Fuel in oil???

[tomhamrick]

We put Jakes on my 6V92 Eagle in April and all has been well with the exception that it does not crank as well. It has always fired on 1/2 a turn, now it takes several turns and sometimes will shutter and shake and die. The second try it will crank and run fine. My diesel mechanic friend says that we have a small leak in a crossover tube letting the engine lose just enough prime to cause cranking problems. I would not care except I do not want it to get fuel in my oil. How can I test to see if the fuel has invaded my oil yet? I have driven maybe 300 miles since the Jakes were added and do not notice an increase in oil and do not smell fuel in the oil. I seem to remember someone telling me once before that if diesel was mixed in it would run on a paper towel when cleaning off the dipstick. Is that so? Mine does not do that. I have so much insulation and sound proofing under the bed, I hate to take it up if I do not have a leak. But I do not want to ruin an engine either.
Thanks,
Tom Hamrick
1984 Eagle 10S

[luvrbus]

Tom, the only way to know for sure is pull a sample and send to a lab I use a Cat dealer myself for the kit and testing.
About the paper towel test I guess it has to be certain brand of paper towel but I never found the right brand .
I could never make it work even on a engine I knew was full of fuel then I poured fuel on Bounty and it just soaked in to the towel.     

good luck

[NJT 5573]

I'd maybe want to be sure that the Jakes are not set to tight and not letting some of the exhaust valves stay on the seats.

[tomhamrick]

Thanks luvrbus, I wondered if the paper towel trick would work or not.
 
NJT5573, if the valves are adjusted too tight would cause the same cranking symptoms? Looks like that would also effect the power as well. The Jakes are all set at .057 and I double checked them when I installed. Could they have moved?  The valves where adjusted at the time of the Jake install but I did not do it and the mechanic said they were loose and he tightened them. I should have written down what he said he set them to. Looks like I am going to pull the bed and the valve covers either way.

Thanks again for the help!!!
Tom Hamrick

[Dallas]

This may be a little insight. Pull the valve covers and look for a clean spot where the fuel jumpers are. if you see a clean spot, you have a leak.

[NJT 5573]

Tom,

I was just guessing from the shake , shutter, and die deal. I don't think anything would move once it was adjusted and locked down. Its not unusual to find something that has come loose though right after they are worked on. Just takes someone to interrupt what the mechanic is doing and...

I would think it would be down on power if it did that, but I have seen them run in and then out if they come loose. Nothing wrong with the air idea either though but you probably know the symptoms that causes. If it acts like its just picking up fuel and then runs OK, that's probably it. Maybe even a loose fuel filter.

When my DDEC 92 loses its prime, its not going to run. The 71 is a lot more forgiving, it will suck the air out sometimes and take off.

[tomhamrick]

I am going to take everything out tonight after work to see what is going on. Thanks for all the pointers.
Tom Hamrick

[tomhamrick]

One more question. Best place to buy the Fuel Pipe Nut Wrench (socket)? Might as well have one in my tool box. There also seem to be several, the one listed in my Jake instructions is J-8932-01.

Tom Hamrick
1984 Eagle 10S

[luvrbus]

Tom, Snap/On #M35038 for the socket about 25 bucks.( getting hard to find)
I use the ping method to check the fuel lines if they ring when you tap it with a wrench they are good a dud is no go when using this method if you have the wire holder between 2 of the lines you need to remove it from the lines or it won't ring    

good luck

[tomhamrick]

I'll try to find one.  Thanks.
Tom Hamrick

[tomhamrick]

Here is my latest...Got the bed and insulation and lead sheets and plywood and metal sheets removed from over the engine.....whew!!!   Removed the valve covers and could not see a place where a fuel pipe had been leaking. The engine does not have a lot of miles on it and the area in there is very clean anyway so it is hard to tell. I did find though that the exhaust valves do seem to be tight. First one I checked I could not get a .013 feeler into and they are supposed to be set at .016. I thought I remembered the mechanic that set those telling the shop owner he set them to .012 because they were loose, so I guess he did. So tonight I will get my wife to man the pipe wrench and turn the engine while I set the valves and then we will see if it cranks easier. If it cranks without the shake, rattle and roll, then I will know that is/was my problem. If not I will look for leaks while it is running without the valve covers on, and if I still do not see any I am going to remove the fuel return line and pressurize the fuel system to see if I can force a leak.  Don't know if I can accomplish all this after work today or not.. but will try.  Oh yeah... I am going to re-check myself on the Jake settings as well.
Tom Hamrick

[luvrbus]

Tom,who set the valve bridges clearance you or the other guy some do set those on .012 I use.015 per the book some that don't know will try and set the valves with the bridge adjustment.
FWIW the valves are going to a bear to set without the offset wrenches and a go/no go feeler gauge hope you have them   good luck

[Dallas]

Tom
I agree with Clifford.
The valve bridges sound as if they may be done incorrectly also.
You set the valves on the top of the outside  2 valves themselves. My method comes from the olden days of being out in the cold in the woods repairing logging truck engines with balin' wire and bubble gum, but basically it's the same as with the go/nogo gauges.
Set the valve PUSHROD with an offset wrench and hold it with a 1/2" angle wrench. Set the valve to .015 and tighten it back up. then check with two feeler gauges. Try first with a .017, if that goes, reset. Do that until the .017 won't go. then check with a .015. It should go. If it doesn't, start over again.
Oh, and if you do this with a cold engine as soon as it warms up, all your settings will change so you'll do it all over again.
It worries me somewhat that the mechanic thought the valves were too loose.... I would much rather have a loose valve than a tight one. The longer the valve has to rest against the face of the head, the more it will cool. Tight valves have little or no time to cool because they aren't in contact for long enough with the head. this can eventually cause a warped or burnt valve.
You'll also have to readjust the clearance on the Jakes most likely. Jacobs recommends .062 or .059 and you'll get better results with setting them at .055

Good Luck, I hope this helps,

Dallas

[tomhamrick]

Thanks again fellows for the input. I actually set the valve bridges myself. Based on the Jacobs instructions these where set at .0015 . If I understand the concept this is only to equalize the bridge on both valves. The bridges on each cylinder uneffected by the Jake addition were not touched. Clifford, I do not have a go/no go feeler but am using the .015 and .017 as Dallas indicated.  If the settings change after warmup, do they get tighter or looser? Not sure why the Jake settings would change with valve adjustment unless the bridge was change??  I have mine set at .057 and would like to set them at .055. I have heard this before just want to be sure that .055 is safe??? Can't afford an engine! 

Thanks so much for the help with this.  You guys are great.
Tom Hamrick

[luvrbus]

Tom, the valves get tighter on a warm engine and about .055 setting it is good only if you know which valves your engine has because 92 series have several different valves and some will hit the top of the piston even with the .057 setting (the P ).
And you having a rebuilt engine  more than likely the heads were surfaced getting you even closer. 
To each his own but Jake had the .059 setting to be sure for all valves    

good luck