oil pressure

[estang302]

hey guys ive gotta 94 gt its about 100k orig miles i bought the car with close to that about 3 weeks ago the previous owner was unsure of the oil he used wether it be synthetic or petrolium based, apparently he didnt own the car for very long. when i first purchased the car i did an oil change and was very sketchy about useing a synthetic because of the milage so i decided to go with valvoline racing oil it was sae 50 the engine knocked pretty bad because of it so i switched it to castrol syntec 10 30 and the knocking quieted down but now as i drive the vehicle the oil pressure is unusually low but there plenty of oil in her. i have a feeling its the oil and im aware i probly need a new bottom end, and im going to be rebuilding it as soon as possible. my oil pressure was fine when i was running the sae 50 but is there a possiblity the problem lies in the oil pressure switch?... the gauge is only moving during start up it doesnt move when i mash the gas. please can i get a few sugestions. heres a pic of her

http://img45.imageshack.us/img45/2377/p10100430co.jpg

 

[DMAN302]

well if I understand you...you were running straight 50 weight oil...now that's like trying to draw cold syrup up a straw when cold. You very likely did some internal damage simply because the system was starved for oil for some time during starup/cold idle. pretty much every engine will have nice pressure with 50 weight...it's thick and remains thick at temp creating more resistanced and with that more pressure. I'd be inclined to save for the bottom end and keep the 50 weight for the racers.

 

[RYC CUKR]

Couple of things you can do.

When I got mine the gauge was erratic. Sometimes it would have oil pressure and some times it would jump around. Try cleaning the sending unit and make sure that it doens't have some sludge or gunk built up in the passage. If that doesn't work. Get a cheapo mechanical gauge from the parts store and hook it up in place of the sending unit. Then you will actually be able to put some numbers to it.

 

[HISSIN50]

Get a real gauge. The 94-95 gauges are way more useless than fox OP gauges, and that's saying a LOT.

If it was moderately warm when you ran the 50 weight, it shoulda been alright - I used to run that stuff in my turbocharged Porsche (air cooled turbo fried the oil, and this was before synthetics were prevelant). That said, I agree with Derek and wouldnt do that again.

It's a great lookin car BTW.