Forums
New posts
Search forums
Image search
Shop
Amazon Store
T-Shirts
Stickers
Members
Current visitors
Supporting Member Upgrade
Sponsors
About
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Image search
Search
Search titles only
By:
Search titles only
By:
Menu
Install the app
Install
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Jeep Wrangler JK
JK General Discussion
Help needed: Jeep suddenly overheating after changing the thermostat
Reply to thread
Message
<blockquote data-quote="TMan68" data-source="post: 458453" data-attributes="member: 25102"><p>This is gonna be long so hold on to ur shorts….</p><p></p><p>I experienced an under temp code so I changed the thermostat. (BTW anytime you put in a new thermostat, ALWAYS take it apart and work the action to ensure there is no factory gloss seal inhibiting it from opening on its virgin trial)</p><p></p><p>A week later I started getting overheating codes thrown. Tried several things to include new water pump, coolant flush etc… no bueno… was still getting super heated on the back side of the thermostat.</p><p>Had noticed a bit of oil in the coolant after the flush. Went back and looked at the coolant I had flushed out and there was oil in it as well. Checked the oil and thank the Lord above, no coolant in the oil. Did however find the valley between the heads full of oil and coolant mix.</p><p>Pulled everything down to heads and found slight seepage around 4 and 6 cylinders… bad juju.</p><p>Ended up pulling heads, which were warped and gaskets blown.</p><p>Milled heads put everything back together and still an overheat issue.</p><p></p><p>NOW FOR THE REAL ISSUE THAT CAUSED EVERYTHING TO CASCADE INTO MAJOR ISSUES:</p><p></p><p>The TCIP (computer mounted on the cooling fan) had malfunctioned well before the under heat issue. It was, unbeknownst to me, only running when the ac was on, thus overriding the tcip and coming on at low speed and quasi-cooling the engine.</p><p>Over a period of time, the engine was overheating somewhat on a daily basis… which later lead to the plastic oil cooler/filter housing in the valley to eventually crack and loose it’s seals, thus mixing oil and coolant on the coolant side.</p><p>This eventually led to a development of the heads overheating on a regular basis, which in turn led to warped heads and head gasket failure.</p><p>All is fixed now, but it was an expensive lesson learned about the JK 14 and later coolant fans.</p><p></p><p>IF YOU BEGIN EXPERIENCING OVERHEATING ON A 14 OR LATER JK:</p><p>Start the engine and get it to 225 degrees F. If the coolant fan does not kick in at precisely 225 F, replace the fan immediately. It will throw a code that does NOT set off the check engine light and will let you keep on driving with an ever increasing overheat issue that you simply don’t know about until catastrophic problems have already developed.</p><p>Hope my experience helps other JK’s 14+ out there<img class="smilie smilie--emoji" loading="lazy" alt="😁" title="Beaming face with smiling eyes :grin:" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f601.png" data-shortname=":grin:" /><img class="smilie smilie--emoji" loading="lazy" alt="😉" title="Winking face :wink:" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f609.png" data-shortname=":wink:" /></p><p></p><p>And yes, I replaced the oil cooler/filter housing with the aluminum Doreman housing to avoid the plastic sitting in the valley of heat death issue as well.</p></blockquote><p></p>
[QUOTE="TMan68, post: 458453, member: 25102"] This is gonna be long so hold on to ur shorts…. I experienced an under temp code so I changed the thermostat. (BTW anytime you put in a new thermostat, ALWAYS take it apart and work the action to ensure there is no factory gloss seal inhibiting it from opening on its virgin trial) A week later I started getting overheating codes thrown. Tried several things to include new water pump, coolant flush etc… no bueno… was still getting super heated on the back side of the thermostat. Had noticed a bit of oil in the coolant after the flush. Went back and looked at the coolant I had flushed out and there was oil in it as well. Checked the oil and thank the Lord above, no coolant in the oil. Did however find the valley between the heads full of oil and coolant mix. Pulled everything down to heads and found slight seepage around 4 and 6 cylinders… bad juju. Ended up pulling heads, which were warped and gaskets blown. Milled heads put everything back together and still an overheat issue. NOW FOR THE REAL ISSUE THAT CAUSED EVERYTHING TO CASCADE INTO MAJOR ISSUES: The TCIP (computer mounted on the cooling fan) had malfunctioned well before the under heat issue. It was, unbeknownst to me, only running when the ac was on, thus overriding the tcip and coming on at low speed and quasi-cooling the engine. Over a period of time, the engine was overheating somewhat on a daily basis… which later lead to the plastic oil cooler/filter housing in the valley to eventually crack and loose it’s seals, thus mixing oil and coolant on the coolant side. This eventually led to a development of the heads overheating on a regular basis, which in turn led to warped heads and head gasket failure. All is fixed now, but it was an expensive lesson learned about the JK 14 and later coolant fans. IF YOU BEGIN EXPERIENCING OVERHEATING ON A 14 OR LATER JK: Start the engine and get it to 225 degrees F. If the coolant fan does not kick in at precisely 225 F, replace the fan immediately. It will throw a code that does NOT set off the check engine light and will let you keep on driving with an ever increasing overheat issue that you simply don’t know about until catastrophic problems have already developed. Hope my experience helps other JK’s 14+ out there😁😉 And yes, I replaced the oil cooler/filter housing with the aluminum Doreman housing to avoid the plastic sitting in the valley of heat death issue as well. [/QUOTE]
Verification
Post reply
Jeep Wrangler JK
JK General Discussion
Help needed: Jeep suddenly overheating after changing the thermostat
Top
Bottom