Heater not getting hot??
 

Sometimes it is most of the time just blows barley warm. I have a new 160 T stat in it and my temps never get above 160. the hot water source comes from the top by the intake. My shower comes out burning hot!!! and that source is from the block. Should I switch them? I would think the intake would be hot enough??? Could it be clogged??

Did it ever blow hot? If it did, it could be clogged. Take the hose off, and remove the fitting. You might have some scale in there. If it's clean, you might have a clogged heater core. Remove both hose's at the engine, put one in a bucket, and blow some air into the other hose. See what comes out. If you can't unclog it, you need a new heater core. The guys at Heatercraft are super helpful. Danny really took care of me, but they're all great.

Yes it did and sometimes still does. You referring to the fitting on the engine or heater??

mine runs cool at idol and hot when driving.

thats the issue, while driving it was cool

I would start at the engine. Make sure that both of the fittings arn't clogged. Then blow some air, or water through and see what happens.

The first time that happened to me The mechanic at Bakes said it was common due to weeds. Had me check the transmission cooler and sure enough, filled with Milfoil. Now whenever, i feel the heater temp drop slightly, I know it is time to scoop out the weeds. Definately start there 1st. it will take 30 seconds to check. Good luck

Never thought of this. So I assume this is after the raw water impellar? Anyone have a pic of what I should be cleaning. BTW, my lake is very weedy.

Mine looks like this, it is located just past the water pump. if you follow the line from the water pump, the weeds will be on the side the water enters the cooler, they will be caught up in the screen. Also check for rubber chunks, that would mean your impellar is getting ready to fail.

I am guessing this is what the poster on the wakeworld link is referring too, the thing with the metal clamps on it? It is the only thing that looks like what you pic is so I am guessing this is the trans cooler he wants me to check and see if clogged or not. I just don't understand how that being clogged would affect the heater.

I checked the water flow and and it doesn't seem clogged, it is coming out of the fitting fine and then must be circulating through the heater core because it is also coming out of the return line. It pours out like water would come out the end of a garden hose.

My boat never got past 164 degrees and it is a new 160 thermostat Should I attache a high pressure hose to one line and try and flush it out??

Attachment 6998

You could have an air lock in there, heaters can be hard to bleed the air out of. I had a lock in a heater in one of my cars that kept coming back (blown head gasket or something, I dunno I sold it while I could) and the first sign was always the heater blowing cold. The best way I've found to get them out is to disconnect one hose and fill everything with water then put the hose back before the water can run out again but this was a closed system so a boat might be different, I don't have much experience with open cooling systems.

I honestly don't know why it affects the heater and my boat never got over 160. But every time it stops blowing hot air, I pull the weeds out and the problem is solved. I cannot tell from your picture but the tranny cooler will have a water hose going in, and a hose going out. There will also be two oil lines(they are noticably smaller than the water hoses), but you don't need to mess with those. It won't take more than a couple of minutes to check for weeds. At least if it is not the problem, you can rule it out.

Good Luck

well I did clean the trans cooler and yes it was full of weeds but that didn't do it. I then removed the ball socket shut off valve I put in right by the hot water source and shortened the length of the hose to the heater (less up and downs) and it started to come out warmer but no where near what it should be. I varified I have hot water getting to the heater core TRUST ME on that one. Then it started to get dark. I wanted to shorten the run to the Y fitting which is hooked up right after the raw water intake.

So......bad core? I would think that would leak and it's only 1 year old.
Air in the lines? How and if so how do you get it out?
Clogged core? Do I need to blow air through it or will a high pressure water hose work?

Sorry that did not do the trick. I know nothing about cores. Maybe start a new thread asking for advice on the core on a more boat specific website. I get good advice on the malibu crew website when I have mechanical issues.