Engine hot on the highway, already bled coolant - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Engine / Exhaust / Cooling
\ From the radiator, through the case and out
the exhaust. If it has to do with the cooling,
engine or exhaust, discuss it here!

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 04-03-2017, 11:03 AM Thread Starter
Member
 
Join Date: Nov 2016
Location: New York
Posts: 92
iTrader: (0)
 
Exclamation Engine hot on the highway, already bled coolant

Hey, my bike is getting pretty hot even when riding on the highway.

Yesterday there was a small leak from the right coolant tube going into the engine block. I tightened the hose clamp and everything was okay. Right after I was riding at around 60-70mph when I saw the temperature gauge slowly creep up from about 1/4 of the way up to halfway, then almost 3/4. Getting off the highway and going 30-40mph resulted in the gauge sticking around 3/4 and a little above that, almost in the red. I didn't see any steam coming out.

Coolant levels are okay, I changed the coolant about a month ago and properly bled the coolant system. Just to make sure there wasn't any air in the system I bled it again this morning. I can't see any coolant leaking out, there's definitely enough coolant in the system and overflow tank. I'm really at a loss.

P.S. I changed out the radiator for a used one off eBay about 2 months ago since mine leaked. It's in good shape

'86 VN750
snoopyonderdonk is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 04-03-2017, 11:32 AM
Senior Member
 
ubertalldude's Avatar
 
Join Date: Jun 2016
Location: NE Florida
Posts: 662
iTrader: (0)
 
Did you do anything with the thermostat while you had it apart? Seems strangely suspect that this is with fresh coolant and a radiator. Maybe a radiator flush might be in order? Good chance of crud deep in the fins, especially with is being a used unit.
ubertalldude is offline  
post #3 of 14 (permalink) Old 04-03-2017, 11:38 AM Thread Starter
Member
 
Join Date: Nov 2016
Location: New York
Posts: 92
iTrader: (0)
 
Quote:
Originally Posted by ubertalldude View Post
Did you do anything with the thermostat while you had it apart? Seems strangely suspect that this is with fresh coolant and a radiator. Maybe a radiator flush might be in order? Good chance of crud deep in the fins, especially with is being a used unit.
No, I kept my old 'stat in there. I've been reading about replacing it with a failsafe 160 degree thermostat from an '89 honda accord, maybe that would help? I'm not sure what the stock temperature is for our thermostats though.

When I replaced the radiator I spent a good couple of minutes blasting water through the system from a garden hose until it came out clean so I'm not sure if using radiator flush would help...

'86 VN750
snoopyonderdonk is offline  
 
post #4 of 14 (permalink) Old 04-03-2017, 12:05 PM
Senior Member
 
ubertalldude's Avatar
 
Join Date: Jun 2016
Location: NE Florida
Posts: 662
iTrader: (0)
 
Yeah, if you have an '86 I wouldn't trust a 31-year-old t-stat, even if only OEM I would replace it. Sticking closed would definitely cause this, as could a clogged up radiator. If you flushed the engine coolant passages with hose water that's good, but there is a chance the radiator itself is sludgy on the inside, which could cause issues (not my first guess, though.)

I would probably go for a thermostat first and foremost, unless others on this site might have more insight. (Never done any cooling stuff on these bikes but did just do a massive cooling system overhaul on my '92 Pathfinder. Different beasts, but cooling systems aren't all that different from one vehicle to another)
ubertalldude is offline  
post #5 of 14 (permalink) Old 04-03-2017, 12:12 PM Thread Starter
Member
 
Join Date: Nov 2016
Location: New York
Posts: 92
iTrader: (0)
 
Quote:
Originally Posted by ubertalldude View Post
Yeah, if you have an '86 I wouldn't trust a 31-year-old t-stat, even if only OEM I would replace it. Sticking closed would definitely cause this, as could a clogged up radiator. If you flushed the engine coolant passages with hose water that's good, but there is a chance the radiator itself is sludgy on the inside, which could cause issues (not my first guess, though.)

