halostryker

Hey I've been having this problem right after i got my flex plate changed. now every time a come to a stop, once i slow down past 10 MPH the oil light starts to flicker and it sounds like the engine is going to die, but if shift it to neutral it stops and the engine sounds fine. got any ideas why this started happening after i got the flex plate fixed?? the engine is a LE9 with 700r4 tranny.
thanks in advance

Rolling Thunder

A low idle can cause low oil pressure. When it sounds like its about to die im assuming thats what you mean that the idle has dropped to the point its almost cutting out. What is it idling at? I wonder if its not a problem with the torque converter staying locked putting a big load on the motor causing the idle to fall. Might want to check out the wiring to the trans to make sure everything connected and no wires are being pinched or damaged. Also may want to take it back to the shop who did the work and tell them because if it is their fault they wont want to hear about it if too much time passes or you start tinkering with it. I assume no check engine codes? May want to inspect your IAC motor and the ignition timing.

halostryker

it idles just fine when i first start driving whether in park, neural, or drive it just starts to do it when i come up to the first major stop in the road ie: stop light, from what i can see all wiring to transmission is fine. also it was parked after the flex plate got fixed so it to late to take it back. im starting to think it may be a vacuum leak in the brake booster, because I recently noticed the brakes start to become stiff when the problem starts. how would i be able to fix this???

Rolling Thunder

Do you by chance happen to have a vacuum gauge? If you do i would try checking out what your manifold vacuum is. Second if you suspect maybe your brake booster is going The first thing i would try is dissconnecting it and plugging it. You will lose power brakes but if the brake booster is leaking the problem should no longer exists. The hard brakes could a bad booster, vacuum leak, low manifold vacuum ect. I would start by plugging the booster and also measuring the manifold vacuum if at all possible.

halostryker

nope i dont have a vacuum gauge but i will try your idea tomorrow thanks for the idea

dellman83Z

iTrader: (9)

I had a problem last year with another sbc, it sounds stupid, but check the oil level. If its a couple quarts low, when you brake, the oil moves away from the sump, causing it to draw some air, and thus, low pressure.

blklblsk8r16

i may have misunderstood something here but im gonna throw in my2 cents. lol. you said that when the car starts to shut off the brakes get stiff. thats normal on any car. when the motor starts to stall the rpms drop down and the motor isnt able to pull a good vacuum... causing the pedal to get stiff

3rdgenmaro

iTrader: (9)

yep, Ive had the same problem. Would notice my oil pressure drop. I was low on oil.

305sbc

iTrader: (3)

If the oil pick-up tube has fallen off of the pump the pressure will drop on deceleration.

Sometimes the engine grounds are moved to one of the bolts that hold the transmission to the engine, and sometimes people overlook that when the trans is pulled and reinstalled. Check as many things as possible.

JakeJr

RPM is dropping too low which causes oil pressure to drop to the point that the Low Oil Pressure light flickers.

Cure the low RPM and the oil pressure light problem will be cured.

Jake

Air_Adam

You say you are using a 700R4, and this happens when you are slowing down, unless you take it out of gear...

This sounds like it could be a problem with your TCC (torque converter clutch) sticking and bogging the engine down. This isn't uncommon with GM stuff from the '80s and '90s.