Can i drive my car without a thermostat?

[luskred]

hello all
i hope someone can advise me, i live in dublin and i drive a 1999 E300TD as a taxi, yesterday i was changing the thermostat and when taking out the old one i broke a piece of the housing which holds the thermo in place, so i had to order the new housing which i hope to get on monday, but im wondering if it is possible to drive the car useing the damaged housing without the thermo inside, can it do any damage to the engine considering i do a 10 hour shift while working, i would be gratefull for any advice and thanks in advance for your help.
LUSKRED

 

[ibrar]

Well if your engine were to overheat you may cause a vast amount of damage to the engine itself. My dad has an E240 1997, his thermostat went whilst on the motorway and his engine's temp. went sky high. You may be able to tell any difference if your car seems to be getting hot whilst driving (even though the heating is off)

 

[cookci]

as long as coolant passes round your engine then it wont damage it.

Thermostats are in place to allow engines to warm up and maintain around a 90 degree operating temp.

Without a thermostat your engine may never reach 90 degrees so MPG and performance might suffer but your engine will be fine

 

[luskred]

Cheers Ibrar
Thanks for the swift reply, i think i better cut my loses and wait for the new housing on monday to be on the safe side, Thanks again.
LUSKRED

 

[ibrar]

Also feel the coolant pump, if it is cold it may reflect your engine going AWOL

 

[BTB 500]

Without a thermostat the engine will take much longer to warm up and may run slightly cooler even then. So it will probably affect the fuel consumption and emissions a little, not something you'd want long-term but nothing to worry about for a day or two IMO.

 

[ibrar]

Without a thermostat the engine will take much longer to warm up and may run slightly cooler even then. So it will probably affect the fuel consumption and emissions a little, not something you'd want long-term but nothing to worry about for a day or two IMO.

Surely not only may the engine remain cooler, it could also get hotter than the norm?

 

[BTB 500]

Well if your engine were to overheat you may cause a vast amount of damage to the engine itself. My dad has an E240 1997, his thermostat went whilst on the motorway and his engine's temp. went sky high.

Your dad's thermostat must have failed closed (unusual). Having no thermostat will make the engine run cooler than normal - no chance of causing overheating.

 

[ibrar]

Your dad's thermostat must have failed closed (unusual). Having no thermostat will make the engine run cooler than normal - no chance of causing overheating.

Hmmm, but I have heard elsewhere that having no thermostat may also increase the temp. Might have heard wrongly

 

[BTB 500]

Surely not only may the engine remain cooler, it could also get hotter than the norm?

Definitely not.

A thermostat is closed when cold, stopping water from flowing round the radiator (just round the engine block) to make it warm up more quickly. When up to temperature the thermostat opens, allowing water to circulate through the radiator.

With no thermostat the coolant will flow through the radiator at all times. This can only make the engine run cooler (if anything).

 

[cookci]

Definitely not.

A thermostat is closed when cold, stopping water from flowing round the radiator (just round the engine block) to make it warm up more quickly. When up to temperature the thermostat opens, allowing water to circulate through the radiator.

With no thermostat the coolant will flow through the radiator at all times. This can only make the engine run cooler (if anything).

I agree with Bill

 

[panason1c]

Hmmm, but I have heard elsewhere that having no thermostat may also increase the temp. Might have heard wrongly

It is impossible for the engine to run too hot because the thermostat has been removed, if anything, the engine will run cooler than normal due to a full, unrestricted flow of coolant through the radiator 'overcooling' the engine.

The 'stat is there to constantly allow/restrict the coolant flow to maintain an even engine temp of around 80 degrees.

As mentioned, if the 'stat fails in the 'closed' position the engine will quickly overheat due to the flow of coolant around the engine/radiator being stopped by the closed 'stat.

 

[DieselE]

It is impossible for the engine to run too hot because the thermostat has been removed, if anything, the engine will run cooler than normal due to a full, unrestricted flow of coolant through the radiator 'overcooling' the engine.

The 'stat is there to constantly allow/restrict the coolant flow to maintain an even engine temp of around 80 degrees.

As mentioned, if the 'stat fails in the 'closed' position the engine will quickly overheat due to the flow of coolant around the engine/radiator being stopped by the closed 'stat.

I agree with most of what you say. But, even with the thermostat closed coolant still flows around the engine. Under light throttle steady state cruising it might actually not overheat. The first traffic jam would cause serious problems though.

 

[230K]

Drive away at her, as long as there is water in it you have nothing to worry about she will run cool but will be fine. Get taxiing!!!! Saturday night is bound to be one of the best nights dont miss it.

230K

 

[Bazzle]

Just drive it, ensure you top up 1st.
And Yes, engines can overheat without thermostat, very rare but it can occur.
What happens is (normally in a hot climate) the coolant goes thru radiator too fast to be cooled.
I wouldnt worry re that scenario in your part of the world...

Bazzle

 

[fredfloggle]

I agree with Bill

Actually not entirely true.
Dependent apon system design and stat location, removing it and taking all restriction out of the system can result in overcooling one cylinder or exhaust valve pocket, and undercooling another.
This is particularly noticeable with British Leyand A series engine where removing the stat results in undercooling of #4 cylinder.

 

[panason1c]

Yes, engines can overheat without thermostat, very rare but it can occur.
What happens is (normally in a hot climate) the coolant goes thru radiator too fast to be cooled.

I would suspect that the highly efficient cooling capacity of modern day radiators is taken into account to avoid the above scenario.

Also, i would have thought that with a 'stat removed, the faster flow of coolant around the system would, in fact, carry heat away from the engine at a faster rate resulting in a much cooler running engine (as is the case).

 

[dogan124]

Hii,

This discussion reminds me my overheating worries in hot summers while caravan towing.

The temp is above 30 degrees almost all the day and 40 degrees in same cases. Imagine this on a very step road with a 1300 kg on the back of the car.

Can I then expect a better cooing without the thermostat and not effecting other things much ?

Cheers

Dogan/Turkey

 

[television]

Actually not entirely true.
Dependent apon system design and stat location, removing it and taking all restriction out of the system can result in overcooling one cylinder or exhaust valve pocket, and undercooling another.
This is particularly noticeable with British Leyand A series engine where removing the stat results in undercooling of #4 cylinder.

This was also a big problem on pre war RR engines, where we had to blank off the last 4 sets of water tubes to force the water to the front of the engine. This effectivly left number 6 with no cooling water, but the head was uniforn in temp across the whole thing, and head problems became a thing of the past.

 

[fredfloggle]

I would suspect that the highly efficient cooling capacity of modern day radiators is taken into account to avoid the above scenario.

Also, i would have thought that with a 'stat removed, the faster flow of coolant around the system would, in fact, carry heat away from the engine at a faster rate resulting in a much cooler running engine (as is the case).
Originally Posted by Bazzle
Yes, engines can overheat without thermostat, very rare but it can occur.
What happens is (normally in a hot climate) the coolant goes thru radiator too fast to be cooled.

No, that's not the way that heat transfer between mediums occurs, it is all down to surface area and mass flow, unless of course you move water so fast through the rad that cavitation occurs.