Greetings Threaders!

I recently owned my 2007 Ford Ranger 3.0l TDCi for 8 months now, it developed a check engine code a couple months ago pointing towards the ECT sensor.

I was told it might be a faulty ECT sensor or damaged wiring and the worst case scenario would be poor fuel efficiency which I noticed.

I also noticed after driving for 30 mins, after she's warmed up, when I come to a stop and the truck tends to idle rough intermittently, almost like sporadic jerks from the engine, similar to a misfire but it only happens on idle.

Fast forward to 2 days ago I noticed coolant seeping out of the overflow reservoir cap which really startled my paranoia.

So far I bought a new radiator cap and replaced it but to no avail, there's still coolant leaking from the overflow.

I am thinking next to purchase a new Thermostat and see if that rectifies it.

I am an overthinker and I really don't want to drive her anymore without resolving the issue, I am hoping it isn't the head gasket......

I am hoping someone here may have experienced this issue and can point me in the right direction before I go unbolting parts potentially wasting valuable time.

I also plan to investigate the ECT sensor issue and perhaps change it if needed while I am replacing the Thermostat one time.

 

I had a similar problem. The thermostat housing is very tricky to install and if it is not perfectly sealed and in the tiny groove all the way around, forget about it. When the thermostat opens it will suck air through the breach and cause "coolant barf" out of the expansion tank and sound like the end of the world. I threw in the towel and let a NAPA shop install a new one. I am in the process of ordering a coolant pressure test kit because I have a small leak coming from somewhere and I cannot lock it down. They screw onto the expansion tank and have a hand pump that pressurizes the system as well as having a vacuum assembly and gauge to pull a vacuum and get all the air out and add new coolantt.

While on the subject of coolant system pressure test kits, can onyone recommend one? There is a 14 piece set by the brand name VEVOR that seems legit, but they are real sketchy about what vehicles the tank adapter caps will fit. Lowes claims to have them at for less than 40 bucks I guess I'll have to take a chance.

 

Well... looks like a new Thermostat did the trick , when I removed the old one it looked pretty rough and rusty, basically confirming a previous owner ran her with water in the cooling system

After driving around for the entire day I checked the bottom radiator hose and it was hot to the touch just like the upper hose which confirmed the new Thermostat is allowing the coolant to flow through when it reads between 80 - 84 Degrees Celsius.

To make things better, I noticed there was no leaking coolant from the Overflow Reservoir Cap any longer.

I hope this thread helps someone in the future because not once did a local mechanic mention anything about the thermostat, all I heard was " Might be EGR cooler, Might be Head Gasket or Water Pump.

In the end it is always a great idea to start with the easy and basic things first before moving onto more labor intensive testing.