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View Full Version : Impeller blown - how long before serious damage to engine?


qtpieash3
07-25-2011, 11:10 AM
We've had our '96 Prostar 190 for a whopping 4 days. We took it out yesterday (2nd trip ever) with some friends and had to be towed back to the marina after the impeller went out (at least, this is our amateur opinion).

My husband was driving and we were puttering through a no-wake zones (two back to back). When he went to take it back up to speed, the engine sort of cut off (we now know this is survival mode/limp home mode). It happened again a minute later. He didn't have to re-start and we thought maybe we were out of gas - we had been giving the side-eye to the fuel gauge since it didn't seem to have moved after we put gas in it our first time out. Then the check engine light came on and we noticed the temperature gauge was pegged. We turned it off, lifted the engine cover, and got a tow back to the marina. We're taking it in today, but we're both scared to death that we may have done serious damage to the heads. All told, we probably puttered around like this for 10 - 15 minutes before we realized what the issue was. Fortunately, we were in a no-wake zone and were going slow.

How long can you putter around with a blown impeller before you start to cause serious damage to the engine? He checked the oil last night and there didn't seem to be any water in there, though he did notice some oil around where the head attaches to the block, though it looked sort of gritty and old. There also looked like there was what could be slight oil spatter in hull under the engine, but it could be the fibers mixed with oil and water from the engine cover.

HWHanke
07-25-2011, 11:22 AM
happened to me on my 2000 prostar last year, I noticed the temp guage was high after I got back in the boat after a slalom run ( my wife was driving), drove back slowly to the dock let engine cool down and opened up the impleller housing, all blades gone I mean every one. spent some time cleaning out all the blade bits that were caught in the screens, replaced impeller, all good never had any further problem.
I would check the impeller before taking the boat in for service, it only takes a few minutes to replace (very easy)
good luck hope no other damage

CantRepeat
07-25-2011, 11:25 AM
x2 Change the impeller, check the down stream water routes for impeller parts, and take it back out for a test.

qtpieash3
07-25-2011, 11:26 AM
Hank - what engine do you have? Ours is the LT1.

qtpieash3
07-25-2011, 12:15 PM
:confused:Thanks to you both - the blades are a little shredded so I'm hoping once we replace the impeller everything will be ok again. Still nervous we may have broken something major since we puttered around for 10 - 15 minutes.:confused:

oldairboater
07-25-2011, 12:23 PM
I have to ask this. You aren't dry starting this engine before putting it in the water are you? I see people dry start engines quite often---hard on impellers. Your new but change out your impeller annually. You can get by not doing it annually but eventually impeller will fail. Waste the money--change your oil since you got this engine hot. Change out the impeller and find all the pieces you can. I found mine around the thermostat. Impeller has a rotation on my boat so that means it goes in one way only even though it will go in either way. Then go try it out. If boat runs good and there is no water in the oil---your good to go. This probably sounds like your daddy but watch all your gauges---not just the ones you like.

kjb
07-25-2011, 12:27 PM
I would also change the thermostat if it got that hot

qtpieash3
07-25-2011, 12:35 PM
I have to ask this. You aren't dry starting this engine before putting it in the water are you? I see people dry start engines quite often---hard on impellers. Your new but change out your impeller annually. You can get by not doing it annually but eventually impeller will fail. Waste the money--change your oil since you got this engine hot. Change out the impeller and find all the pieces you can. I found mine around the thermostat. Impeller has a rotation on my boat so that means it goes in one way only even though it will go in either way. Then go try it out. If boat runs good and there is no water in the oil---your good to go. This probably sounds like your daddy but watch all your gauges---not just the ones you like.

No, the boat is never started until it's in the water. I've heard that you should change the impeller annually and one friend says he actually keeps a spare in his boat. Good rec on changing the oil - will add that to our list.

I'm new, but have been around MC's since I was a baby. My dad has a mint '86 MC so I grew up around them, but am not so used to having to deal with all the mechanical stuff that comes with being responsible for it. He would have had my head if I started it out of the water. And he did tell me we need to keep a better eye on the gauges.

oldairboater
07-25-2011, 07:10 PM
Cool, Hopefully you didn't hurt anything, If you did it will fix. My Dad is 79 years old and still reminds me to do stuff mechanically. A little off thread but after I got my boat back together he went with me to try it out. He had been checking on my progress since I bought the boat and was repairing it. To get to the point we took it out and it was running good. I told him I was going to make a fast power turn. I asked him if he wanted to be on the high side or low side of the turn. He said high side. I turned this boat right which put me low at 45 mph. We powered turned ---I straightened it out and slowed down as we crossed our own wake. My Dad who is fearless looked at me and said "I didn't like that--don't do it again." Everytime I looked at him the rest of the day I would start laughing. This is the same man that has cartwheeled across salt grass after rolling over airboats. Dove into the gulf to cut ropes out of the props. I know he has been in two boats that sunk out from under them. He has pulled me water skiing behind boats that are museum pieces now. But he didn't like that power turn.

TxsRiverRat
07-25-2011, 07:25 PM
Next time, get the boat up to speed and see if the temp doesnt come down instantly...

it takes 15 minutes to swap an impellar (after you've done it the 1st time)...

best thing I found to remove the old one was 2 allen wrenches to wiggle it out.

use soap to lube up the new one and push it in.

MC

coz
07-25-2011, 07:43 PM
and one friend says he actually keeps a spare in his boat. .

That's the best advise right there, a spare can be the difference between a good day on the water or having to get a tow and a ruined day on the water.

joniron1
08-23-2011, 04:49 PM
My 89 prostar 190 had sporadic overheating problems when I bought it . it would heat up after it was turned off .the temp would rise very quickly and then not want to start for maybe an hour or so.Also it would sometimes overheat at high speed,but I wakeboard at 23 mph and usaully cruise around 30 MPH so it wasnt a constant problem.This spring I replaced the engine do to corrosion through the water jackets in 1 head (I ran the boat 400+ hours with the starbaord side head with jb welb applied like bondo the keep water from squirting out)When I pulled the heads off the old motor I discovered impeller blades and rust completely blocking 8 out of 10 waterports between the block and heads.Aparently the PO had an impeller failure maybe thats why they let the boat sit with brackish water in the motor for 5 yrs prior to me buying it .The moral of the story i think is if you have an impeller failure and have overheating issues afterward it may be due to blocked water passages in the engine.I thought I hadf pics on my work computer of the waterpassages but all I have is a pic of the jb weld.My new engine w/GT40 P heads runs awesome and run a steady 140 deg.

east tx skier
08-23-2011, 06:00 PM
In addition to the above,

Shine a flashlight up the exhaust pipes and look for blistering. If everything looks nice an smooth, there's a good chance you didn't do anything too bad.

Also, check the raw water hoses. Are they pretty stiff or are the a bit more soft and bendy than they should be?

I'd also pull the RW hoses and check for little bits of impeller all the way back to the transmission cooler screen.