1994 Nissan Pick up "HELP"

[huntingidaho]

I have a 1994 Nissan Pickup 4X4 with the 2.4 liter with 127,000 miles and I've been in the process of fixing all the oil leaks and a friend was over and he took the oil cap off while the truck was running and he said there was way to much pressure pushing out of the oil cap and he advised me to replace the PCV valve, I replaced it but I still have the pressure is this normal? if I leave the oil cap on and remove the hose from the back of the valve cover to the air cleaner it's sucking in?ThanksRob

[seang]

The breather on top of the valve cover is the pcv intake. The pcv valve is under the intake manifold somewhere on the side of the block. Now on to what your friend has found. I discovered the same thing your friend did when I let the engine idle with the oil filler cap off. There are pulses that aren't present on v8 engines. Pistons move faster at TDC than at BDC. Since (in an inline 4) two pistons hit TDC every 180 degrees, they create a pulse in the crankcase. Flat plane v8's (Ferrari, TVR, Lotus, etc...) probably do this, too. American (yank) v8's are cross plane, and are inheritly good at not creating these pulses. My ka24e does the same thing you described with the filler cap off, and it runs great. I hope someone else has some input on this, too, because I think that is normal. And I know for a fact that my PCV is working, because I have all the power, and my breather filter (yes, I put my own on), gets dirty after a while, so I know there is air going through the PCV system, alot of air.
Modified by seang at 4:34 PM 8/21/2009

[huntingidaho]

Thank you very much for your help and that makes me feel better, I did replace the PCV valve on the block behind the oil filter.Thanks and have a great weekend.

[seang]

You're very welcome, you are in the right place if you want good info on your little Nissan. Please feel free to read through all the old posts, and create new ones if you need to.