2012 Ford Ranger

**Jadee** · September 9th, 2014 07:05 AM

Originally Posted by JX290

This is my take on the turbocharger problem encountered on Puma engine 2.2. and 3.2. (RANGER t6 engine). I am no expert but
as an engineer I guess I might be of help troubleshooting. The puma engine uses vgt and doesnt have a waste gate. Vgt has movable vanes, varrying the angle depending on load. The higher the load, the more it will open and vice versa. This turbo start spooling even at low loads as it is able to adjust opening of the turbine nozzle so as to maintain exhaust gas pressure to force the turbine wheel to rotate. At high rpm and loads this is full open and all the exhaust gas pressure will pass through the turbine,all forcing the blades to rotate really fast that may create excess pressure unlike if it has a waste gate, the waste gate will open and exhaust gas will by pass the t/c.

Only thing for the ranger is the opening of the vanes is controlled electronically by the ecu and coupled with it, new crdi diesels nowadays have a throttle body controlling the mass air flow to the engine. Diesel engines used to have full open intake air all the time. On, the ranger's engine it is not the case. So, my analysis points to the ecu as the culprit. If ecu is properly tuned this vgt control and throttle plate control is smoothly executed. If not, there is a scenario in which the turbo is now full boost but the throttle plate is just partly open, the result? hose rupture! due to over pressure on the hose. Why a hose so new will rupture in the first place? If the hose withstand the pressure, then your turbo will get damaged as it absorbs the pressure back, creating tremendous overloading to the turbocharger bearing and then it fails. ThAt's the time you will hear the whining sound of the turbocharger. It is the sound of a bearing failure.
I really think there is an issue with the ecu, otherwise some sensors or actuator motors are not functioning correctly.

Feel free to rebut my analysis on the issues.

I'm not expert with engine but I totally see your point. Thanks! Before my truck had this problem, I did cruise it in NLEX and had some burst acceleration till 160kph at some point and this might probably trigger the turbo problem.

**12vdc** · September 9th, 2014 11:34 AM

When you say bearing failure, there could only be two possible results - a loss of power (when impeller/blower got stucked or noise when destroyed), and oil breaching your intake or exhaust resulting to smoke..

Any of the symptoms described (smoke, permanent loss of power) were not present from what i read, all symptoms described here are intermittent loss of power so it could be just boost settings or a leak in IC piping..There is a boost sensor in the intercooler that shutdown fuel delivery when it senses overboost condition, hence limp mode. Also there is what they call FPRV fuel rail pressure relief valve and sensor that shuts also fuel delivery when over pressure in the rail is detected.

It might be helpful if somebody could check if the IC piping baloons when Turbo is boosting.

**JX290** · September 9th, 2014 12:11 PM

A bearing failure doesn't mean the turbo will stop rotating. It is not using ball bearings that when damaged it will seize.
It is using a bushing type bearings. Bearing failures on this type of bearings will only scour the bearings damaging its smooth surface lining or damaged to the shaft of the turbo causing pittings and so on.Unless otherwise oil flow is interrupted it will surely cause a seizure.
So power is still available but with that obvious noise.

**12vdc** · September 9th, 2014 12:27 PM

A scored bearing could eventually leak oil, or worse damage the blower due to vibrations.

Sleeved bearing is not immune to seizure. Remember that turbo shaft is cooled by the same motor oil and what happens when it leaks or coke, it forms a varnish seizing the shaft, hence seizure..

**JX290** · September 9th, 2014 12:53 PM

In the long term, yes! coking will eventually lead to bearing failures. But thinking, the engine is new, and coking may not be at all present yet. The only thing I think why this new engine t/c fails because of the overloading of the bearing due to overboost. And why overboosting happens?

**12vdc** · September 9th, 2014 01:19 PM

Overboosting due to VNT failure, failed to fully open on WOT?

AFAIK the only restriction is before the EGR valve which is the air-intake shutoff valve, purpose of which is to shut the air preventing engine vibrations due to self detonation of extra fuel everytime engine is turned off.

Just my thoughts, but then again were just guessing. Lets wait for the actual diagnosis and see what really went wrong with the turbo. It would help if some motorhead owners experiencing these probs could actually share some DIY intitial diagnostic info like boost pressure, rail pressure, etc...

Im actually monitoring this thread for the issues i have to face if ever i will replace my pickup with this ranga.

**Sweetlucious** · September 9th, 2014 07:38 PM

Ganun ba kadami problema yun t6? Planning to buy a 3.2 a/t to replace my fxt, pero parang nakakadiscourage bumili.
Or might as well wait till next year, para sa nisssn np300, saw it in Thailand last week, maganda rin naman.