over heating seriously--help!!

[madera]

i have 4 cyl volvo aq130D/280out.Replaced impeller, cleaned heat exchange, still having serious over heating problem. what should i check next?

 

[PT@work]

Re: over heating seriously--help!!

Thermostat

 

[madera]

Re: over heating seriously--help!!

this is a cooling system that draws it water from the lake, no thermostat that i know of at all

 

[mikecjn]

Re: over heating seriously--help!!

Can you tell how much water flow you are getting thru the motor?

 

[madera]

Re: over heating seriously--help!!

I HAD THE MOUSE EARS ON IN THE DRIVE WAY FOR A SHORT TIME AND WATER WAS GURGLING OUT OF OUT DRIVE, HOWEVER WHEN I PUT IT ON THE LAKE YESTERDAY, TEMP STEADLY ROSE TO PAST 210, THEN I SHUT OFF AND GOT A TOW IN. WHAT WOULD YOU LOOK AT?

 

[sea wolf]

Re: over heating seriously--help!!

u may have an obstruction somewhere in the cooling system. when u changed the impeller was it in pieces? sometimes a piece of the impeller will break off blocking coolant flow. are u sure there's no t-stat in the engine? how does the drive look? any seaweed or something else blocking the intakes? what yr. is it?

 

[tjkprop]

Re: over heating seriously--help!!

Almost positive there has to be a thermostat somewhere.

 

[zzzzz]

Re: over heating seriously--help!!

yep-you have a thermostat(part #824912)in the housing in front of the oil fill cap !

 

[Juancho]

Re: over heating seriously--help!!

Madera,<br /><br />If you have a temp gage then you have a thermostat. Moreover, you said you checked the heat exchanger so you must also have fresh water cooling. Change the thermostat, but I doubt this is your problem. You most likey have a blockage in the cooling system somewhere. Start at the lake water intake on your outdrive and go from there. Also, your exhaust manifolds might be toast. Do they get real hot? Exhaust manifolds should be luke warm at most.

 

[Larry S]

Re: over heating seriously--help!!

I have an AQ 131, and had a lot of problems with the temperature going up to and over 200 deg. After changing the impeller on the raw water side and changing the themostat on the engine coolant side, I still had a problem. Running the motor with the ears on will not put enough strain on the unit until you run in open water, under normal conditions. I was told to check for air being sucked into the raw water side and not allowing enough raw water to be drawn into the impeller. This was not my problem but I did check it out.I also removed my heat exchanger and had it professionally cleaned which was not my problem. My solution was a new exhaust manifold. Even though some raw water was being pushed out through the exhaust, just not enough to keep the engine cool. Once replaced the temp sits at 180.

 

[echozulu]

Re: over heating seriously--help!!

if you run one of the aq drives on a flusher without plgging the drainhole in the nose of the lower unit you may have smoked the impeller there is a thermostat, its a closed cooling engine anothr possibility is a plgged exhaust riser you can have all the water flow you want but if it cant get out of the heat exchanger fast enough its still going to bake

 

[madera]

Re: over heating seriously--help!!

i pulled the thermostat and it was totally rusted will get new one. only open about 1/8" is that all it does? i was planing to remove exhaust manifold and check for plugging, what do you think of that.larry s. how much did you give for new exhaust manifold and were did you get it? "thanks every one i really appreciate all the great help, working on a shoe string trying to keep this family boat afloat"

 

[Monte Cryts]

Re: over heating seriously--help!!

May also check the intake hose on the outdrive. A buddy and I finaly found that his hose was colapsing and when in idle everything was fine then when he gave it throtle it began to overheat. A lot of money and time wasted!

 

[Larry S]

Re: over heating seriously--help!!

When I pulled my exhaust manifold I found a lot of rust and clogged ports. I was told not to even try to save it and get a new one. Any marine on line parts house. Around $240. Money well spent after losing a summer over overheating. Get the parts and repair book and you will need new gaskets and maybe bolts. You can buy these as a pkg. Good luck, I'm off to put a timing belt on mine. It's always something but you gotta love it!