Mep002 blows out oil fill

[mitchsc0tt0]

Hi All,
Just quick question is it normal for a mep002 to blow air out the oil fill tube when running if I open it?

Thanks,

Mitch

 

[Scoobyshep]

Not sure on that specific engine, but i know of several other diesels that will

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[Light in the Dark]

Some diesels have positive crankcase pressure (like my 7.3IDI in my Ford, it has a CDR valve for this reason), others (like the 80x series) have negative crankcase pressure (ie vacuum). Even with negative pressure, sometimes the spinning internal components do create air movement out.

Off the top of my head... I don't recall which the 002/003 series is. But how much oil are we talking about?

 

[Scoobyshep]

Weren't they made by Cummings? The few cummins engines i used to work with would puke if the stick was out

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[Chainbreaker]

They were made by Onan, which was bought by Cummins.

The -002a is positive crankcase ventilation and there is a lot of crankcase air movement with both cylinders moving up/down at the same time.

Though it would be a good idea to check/clean the breather filter screen to make sure its not crudded up, it sits next to the left most cylinder up above the dipstick tube (the canister with rubber tube out the top). You can find it in a diagram in the -24P manual.

 

[rickf]

The OP is asking about the 002, isn't the 002A water cooled? The 002 is a very basic air cooled 2 cylinder and even though I have not tried it on mine it would be normal for a fair amount of blowby to come out.

 

[mitchsc0tt0]

Thanks all sounds like it's pretty normal. And correct it's an air cooled.

 

[Chainbreaker]

The OP is asking about the 002, isn't the 002A water cooled? The 002 is a very basic air cooled 2 cylinder and even though I have not tried it on mine it would be normal for a fair amount of blowby to come out.

The OP's thread title refers to "MEP002". There is only one MEP in the Military's spec'd generator lineup designated as a -002 and its the MEP-002a. The water cooled unit is the MEP-802. Two different beasts.

 

[rickf]

DOH! And I have two of them in the yard!! Right there in my sig!!! I was just working on mine and didn't think to try the fill tube blowby check. It is just not natural to me to pull a fill tube while an engine is running, on many engines that is a recipe for a face full of oil!

 

[Triple Jim]

As Chainbreaker said, the 002A has two pistons going up and down together, so there will be a lot more pulsing of air in the crankcase than the 003A that has two pistons going down while the other two go up. I don't have an 002A, so I don't know what is "normal" though.

 

[Bmxenbrett]

DOH! And I have two of them in the yard!! Right there in my sig!!! I was just working on mine and didn't think to try the fill tube blowby check. It is just not natural to me to pull a fill tube while an engine is running, on many engines that is a recipe for a face full of oil!

Me and you both. Pull a 3in dip stick on any engine while it's running and your going to get some splashing. Even my 200hr 802 will splash oil.

Put the stick back in.

 

[Zed254]

I put a peanut butter jar inline with my manometer to dampen the pneumatic pulses when checking my 802. What I thought was a pressurized oil reservoir turned out to be under vacuum.

 

[Guyfang]

I put a peanut butter jar inline with my manometer to dampen the pneumatic pulses when checking my 802. What I thought was a pressurized oil reservoir turned out to be under vacuum.

RTB.

 

[Zed254]

I RTB. What have I missed? My average vacuum is 1" WG. In my case I used coffee, so it's actually CG.

3-5. CRANKCASE VACUUM,
3-5.1. General. The value depends to some extent on the type and size of air cleaner installed on the engine.
Regardless of type air cleaner used, vacuum with a clean air cleaner must not be less than a minimum of 0.79 in. (20
mm) water gage (WG). The vacuum is measured with a manometer at the lubricating oil dipstick hole with the engine
running. In engines in good condition vacuum increases slightly with engine speed but not proportionally. A fluctuating
vacuum may indicate faulty oil seals, valves, or piston blow-by troubles. Crankcase pressure can cause serious oil leaks
and often occurs in engines which need overhauling.
3-5.2. Measure Vacuum
a. Remove lubricating oil dipstick.
b. If water manometer is available, connect one end of a 0.374 in. (9.5 mm) OD plastic tube to a water manometer.
Insert other end of tube into dipstick hole, refer to FIGURE 3-1.
NOTE
Average vacuum should be 1.37 in. (34.8 mm) WG. Minimum allowed is 0.79 in. (20 mm) WG.
Warning
The noise level when operating could cause hearing damage. Ear protection must be worn.
3-14
ARMY TM 9-2815-252-24
AIR FORCE TO 38G1-92-2
c. Start engine and record reading on manometer.
d. Stop engine, disconnect manometer and install oil dipstick.
e. If water manometer is not available, place a piece of thick paper over the oil fill opening. If crankcase vacuum
retains paper, vacuum is good.


FIGURE 3-1. Locally Manufactured Water Manometer

 

[Guyfang]

What I thought was a pressurized oil reservoir turned out to be under vacuum.

3-5. CRANKCASE VACUUM,

The top sentence, made it sound like you thought, it would have positive pressure, not vacuum. My mistake.