2015 Hisun HS700 Crew Running Hot

[Fib103182]

I have owned my 2015 Hisun HS700 Crew  for about 3 or 4 months now. I got it used and was supposed to run good but was not put all the back together from a stator upgrade due to previous owner said he was going to out a stereo system on it. Anyway I have worked it much more than I have rode it. I seem to work on it 2 days and ride it for a hour. Me, my wife, and 2 kids (10 and 18) enjoy it but the engine compartment gets so hot. I've replaced the water pump and burped the cooling system and any other thing I could think of to bleed the air out and think its good with no air and water circulating. Fan seems to run fine and be on about all the time. Changed the coolant twice and oil 3 times. I noticed the engine really has nowhere for heat to go because heat rises and no air flow at all. Has anyone had any experience in this area? Any DIY tricks or any advice in removing the heat out of the engine compartment and getting it to a tolerable temperature. Im about to sell it if I can't figure something out and go waste money on a big name brand but I won't have red legs and arm from engine heat burning me and my wife. They machine never acts like its to hot or anything but it feels like it is. Thanks in advance for any and all help. 

[Fib103182]

Guess noone looks at this forum or maybe just have no advice in this area?

[Fib103182]

I have continued to try and cool this thing down and I'm not having any luck. I can let it run with the radiator cap off and with the front end point up on a steep hillside and burp some air out till I think its gone and completely full. Then go on a 45 mintue ride and without shutting it off when I get back, take the cap back off in same position and get more air out, fill it up with coolant, shut it off to cool over and over. Its is almost unbearable heat. Very unpleasant sitting in the seat and I have placed 2 layers of insulation underneath them and dont seem to cut it anymore? Help!!!! Please!!!!! Head Gasket????

[scott ryan]

Sorry, no experience with this model. Looks like back of engine compartment is vented but I can't see the front.  Forced air front to back should help some. Otherwise that engine heat will just hang at the top of the shroud and continue to cook you. Doesn't look like much space for air to circulate to the front of the shroud.  You might try to wire a 12 volt fan into the front of the shroud to constantly force air. I have no idea why your cooling system would continue to build air if there are no leaks. Maybe vacuum test? Best luck to you.

[Fib103182]

55 minutes ago, scott ryan said:

Sorry, no experience with this model. Looks like back of engine compartment is vented but I can't see the front.  Forced air front to back should help some. Otherwise that engine heat will just hang at the top of the shroud and continue to cook you. Doesn't look like much space for air to circulate to the front of the shroud.  You might try to wire a 12 volt fan into the front of the shroud to constantly force air. I have no idea why your cooling system would continue to build air if there are no leaks. Maybe vacuum test? Best luck to you.

I appreciate you taking the time to reply and your thoughts. They seem to be about the same as mine. I will try to let you know how it all turns out.

[Joe Breaux]

I think you have the dreaded HISUN leaky head Gasket syndrome.. you get exhaust gases  into the coolant causing a block .. had same issue with my 500.. had to replace gasket and head ........look at the recovery bottle when it gets hot.. you will see tiny bubbles rising while running

[Fib103182]

Ok i am now pretty sure head gasket is the issue as anyone that has read this probably know already. I've tried a few different stop leak type products to try to push it off till spring but dont think its going to happen. I replaced the old cooling fan which seemed to be good in till a removed it and the new one is so much better. My issue probably originally was the fan and thats what I've been trying to pen point before head gasket replacement. I appreciate everyone's input.

[Joe Breaux]

I suggest after new gasket, replace or just remove Thermostat and bypass switch on radiator to make fan run 100% .. .....After that, I have had zero overheat issues even in 95* weather in the mudholes ... ............oh, and the cabin heat issue with mine also went away after getting the engine temp down.. we also tested the HISUN sender on radiator . It was set to turn fan on when engine reached 238*... and its on the return side!!!  eliminated it.  installed adjustable fan controller.. set to engage fan at 160*. Cabin is no longer hot

Edited December 22, 2021 by Joe Breaux
dropped my beer

[Fib103182]

Just a quick update. I this thing always down to one bolt and it is stuck. So put back together and adjusted the valves mainly the exhaust side and seem to run alot better and a little cooler. Who would have ever thought that letting exhaust out would help in staying cooler. Lol. Still need to get the stripped bolt out to do head gasket.

[Joe Breaux]

Try with engine hot 

[Fib103182]

That was what I was going to try when I have time again. It actually kinda seems to not be losing any water since the exhaust valve adjustment.

[Fib103182]

Anyone know where to get a radiator  cap? I didn't realize they was so hard to find.

[Fib103182]

Got it down to one bolt again and its stuck. It is a different one but I all I did is just crack them lose. Maybe a 1/4 to 1/2 turn but last one is stuck. This thi g is coming apart this time it dont matter if I have to take it to the scrap yard after this. I can't seem to find a radiator cap anyway. These things are officially junk in my book. I will not ever own another or even work on another one. POS....

[Joe Breaux]

agreed