Chev Cameo

1994 Chev Cameo Drive Train / Driveline Malfunction When shifting Always

i recently had a used engine (3400) installed and i find that i can not down shift manually and also have defrost air flow that blows to the floor vents under power. i think it is a vacumnn hose or leak, but i'm not sure where or which one to look for under the hood? apprecite your help. thanks, jon

also have a low oil light that comes on at first start and will go off if turn engine off and retart. i have good oil pressure @ idle 35-40lb and oil level is good.

i'm not sure if i understand your answer of i don't have the answer? or is it that you have not gotten to it yet? please reply either way. thanks, jon
9/12/06

Sorry for the delay, I had passed on this question- I figured another mechanic would answer.

Was there any warranty with the work performed? Unless they gave you a heck of a deal the installer should take the responsibility of hooking everything back up and testing things to make sure they work okay. Contact the installer and see if they'll double check their work, as they should.

The vacuum feed should be somewhere in the firewall area- likely a broken, unhooked, or pinched vacuum line.

This is an automatic trans, and you've lost the ability to downshift?? for performance driving purposes? Or do you simply mean you cannot shift into anything below Drive regardless of whether the car can move or not?

Do you have good oil pressure on the gauge WHEN the oil light is on?

thanks for your return reply douglas.
the install was done by a part time mechanic as a favor more less $500. he did mention having to drop the tranny to make room for the exchange and i did have to add almost a quart of fluid. also, had a vacumnn line unhooked on top of the intake manifold at the rear passenger side,but i repaired that one. i may have used a line with a slightly bigger inside diameter. could that cause problems? i don't believe it is leaking.
oh, it is an auto trans.
the oil pressure and levels are good 35-40lb @ idle even with the "low oil" light on. again it will go off if i shut the engine down and restart it?
oh, the tranny does shift down automatically when i stop or punch the throttle, just can't get it to shift down say going down hill @idle speed.
thanks in advance for your suggestions,
jon

It's possible for a bigger vacuum line to leak, double check this. Do you have the underhood vacuum diagram still on your car, if so look at this and see if it is the 'accesories' or similar vacuum hose that is off. Also take a peak in the area of the power brake booster vacuum line to see if it is possibly teed off in this area.

Apparently the oil sensor switch is not responding quickly enough to initial oil pressure. See if this changes by resetting the computer (disconnect the negative battery cable for one minute) and reconnect. Also, you should change the oil fairly soon (not sure how many mile you have put on the engine), and this might do the trick.

Is your check engine light coming on? I still don't understand the problem you are having with the transmission- it won't downshift on its own or you cannot manually downshift it? Has something changed that with the shifting behavior?