]

Guys, checked everything .... all seems to be in order (i didn't get the head opened yet).... remaining all seems fine.
@mehran Bro I usually get such parts from fresh-imported half-cuts ! To ensure 100% originality.

getting wear parts like water pumps etc from used engines is completely wrong in repair.

[molvi82]

Assalam o Alaikum.

I have a 2003 Vitz on Petrol locally driven 80k in Khi and now Lahore.

I have very recently experienced the same issue for the past 6 months. Last month, first for the radiator replaced with a good Kabli one from Bilal Ganj, got it serviced before installation, still the water was evaporating and I needed water fillup, although less intensely now.

Then my mechanic suggested to check the Head Gasket, we opened the engine block, first time ever, and yes that was all expired due to excessive overheat.

We got the gasket replaced, head block shaped from a Lethe machine, fine job he did. Some belts, seals and rubber pipes were also changed as I didn't want to make frequent visits to my mechanic in near future

Alhamdolillah, this past weekend, I made a round trip to my native town in South Punjab 550KM from Lahore on the Vitz. Remarkable performance by the engine, AC and awesome fuel consumption of 16.3 km/L with AC all the way, speeding at av. 100km.

I suggest u get the gasket checked, but also if u get the car scanned for any out of spec settings, may be that would help.

Good luck bro!

Sent from my iPhone using PW Forums

[venomdesire]

I know its not the best solution out there, but thats the better choice compared to getting the original-look-alike pumps from the spare parts market.

getting wear parts like water pumps etc from used engines is completely wrong in repair.

[venomdesire]

Any coolant with anti-cavitation and good head-conducting properties that you can recommend ?? Which is available in the market ?

a bit from experience.

If you dont remove all the air from your old honda engine, the water pump impeller can corrode from cavitation, This is accelerated if your coolant does not have good cavitation protection in it. Meaning if you use oldschool green silicated coolant then change it every 2 years at max.

[venomdesire]

Yes i have same scenario, the radiator is clean and clear. No corrosion anywhere in the radiator (although when i had opened the thermostat valve it was chocked to death with rust).

Secondly, is it necessary to get it shaped again from Leith machine??? I frankly am not too comfortable with the leith guys and kharadias (never rebuilt confidence in them after some ugly incidents)..... cant i just change the gasket only??

Thirdly what belts and seals did you change? Estimated cost and time ???

Assalam o Alaikum.

I have a 2003 Vitz on Petrol locally driven 80k in Khi and now Lahore.

I have very recently experienced the same issue for the past 6 months. Last month, first for the radiator replaced with a good Kabli one from Bilal Ganj, got it serviced before installation, still the water was evaporating and I needed water fillup, although less intensely now.

Then my mechanic suggested to check the Head Gasket, we opened the engine block, first time ever, and yes that was all expired due to excessive overheat.

We got the gasket replaced, head block shaped from a Lethe machine, fine job he did. Some belts, seals and rubber pipes were also changed as I didn't want to make frequent visits to my mechanic in near future

Alhamdolillah, this past weekend, I made a round trip to my native town in South Punjab 550KM from Lahore on the Vitz. Remarkable performance by the engine, AC and awesome fuel consumption of 16.3 km/L with AC all the way, speeding at av. 100km.

I suggest u get the gasket checked, but also if u get the car scanned for any out of spec settings, may be that would help.

Good luck bro!

Sent from my iPhone using PW Forums