..another DK 35 making oil

[ritcheyvs]

10-4. I assume I can test it for the pinhole with a vaccum pump? Thanks!

Should work (although it may only leak on compression or at certain positions of the stroke). Be sure to order the gasket too, just in case.

 

[Coyote machine]

Good call. I have to CAT dealers within 15 miles, I suspect they can do it, and I found a shop in town that specializes in diesel injectors. I'll make some phone calls on Monday.

Thanks! And you're welcome.




The oil sample has 100 hours on it. 5.5% fuel dilution, but I believe that only happend in the last 15/ 20 hours based on the increased smoke at startup.

As has been suggested you may have a leaky lift/feed pump in addition to some sticky injector(s), sticking injection pump rack, or other things contributing to what was initially an injector knock sound.
What's you fuel supply like- do you have your own tank- local supplier? Sometimes its all about the fuel you are using in your machine, and how clean or dirty it may be.

I have no idea what started this, I really don't. I've been a bit remiss with checking the oil - obviously.. leasson learned there.

There has alyways been a good deal of fuel knock, since hour new. - I bought it from Wallace and thought it was just the way the daedongs ran..

Did you buy this unit used, and if so how many hours on the clock total?

Possibly it was always a problem, but has gotten bad enough to show on the dipstick?

Marginal parts like malfunctioning injectors, as but one of many examples can do damage over time if not caught, but it sounds like a 'perfect storm' scenario where one thing led to another until fuel diluted your oil. Don't be hard on yourself- at least you caught it before it spun a bearing or worse!

See replies above in your quoted post.

 

[zukota]

Got an injector place lined up. Going to order the lift pump tomorrow. Should I get new gaskets and heat shields for the injectors? Unit only has ~120 hours.

 

[VictorW]

With 120 hours, I would think that they would be alright but for $5/injector, I would order them and save if not needed. Whenever I have tried to cut costs, it seems to always bite me in the end. Some of the members have replaced a few injectors with I think more engine hours. Maybe they can give you better advice on the condition of their old parts and if they replaced.

 

[ritcheyvs]

You may want to see this video:

[ame=http://www.youtube.com/watch?v=qGcEbmGQoBo]Mercedes Diesel Fuel Injector Spray Pattern Test by Kent Bergsma - YouTube[/ame]

These are Mercedes injectors but the principle is the same. You want a highly atomized conical spray with no after drip. Ideally all injectors should "pop" at nearly the same pressure within the spec range.

 

[zukota]

Thanks for everyone's help.

Ordered up a lift pump & gasket, as well as the injector gaskets & heat shileds.

$75 plus shipping from Michigan Iron.


I will report back with the results of the injector pop tests in about a week or 2.

 

[zukota]

What's you fuel supply like- do you have your own tank- local supplier? Sometimes its all about the fuel you are using in your machine, and how clean or dirty it may be.

Fuel usually comes from the offroad pump at the exxon down the road. I live in a fairly rural area, and it gets some decent traffic.. (I've even seen a few dimestore cowboys filling their shiny diesels there). There have been a few times where I've gotten road fuel at different places if I'm on the move.

Dirty fuel could very well be a problem.. and I may look at plumbing a better filter into the system if that turns out to be the root cause.

Did you buy this unit used, and if so how many hours on the clock total?

New used. It is the kubota GST prototype that Wallace had a few years ago.. a brand new 2003 in 2009 serial number is ~000002. I think it had 2 or 3 hours on it when I bought it. but alas no warranty.

 

[VictorW]

On my CK30hst, the fuel gravity feeds to the lift pump. There is no filter prior to the lift pump and some members have installed one there. If you go to fine a filter, you may not feed the lift pump enough being that it's only gravity to it. If a big enough piece of dirt made it to the lift pump, the diaphram may be damaged but via Michigan Iron, they rarely see that. My actual fuel filter, which probably is the same as yours, should take out anything that would hurt the injectors. I'm careful when changing the fuel filter to not get any dirt in the filter bowl which may go directly to the injector pump and then the injectors. With yours at 120 hours, I can't imagine a problem with the filter. Usually the filters plug and starve the fuel flow instead of dirt just going through. I do use a fuel additive for freezing, cleaning, cetane number change, etc. Members here have various ideas on fuel additive use, so that one is up to you.
Please let us know what you find out. That's how all of us learn.

 

[ritcheyvs]

Typically, lift pumps fail in one of three ways: an external leak, check valve failure (which can be caused by debris in fuel), and diaphragm failure (which would let fuel leak into the crankcase).

 

[5030]

I'm curious as to what 'fuel knock' is?? Having been around oil burners all my adult life, I've never heard fuel knock.

Please enlighten me??:confused2: