Question if I'm damaging my engine by running it with no water

big_luke said:

I have a Baja with a Merc 454/Bravo 1 out drive.

I'm in the process of winterizing my motor/changing the oil.

I have the boat in my shop and it always gets messy if I plug water in while running it in the shop.

I've done this a couple of times without problem so far. But wondering if there is anything that I don't know about that I might be damaging.

I've been running the motor with no water by taking off the belt so no water enters the engine. If the raw water pump is not turning (damaging the impeller) and don't let the boat idle more than 10-15 minutes, is there anything else I could be damaging? I know the Alpha drives have the raw water pump in the out drive, but I know that is not the case for the bravo. I'm only doing this to let the oil get hot to pump it out.


anyone think of any damage I might be doing? or is this a safe practice?

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Bond-o said:

Ayuh,... Welcome Aboard,...
Nope, not a safe practice, 'n Yep, yer burnin' up All the rubber parts in the exhaust system...

How hot is the gauge gettin' in 10-15 minutes,..?? there IS water in the block, Right,..??

If yer runnin' it 10-15 minutes, with no water flow, 'n the block is drained,..??

I'm surprised it ain't seized up yet....

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big_luke said:

well there is some water in the block from the last time I ran it at the lake, but no water flow. I thought about the rubber exhaust tubes after the risers running with no water, but I never smelled anything burning. And they never got any hotter than when I do run it on the hose.
It took 10-15 minutes to heat up the oil as I was checking the oil filter temp constantly while running.

I've only done this once, but can't think of how you can seize up the motor until the motor actually overheats. As long as the oil doesn't break down by overheating.

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Bamaman1 said:

Your problem running the boat without water is not the engine, it's that your heating up the rubber water pump impeller in the lower unit. Heat will distort rubber.

Don't run it without a water muff for a second. Go ahead and make the mess. Water doesn't hurt anything.

And how long has it been since you changed the lower unit water pump impeller? They're a cheap insurance on protecting your motor.

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Bond-o said:

Ayuh,.... I asked if the block was Dry, which would lead to a seized motor, in 15 minutes of runnin'.....
Did the temp gauge show heat, or not,..??

There used to be rubber coated shutters in the top of the y-pipe,...
I'm guessin' their burnt up, 'n layin' somewhere in the transom, or outdrive by now...
'n, Yes, you most certainly burnt the rubber couplers, smell, or no smell....
It also puts undue heat into the seals in the drive, 'n the bellows...
Boat exhaust is water cooled for a reason,...
Run it Dry, 'n Yes, yer gonna have Issues...

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big_luke said:

anyone think of any damage I might be doing? or is this a safe practice?

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emilsr said:

Is it worth doing damage just so the oil is easier to drain?

Water cooled exhaust won't survive the temps of running dry. You may or may not have damaged things yet, but why risk it?

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tpenfield said:

Yes, I can think of damage that running without water is doing . . . particularly if you are running for 10-15 minutes.

As mentioned, the exhaust components, . . . but I'm thinking that the engine has overheated in some internal areas and suffered some damage, even though the temp gauge may not have complained.

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wrestling coach said:

Would you drain the coolant of your automobile, drive it around town and then return home and change the oil? You need a sign.

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big_luke said:

until the engine oil exceeds temperatures when bearings/rings start to break down, the motor should be just fine. You start breaking stuff when your oil is not working properly.

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thumpar said:

You also have to worry about warping and other problems from expansion.

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big_luke said:

you need to back out of this thread if all you're going to do is flame. I'm not talking about driving around in a car without coolant.

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emilsr said:

You're running a water cooled engine without any coolant. Same deal. Hot spots will develop, and you won't even know as without a water pump your temp gauge is only reading what little coolant is in the area. Bad ju ju.

No flaming here, only trying to help.

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