Do I have a problem or just typical cold weather symptoms?

[Dante04SRT]

As the temps have dropped here in TN, it is getting between 25-35 at night. I've began to notice a couple things - I don't know if they are actual issues or if they are just typical occurrences for a 6.0 in cold weather. It has not been plugged in.

First thing - When waiting for the glow plugs - The noise that the system makes usually is a sound that changes tone as it works, but usually doesn't change speed. I've noticed lately that it starts out SLOW and isn't as "smooth sounding" as usual - My truck cranks fine so I can't help but think it is NOT battery related. No matter how many cycles it gets, it just sounds "weak".

Second, when starting the truck, it actually starts fine, but runs really rough for a few seconds - I noticed this problem coincided with my recent oil change (went from Motorcraft to Delo400 - price related). I get a small, quick puff of smoke at startup that I assume is normal at cold temps. In these temps, it will go to high-idle until I tap the pedal to bring it back down.

Last, I've noticed a performance issue. After letting the truck run for anywhere from 1-5 minutes, I pull out of the driveway. Under low-throttle, normal driving there is no issue noticed. If for any reason I have to give it a little throttle (before the engine is up to temp), it has very little power. It almost feels like a fueling issue - Until the truck is warmed up it just won't kick down into passing gear - In fact, the truck stays in its current gear and it feels like the engine is cutting out; You can feel a shaking if you try to floor it. Bear in mind, I'm not talking about starting a cold engine and immediately flooring it, I'm talking about needing to accelerate faster than normal before the engine is completely warmed up. Once the engine is up to temp, it begins to behave normally.

This is the first diesel I've owned in a cold winter-weather climate. I just want to know (a) what is normal 6.0 cold weather operation and (b) if I have a problem and where one would normally start to look for it.

Thanks!
-Brian

[a2elvis]

I have heard that these trucks have some sort of programming that detunes the engine until warmed up... Could be bs, just heard it somewhere. As far as the noises when turning the key on it should be the injectors buzzing. All the symptoms you are describing sound like maybe you have an injector(s) that are not 100%. With the cold heavy oil its hard to get the injectors to fire correctly and as the oil warms up then the injectors come to life.

[Term3]

Now sure what your talking about with the noise. The only noise I hear are the vacuum pump start up and the fuel pump start up. It gets down to -35 C here in the winter and to me it sounds like one or two of your glow plugs are bad. Remember the glow plugs stay running for a few minutes after startup in cold weather.

[dhanna6powerstroke]

I say you have injector stiction which is very common for the 6.0's. Get a couple bottles of Rev-X and pour in with the oil. I'll bet that helps or eliminates your issues.

[a2elvis]

With most of the 6.0L in the Ford vehicles with the key in the on position but the engine not running it should buzz the injectors for a few seconds. The theory was to buzz the spool valve in the top of the injectors to eliminate stiction. That "stiction" will be worse when cold(cold heavy oil).

[dhanna6powerstroke]

Originally Posted by a2elvis

With most of the 6.0L in the Ford vehicles with the key in the on position but the engine not running it should buzz the injectors for a few seconds. The theory was to buzz the spool valve in the top of the injectors to eliminate stiction. That "stiction" will be worse when cold(cold heavy oil).

Their theory doesn't work, especially when the oil isn't synthetic. The varnish buildup in the spool valve is what causes it. The Rev-X will clean the varnish out and eliminate the issue. Switching to a synthetic oil will help tremendously too.

[a2elvis]

Originally Posted by dhanna6powerstroke

Their theory doesn't work, especially when the oil isn't synthetic. The varnish buildup in the spool valve is what causes it. The Rev-X will clean the varnish out and eliminate the issue. Switching to a synthetic oil will help tremendously too.

What he said

[Dante04SRT]

I'd like to switch to synthetic but really don't want the oil leaks - I've already got 152k on the truck. Every vehicle with higher mileage that I've switched to synthetic has developed oil leaks.

Looks like I'll have to give the Rev-X a try.

[Loubell]

First, Rev-x cured my stiction last winter, period. I have never seen such dramatic results from any type of additive. (2 bottles)

Second, my truck behaves just like yours below 40F. Two years ago I switched to Motorcraft 10-30 (and now Rotella T5 10-30) which dramatically helped the trucks cold weather acceleration.

[a2elvis]

Dont think it would be a bad idea to switch to a little lighter oil in the winter, just not sure if that will have any negative effects as far as lubrication? We run 15W40 all year long here but the coldest we see is probably around 40*.