I would probably go for a thermostat first and foremost, unless others on this site might have more insight. (Never done any cooling stuff on these bikes but did just do a massive cooling system overhaul on my '92 Pathfinder. Different beasts, but cooling systems aren't all that different from one vehicle to another)
Thanks for your help. I'll probably pick up that new thermostat from Autozone later today then flush everything out with that Prestone flusher.

'86 VN750
snoopyonderdonk is offline  
post #6 of 14 (permalink) Old 04-03-2017, 02:05 PM
FREEBIRDS MC CENTRAL NY
 
OleDirtyDoc's Avatar
 
Join Date: May 2011
Location: Norwich,NY
Posts: 15,873
iTrader: (0)
     
Garage
Send a message via Yahoo to OleDirtyDoc
I don't want this to sound stupid,but is the fan coming on?

Sent from my LGL34C using Tapatalk

ONE RATS ASS GIVEN PER POST
Support your local FREEBIRDS MC
1986/5 Vn700/750 Frankenfook cross eyed bitch "Mellisa Fayhe"
I am a BIKER and i'm proud.FREEBIRDS MC CENTRAL NY

lowered with progessive 412 10" shocks
rejetted for K/N Pods part#rc 2340
sportster seat

'I didn't lose my mind.i gave it away

BRING BACK WOLFIE."Peace and Carrots"RIP
"And I'm free...as a bird"John Lennon Free as a Bird
"I only carry when I have my pants on"Joe Robinson RIP aka Old Dog
OleDirtyDoc is offline  
post #7 of 14 (permalink) Old 04-03-2017, 02:12 PM Thread Starter
Member
 
Join Date: Nov 2016
Location: New York
Posts: 92
iTrader: (0)
 
Quote:
Originally Posted by OleDirtyDoc View Post
I don't want this to sound stupid,but is the fan coming on?

Sent from my LGL34C using Tapatalk
Yeah the fan does kick on about halfway up the gauge. Though it wouldn't matter on the highway..

'86 VN750
snoopyonderdonk is offline  
post #8 of 14 (permalink) Old 04-03-2017, 02:19 PM
FREEBIRDS MC CENTRAL NY
 
OleDirtyDoc's Avatar
 
Join Date: May 2011
Location: Norwich,NY
Posts: 15,873
iTrader: (0)
     
Garage
Send a message via Yahoo to OleDirtyDoc
halfway is right where it should kick on.just thought I'd ask.

Sent from my LGL34C using Tapatalk

ONE RATS ASS GIVEN PER POST
Support your local FREEBIRDS MC
1986/5 Vn700/750 Frankenfook cross eyed bitch "Mellisa Fayhe"
I am a BIKER and i'm proud.FREEBIRDS MC CENTRAL NY

lowered with progessive 412 10" shocks
rejetted for K/N Pods part#rc 2340
sportster seat

'I didn't lose my mind.i gave it away

BRING BACK WOLFIE."Peace and Carrots"RIP
"And I'm free...as a bird"John Lennon Free as a Bird
"I only carry when I have my pants on"Joe Robinson RIP aka Old Dog
OleDirtyDoc is offline  
post #9 of 14 (permalink) Old 04-03-2017, 02:25 PM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,490
iTrader: (5)
   
Seems to point to a sticking thermostat. Assuming no air in system, rad not plugged.

I suppose the water pump impeller could be gone. I guess I would take the t-stat out, put it back together without it, and see if the coolant is circulating. Meanwhile, the t-stat can be boiled in a pan of water to see if it sticks open/closed, though not a conclusive test, sticking can be intermittent. But if it sticks once, it can stick again.

Not a fan of 160 stats, running too cool all the time creates several problems.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
post #10 of 14 (permalink) Old 04-03-2017, 02:26 PM Thread Starter
Member
 
Join Date: Nov 2016
Location: New York
Posts: 92
iTrader: (0)
 
Quote:
Originally Posted by OleDirtyDoc View Post
halfway is right where it should kick on.just thought I'd ask.

Sent from my LGL34C using Tapatalk
I appreciate the thought, Doc. Hopefully this 160 thermostat will fix my woes

'86 VN750
snoopyonderdonk is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Once registered, your User Name"cannot be changed". We can make exceptions within 7 days, but after that, it is set in stone.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome