Heres a question for you guys. Could a bad turbo cause the truck to run hot? I heard this from someone and didnt know if it was true or not, so I thought id ask. I am aslo susspecting a bad turbo in my truck because it dosent seem to have any darn power when I do tow. I feel like i need to fight it to keep it at regular highway speed (55-60). and it seems like its getting worse as time goes by. Even without a trailer it seems like there is less power. Any ideas? thanks guys

 

With the 6.0, I would think there would be more symptoms as well (blowing coolant out of the degas bottle, cac hoses coming off, intercooler failures) If you have low power because of a defective turbo (which is possible) overheating is a possibility from the vehicle having to work that much harder to do the same job.

 

2005 Ford...has it had the recall flash?

 

I can't say exactly whether engine overheat can be a result of a bad turbo or not.

However let me tell you where I am:

Yup, have had intermittant engine overheat when heavy towing or on long grades at altitudes above 2000 feet. Below that., pulled like a "hoss".

For me not until reaching altitudes over 2,000 feet.

Don't know your truck, but I believe it may be related to a sensor called the Barometric pressure sensor.

There is another thread about this going on now in FTE, and all of us hope this is at least the beginning of the end for the rash of ford 6.0 turbo problems.

Looks like Ford is replacing turbos like candy all of a sudden. Some of us think this is a sensor issue that might cause turbo failure or performace issues and engine codes that might lead Ford service techs to replace the turbo.

Some of us on the forum are looking at the barometric sensor or (BARO) as root cause. However, it is unclear how the BARO sensor regulates engine or turbo opeartion.

We await the professionals to come in more on this.

What we do know is that Ford revised this barometric sensor from the problamatic '03 diesels to the '04 model year. (There is a ford service publiction on this.)

Obviously none of us yet know about the reasons behind the specific part number change for the BARO sensor or it's interface to the computerized engine control.

At least this might help?



Feed back appreciated.

 

now that you mention it catfishman, i dont recall ever overheating at low altitudes. The only difference is that I dont tow heavy at all, under 4000lbs but my problem does seem to be intermittent. It will get hot on some little puny hill, but stay right at normal over a massive mountain. It did seem very odd that It would not get hot over the big ones (most of the time). It dosent blow coolant though, but this BARO sensor might be the key. Ill get the truck to the shop and ask them about all of this and the turbo, then report back to you guys. thanks for the advice.

 

2005 Ford,

Obviously you don't have the same issues on your truck as I did. So don't go jumping to conclusions on what I have posted, PLEASE!!

Your symptoms are in most situations very different from mine:

You said you don't tow heavy and don't blow coolant.

But you didn't say at what altitude you live and whether you problem was clearly alltitude related.

I went from about 700 feet above sea level to 2000 feet before my probem showed. Did you do this or make a similar ascent of 1200 feet or more??

"Intermittant" is nothing if you track the grade climbing and altitude change. It's hard to say your true altitude in the hills unless you are tracking this with a GPS. In my case I went about 100 miles, but only six times exceeded 2000 feet in elevation on hard pulls. No doubt, the harder (and longer) I pulled hard at high elevation the more likely I saw a sudden climb in engine temps and lack of power.

I'm trying to figure out why my 6.0 has an issue pulling hard at elevations above 2,000 feet while it seems to pull fine below that elevation.

The only thing I can tell you about being intermittant is that it might be altitude related?

I still don't have a clear view on this issue but would caution you about taking your truck to a dealer claiming a bad BARO sensor based simply on what's been said here.

I have a couple of other questions out there regarding this and wheter there is an easy way to test the BARO sensor and whether it controls the fuel or turbo in any way.

Note that this sensor is in the cab of the truck and so it seems that this pressure sensor could easily be confusd by simple things like whether you have the A/C on recirculate or not. Whether you have a window cracked or not in the cab and all kinds of other things that might make the percieved atmospheric presure in the cab different from what is true ATM pressure or (better) atmospheric density outside of the cab.

