Started getting an engine code. My cheap code reader read one of those nonspecific codes: $07E8, $07E9. I tried erasing it several times but it would always return. In my nonstop reading I did co e across the oil cooler problem these JKs have. Well sure enough mine is leaking oil too that I didn't realize although idk that by itself would trigger a code. I know I have to fix the oil cooler but any thoughts on the code? I am getting a friend to use his reader tommorrow and maybe his will show more
Engine code and oil leak
- Thread starter Erbowman
- Start date
Update: Friends code reader immediately read code P0128. I had noticed when I did reset the code it would always come back quicker when it was cold outside. I assume it's the thermostat since it does seem to take longer to warm up than it once did but I have not noticed any erratic fluctuations so I am not thinking sensor. Enlighten me if I should think differently
The oil cooler leak was just an accidental find. Now I have to see if I want to tackle the job or pay someone. Anybody have a clue what labor typically cost for the oil cooler repair???
The P0128 code is an easy diagnosis and I have personal experience with this code.
Cold start your Jeep and wrap your hand around the upper radiator hose. If the t-stat is operating properly, you should not feel any fluid flow thru that hose until the engine temp is around 180 or a little higher. If you immediately feel fluid flowing thru the upper hose upon start , your t-stat is stuck open. It isn't going to hurt your engine, but your CEL will remain.
Your oil cooler replacement cost is dependent on the year/engine. The older 3.8L will run you around $500, while the newer 3.6L could run you as much as $1200. This according to the shop who works on my Jeep when I need help.
Cold start your Jeep and wrap your hand around the upper radiator hose. If the t-stat is operating properly, you should not feel any fluid flow thru that hose until the engine temp is around 180 or a little higher. If you immediately feel fluid flowing thru the upper hose upon start , your t-stat is stuck open. It isn't going to hurt your engine, but your CEL will remain.
Your oil cooler replacement cost is dependent on the year/engine. The older 3.8L will run you around $500, while the newer 3.6L could run you as much as $1200. This according to the shop who works on my Jeep when I need help.
Dang. I have 3.6L. Looks like I will borrow friends torque wrench and save some money. Do some plugs while I'm there.
WestCoastDan
JK Enthusiast
You might want to take a look at a few videos of the process before you commit to doing it yourself.
I'm all about saving money when it doesn't need to be spent, but I think this particular repair may be best suited to someone that has done it before with all of the horror stories I have read/heard about the difficulty of flushing out the oil (if they mixed) & purging out the air so that it doesn't overheat afterwards...
Not to mention the "which oil cooler and which gaskets/seals do I use?" issue.
Well I did it. I actually can do most repair work when given a video and the proper specs. Yes it's a b$$$ch to take apart. Imo. Easier to go back together though. I took my time, marked all my hoses with blue paiters tape so I would remember to reattach. Watched several videos and I would advise to not detatch fuel rails but simply detatch fuel line, that way you avoid the O rings.
Biggest problem I had with oil cooler: attaching the new Dorman oil sensor. It would not fit! Had to instal old oil sensor and send back new one. The Dorman was a millimeter or so too big for connector.
Other issue was I was replacing thermostat. It was simple! However the air plugs, gap whatever u want to call them are real and a pain to get rid of. It took several cycles but finally got heat in the cab and rid of all the air bubbles. Definitely use the air valve on thermostat to get rid of air but it will still be a pain
Diy repair will save lots of money but will cost lots of time
Biggest problem I had with oil cooler: attaching the new Dorman oil sensor. It would not fit! Had to instal old oil sensor and send back new one. The Dorman was a millimeter or so too big for connector.
Other issue was I was replacing thermostat. It was simple! However the air plugs, gap whatever u want to call them are real and a pain to get rid of. It took several cycles but finally got heat in the cab and rid of all the air bubbles. Definitely use the air valve on thermostat to get rid of air but it will still be a pain
Diy repair will save lots of money but will cost lots of time
Yea I replaced that. See above. Now, hottest air in have had in a long time. I guess I never checked what temp it was supose to be and where thermostat was opening up around 180 I assumed it was OK. Now around 203 and hot as hell heat