Help!? Intermittent High Temp Alarm - 2012 TXI 5.7 Monsoon

[skibug]

Getting an intermittent High Temp Alarm and temp is going up. Impeller good and all lines clear. Could it be the thermostat? Any other suggestions to check? Also, took impeller pump off all together because rear seal was on housing was leaking; but, now it seems to be baked onto the pump housing and only part of it came out in peices. Any tricks to removing the rest of it with scratching up the housing surface?

 

Thanks in advance.

[Waternut]

Do the malibu's have a filter screen going to the raw water pump? If so, it could be clogged. Could also explain why the pump housing got so hot. Maybe the belt is loose too? I find it hard to believe a 2012 thermostat would be going bad already so I'd rule out the other stuff first.

[gregy]

I had to take mine off on my 99 Lx. The shaft slid out the back and I think I used a socket to drive it and put the new one in.

 

I don't think there the same though. Have you looked at themalibucrew website.

[MISkier]

I thought thermostats were designed to fail in the open position. Thus, you would actually have trouble generating a higher temperature in the engine.

[Chuck_Dickey]

Impeller only sees raw water and should not have heated up unless it was starved for water due to a clog pre or post impeller. Most likely the strainer is blocked.

[skibug]

Nope, all lines are cleared and not starved for water. I thought the same thing about thermostats.

[gregy]

Thermostats do not necessarily fail in a open position. Also they are damaged everytime they are over heated. I've seen instances on vehicles were just one overheating damaged the thermostat to where the engine overheated easily afterwards.

[Dacon62]

I know you mentioned that all lines are clear. However I had a similar situation happen on my '08 Malibu VTX...sucked up some milfoil which the impeller chopped up and the pieces got hung up in the tranny cooler holes reducing flow enough to give me alarms occasionally. Have installed strainers ever since for piece of mind.

[skibug]

Replaced thermostat, all clear.

[brody]

Tranny cooler is definitely one to look at, the other one we have had a problem with is the actual water pick up under the boat, have a good look inside there

[DW]

@skibug: high temps could be caused by a poor prime condition, you noted the rear seal leak, it could also cause the pump to attempt to suck air and thus not push enough water through the system. Make sure all the hoses are sealed and clamps tight and seals are good. End gap on the impeller to housing could also lead to low water flow / pressure.

[skibug]

@DW @brody, thanks for all the input. I have check all the strainers, intake, etc. and all are clear. Once we replace the thermostat; the problem was gone. It ran fine for the remaining 3 months of the season with no issues. We did also replace the seal on the impeller pump housing.