Thermostat removed...help!

[GaLynxmo]

Though there are a number of threads dealing on a vehicle's cooling system, this is a very specific problem I encountered. My car had overheating twice on that stretch of SLEX, and will start only if radiator cooled awhile, when I went to Sta Rosa, the other week. And when I reached Sta. Rosa, a mechanic simply removed the thermostat, saying it was the culprit. The car moved anyway for a while around Sta Rosa but again stalled when it overheat again and would not even crank. Another mechanic suggested that my battery needs replacement, and when I did replaced it, I had no overheating until I reached my residence in QC. Do I need to put a themostate at it again? Or can I dispense with it. Mga tsikoteers, your wisdom is badly needed here. tnx.

[OTEP]

I'd elect to put a thermostat back in. Especially since you run an EFI (computerized) engine which takes into account coolant temp to adjust idle speed and engine parameters. To simplify it, as long as the engine detects that the coolant is 'too cold' it will maintain a high idle speed (wastes fuel).

Since the thermostat is out already, just buy a new one (they're not expensive) and put it in.

And while you're replacing the thermostat, drain the old fluids out and put some fresh coolant and distilled drinking water in the system.

[CVT]

Though there are a number of threads dealing on a vehicle's cooling system, this is a very specific problem I encountered. My car had overheating twice on that stretch of SLEX, and will start only if radiator cooled awhile, when I went to Sta Rosa, the other week. And when I reached Sta. Rosa, a mechanic simply removed the thermostat, saying it was the culprit. The car moved anyway for a while around Sta Rosa but again stalled when it overheat again and would not even crank. Another mechanic suggested that my battery needs replacement, and when I did replaced it, I had no overheating until I reached my residence in QC. Do I need to put a themostate at it again? Or can I dispense with it. Mga tsikoteers, your wisdom is badly needed here. tnx.

Medyo nalito lang ako rito.... Why would it overheat when the thermostat was removed, and it turned out that the battery was the culprit? And, when a new battery was there, there wasn't any overheating problem?....

IMO,- replace your thermostat bro.

2901:pokemon:

[OTEP]

The battery might have been too weak causing the electric fans to turn too slowly. But it's always a good idea to check the whole system while you're at it.

[d j]

I don't think that removing your t-stat would make that much of a difference given that you are in a warm climate area. now if your in Alsaka or another region that has a colder climate, then the t-stat would definitely affect your engine's performance.
did your mechanic confirm that it was definitely the t-stat? you can check it by dipping your t-stat in bucket/cup of hot water. depending on it's rating, the t-stat should start opening at 175deg-180deg F ...if that didn't do anything then it's safe to say that your t-stat is stuck closed. well, just in case it does open, confirm that it opens all the way. another thing to check is if you have an electric fan, see if it turns on when it should. if not check your fuses, wiring and finally your coolant temp sensor/switch. this switch is responsible for activating your fan at a certain temp. normally about the same time the t-stat is supposed to open. hope that didn't confuse you =)

[LexTer]

I'd elect to put a thermostat back in. Especially since you run an EFI (computerized) engine which takes into account coolant temp to adjust idle speed and engine parameters.

+1

apektado system mo sir.

[Asus700]

absence of thermostat will take the engine quite a while longer to achieve the ideal operating temperature from a cold start, even in a hot climate like here in manila. this is not good for the engine.

the absence of thermostat may not even allow your engine to reach its peak operating temperature, because the coolant will be free flowing, this is especially true when you are on highway driving.

and when the engine is not operating in its ideal temperature, it will eat more fuel.

happened to me, so i put back the thermostat.

[OTEP]

I don't think that removing your t-stat would make that much of a difference given that you are in a warm climate area

Unfortunately, it does. I've driven units with deleted thermostats and the gauges don't even register 1/4. The engines are running cold and would not go from the high idle 'warm up' mode into the regular idle at optimum engine temp. Some engines also do not give max power because the ECU is fooled into thinking that the engine is still too cold.

And the Philippines is only daytime for around 12 hours, there is also the other 12 hours which is [relatively cold] nighttime. Then there's the cold/rainy season [which is about to start]. Plus there are areas of the Philippines cold enough to allow for the use of the cabin heater.

[impulzz]

have you checked the simplest part of all? the radiator cap.

[OTEP]

Yeah, that Php150.00 part cured my overheat incident in the MB100. Buti na lang sa tapat ng Auto Supply inabutan.

[wildthing]

....that removing your t-stat would make that much of a difference given that you are in a warm climate area...

this is one of those urban legends that the myth busters have to test

[CVT]

this is one of those urban legends that the myth busters have to test

We could have missed it....

Pero kung hindi pa,- calling on Adam and Jamie!!!

