So, How long would you be happy to run an engine for with no water?

Orionaut

Orionaut

Orionaut

Soldato
Joined
2 Aug 2012
Posts
7,809
Not talking about serious driving here.

But consider this scenario. You are working on a car and have the cooling system drained. However, you need to move it, either in/out of the garage or to another part of the yard.

How long would you be happy to let the engine run under these circumstances?

My position

From a thermal POV, Probably quite a long time, especially if it is an "Old School" diesel which are practically air/oil cooled at idle anyway (You can rest your hand on the exhaust manifold, the hottest part of the engine, of an idling "Old School" diesel like an old Transit or similar. I wouldn't try this unless the vehicle is going to be scrapped anyway, But I would think you could let an old transit diesel idle almost indefinably (Though not operate under any load) without it seriously overheating!). The main issue to my mind in the short term is the possibility of damaging the water pump seals/bearings which rely on water being present. though that could be mitigated by removing the relevant drive belt.

What say Motors? :p
 
Orionaut said:
Not talking about serious driving here.

But consider this scenario. You are working on a car and have the cooling system drained. However, you need to move it, either in/out of the garage or to another part of the yard.

How long would you be happy to let the engine run under these circumstances?

My position

From a thermal POV, Probably quite a long time, especially if it is an "Old School" diesel which are practically air/oil cooled at idle anyway (You can rest your hand on the exhaust manifold, the hottest part of the engine, of an idling "Old School" diesel like an old Transit or similar. I wouldn't try this unless the vehicle is going to be scrapped anyway, But I would think you could let an old transit diesel idle almost indefinably (Though not operate under any load) without it seriously overheating!). The main issue to my mind in the short term is the possibility of damaging the water pump seals/bearings which rely on water being present. though that could be mitigated by removing the relevant drive belt.

What say Motors? :p
Click to expand...
Why can't you just fill it back up with water or coolant ? :confused:
 
As others have said, push it. Or if you want tow it. This is not recommended as your starter might be a touch unhappy/break but I have moved a car on the starter for a few yards (car was going to the scrap yard anyway). Ironically the starter was fine afterwards.
 
Push it.

Coolant is there for a very good reason, engines develop a lot of heat when running - my e38’s temperature gauge moves almost as soon as it’s running - this heat buildup is exacerbated massively with no coolant in the system.

If you can’t push it due to an incline for example then use the starter.
 
I'd start an engine without coolant to check it turned over (for example diagnosing an issue). But I'd turn it off moments later. I wouldn't drive it anywhere. You might be OK just moving it to the other side of the yard. But personally I wouldn't even chance that. Without coolant the engine will heat up fast. In the immortal words of Salt n Pepper, just push it.
 
My car the water temp starts rising on gauge within probably 30 seconds, so my guess is its gaining 5 degrees or so every 10 seconds, its showing full temp by 1.5 miles or so (external temp has some minor effect)
Oil temp however takes about 5 miles to hit the normal range
 
I had a failed waterpump in my car before, I drove to work 15 miles without realising (no temp gauge in the car) I was only suspicious something was wrong because the heating didn't work. Opened the bonnet and saw the header tank pretty much empty. Let the local garage look at the car on my lunch break and wanted crazy money to replace the cambelt and waterpump, I said no as it was a huge ripoff so I filled the tank back up with water and drove it home.

I managed a good 12 miles before it was obvious the car was getting stupidly hot so pulled over and discovered the water had all leaked out again. Not something I'd recommend anyone do and I could have really trashed the engine, I should have just crawled the car to another local garage or had it recovered but my point is the car should be fine to move short spaces if it cannot be helped. Just turn your heating and fans right up so the engine fan runs as that will help a little with cooling.
 
Couple of miles driven gently.

Watched a tear down yesterday of a 427ci Twin turbo LS that had ran 5 1/4 mile passes with no coolant at somewhere in the region of 1300-1500hp. That's a serious amount of stress/load/heat repeatedly and it spun 1 rod bearing
 
Frozennova said:
Couple of miles driven gently.

Watched a tear down yesterday of a 427ci Twin turbo LS that had ran 5 1/4 mile passes with no coolant at somewhere in the region of 1300-1500hp. That's a serious amount of stress/load/heat repeatedly and it spun 1 rod bearing
Click to expand...

I watched that as well - Cleetus' one? To be fair that was an incredibly well built engine for that task, not a production engine.

I personally wouldn't have an issue with starting a coolant-less engine to move it across a yard or similar.
 
Jamesyboyjim said:
I had a failed waterpump in my car before, I drove to work 15 miles without realising (no temp gauge in the car) I was only suspicious something was wrong because the heating didn't work. Opened the bonnet and saw the header tank pretty much empty. Let the local garage look at the car on my lunch break and wanted crazy money to replace the cambelt and waterpump, I said no as it was a huge ripoff so I filled the tank back up with water and drove it home.

I managed a good 12 miles before it was obvious the car was getting stupidly hot so pulled over and discovered the water had all leaked out again. Not something I'd recommend anyone do and I could have really trashed the engine, I should have just crawled the car to another local garage or had it recovered but my point is the car should be fine to move short spaces if it cannot be helped. Just turn your heating and fans right up so the engine fan runs as that will help a little with cooling.
Click to expand...
Your situation was a little different in that you had some water but it wasn't circulating. The radiator would still have had some cooling action though.

I don't know whether modern cars are the same but older car heating systems were driven from a heater matrix (effectively a small radiator) which is part of the water system. If there's no water then turning on the heater won't help.
 
Frozennova said:
Couple of miles driven gently.

Watched a tear down yesterday of a 427ci Twin turbo LS that had ran 5 1/4 mile passes with no coolant at somewhere in the region of 1300-1500hp. That's a serious amount of stress/load/heat repeatedly and it spun 1 rod bearing
Click to expand...

Was that Cleetus' car? If so so I watched the same video.
 
You must log in or register to reply here.
Back
Top Bottom