Impeller Damage Questions

[Classic Doddy]

Good afternoon and welcome to my life,

I fired up the 18' last week (2004 with 6.2 and a bravo) and took it for a spin. To make a long story short, had virtually no water pressure and temp. hit 200 or so (not much more than that). My brother, read super mechanic, changed the impeller for me - and it was toast. All eight fins/blades were gone and through pain staking labor - by him, we came up with all of them minus one. Thank-you brother and he has a 550 hp 27' Powerquest.

So here is where we are in the story as of right now, pulled the power-stearing cooler, strainer, thermostat housing, inlet valve (this is where found most of the pieces), and all of the the houses. Checked and blew them all out.

Today we took it for a drive and have perfect water pressure after the impeller change - no leaks or anything. 3 to 4 pounds at idle and great than 15-20 during the power runs. However, anything greater than casual driving (below 3400 rpm) resulted in the temp rising to 185 and then falling to 165 (operating temp.) when returned to a slow cruise. So it appears to me that the rubber fin/blade of the impeller is still somewhere it shouldn't be and at high RPM's it's obstructing the flow; or something else. With my luck it is lodged in a water jacket somewhere in the vortec heads.

My questions are:
1.) Has this sort of thing happened to others and if so tell me your story of the fix,
2.) Any other ideas where this little rubber bastard may be,
3.) Is anything other than pulling the motor and having it gone through going to fix it correctly??

Side note only - if I have to pull the 6.2, does anyone know of a cam grind or a performance cam for this motor, roller rockers, ect (no blower, yet). And, who can reprogram the computer.

Thank-you very much for any help at all,

Classic Doddy with a broken baby :(

[BUIZILLA]

what inlet valve?

[Classic Doddy]

what inlet valve?

I wasn't there, but it sounded like a valve prior to the waterpump, in-line maybe. All I heard was "broken Donzi"

[BlownCrewCab]

If you have ample water coming out of "Both" exhaust I wouldn't worry about anything. It's probably been pushed out by now, or it's found it's permanant home.

[gcarter]

Sea water strainers are helpful.

[fogducker III]

Sea water strainers are helpful.

I thought strainers were plumbed in BEFORE the Bravo impellor pump....:confused:

[gcarter]

I thought strainers were plumbed in BEFORE the Bravo impellor pump....:confused:

Well, that's a big "DUH"! :wink:
But they're still helpful.
Maybe two.

[mike o]

My 02 6.2L 18c runs at 180........ always, even in 40 degree lake water in the spring time.

[fogducker III]

Well, that's a big "DUH"! :wink:
But they're still helpful.
Maybe two.

I thought you had come up with a "special" routing system George..:yes:

I was hoping it was better than what I have.......:frown: Who ever installed my strainer did it BELOW the waterline so I have to be very quick when cleaning out the seaweed....:nilly:

The next changes in my bilge will be to raise the strainer.....but back on track....Doddy, I had my impellor go south last summer and it did the same thing, left peices everywhere, temp was high at high rpm for a while but eventually it found it's happy spot, I assume the pieces worked their way out....:confused:

[BUIZILLA]

do you have a transom mount flusher with an inline switch valve T'd in?

[The Hedgehog]

I am with Crew Cab. You don't have an oil cooler so it has probably flushed through. If not you are probably ok. Just watch it for a while.

I don't know of anyone that completely reprograms the PCM 555. Dustin Whipple has some ability.

Best bet is probably to convert it to a MEFI 4. Eddie Young at Young Performance does that type of work. I have seen some dyno sheets of his small block stuff. He can make some power.

