Chevy OPTRA Engine Temp

[Tann]

FYI

http://www.autoworld.com.my/forum/allposts...ine+temperature

[Tann]

Do u find that CHEVY engine is terrible compare to Jap car.

Base on that kind of heat it will drain our radiator & battery water faster, and we need to check our water more offer compare to other car and if you are not careful of forget good luck pal, then we just need to spend more money on the repair lor.

[Bigfoot]

In case you didn't know, the Nabira they are talking about is the Opel Zafira that is sold in Singapore. Different car, how to compare?

 

How do you define terrible? The Optra has one of the most stable engine temp control compared to other jap cars. The temp gauge does not fluctuate even when I climb Genting.

 

Another thing to note is that even after extended driving, the bonnet only becomes slightly warm, and not hot to touch as compared to other cars. To me, this is good for the paint finish of the bonnet. Less watermarks and tree sap that eats into the paint after rain. As long as the cooling system is good enough that the engine temp does not fluctuate on hard driving, I think there's nothing to worry about.

 

In case u didn't know, this car has been designed by qualified Engineers. U seem to doubt their ability when they incoporate such a design into our Chevys, such as the 'problem' with the air-conditioning system of our cars that you talked about. They would have sure took the temp of the engine bay into consideration when designing such features into the car.

 

Perhaps you u are better informed that the Engineers?

 

So, Whats the 'terrible' thing about?

[Tann]

Well, I know i can trust the designer ability for use in cols country like europe, buut not for ASIA country like SINGAPORE, Malaysia which is hot area (I'm not worry about over heating. And for OPTRA 1.6A the heat in the engine compartment with poor ventilation that also cause our FC to be high too. If you can draw more air in to the engine compartment, i believe the FC will definately be better (take for example during raining season the engine is reduce lower and your FC is lower too). I can go by the book if i'm in europr but not here appication has to change. If GM Motor or Starsauto nt going to anything about it that it is going to back to square 1 (just like Daewoo, Skoda...). And prviously I own a 93' & 01 Corolla the engine is not that hot (is nt like what you say

JAP car also like that??).

[Bigfoot]

If you still think you are more capable than the engineers that designed the car, so be it. Just wondering, how do you manage to measure the temperature of the Optra's engine? Even if it is running hotter than your Corollas, do you know the optimum running temp of the Optra's engine? Your comments are baseless.

 

Please read my post carefully, I never said that Japanese cars are running hotter than the Optra. I only meant that the Optra has better temperature control, as in being able to keep the engine at stable temperature, which i believe would be the same temp whether in your 'Europe' or in Singapore. By the way, this car is designed by the Koreans to run in their 'Asian' country. So, why would you 'trust' them when using your car in europe??

[Tann]

Well the issue also have been consulted by someone who is a ex-engineer and also find that if i can further improve the air circulation it would be good for the FC and other issue, but all this while i m not talking about over heating but to have better vetilation. Dont forget not everyone travel highway all the time(there get better FC) but those who are like me every morning and night kena the jam at lornie to Queensway.

[Nicoduc]

I also find the engine quite hot compare to other cars. The hot spot is at the driver side of the bonnet. And always get this burnt smell.

BTW, just add one of the engine sensor replaced yesterday. It was broken and my engine runing all haywire and couldn't hold idling. FC went up by 20%.

Is it another common pb of optra???

[Kklee]

This "heat" problem did bother me a fair bit. IMHO, to lower the temperature, might just need to ....

 

a) tweak the cooling system sensor to kick in at a lower temperature - how to??

b) tear off the insulation material on the bonnet - a little crazy

c) ventilation vents on the bonnet - legal?

d) additional fans - increase FC?

 

Tweak the cooling system sensor seems to be the right bet, just need to know how to and whether there are any side effects.

 

I'm no engineer or designer, but I think the Optra is designed to run hot so that this heat can be used in places with colder climate..just that this heat is not needed in SG! With the bonnet insulation, it gets hotter!

[Tann]

Yes, to me it is too hot, but some of the so call guru out read the manual and say that it is like that one. First there have not encounter problem like you do or we do and there just read the manual and comment and the manual are written and refer to car for cold country. Especially OPTRA or CHEVY aircon compressor is over work from the moment you or we on the aircon till we stop the engine. That's why i think we OPTRA should meet up to help find solution to solve the problwm.

[Tann]

Hi KKLEE

 

My previous OLD TOYOTA was @90 deg when i when to Malaysia along the causeway it was a heavy jam and ialso very hot weahther suddenly the temp shoot up almost full mark and i had to stop the car to splash water on it to cold down and run the car with out aircon.

 

a) tweak the cooling system sensor to kick in at a lower temperature - how to??

Below is the Aircon/Battery shop that did the sensor to kick the sensor at lower Temp.

 

b) tear off the insulation material on the bonnet - a little crazy

I would recommend that.

 

c) ventilation vents on the bonnet - legal?

It is Legal and some CHEVY car owner already did it but i dont like it and i will think of other solution.

 

d) additional fans - increase FC?

Same here

 

 

Nam Sing Battery Service

10 Ang Mo Kio Ind Park 2A #02-05

Autopoint Building

 

Contact : Mr Dennis Cheong

[Kklee]

Was reading thru the service manual for Optra/Forenza. Apparently, cooling system thermostat opens from 87 degreesC onwards and is fully opened at 102 degreesC.

 

The shop that could do the thermostat mod, do they replace this sensor with a different type?

[Genie47]

Don't fool around with the thermostat. Consider this if you allowed it to open up fully at a lower temperature:

 

1. Engine does not reach operating temperature quickly

2. Due to 1, the ECU keeps the engine at open loop. You suffer poor FC.

3. Overcooled engines suffer from engine oil sludging.

[Genie47]

Which sensor is this? O2 sensor? If it cannot hold idle, it could also be the IAC which takes the info from the O2 sensors.

[Kklee]

Add to the above post...

 

Seems like the cooling ssytem is not so simple. From the service manual, apart from the thermostat, the electrical cooling fan is controlled by the ECM.

 

a/c off - cooling fan at low speed at 97.5 degreesC (coolant temperature)

a/c off - cooling fan turn off at 95.25 degreesC

 

a/c on - cooling fan automatically turn on at low speed

a/c on - cooling fan change to high speed at 101.25 degreesC ( coolant temperature )

or when A/C pressure is high

 

Since the electrical cooling fan is controlled by the ECM, just need to program the ECM to trigger the fan to high speed at a lower temperature ? Probably need to ask SA to do it? I think we might just have stumble upon the solution.

[Genie47]

This is indeed a better solution, since air circulation and not overheating is the problem. But you got to consider this, A/C pressure will always be high when the A/C is on so the fan constantly turns at the high speed mode.

 

So the Optra with the A/C on in a slow city traffic condition already has the fan running at full speed. If this is still too hot for Optra owners, a 3rd party high CFM fan should be installed. Check the size of the fan and see if there are any 3rd party sizes that can bolt on directly.

[Kklee]

From my follow-up post, don't think need to mess with the thermostat. Can maybe mess with the temperature setting that trigger the electrical cooling fan to high speed.

[Genie47]

Too bad it is ECU controlled. It is just a simple feedback. Disable it and the fan runs continually.

[Kklee]

Yeah, that's a possibility. But having them continually on will affect FC when not in traffic jam condition. Also, there is a possibility of over-cool in the wee hours of the morning not to mention the noise!

 

Guess there are no hard and fast rule. Just need to find the balance. Maybe a remote control third fan?

 

So far, done only a 1-wire grounding. Got a EZ-STAB but have not installed. I'm not really a great fan of mods. Best is not to touch stock config. If really need to mod, must be sure can revert back to the original condition.