Md7a volvo rising oil

[roland stockham]

While checking things out do a compression test. I have heard of worn rings allowing diesel to pass but only on old industrial engines. Would expect to see smoke when starting ascwell if that is the route

[Pavel24]

I have verified the fuel pump and every thing looks good. So far i think the the problem was me , i didnt always close the the fuel valve when i stoped the engine. Now i close it and let motor run 10 -30 sec before i shut it off and my oil stays the same . i will purchase electric fuel pump in case the mechanical goes bad.

The advise vas given by my friend because the fuel tank is higher then my motor ,he said that injectors can leak if there is pressure.

[a64pilot]

Originally Posted by Pavel24

I have verified the fuel pump and every thing looks good. So far i think the the problem was me , i didnt always close the the fuel valve when i stoped the engine. Now i close it and let motor run 10 -30 sec before i shut it off and my oil stays the same . i will purchase electric fuel pump in case the mechanical goes bad.

The advise vas given by my friend because the fuel tank is higher then my motor ,he said that injectors can leak if there is pressure.

Never seen that before. Farm tractors often have the tank higher.
But if it’s happening, that’s hard to argue.

[Symphony]

I've had tanks higher than engine too without this happening... but thanks for posting this fix. always helpful to hear what worked

[Compass790]

If your injectors are leaking from a gravity feed unless your tank is 300ft high they are knackered & need immediate servicing.
However I very much doubt its them. Still if your method works you may be fine with that

[Pavel24]

Hmm i will keep close look on the oil, so far it looks good and didnt rise (at least what i observed this far). The tank is a little bit higher.

[Pavel24]

After 100 hours of use (or close ), closing the valve few seconds before turning off the motor still works and the oil level doesnt rise.

[Compass790]

Thanks for posting back your results.
. Good that it's solved your problem but I think, if it is leaking thru the injector,you need to service them. Far more likely it's leaking thru the lift pump.
The injectors dont open till they reach over 2000 psi approx. When a diesel tech pop-tests them, if they drip before the designed opening pressure, they will replace the nozzles.
Personally I would rebuild the lift pump anyway but you may be happy with your fix. If you didnt have to add oil during/after 100 hrs on that old engine I'd suggest it is still getting diesel in it which is not ideal. Without knowing your engine I'd guess somewhere around 300-500cc oil use for 100 hrs would be about the ballpark
Your engine, your choice

[Pavel24]

Originally Posted by Compass790

Thanks for posting back your results.
. Good that it's solved your problem but I think, if it is leaking thru the injector,you need to service them. Far more likely it's leaking thru the lift pump.
The injectors dont open till they reach over 2000 psi approx. When a diesel tech pop-tests them, if they drip before the designed opening pressure, they will replace the nozzles.
Personally I would rebuild the lift pump anyway but you may be happy with your fix. If you didnt have to add oil during/after 100 hrs on that old engine I'd suggest it is still getting diesel in it which is not ideal. Without knowing your engine I'd guess somewhere around 300-500cc oil use for 100 hrs would be about the ballpark
Your engine, your choice

What you are saying is i better switch my mecanical fuel pump by electrical ? ( i didnt find rebild kit , from what i understand they dont make them for some time .. )

[Compass790]

Originally Posted by Pavel24

What you are saying is i better switch my mecanical fuel pump by electrical ? ( i didnt find rebild kit , from what i understand they dont make them for some time .. )

I would try the electrical fuel pump & see if your engine begins to use oil. You can rig it up temporarily & see what happens. What you want to avoid is diesel diluting your engine oil. If you aren't using any oil on an old diesel engine it is likely something else is getting into the sump.

Try a diesel injection shop for your lift pump parts if you want to repair that.

[wguinon]

I went down this road with a Faryman 2 cyl. Diaphram, injector seals, injector dripping etc. At the end of the day it was blowby in the cylinders. I re-honed the cylinders and all was well.

[Compass790]

Originally Posted by wguinon

I went down this road with a Faryman 2 cyl. Diaphram, injector seals, injector dripping etc. At the end of the day it was blowby in the cylinders. I re-honed the cylinders and all was well.

That sounds wierd. Did you use heaps of oil when you had all that blowby?
We certainly used a lot of oil when we had heaps of blowby before it had a rebuild

[wguinon]

We didn't so much use oil but experienced an eruption out of the dipstick hole when the oil level rose to a critical level.