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Ski Tart

Ran boat without impeller!

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Ski Tart

Okay, I need feedback about just how insanely dangerous it is to run an inboard boat WITHOUT an impeller! We took our boat into our local marina last week to be de-winterized, and their mechanic apparently neglected to re-install the raw water impeller! Our boat had crazy temperature fluctuations when we ran it; the engine temp would go to just over 200 degrees when idling, but cool down to 160 at ski speed. It was acting so quirky that I called it a day, and assumed I probably had a sticky thermostat. Now I have installed a brand new impeller, but I'm wondering what kind of consequences I should expect. I've spoken with the marina (who shall remain nameless for now), but at this point I don't have much confidence in them. This may be a first in stupidity, and I guess the moral of this story is don't be lazy; do your own boat maintainance! Any feedback on the consequence I should expect? Thanks

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Ndawg12

How long did you leave it run at 200? Any more than a few minutes and you could some serious problems on your hands. Hindsight is 20/20 but after you found out the problem you should have played dumb with your dealer, took the boat back to them and explained the temperature fluctuations and let them figure it out, and fix anything that was consequently damaged. Good luck!!

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Bill_AirJunky

Ouch. Hope your head is OK from pounding on it. :crazy:

Assuming your engine is all cast steel, 200 shouldn't be a problem. But much more than that might be. If it's an LT1 or any engine with aluminum heads, all bets are off.

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Calimali2

I wouldn't recommend playing dumb at all! Playing dumb will only make them think you are dumb and let them think they can take advantage of you, if that is their character as a repair facility. If they left the impeller out, they are liable for any resulting damages! It's the same as if Jiffy Lube left your oil drain plug out after changing your oil, they would be buying you a new motor! If there are no immediate damages, I would attempt to get something in writing where they admit to the mistake and they agree to fix or be financially responsible for any repairs needed for a certain number of hours...? This is clearly their mistake and their responsibility to make it 100% correct.

Just my opinion...

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Ndawg12

Ouch. Hope your head is OK from pounding on it. :crazy:

Assuming your engine is all cast steel, 200 shouldn't be a problem. But much more than that might be. If it's an LT1 or any engine with aluminum heads, all bets are off.

He's got the 340 Monsoon. I ran mine around 200-205 for about 2 minutes the very first time I changed my oil (impeller wouldn't prime with graden hose), 120 hours later I've had no issues.

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Bill_AirJunky

He's got the 340 Monsoon. I ran mine around 200-205 for about 2 minutes the very first time I changed my oil (impeller wouldn't prime with graden hose), 120 hours later I've had no issues.

Yea, shouldn't be a problem then. Your truck will get to 200 in the summer pulling up a hill.

Getting the shop to admit it in writing is a good idea. Making that happen is a whole different game though.

I'd say put the boat in the lake & run it. Check the oil often. If there is any damage, it'll most likely show up as chocolate milky oil or a leaky valve cover. At least if it doesn't show up, you will be able to sleep.

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WakingMeHappy

There's one mechanic who would never touch my boat again. You said you talked to the marina. Did they take any type of ownership? If they just blow it off and say everything will be fine it may turn real ugly if something is wrong with the engine. It would be a good idea to check over all of the hoses. You can either has a mechanic check out the engine or just go out and hit the lake. If something is cracked you'll probably find out when on the lake.

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obski

Hopefully no damage, but I agree, you should get some sort of owning up by the marina in writing in case there is a problem later.

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srab

Okay, I need feedback about just how insanely dangerous it is to run an inboard boat WITHOUT an impeller! We took our boat into our local marina last week to be de-winterized, and their mechanic apparently neglected to re-install the raw water impeller! Our boat had crazy temperature fluctuations when we ran it; the engine temp would go to just over 200 degrees when idling, but cool down to 160 at ski speed. It was acting so quirky that I called it a day, and assumed I probably had a sticky thermostat. Now I have installed a brand new impeller, but I'm wondering what kind of consequences I should expect. I've spoken with the marina (who shall remain nameless for now), but at this point I don't have much confidence in them. This may be a first in stupidity, and I guess the moral of this story is don't be lazy; do your own boat maintainance! Any feedback on the consequence I should expect? Thanks

I'm not sure I understand this at all. You mean the mechanic installed the cover plate on the raw water

pump without installing an impeller? If he did this, assuming the engine was dry, then I don't understand

how any water reached the thermostat, let alone the engine. And, if water wasn't reaching the thermostat,

then any readings on the thermostat wouldn't correlate with the actual temperature of the engine.

I'd have expected the exhaust manifolds to be smoking hot and the gaskets and plastic elbows to be melting. And,

who knows how hot the actual engine was running without coolant. How long did you run her before shutting

her down?

Edited by srab

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Lance B. Johnson

I'm not sure I understand this at all. You mean the mechanic installed the cover plate on the raw water

pump without installing an impeller? If he did this, assuming the engine was dry, then I don't understand

how any water reached the thermostat, let alone the engine. And, if water wasn't reaching the thermostat,

then any readings on the thermostat wouldn't correlate with the actual temperature of the engine.

I'd have expected the exhaust manifolds to be smoking hot and the gaskets and plastic elbows to be melting. And,

who knows how hot the actual engine was running without coolant. How long did you run her before shutting

her down?

