Engine Too much vacuum?

[Flatfoot]

1988 mustang H/C/I car. The previous owner removed the fitting from the throttle body that the hose attaches to that runs to oil filler neck on the valve cover. He had the hose attached at the oil filler neck and run down towards the ground venting to the atmoshpere. Soooo i have unmetered air coming into the engine. The throttle body where the fitting is supposed to be is capped. Can I just cap the side of the oil filler neck or will this cause too much vacuum in the motor?

 

[jrichker]

If the engine's PCV system is working properly, capping the oil filler vent shouldn't cause any problems. Check the oil separator screen in the PCV hole in the block to make sure it isn't clogged or damaged.

 

[Flatfoot]

Previous owner removed that as well. It's on order already. Thanks for your quick response.

 

[Stevenmverrill]

Do not cap the one on the filler neck. That is supposed to be the draft. In the back has a check value so if you cap it there could be situations you have no crankcase ventilation.

if not already do cap the stem on the throttle body.

adding a tiny filter to the one on the filler neck would be a good idea, just keep an eye on your oil for water dilution. ( milky stuff on the fill cap)

Sorry if I interpreted the Op incorrectly but, it reads to me like you are mistaking the nipple on the filler neck as a place of engine vacuum. This is not the case. That is where your crankcase ventilates. (Blow by gets out there) it's imperative that gets vacuum, or atmosphere. Otherwise things like valve cover gaskets, oil pan gasket, dipstick.. will be under pressure until something gives out.

 

[Blown88GT]

1988 mustang H/C/I car. The previous owner removed the fitting from the throttle body that the hose attaches to that runs to oil filler neck on the valve cover. He had the hose attached at the oil filler neck and run down towards the ground venting to the atmoshpere. Soooo i have unmetered air coming into the engine. The throttle body where the fitting is supposed to be is capped. Can I just cap the side of the oil filler neck or will this cause too much vacuum in the motor?

'88's don't have a meter.

 

[jrichker]

'88's don't have a meter.

1988 Mustangs originally sold in California came with Mass Air as standard equipment in order to meet the state's clean air regulations.

 

[Blown88GT]

1988 Mustangs originally sold in California came with Mass Air as standard equipment in order to meet the state's clean air regulations.

OP is in Florida, not a Cali car.

 

[jrichker]

OP is in Florida, not a Cali car.

The car may have started its life in Cali, the VIN code would probably have the clue. One way or the other, it looks like Mass Air is what is currently in the car....

 

[mikestang63]

i would reinstall the factory PCV system and the hose from the VC to the throttle body.