We don't know these thing yet, but a Ford Expert is going to jump on this thread quick I think.

Hold your truck's and let's see.

.

 

Catfish, yes, the baro is one of the sensors governing turbo strategies, and fuel usage. It only stands to reason that thinner air wont work as well as dense air in the combustion chamber. We have been working that angle ever since we first lined up at the drag strip. There is different calibration for vehicles at higher altitudes ( gotta get the dreaded reflash). Remember, the 6.0 is to my knowledge, the only engine that totally relies on computer information to run. You actually have to forget all your established methods of diagnostics to work on this thing. The "mechanic" is on the way out, we are known as "technicians" now. Oddly, you have to bring the "mechanic" out of the toolbox occasionally.

 

ok catfish man, ill hold my horses, and wait out this thread a little. Im just getting ansy and i want the only two problems the truck has had to be history. the lack of power and the extreme heat ups. thanks for the info guys.

 

vloney,

So if you want to maintain power at higher altitudes you have to spin the turbo faster to create enough intake pressure to the combustion chamber pressure at high altitudes. (Given you are dumping near max fuel for the load.)

Now the question is: If you work a turbo hard like this does it not take the temps up? And the answer is yes. Because you are compressing a less dense gas to the same target density. For a given intake air temp and a target discharge pressure. A compressor (turbo) with denser intake air will run cooler than one taking in less dense air.

Now if Ford is working with towards optimum air/fuel ratios in the combustion chambers for both power and emissions, the Ford must either cut back on fuel (not good, causes power loss), or they must run the turbo harder to compress the air more. Right?

Now to tell how hard the compressor has to run, they need a way to tell how dense the air is to begin with. Right? The density of air is generally based on altitude or moreover, barometric pressure. So Ford is aparently using a barometrtic pressure sensor to tell the engine computer how dense the air is BEFORE it is compressed.

Further some of the input from the barometric sensor is used to control (by estimate) how "hard" the vgt turbo is required to work to produce adequate air density for fuel demand.

(This is a fault in design in my opinion, because what is critical is the density of air that is actually going INTO the combustion chamber AFTER compression by the turbo for any given fuel flow, not the intake air density! Ford must have assumed the turbo has a fixed efficiency. (But everrybody knows turbo efficiency varies with wear, carbon build-up and other age-related stuff.)

Apparenty if a barometric sensor fails by being too high or low (vs actual altitude) or fails by "sticking" at a given sensed altitude, then all bets are off on what the computer will tell the vgt turbo to do.

Assumption in my situation might be that the Baro may be stuck at a lower altitude. This would mean at high altitude the engine would be running too rich. (That is more fuel being dumped in for available combustion air..unburned fuel out of the exhaust). Normally, that might mean black smoke from the exaust because of unburned fuel.

However, because of the presence of exhaust restrictions and other items, a portion of this hot unburned fuel may recombust in the exhaust manifold areas. This might result in high exhaust back-pressure because of further combustion expansion there, and if near complete recombustion occurs the presence of observable black exhaust smoke may or maynot be significant.

Meanwhil the turbo is happy as a lark. not too much work. But the engine makes no more power because it has insufficient air and the engine temp starts to rise suddenly because unburned fuel is being burned fuel is being burned in an area that cannot be cooled because of insufficint cooling galleries or circulation in the exhaust areas. (Remember we have to keep the exhaust gasses very hot for the exhaust emmissions catalyst to work!)

What little bit of coolant that is near the exhaust section begins to instantly flash (or boil). That causes the whole coolant system to burp or suddendly expand. This results in occaisional "coolant puking" out of the coolant reservoir.

The unburned fuel that may occur is recirculated through an emissions control device called the EGR. (Actually intended to burn off a porton of unburned fuel for emissions purposes.) Unburned fuel contains a significant amount of carbon, gums and varnishes. These unburned fuel substances clog the EGR valve and often render it inoperable over time.

Take this like you want, and I'm not doctor diesel!!! In fact, I've only operated a few.

All I am is a dumb owner with a hard education in solving machinery problems that no body else can fix.

But let me repeat some of what I said above:

1.) I believe Ford made a mistake in making the Barometric Sensor a principal input for turbo regulation and performance. And that Ford mistakenly placed this sensor within the passenger compartment of the vehicle where influences such as the cabin pressure can influence this critical sensor. Furthermore, in using this sensor as a principal input to assumed engine and VGT turbo control schemes, I believe that this lends the system that apparently assumes given turbo efficiency many parths to various and possible engine issues.

2.) I believe that this control and sensor scheme is prone to various problems that are difficult to diagnose and that are likely related to present, average or past sensed altitudes. The location of the Baro sensor within the passenger compartment of the vehicle lends itself to wide fluxuations of percieved barometric pressure depending a huge number of variables. Thes may include: various HVAC concerns in the cabin area. Whether windows are open, which ones and to what extent. The operability of cabin door seals or window seals. What the vehicle speed is in terms of areodynamic pressures and sucction on the cab are concerned. They style or type of towed vehicle from areodynamic perspectives that might influence cabin pressure. Perhaps whether one drives a vehicle predominately in three or more lane traffic where air dams created from adjacent or leading vehicles can affect atmospheric pressures.

I believe personally that these pressures may vary in terms of true barometric presure by significant amounts.

There is further a possibility that any averaging algorythims applied by Ford for Baro pressure may be inadequate to compensate for various and changing road conditions. For instance a sudden ascent or decent of a 5% grade with AC on and a private two lane road may not be the same as the same ascent pulling a different trailer with the windows open on a busy interstate.


3.) I believe Ford ignored the possibility of turbo inefficiencies that cannot be sensed by the Baro sensor in their engine control schema.

4.) I believe that the above items 1 and 2 , and 3 can sometimes result in a rich running condition if the baro sensor senses a higher pressure than actual, and that under such certain conditions, cause excessive soot within the engine system. And that such soot can clog the exaust gas relirculation system of the engine.



OK I'm going to quit and leave all of the above to the better people.

But because ford themselves changed this part once, there is something cooking here.

 

You do have a handle on how things work, but remember, this is 1 of 2 different intake systems. Mass air flow, and speed density. This one relies on a correlation between several sensors (map, baro,ebp, and maf) If one sensor has a large discrepancy from the others, a dtc is set and it moves to a default setting.

 

vloney,

So if a DTC is set, does it give the driver a CEL? (I guess a DTC is a Device Trouble Code?)

I never saw a Check Engine Light on my truck!

If not seeing a CEL, why would a defective "emissions dependent sensor" not alert me?

In my case, you are saying that Ford service is the only one that would know if a emission sensor had gone haywire by setting a DTC?

Like I said I had code P0478 stored, but I never had a CEL.

Makes no sense to me that if an emission critical sensor goes haywire that a CEL does not come on to alert me.

I understand why there might be a reset to a defaut operating condition if the engine computer determines a sensor is defective. But why not notify the vehicle owner with a CEL?

The more I learn about this the less confidence I have.

Never the less, thanks for the feedback!!

 

catfish you really are thinking alot arent you? just to help you a little if by any chance you run hot or hotter at above sealevel then yes you could have a sensor coherency problem. the turbo is highly unlikely to cause and engine over heat because it is easier to remove heat from air than a solid or liquid. your truck may be over fueling due a turbo sticking (not fuuly boosting) or a restriction it the air inlet or like my buddy vloney said sensor(s). i been working on these trucks since they came out and never seen a ck engine lt unless it was electrical hard fault, same way as 73. i have had tons of codes and no light whatsoever. so just relax. these engines are not that hard to understand once you know the basics and if you dont get the basics then you will never understand these babies for sure.