I dont' have any direct experience with this but I have heard that at speed enough water gets pushed into the cooling system to efectively cool the engine. The real problem is idling. When I was racing cars we would sometimes see 230 degrees. certainly not good but never had any temp related problems either. Should be ok but document the situation with the shop.

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areamike

You may now have a stuck T-stat. Other than that I would not worry too much.

This is a 350 Chevy engine basically. When in a car these motors run at 180-210 plus.

The very worse scenario, I would think, would be a blown head gasket from overheating an engine. Check your oil and make sure it is not milky or the level has not gone up. You would also notice a small amount of a mayonaise like substance under the fill caps when you remove them. This is an indicator that small amounts of water are getting into the oil. Then again, if you are getting water in your oil it still is not a clear indication that your head gasket is blown.

Sounds like you did not run it long enough at higher temps to do any real damage to be honest. But then again... :unsure:

Edited by areamike

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D-GOOSE

The PCM has a temp cut out and when the temp hits that magic number the eng go's into limp in mode, cuts RPMS down.

Replace the thermostat and impeller and it should be ok.

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Luciano Chedrese

The PCM has a temp cut out and when the temp hits that magic number the eng go's into limp in mode, cuts RPMS down.

Replace the thermostat and impeller and it should be ok.

I think you wont have problems with the engine. Just go to the marina and Kill that Fuc$%··&//((%·$· stupid mechanik.

The maintenance of the engine is easy to DIY.

Good luck

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tvano

The PCM has a temp cut out and when the temp hits that magic number the eng go's into limp in mode, cuts RPMS down.

will the thermocouple return a reasonable temperature value if it's not immersed in coolant?

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LS-One

I'm only half kidding here but if it only got to two hundred with no impeller I'd be tempted to leave it out and never have to screw around with another one. :crazy:

That's this weekends job and I hate it.

Edited by LS-One

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Bill_AirJunky

Pull the engine cover & make the job a ton easier. :rockon:

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Woodski

I would suggest a compression and leak down test, those two tests will tell you if there is any damage. The more running time you put on the engine the more opportunity you provide another party of discounting the root cause of a potential problem. A true reading of 200-210 even 230 degrees farenheight will not harm your engine. Running the engine w/o a water supply will potentially hurt the engine, the impeller's job is basically to keep enough water at the engine water pump or circulation pump to allow it to push water through the engine. A ski boat can create enough water pressure at speed to not need the impeller, but at idle, the engine water pump will not suck any water to provide a water flow to the engine and keep it cooled. A gauge will actually drop in temperature reading as the air temp will not be over 200 deg F if the water is not at the sensor, similar to what happens when all the water boils out of a closed cooling system and turns to steam. Bottom line, you may not really know what peak water temp your engine reached, thus my recommendation to perform the tests. Given your description, I doubt you boiled the waterand you should be fine, but I would err on the cautious side.

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travlnmannn

I would suggest a compression and leak down test, those two tests will tell you if there is any damage. The more running time you put on the engine the more opportunity you provide another party of discounting the root cause of a potential problem. A true reading of 200-210 even 230 degrees farenheight will not harm your engine. Running the engine w/o a water supply will potentially hurt the engine, the impeller's job is basically to keep enough water at the engine water pump or circulation pump to allow it to push water through the engine. A ski boat can create enough water pressure at speed to not need the impeller, but at idle, the engine water pump will not suck any water to provide a water flow to the engine and keep it cooled. A gauge will actually drop in temperature reading as the air temp will not be over 200 deg F if the water is not at the sensor, similar to what happens when all the water boils out of a closed cooling system and turns to steam. Bottom line, you may not really know what peak water temp your engine reached, thus my recommendation to perform the tests. Given your description, I doubt you boiled the waterand you should be fine, but I would err on the cautious side.

So well put I wanna go get my engine tested. Damn thing will probably come back with an STD..

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Sixball

I was on a buds boat and he lost his impeller. Yes we pulled the impeller and put the boat on plain and it held 160 deg. It was on a SLXI. I lost one on my Centurion V drive. I was idling at the time. I let the boat cool down started it up put it on plain ran it back it also held operating temp. I did keep very close watch on the temp but I bet most of inboards will run at speed without an impeller.

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bnew03xti

I lost my impeller too and it held normal operating temp at cruising speed...200 deg. isnt bad, 230 deg. is when you should be concerned.

I was a mechanic, learned from the best. :thumbup:

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LS-One

Pull the engine cover & make the job a ton easier. :rockon:

How does it make it easier, rear access from the platform?

Edited by LS-One

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Bill_AirJunky

How does it make it easier, rear access from the platform?

Exactly. Kneeling on the swimstep was way less of a problem for me than laying on the engine/side hatch & contorting my hands to get to the impeller.

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LS-One

Exactly. Kneeling on the swimstep was way less of a problem for me than laying on the engine/side hatch & contorting my hands to get to the impeller.

How hard is it to get the hatch off ? The boat not near me right now to go look at it.

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Bill_AirJunky

How hard is it to get the hatch off ? The boat not near me right now to go look at it.

Two pins secured by circle clips, plus two gas shocks. Comes off in a minute or two.

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LS-One

Two pins secured by circle clips, plus two gas shocks. Comes off in a minute or two.

Sweet I'll give that a shot. Never gave it much thought before.

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