Engine dies when it reaches operating temperature.

2019CTD · **Joined:** Wed Jan 11, 2023 4:43 pm **Posts:** 3

I recently purchased a 2005 2.8 CRD Liberty that dies once it reaches operating temperature. The engine fan runs from the time the engine starts until it dies. No check engine light, no codes.

I have replaced
coolant temp sensor and pigtail
crank sensor
fuel filter
added inline pump
cleaned MAF

This liberty was previously owned by a family member and has around 70k miles on it.

I'm thinking its an ECU issue but wanted input from someone a little more experienced with the CRD's I have years of experience working on medium and heavy duty diesel engines but very limited experience working on the 2.8.

WWDiesel · **Posted:** Wed Jan 11, 2023 9:13 pm

Have you scanned it? What are the codes? A DTC code could at least tell you what area to look for problem. Need more information to properly diagnose.

FYI, the MAF sensor itself will not prevent this engine from running, it is only used for EGR operation and nothing else.
You can totally unplug it and run without it and the engine will run and function perfectly without it.
What about the MAP sensor, it was not in your list? Very important sensor on this engine.
There are also several other sensors on the injection system that can stop the engine from running.

Have you checked all the grounds? A bad ground could be causing what you describe.
Especially the one on top of the left fender under the battery behind the left headlight. see picture
A short to ground or a broken wire in one of the engine wiring harnesses could also cause your issue.

2019CTD · **Joined:** Wed Jan 11, 2023 4:43 pm **Posts:** 3

No codes, I pulled the map sensor and cleaned it as well. I checked what grounds I could see, checked wire harness to make sure it wasn't chafed around the fuel filter and other tight places. Does this engine have a separate MAP and air intake temp, I cant remember if it was 3 or 4 wire sensor. Once the engine reaches operating temperature the engine shuts off and will not start back until it cools off. This isn't intermittent its 100% of the time. It runs and drives fine until it shuts off. The other thing I noticed is that the electric fan runs 100% of the time and if the defrost or A/C is on the compressor will not cycle and the high side line gets hot enough to almost burn you.

WWDiesel · **Posted:** Thu Jan 12, 2023 12:26 pm

Sounds like something is heating up and shorting out or a sensor loosing its signal completely when it heats up.
The crankshaft position sensor is notorious for complete loss of signal as it heats up during the engine warm up cycle, and most times it never sets a DTC.
I known you said you have already replaced the CPS, but there is always a possibility that that it is a bad one right out of the box. It happens!
If it were mine, I would try another crankshaft position sensor and a new camshaft position sensor.

If you can get your hands on a scope like a PicoScope Automotive oscilloscope, you could monitor and test the signals for different sensors to find which one is failing as it heats up.
As far as I know, the MAP sensor will not totally stop the engine from running, if bad it just makes the engine run poorly.

There are some other sensors that are vital to engine operation such as fuel rail pressure signal, Fuel Quality Sensor on the CP3 injection pump, etc...but there has not been any reports of these failing due to engine warmup cycle that I know of.

Where are you located, you don't have a signature?
Adding a signature, location, vehicle information, etc... to your profile can help others when trying to answer your questions or simply providing advice.
To add a signature, click on "User Control Panel", then "Profile", then "Edit Signature" where you can add your information. :rockon:

See picture below.

If you have not read Sam's CRD Noob Guide, please do so as there is a lot of very useful information contained in it and it will help educate you about this unique little diesel engine.
Factory Service Manuals are available for viewing and / or downloading at:> http://www.colorado4wheel.com/manuals/Jeep/KJ/

:SOMBRERO:

2019CTD · **Joined:** Wed Jan 11, 2023 4:43 pm **Posts:** 3

I will replace the crank sensor again, is there a preferred brand? For example 7.3 power strokes are are finicky on aftermarket cam sensors, you about have to go through ford or international to get a good sensor.

WWDiesel · **Posted:** Fri Jan 13, 2023 12:54 pm

2019CTD wrote:

I will replace the crank sensor again, is there a preferred brand? For example 7.3 power strokes are are finicky on aftermarket cam sensors, you about have to go through ford or international to get a good sensor.

It has to be an OEM Bosch sensor. Not some off brand copy or chinaism knockoff.
You should always purchase and use OEM electronic sensors only. Using cheap aftermarket sensors can cause many problems.
Mopar OEM crankshaft position sensor - 5066882AA (made by Bosch)

IDParts.com
Crankshaft Position Sensor (Liberty CRD -- Bosch Part) https://www.idparts.com/crankshaft-posi ... -4484.html

AutoZone.com -- Sells a reboxed Bosch Sensor in their Duralast Line:
Duralast Crankshaft Position Sensor SU8492. https://www.autozone.com/engine-managem ... 793836_0_0

Engine dies when it reaches operating temperature.

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