 

Bowtiehater,

Well I guess I'm just plain dumb about my diesel truck.

But thanks for confirming that I as an owner could have a sensor (even an emissions sensor failure) that only a Ford service dealer would know about. That type of sensor
failure diagnosed only by reading DTC codes.

And that such a sensor failure might not result in a CEL light.

I guess my service dealer put in a new turbo NOT because of over fueling, but because the turbo might not have been able to deliver enough compressed air for the amount of fuel required by the load.

My question was about turbo control at higher altitudes because we both know the turbo has to work harder to compress less dense air at high altitudes to make enough air to the cylinders in order to meet the air/fuel mixture target.

At higher altitudes or loads the Variable Gate Turbo should have "opened" wide open to get the required amount of air into my "foot in the throttle" fuel needs.

Now my issue was only at higher altitudes if you read back. And I know that the Baro sensor (BPS) sensor is one of the inputs to controllng the VGT behavior.

I'm trying not to be a true butt-hole on this, but I can't yet figure how it was required to put a turbo in when the truck ran just fime at lower altitude.

Furthermore, there appears no way for even a Ford Service dealer to test the validity of output of the baro sensor over it's range except by actually moving the truck across significantly varing elevations. (Your service dealership may be at 6,000 feet above sealevel, mine 200 feet above sea level.) But, the truck you are working on today might leave tomorrow and pull a load at 10,000 feet above sea level.) Right?

Do you know if Ford has a procedure to test the baro sensor acroos it's intended altitude range in your shop or at mine?

I'd like to have my Ford Service dealer check the output of my Baro sensor across it's range in their shop. Can this be done?

 

i am not sure to be honest because i have never had aproblem with a baro sensor. it is not even in the engine compartment and i dont see how it could go bad because all vehicles had have some type of barometer on them since fuel injection came out. i would say with my knowledge of these trucks and other vehicles i doubt you have abad baro. if it will make you feelbetter try looking at the map sensor and hose/nipple.

ps i was not calling you dumb so if it sounded that way iam sorry. i am the last person to call anyone dumb, unless you cut me off on the road but that is a different story.

 

Neither has any other Ford tech around here found Baro sensor problems.

But Ford apparently found issues with the Baro sensors themselves back at the early release of the 6.0. (Or for some reason they changed the sensor output to match new engine programming) In fact, Ford changed the baro sensor and alerted their Service dealers and technicians about this. (see above notice.)

When I see an issue like this I'm going to ask a lot of dumb questions. Hopefully for my own benefit and understanding, but also for the benefit of other 6.0 owners.

Some other owners have had similar issues. And some owners may not have realized that their performance issue was related to altitude changes.

Ford seems to want to throw expensive parts at the 6.0 for performance-related complaints. Recently, that appears to be a considerable amount of turbo replacements. Some owners have no problems, some even have repeat issues.

I personally believe that that there is usually a simple solution to a complex problem that cost's many people a lot of headaches and money.

If we both hang in here we might just make everybody's life a lot simpler. You might even figure a way to test the baro yourself and get a huge Ford award for this! (snicker)

I'm discouraged to know that there is apparently no shop testing procedure for the baro sensor.

So you as a tech really would not know if the sensor was good or bad and have no way to test in your shop.

It there a DTC for the Baro sensor on the 6.0? (But that would just say the sensor is shorted or open, right?)

Further, you like many other techs might just put a new turbo in your customers truck at Ford's own reccomendation when "altitude sickness" is likely.

That's not your fault, you are just doing your job.

But what we don't know is how to shop test the Baro sensor. And we don't know how many "bad" turbos have been replaced because we did not or COULD NOT TEST that sensor in the shop.

Not only that we don't know how many "problem" trucks might have been running EVEN since new with a possibly defective Baro sensor.

PS: I will not cut you off on the road. And when you need to merge, I'll make you a hole if I can.