I was wondering if I over fill motor by 1/2 quart if it will do any damage to 4.0 motor,I don't think it is over filled enough to spin a bearing ,but as testy as mine is I figured I'd get a 2nd opinion

 

If you are 1/2 quart over the full mark, I would drain a little off.

 

No. The oiling system on the vehicle is a high flow, not high a pressure system. Extra oil (within reason) will not effect anything but the oil temperature (it will be lower). Racers have being putting a quart over for years. We use 1/2 quart over regularly.

James

 

For the record, overfilling an engine can cause seal problems, be it for the engine or tranny.

 

No it can't with this engine Mike. You are thnking of other engines that rely on high oil pressure. We can't be calming people when they first see the remarkably standard low pressure on a 1995 LR (compared to other vehicles) and then tell them they are going to blow seals because of high pressure when they add an extra 1/2 pint.

Seals can only be affected if the oil pressure goes up. As I said this is a volume not a pressure system so no damage to seals can occur and you will find oil pressure completely unaffected by adding a bit extra. Racers like us have running these engines over "full" (up to a pint over) oil for decades without a problem. It started in the days of the first small sumps. More oil less heat. That is why the last of the sumps held 1.5 pints more than the first.

Of course, if it makes one feel more comfortable, one can try draining a 1/2 pint of motor oil to bring the level below the full mark. It simply doesn't make a real difference beyond increasing the oil heat a bit.

James

 

youre both kind of right here... too much oil will cause a drop in oil pressure due to airration caused by the crank spining in the sump too much, however, yeah, this engine is pretty forgiving, half a quart will not do any damage