cat D7 17a

diesel1234 · Dec 1, 2018

My cat has a 339 engine, is it possible to remove the pistons without taking the engine out?
There is a inspection plate on the under side of the oil pan, will there be enough room to undo the big ends from here?
Thanks for any feedback

diesel1234 · Dec 1, 2018

Reason i ask this is when not under load it slobbers oil out of the exhaust, but when in hard work the slobbering stops.
There is no blow back through the crankcase breather and it is not blocked.
Im thinking the bores may be glazed or valve stem oil seals, am i thinking on the right track!
Not had the crawl long.

epirbalex · Dec 1, 2018

should be plates on the side of the motor that you can access the bigend caps .

Dave Neubert · Dec 1, 2018

ld look at your valve guides and seals if you take the exhaust manifold off you can normally see if oil is running down the stems

TomA · Dec 1, 2018

It is probably just slobbering from lack of hard work. Work it hard and get it to operating temperature for a few hours before you tear into it. All the old diesel Cats are like that. You could completely rebuild it and end up the same

Old Magnet · Dec 1, 2018

There are no valve stem seals, just guide bushings.
They tend to slobber if not worked hard or left at idle for long periods of time.
Make sure you have a thermostat that is working properly and allows proper operating temperature.

Mark250 · Dec 1, 2018

we used to let them suck a spoon full of bonami into the inlet manifold. it used to help if they were not worked hard enough
Mark

old-iron-habit · Dec 1, 2018

Mark250 said:
we used to let them suck a spoon full of bonami into the inlet manifold. it used to help if they were not worked hard enough
Mark

Adding wear material to the engine instead of working it. Bonami was designed to help seat rings when the cylinders were glazed by acting like sandpaper. Just work it like it was supposed to be.

kshansen · Dec 1, 2018

All diesels will tend to slobber if not worked hard enough, especially right after an overhaul.

But if you want to see real slobbering try running a 2 stroke Detroit Diesel at about 20% or less rated load for hours at a time! We had a 3-53 in a genset that they used to run a few lights an a block heater for a 3412 Cat Genset, ran all night during the week then all week-end. It was painted gold but looked like someone mixed coal dust with used oil and dumped it over the engine!

DMiller · Dec 5, 2018

Low load slobber is to be expected as noted above. These engines were intended and designed with full load at most of the time in use not partial loads and left to idle unloaded for long periods.

cat D7 17a

diesel1234

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diesel1234

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epirbalex

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Dave Neubert

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TomA

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Old Magnet

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Mark250

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old-iron-habit

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kshansen

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