Engine Underheating

[bhathiya_u]

recently this CR42 engine had problems with cold start and mechanics told that it has to be overhauled. They did it and now it seems ok. but I noticed that the temp level is below the normal level (does not come to halfway as usual). Please let me know;

1. What could be the reason for this?

2. will it harmful if it contuously run at low temp in long term?

[deco]

There is a mechanical part called "Thermostat" in every engine to keep the engine in optimum operating temperature. this helps to burn fuels in more efficient way keeping the fuel economy and minimizing the pollution.

The thing is Sri Lankan mechanics always tend to remove this part every time they do a engine repair.. better check the thermostat is still there with the engine.

[virensti]

As far as I know, the thermostat valve is there to get the engine to operating temperature asap. what it does is, it's a valve that closes and prevents the coolant from going to the radiator, so it keeps circulating withing the engine block, so the coolant is not being cooled, thus causing the engine to get to its operating temperature fast. Once it gets to the operating temperature, the thermostat valve opens, and the coolant flows through the radiator to cool down. so yeah it is there to maintain operating temperature. so yeah some mechanices in SL remove it saying SL is too hot to need it and blah blah, or your thermostat valve could be broken. just check on it.and yes its not that good for your engine to run without it reaching operating temp, it'll probably burn quite alot of oil, and it'll scrape your newly done cylinders and piston rings as well. (if you changed them that is) and you wont get maximum performance from your engine..

[ravisam]

  virensti said:

As far as I know, the thermostat valve is there to get the engine to operating temperature asap. what it does is, it's a valve that closes and prevents the coolant from going to the radiator, so it keeps circulating withing the engine block, so the coolant is not being cooled, thus causing the engine to get to its operating temperature fast. Once it gets to the operating temperature, the thermostat valve opens, and the coolant flows through the radiator to cool down. so yeah it is there to maintain operating temperature. so yeah some mechanices in SL remove it saying SL is too hot to need it and blah blah, or your thermostat valve could be broken. just check on it.and yes its not that good for your engine to run without it reaching operating temp, it'll probably burn quite alot of oil, and it'll scrape your newly done cylinders and piston rings as well. (if you changed them that is) and you wont get maximum performance from your engine..

There will be no problem to your engine if it runs under the designed temperature. If the engine is operated in it's designed temperature (ie 90 degree C) it will give you maximum fuel efficiency. So do not worry it will do no harm to your engine except a fraction of diesel quantity. Here in Sri Lanka most of the vehicles are operating the same way.

[bhathiya_u]

thanx for the replies guys. I think they may hav damaged the thermostat. But is it true that in SL most of the vehicles operate in the same way ? and it's no harm to the engine except fuel consumption?

BTW is this thermostat can be repaired without dismentelling the engine? is it visible outside?

Edited September 19, 2009 by bhathiya_u

[MkX]

  bhathiya_u said:

thanx for the replies guys. I think they may hav damaged the thermostat. But is it true that in SL most of the vehicles operate in the same way ? and it's no harm to the engine except fuel consumption?

BTW is this thermostat can be repaired without dismentelling the engine? is it visible outside?

Most of the old vehicle their thermostat valve removed by our basses.. when ever they come across engine over heat.. remedy is remove the thermostat. Any way thermostat should be easy to locate. Should not be a major repair.

Are you using engine coolant or 100% water, as we discussed here earlier if you have 100% water then you will have problems in getting operating temperature in short runs. Because water observes more heat.

[ravisam]

  bhathiya_u said:

thanx for the replies guys. I think they may hav damaged the thermostat. But is it true that in SL most of the vehicles operate in the same way ? and it's no harm to the engine except fuel consumption?

BTW is this thermostat can be repaired without dismentelling the engine? is it visible outside?

Thermistat is inside the top radiator retern hose fixing metal fixture (engine side). If you need to purchase it they may be available at recon parts shops. But before replacement check that they have not blocked the water pump bypass hose.

[bhathiya_u]

  MkX said:

Most of the old vehicle their thermostat valve removed by our basses.. when ever they come across engine over heat.. remedy is remove the thermostat. Any way thermostat should be easy to locate. Should not be a major repair.

Are you using engine coolant or 100% water, as we discussed here earlier if you have 100% water then you will have problems in getting operating temperature in short runs. Because water observes more heat.

I use 100% water. no coolant. However, before the repair it reached to operating temp les than 5 mins. Anyway i must check this Thermostat. Also i think this has some relationship with the delayed gearshifting in Auto gearbox i experience in the morning. I heard that ATF is also circulating through the raidaator.

[Car Maniac]

  bhathiya_u said:

I use 100% water. no coolant. However, before the repair it reached to operating temp les than 5 mins. Anyway i must check this Thermostat. Also i think this has some relationship with the delayed gearshifting in Auto gearbox i experience in the morning. I heard that ATF is also circulating through the raidaator.

Yes bro, this ATF circulates. So there could be a relationship between ur radiater issue and gearbox problem. Also checkout the ATF, cos if the ATF is not in good condition, that also creates gear shifting delays in auto gear boxes. The radiator under heating could be either removed thermostat or malfunctioning spring in thermostat or a related issue afaik. good luck

Edited September 29, 2009 by Car Maniac

[terrabytetango]

Does the CR42 have an electric or engine driven fan? 'cos if it's the latter, I don't see the point of a thermostat.

[jaga]

  terrabytetango said:

Does the CR42 have an electric or engine driven fan? 'cos if it's the latter, I don't see the point of a thermostat.

Thermostat valve is operated by the thermo stat.