phantomblackgto

Not trying to start a catch can debate war here, but I was having a strong fuel odor in my oil and was seeing a rise in level. Installing a catch can has seemed to eliminate both issues. It's been 60's - 70's here and I emptied about 4 oz. of a coffee creamered colored liquid with a strong gas odor over 500 miles. Liquid had settled for a day when I took this pic, so it had separated. This was drained at 6,000 miles on my truck. Initial oil change was at 4,000 miles. As mentioned, oil had a strong gas smell and had risen on the dip stick (it is difficult to get accurate dip stick readings on these engines though). Catch can was installed at 4,400 miles. Oil had already acquired a gas odor after 400 miles and appeared to have risen on the dip stick. At 6,000 miles (2,000 on this oil change), oil smells like oil on the dip stick with no gas odor at all. Oil level appears to be right at full mark on the dip stick.

Wannafbody

One thing to consider, if a Ford diesel reaches 5% fuel dilution it's pumping a lot more fuel into the oil than an EB since the EB has a lower oil capacity. It doesn't seem to be much of an issue IMO.

zx12-iowa

If it worries you just buy the toyota. It is a good truck with its own pros/cons. Still will be left in the pack by the Eco. But if you don't care about the extra low end torque, you will like it. Cons are weak tailgate, body flex and poor mpg.

Ron AKA

My interest in the 2015 F150 is the aluminum body and box. I currently have a 1990 F150 bought new, which has about 100,000 miles on it. Looks near new, but that is after fixing a few rust spots. As you can see I keep my vehicles a long time, if they perform well. But, I want a good body AND a good engine. Have to say the EcoBoost has me nervous. I couldn't sleep at night if I didn't change the oil every 3000 miles (which is what I have done on my 1990). Those are downright scary used oil analysis results. I think I would also feel compelled to do something to try and clean the intake carbon deposits at each change too.

Ron AKA

Is the system at the link below what you mean by a catch can?

http://oilcatchcan.com/wp-content/up...ilcatchcan.gif

If so, I can sure see how that would reduce the amount of intake and intake valve carbon deposit build up. However, I can't see how it could reduce the amount of gasoline in the crankcase. If you can get your gasoline in the crankcase to evaporate the gas in oil problem is solved. Since the catch can is downstream of the crankcase, I can't possibly see how it would help.

phantomblackgto

Without getting into a long catch can and PCV discussion, one of the basic by-products of blow by is unburnt fuel. As long as the PCV system is working properly, the unburnt fuel is evaporated by the PCV system before it has a chance to mix with the oil in the crankcase. The PCV system relies upon vacuum from the intake manifold to function properly. One of the so called "flaws" with the Ecoboost (or any forced induction engine for that matter) is the intake manifold actually pressurizes during boost reducing the effectiveness of the PCV or even eliminating the PCV system to work at all. This allows the unburnt fuel to have time to actually mix with the oil. Another problem with the stock PCV system of the Ecoboost is it taps the left turbo inlet pipe for its fresh air source. Under boost, oil is pushed back through the fresh air line back into the left turbo and the intercooler.

By installing a dual valve catch can and rerouting the fresh air source, the PCV system can function under both boost and nonboost by tapping into the turbo inlet pipes for vacuum under boost as well as the intake manifold when not under boost. This combination allows the unburnt fuel and other blow by contaminants to be evaporated at all times. The fresh air source is either ran directly to the filtered side of the air intake or capped off when installed in combination with a clean side separator.

zx12-iowa

It's obvious you have anxiety over the ecoboost, so get yourself a toyota and don't let the fat chicks sit on the flimsy tailgate. Or get the stronger ecoboost with the tin can bed and change your oil more frequently. Seems to me that you are a little OCD anyways based on how you maintained the 1990 (not that it's that unusual). I bet you would change the toyota oil at 3k miles too....

It's a simple decision.

Ron AKA

OK. The basic catch can, does not solve the problem. However, if you can figure out how to keep the crankcase under negative pressure during boost conditions it would help. Have not worked my head around your explanation, but if it can do that then it should work. The alarm bell that is going off though is contamination of the turbo itself if you route oil/gasoline fumes to it, instead of directly to the intake manifold. Will have to think about it longer.

Ron AKA

I change my Toyota Camry Hybrid oil at 5,000 miles. If I lived in the US, I would change it at the recommended 10,000 miles. No direct injection used in it though. But, perhaps more frequent cold start up is the reason why Toyota recommends 5000 in Canada, and 10,000 in the US.

Ron AKA

For those that want to dive into the technical details a little deeper I found an interesting technical article which investigated the influence of both gasoline and diesel dilution of both mineral and synthetic oil. Can't figure out how to give you a direct link to the article, but if you google the following, it should be the first hit:

Influence of engine oils dilution by fuels ljubas krpan

The last two words are names of authors. I believe it is from Croatia, and the English is a little tough to read, technical, and possibly translated. However there are two useful conclusions from their laboratory experiment:

1. You need about twice as much gasoline to reduce the viscosity of synthetic oil as it takes to dilute mineral oil.

2. Diesel fuel reduces viscosity significantly less than gasoline.

This justifies the higher limit of fuel in oil for diesels than for gasoline. It also explains the results I saw in looking at UOA data where the Kendall synthetic out performed the MotorCraft. The other conclusion I got from it was that those Blackstone fuel in oil reports are grossly in error. You need about 5% gasoline to take a 5W-30 down to a 20 weight. If you look at figure 2 (page 77 in the document) all these samples from the EcoBoost are way off the bottom of the chart except for a couple of the Kendall ones and one Mobil 1. In other words most of these samples likely have 10% or more gasoline in them, not 2% like Blackstone is reporting. Adding 0.6 quarts of gasoline or more, likely does show on the dipstick.