Overheating

[dgolla]

Reinell 200 LS with 5.0 V-8. Worked perfect at end of last season. Took it out first time this season and it overheats when used for extended time at RPM of over 2000. Cools down in idle or when I am running real slow. It would run at 180 and then get to 220. Any ideas what could be causing this.

 

[SpinnerBait_Nut]

Re: Overheating

Welcome to iboats Reinell, let's get this to the I/O forum for answers.

 

[bruceb58]

Re: Overheating

A number of things could cause it but most likely it needs a new raw water pump impeller. What brand of stern drive do you have?

 

[dgolla]

Re: Overheating

Volvo Penta SX. My research on the net has lead me to this conclusion of a new impeller as well. My Wife mentioned that last year when I was full throttle for about 20 minutes the engine overheated, but I had a new impeller installed not 6 months before. (Are they that crappy that I have to keep doing it.) Has anyone taken the lower portion of the outdrive off. It looks fairly easy, but I don't want to screw anything up. (Directions? Manual?)

 

[Don S]

Re: Overheating

Why would you want to pull the lower unit off the drive? The raw water pump is either belt driven or crankshaft mounted, depending on the model and year of your Volvo Penta SX.<br />Perhaps you could give us the full model number or serial number of the engine so it can be identified.<br />Here is a link to help you ID your engine.<br /><br /> Volvo Engine ID

 

[dgolla]

Re: Overheating

Yes... you are absolutely correct. Why do I want to pull of the lower unit? (I saw some diagrams that had the location of an impeller in the lower unit...I am now aware that Volvo Penta 5.0 has the water pump and impeller on the front of the motor and easy access.) <br /><br />Any tips on changing this part? Do I just take the pump off and then take it apart?

 

[DHPMARINE]

Re: Overheating

Just a note on this :<br /><br />The pumps aren't crappy,but if you feed them sand bars or run them dry they do not last.<br /><br />DHP

 

[dgolla]

Re: Overheating

Purchased the impeller kit at Napa Auto Parts and replaced the old impeller. The old impeller was still intact but all the fins were loose and rounded over. The new impeller is much stiffer and the fins are straight out.<br /><br />My friend told me that it is possible my thermostat is sticking and as a result my engine is not receiving the full amount of water it should. Any merit to this?

 

[Bondo]

Re: Overheating

My friend told me that it is possible my thermostat is sticking and as a result my engine is not receiving the full amount of water it should. Any merit to this?

Try it,+ See..........<br /><br />AnyThing is Possible........

 

[DHPMARINE]

Re: Overheating

Generally the thermostat is okay,depending on the amount of overheat.At any rate,ya just gotta start at the impeller,and work from there.<br /><br />The new impeller means water should be getting to the engine,now it has to circulate,AND get out.<br /><br />DHP

 

[dgolla]

Re: Overheating

I tested the boat over the weekend and it continues to overheat. However, the problem is not is not as bad as before. The impeller has improved the problem but engine still continues overheat after about 5 minutes of running over 2000 RPM. SUGGESTIONS? (I was in the Sacramento River and that water is COLD.... engine should not have any problem unless it is not getting enough cold water in...)(As soon as I lower RPM below 2000 the engine returns to 160-180 in about 3 minutes.<br /><br />It has been mentioned to me to run the boat without thermostat to see if my situation is improved. Any thoughts on doing this? Is there any potential damage from doing this?

 

[meat76head]

Re: Overheating

Speaking from a hard earned lesson about overheating, just go ahead and pull out that thermostat. You won't do any damage running without one. <br /><br />It should be a cheap enough part though, why not just go ahead and pick one up? If it doesn't fix the problem then you know you've got a good spare and some more work to do.

 

[Kevin70]

Re: Overheating

You could also check the gauge itself and make sure its not the problem. Also, someone on this site had an idea about replacing part of the water intake hose with a piece of clear hose to make sure you wasn't sucking in too much air.

 

[MainstreetUSA1]

Re: Overheating

If the raw water pump is working as it is supposed to, there may be a water flow restriction somewhere. As posted above it usually won't be the thermostat, but it won't hurt to check it and rule it out. <br /><br />Is the motor fresh water cooled or raw water cooled? Also how old are the risers/manifolds. If raw water cooled they may be limiting water flow depending how old they are.

 

[calwldlif]

Re: Overheating

What year we talking? SX drive?<br />Do you see water freely flowing from the<br />outdrive? I think previous posters gave<br />good advice. Bad thermo, blockage.<br />Hows your seastrainer?

 

[dgolla]

Re: Overheating

I tore the thermostat housing apart tonight. Guess what I found? Approximately half of a chewed up impeller stuck in the intake and outake to the thermostat. (The impeller I removed this season and replaced was completely whole and was not missing any pieces.)[Interesting Note: I wakeboarded all last season without overheating, yet these pieces must have been in the system????]<br /><br />This would explain why the boat was not receiving enough cold water at high RPM to keep it cool. <br /><br />I took the boat to a boat mechanic two seasons ago and his bill included changing the thermostat and impeller. Guess what he never did? The bolts on thermostat housing looked like they had never been turned. (Factory paint was perfect and they did not look like a socket wrench had ever touched them.) In order to remove the housing from the engine you have to disconnect the hoses. Imagine my surprise when I found all this rubber stuck in housing when I removed the intake house to thermostat from the impeller.<br /><br />Moral of the story.... learn to do the easy work yourself or know a trustworthy mechanic. This guy could have cost me an engine with his dishonesty.<br /><br />Thanks Guys for all you suggestions and help. I have ordered a manual and I will do all the work I can in the future.

 

[dgolla]

Re: Overheating

Last Post.... the boat runs great. Having bits and pieces of an impeller stuck in your thermostat housing will be an issue. Based on the amount of effort and time spent on this problem, I will be changing my impeller once a season.