2901:pokemon:

[userfriendly]

I don't think that removing your t-stat would make that much of a difference given that you are in a warm climate area.

I'm currently taking up basic car maintenance in Meralco foundation. Our instructor recommends keeping the thermostat. The reasons were the same as those previously mentioned by Sirs OTEP and Asus.

[OTEP]

OT: If only I had the time, I'd be your classmate at Meralco sir userfriendly. Kaso hindi ko talaga ma-fit sa schedule.

[BRROOOMMMM]

I suggest replace by new one mura lang naman yan at napakahalaga sa auto natin yan baka nag malfunction or makitid na clearance nya pag nag-open not like the retracktion of new one, range of opening from 20 to 25mm new thermostat

http://i178.photobucket.com/albums/w...G_0331copy.jpg

[d j]

Unfortunately, it does. I've driven units with deleted thermostats and the gauges don't even register 1/4. The engines are running cold and would not go from the high idle 'warm up' mode into the regular idle at optimum engine temp. Some engines also do not give max power because the ECU is fooled into thinking that the engine is still too cold.

And the Philippines is only daytime for around 12 hours, there is also the other 12 hours which is [relatively cold] nighttime. Then there's the cold/rainy season [which is about to start]. Plus there are areas of the Philippines cold enough to allow for the use of the cabin heater.

I'd argue all day but about this, but opinions could only go so far... first off, most factory analog gauges are dummy gauges (not that accurate) but it can definitely tell if you're engine is over heating. Most engines' normal operating temp would be around 180deg F, an engine's cooling system minus the t-stat wolud still get plenty warm (even on a freeway/hi-way). Also ECU/ECM's doesn't read signals by the digits... but via paramaters sent by a temp switch, normally the same switch that controlls the fan; and if the ECU/UCM doesn't get that signal, it would raise the engines idle to get the signal but that would not prevent it from producing it's "max power" (you get power from fuel, air, spark, exhaust flow).
And that would be the only drawback of not having a t-stat in a tropical climate, a few minutes of higher idle which converts to less than a teaspoon of gasoline.
An engine can never be too cold unless you are in a real cold climate (somewhere around less than 40deg F). And unless you have a double row aluminum radiator, under driven waterpump, higher pressure radiator cap, aero dynamic tested front fascia to create low pressure underneath the engine and running a waterless coolant (NPG) in your cooling sys, the only drawback you would get from not having a t-stat is a longer high idle during start up.
I am not recommending to go driving around without a t-stat but his question was somewhere along the lines of "would it be a big deal if..." by all means put it back on but like I've said it wouldn't really matter since the "stop and go traffic" together with the warm climate will ensure that your engine will reach max operating temp (even higher). Make sure that you keep up with the maintenance 'cause overheating can warp aluminum engine heads.
...and yes I am a mechanic, I've been serving as a vehicle technicin (7 level/craftsman) for the USAF for 6.5 years now

and one last thing, no it does not get that cold over there... you might've been just used to a warm climate so when the temp drops a few degs than normal, your skin shoots signals to your ECU (brain) and convinces your body that it is cold. it's all in your head j/k

[finchy18]

how about those replaced thermostat from carb engine sir otep? is old rotary thermostat good?

[wildthing]

not to flame D_J pero I would only believe your claims if you have better educational background and better experience in car design and manufacturing than those who did those cars that we see today in the market (and also marketed world wide)...

afaik these experienced and properly educated engineers have been designing these engines to contain these sensors (like the humble thermostat) because of the specific needs for fuel efficiency and power output.

[userfriendly]

OT: If only I had the time, I'd be your classmate at Meralco sir userfriendly. Kaso hindi ko talaga ma-fit sa schedule.

Sorry :offtopic: ,you will get bored with basic. For someone with your skills pang advanced ka na.

:Off-Topic2:

[4JGtootsie]

not to flame D_J pero I would only believe your claims if you have better educational background and better experience in car design and manufacturing than those who did those cars that we see today in the market (and also marketed world wide)...

afaik these experienced and properly educated engineers have been designing these engines to contain these sensors (like the humble thermostat) because of the specific needs for fuel efficiency and power output.

Are we talking of the same engineers that designed the 4JX1-TC? There are times that engineers forget to understand long term effects of their design.
And leave the humble mechanic to do task of doing repairs and remedies for their faults.

When i was still studying we had a classmate who was an engineer. I asked him bakit pa siya nagenroll engineer na siya. He said nabilib siya sa classmate niya na mekanico na nag engineering.

I find DJ's claim reasonable. Have you experienced a shut closed thermostat? It can blow your cylinder head and render it RIP.

Userfriendly, how is your class doing? kamusta mo ako kay sir Roger S. Hindi ko na kayo ulit nabisita.