I have a 1995 Buick Lesabre limited. When it is running it sounds like air is leaking from somewhere on the motor..My husband thought it was the exhaust manifold gasket so he replaced that but it did not fix the problem.What else could it possibly be.

Possibly a bad or dirty Idle Air Control motor. The engine computer controls the operation of this motor to control idle speed. A pintle on the motor extends and retracts, according to signal from the computer. The pintle controls an air passage below it to give or take away air during idle -when the throttle shaft is closed, no air will get into the engine through the throttle body except through the idle air passage . The IAC motor or valve is on the throttle body, with a 4 wire connector. Take it off and look for carbon or coking deposits around the valve's pintle, and in the air passage beneath it. With the idle valve off, plug the connector back on it, then watch the pintle as the key is turned to on. If there is no movement whatsoever, the motor is probably bad.

I have also heard that a bad coolant temperature sensor can cause such a hard start. If the computer does not know the engine is cold, it won't put enough gas into the cylinders for easy starts. The engine needs more gas to start and run when cold.

you mean air does not flow. it look to me the blower motor is defect

sounds like sending unit gasket is leaking. drop the gas tank...sorry

Run constant with the key off? As long as the wiring was not messed with, could be the relay is stuck or the contacts fused together or the oil pressure switch is defective. I would unplug the relay first. If unplugging the relay and/or the oil pressure switch don't stop it then you would have to find a fault somewhere in the wiring such as wires melted together somewhere or shorted so the fuel pump is getting power.

Check all your brake lines especially those going to the bleeder valve where you find the most air when bleeding. Also check for leaks at the rear of the master cylinder and at the calipers and wheel cylinders. If either half of the master cylinder is going low, that shows you there is a leak somewhere. If it's staying full, I'd suspect the master as having an internal bypassing problem.

it's the blower motor relay

Hi, it sounds like an electrical/sensor problem. In general terms you have two primary switches that will trigger the fan to run. The first is the temperature sensor, the latter is the air conditioning electrics. You may have a bad sensor, or relay somewhere in the electrical lines that run power to the fan. If you don't have them, get a decent electical multitester and a copy of the Hayne's/Chilton's manual for the car (both good investments in general). Work your way across the circuit for the fan motor. In specific, test the relays and temperature sensors to make sure they are not fused open. Your electrical diagnostics will tell you what to replace.
Take care

Sounds to me like you have a leak leak somewhere. They can put a dye in the lines to find out where the leak is, Then have that fixed and get it recharged again. Its an expensive procedure though. I hope this helped

The dual air on this car has two temp control motors that are electronic. You need to have the car scaned at a dealer to see if it has a code for the left temp feed back circuit. If so you will need to replace the temp control motor for that side.Good Luck

sounds like a vacum leak check your lines for cracks