[Cuda]

I thought you had come up with a "special" routing system George..:yes:

I was hoping it was better than what I have.......:frown: Who ever installed my strainer did it BELOW the waterline so I have to be very quick when cleaning out the seaweed....:nilly:

The next changes in my bilge will be to raise the strainer.....but back on track....Doddy, I had my impellor go south last summer and it did the same thing, left peices everywhere, temp was high at high rpm for a while but eventually it found it's happy spot, I assume the pieces worked their way out....:confused:
,There are advantages to having the sea strainer below the waterline. If you get a leak that the bilge pump can't keep up with, pull the top of the sea strainer and you engine becomes a powerful water pump.

The sea strainers in the 82 22, and my Formula both had sea strainers mounted below the water line. They were both factory mounted that way.

[MOP]

One blade flipped the wrong way in the housing will give the same results, I did it to myself this spring. I said WTF new impeller until I pulled the cover off the pump and saw one flipped backwards. Having one backwards eliminates two!

Phil

[joseph m. hahnl]

Good afternoon and welcome to my life,

I fired up the 18' last week (2004 with 6.2 and a bravo) and took it for a spin. To make a long story short, had virtually no water pressure and temp. hit 200 or so (not much more than that). My brother, read super mechanic, changed the impeller for me - and it was toast. All eight fins/blades were gone and through pain staking labor - by him, we came up with all of them minus one. Thank-you brother and he has a 550 hp 27' Powerquest.

So here is where we are in the story as of right now, pulled the power-stearing cooler, strainer, thermostat housing, inlet valve (this is where found most of the pieces), and all of the the houses. Checked and blew them all out.

Today we took it for a drive and have perfect water pressure after the impeller change - no leaks or anything. 3 to 4 pounds at idle and great than 15-20 during the power runs. However, anything greater than casual driving (below 3400 rpm) resulted in the temp rising to 185 and then falling to 165 (operating temp.) when returned to a slow cruise. So it appears to me that the rubber fin/blade of the impeller is still somewhere it shouldn't be and at high RPM's it's obstructing the flow; or something else. With my luck it is lodged in a water jacket somewhere in the vortec heads.

My questions are:
1.) Has this sort of thing happened to others and if so tell me your story of the fix,
2.) Any other ideas where this little rubber bastard may be,
3.) Is anything other than pulling the motor and having it gone through going to fix it correctly??

Side note only - if I have to pull the 6.2, does anyone know of a cam grind or a performance cam for this motor, roller rockers, ect (no blower, yet). And, who can reprogram the computer.

Thank-you very much for any help at all,

Classic Doddy with a broken baby :(


185F to 165F That's perfect. optimum operating temperature is 190F

Sounds like it has a 185F thermostat. Overheat is at around 250F to 260F

Run it and enjoy.

[Classic Doddy]

By run and enjoy it. I run it and watch the hell out of the temp gauge - if it creeps over 190 then I shut it down??

Should I change the thermostat to a 165 to make sure it has a 165 in it? I'm the second owner.

[VetteLT193]

My 02 6.2L 18c runs at 180........ always, even in 40 degree lake water in the spring time.

I have twin '08 6.2's. kind of acts the same as the initial post. start it up, runs up to maybe 185 then drops down and stays pretty consistent after the initial warm up to 175 ish... analog gauge has a giant gap in that range so it's somewhere around 175.

[joseph m. hahnl]

By run and enjoy it. I run it and watch the hell out of the temp gauge - if it creeps over 190 then I shut it down??

Should I change the thermostat to a 165 to make sure it has a 165 in it? I'm the second owner.

If its gets up over 215F then shut it down . If you are worried about it running @ 190F "which is optimum efficiency". Then You should definitely go with a cooler thermostat.I run a 150F thermostat myself, but I have full closed cooling. When you run at the top of the RPM curve it's going to get hot. It is better to Reduce RPM and bring it through a cool down then just shutting it down in a panic. You don't want to cook the oil .

[Classic Doddy]

Thank-you all for the help and advise. I ran it pretty hard on Thursday with no concerns. Never got any higher than 180 and water pressure was within operating values.

I'll keep watching it though... kind of had the hopes it needed a 525 merc repower though :)

Classic Doddy