GETTIN' DIRTY IN THE 'VILLE
 
HomeHome  CalendarCalendar  FAQFAQ  SearchSearch  MemberlistMemberlist    Merchandise  Local Junkyards  Local Offroad Parks  RegisterRegister  Log inLog in  
CHECK OUT OUR NEW ONLINE STORE UNDER THE "MERCHANDISE" LINK AT THE TOP OF THE PAGE!!
Like us on Facebook!

Add to Favorites

Latest topics
» Any one on here ?
8th March 2015, 4:57 pm by Jason y

» Trail Rated lol
11th November 2013, 2:40 am by Legg

» New member
11th November 2013, 2:34 am by Legg

» 38.5x15x15 bogger 200.00
13th July 2013, 11:07 am by 72Blazerracer

» Slower-poke Build. 98 ZJ 5.9 Limited
2nd July 2013, 3:01 pm by gs69350

» FREE T-SHIRT
15th April 2013, 1:07 pm by gs69350

» My Solid Axle Swap build
7th April 2013, 8:18 pm by fishforlife2007

» stripping an xj lol
7th April 2013, 8:04 pm by fishforlife2007

» LJOC's Guns N Jeeps Meet
7th April 2013, 3:22 pm by ZJ_flexxxer

» Black Betty, my 95 YJ Build thread
2nd April 2013, 9:48 pm by ZJ_flexxxer

Top posting users this month
Your ad here!



Share | 
 

 ZJ Overheat... or is it?

Go down 
AuthorMessage
gs69350

avatar

Posts : 217
Points : 283
Join date : 2012-02-09
Location : Sellersburg IN

PostSubject: ZJ Overheat... or is it?   12th August 2012, 11:00 am

Just wanted to share what happened to my 5.9 the other day.

I had just left a place and was cruising down Hurstborne when I got stopped at the light at Taylorsville road. I started smelling coolant. I looked around to see what car was overheating when I noticed steam billowing out from under my hood!!!

The temp gauge was halfway between 210 and 260, uh oh.

I pull over and pop the hood with the engine still running, my coolant recovery tank is at a rapid boil, spewing coolant and steam from the level sensor and cap.

I couldn't find any leaks, but the radiator cap was definitely not holding pressure and letting it all jet into the overflow tank causing it to violently boil. I popped the cap off the tank to help vent out the pressure so it would stop trying to push the coolant sensor out of the tank.

A previous owner had installed a radiator cap with the valve on it to release the pressure. I stopped the jeep and let it cool, all the while pressure being vented into the overflow. After a few minutes I started opening the release valve to vent the rest of the pressure. This took a while but I finally got it to the point where I could safely remove the cap. On initial inspection, the cap looked fine. I refilled the radiator and reinstalled the cap. The engine cooled down and it appeared to be holding pressure again.

I finish my drive back to work (about another 5-7 miles), and of course, I hit every red light on the way. Temp climbing up at idle, going down if I rev engine in N while stopped. Never let it get over 230.

I let it sit for several hours while I was at work. Towards the end of the shift I went out to see if I could figure out what the hell was going on.

I refilled the system without the cap and checked for flow through the hoses to make sure the pump hadn't disintegrated on this inside. That was good. No leaks anywhere. Finally, went to put the cap back on and noticed the center part was slightly tweaked. There was a plastic shaft in the center that attaches to the release lever, it has broken about 50% on one side. This was causing it not to seal properly and vent pressure.

A little "How things work" here. The pressure in the cooling system raises the boiling point of the water/coolant. Water boils at 212' F. For every 1psi, the boiling point is raised 3 degrees F. It is cruicial for the cooling system to be pressurized to keep the water from flash boiling at the hottest parts of the engine. When water flash boils, it turns to air, air won't cool your engine!!!
Antifreeze also chemically raises the boiling point even further, another reason to not run straight water, even in the summer.

I replaced the radiator cap with a standard style cap. 18psi is what is called for. Now my jeep runs right at the 200 mark, which is where it should be. Prior, it was running at 210 but never got higher until this incident.

It cost me $3.63 (I get wholesale parts costs) to solve this overheating issue and lower my normal operating temp by 10 degrees.



Back to top Go down
View user profile
ZJ_flexxxer
Admin
avatar

Posts : 421
Points : 545
Join date : 2012-01-24
Age : 29
Location : Louisville

PostSubject: Re: ZJ Overheat... or is it?   12th August 2012, 12:44 pm

man i hate having overheating issues. good thing you caught it before it got worse

__________________________________________________
94 Grand Cherokee - 4.5" lift, 32" swampers, skid plates, rocker rails. Soon to come - 8.8 rearend, adjustable control arms, 4.10 gears, 35's
Back to top Go down
View user profile http://www.502mudtrucks.com
 
ZJ Overheat... or is it?
Back to top 
Page 1 of 1

Permissions in this forum:You cannot reply to topics in this forum
502OFFROAD.COM :: Technical :: Problem Solving/Questions-
Jump to: