2005 Limited: Multiple DTC's

Hi everyone!
2005 Grand Cherokee Limited V8 with 124k Miles

On Friday, the Jeep ran hot to the point that engine shut down. Later that evening I added a quart of oil and a gallon of 50/50 coolant to the reservoir before driving to my mechanic. The ride was short so the engine never got to normal temperature but ran good. My mechanic had to replace the radiator because of a hole and then replaced the thermostat but it still ran hot. I was told the problem was the head gasket, cylinder to exhaust issue. I decided to drive the car home and it felt like I was on an aggressive vibrating hotel bed when I started it up. The RPM's were erratic almost to the point of engine shut down, especially when revved to 2K RPM's and then released gas pedal. Similar issues happened on ride home which I assumed was a misfiring issue. The next morning I ran the codes, I have attached screen shots. My question after all the rambling, would a head gasket problem cause the physical issues and DTC codes
Thanks to All!

 

All of the codes listed with the exception of P0128 can be caused by a head gasket leak between cylinders. Thermostat Rationality shouldn't be a symptom, but maybe the code wasn't cleared after thermostat failure and replacement. With the codes you have I might have guessed a bad crank position sensor or that it jumped timing, but throw in overheating till the engine shut down and the mechanic is probably right about the head gasket. I'm guessing that your mechanic did a leak down test already to confirm the gasket leak. Last thing you want to do is replace the gasket only to find out that you still have a leak, so make sure the heads are not warped and a penetrating dye is used to check for cracks when they're off.

 

HELP ME UNDERSTAND - THE ONLY ACTIVE i SEE IS P0300.

The pending issues I would -
p0300 work this as it is current code. Spark plugs may offer a clue 'read' them , worried about head gasket check your engine oil for evidence of coolant mixing with oil. A milkshake gray color is not good.

P0128 give consideration to the new thermostat, was a correct temp T'stat used, OEM is my choice
BUT check with the tech who changed it.

P0562 Give a check to charging system -out put voltage and battery age, Did the jeep have any starting issues that may have required a jump?

P0700 you will need a scanner able to display trans codes.

 

Hi Groundfault, thanks for the response. The only thing that has me confused is the before and after. The engine shut down happened around 2pm Thursday and I got there around 9pm to drive to my mechanic's shop. Granted that was only a 10 minute drive but the engine ran perfectly fine at that point. Do you think the blown gasket just took time to affect the rest of the engine by the time I picked it up Saturday evening? If it helps, I wrote the complete timeline below.

• Thursday 2pm: daughter called & said engine overheated & shut down
• Thursday 9pm: added quart of oil & coolant, engine ran fine on way to mechanic
• Friday by 5pm: mechanic replaced radiator and I went to shop, Shop Manager told me they were running the engine and letting it "burp"
• Friday 6:30pm: jeep was finally driven to front of shop, engine was misfiring & began to run hot, that mechanic stated "something's not quite right and shut engine down", Shop Manager told me it must be the head gasket
• Saturday 11am: Jeep was left overnight and I called shop as instructed, Shop Manager told me about the specific head gasket issue & said they had a few ideas and would call me back in an hour
• Saturday 3pm: I called shop, Shop Manager told me they ran engine for almost an hour before it ran hot but to try K&W Head Gasket Repair
• Saturday 5pm: drove jeep home from shop, engine did the shimmy with erratic RPM's on way home
• Sunday 8am: Used K&W and pulled DTC's

Update: I thought the Shop Manager said they replaced the thermostat sometime Saturday. When I called this morning, he said the thermostat was never replaced.

 

Hi Awrench, thanks for the response. I will check the condition of the spark plugs and reply back. As far as the other items, they had just changed the oil & I just checked and it was normal color. However, the bottom of the cap looks like it has caked on oil. I can send a pic if it helps. The battery is about 4 years old and the positive cable does look a little frayed. I must have misunderstood the shop manager about changing the thermostat.
David

 

P0128 thermostat is bad. It's overheating and the mechanic didn't change the thermostat. ???
From your last post, sounds like the shop was just guessing head gasket.
I'd replace thermostat, clear codes (scanner), run it to see if it overheats and if codes/misfire comes back.
Highly recommend checking everything @Awrench mentioned to potentially confirm or eliminate some possibilities.
Get a second opinion on the head gasket. Mechanic needs to verify head gasket with a leak down test. Too expensive to repair based on shop telling you it's "probably" a blown head gasket.