Need to replace the heat sending unit on 1991 buick regal but cannot find where the part is located can you please advise me of where the heat sending unit is

the oil sending unit is probably faulty and needs replaced. Not an expensive part. google 98 buick regal oil sending unit (images) and you will see what and where sensor is located, and wether you want to tackle the job yourself.

You need to replace oil pump oil pressure should not be highyer then 60 psi

The blower motor on a park ave of the same year looks to be located near the middle of the firewall in the engine cmpt. The blower motor resistor you are referring to is part of that assembly. Please refer to the following diagram. Let me know what you find, good luck!

http://autorepair.about.com/library/images/bl107a-lib.htm

do you have spark if not your could be bad if you have no spark your timing chain could have jumped or is broken

This problem is caused by a defective gas gauge sending unit (senses the level of the fuel in the gas tank), the gas gauge sending unit is located inside the gas tank, the gas tank must be removed to replace the gas gauge sending unit.

Fuel Pump relay is shorted, Replace fuel pump relay.

Under hood, passenger side, rear engine area, below valve cover, mounted in block
hope this helps

I had they same problem a few years back. Aging electronic circuits may be the issue here. That is what happened to cause the remote door feature to operate intermittently in my 1991 Buick Regal. Over time the heat of summer and the cold in winter stress solder joints on printed circuit boards. That stress can bring about what is known as cold solder joints.

I located the remote door receiver module behind the back seat under the cover that holds the Third Brake Light. Once removed from the car I opened the module up and inspected the printed circuit. Sure enough I saw the problem using a magnifying glass. Many of the solder points had cracks around connectors, resistors, capacitors to name a few. Resoldering each bad point sovled the intermittent operation. I hope this helps...

More than likely (and we will hope) it is the oil sending unit. In comparison it is a very cheap and quick fix to replacing the oil pump. Auto Zone has a pretty good componet location section that has tips for replacement if you cant find the sending unit or the oil pump. Try that first it may save you a lot of work.

It probably has an airlock - so needs the air leting out of it.

If you have the bleed screw on the pipe that goes from engine to bulkhead, then, with engine cold, and heater turned to heat, start engine( KEEP CLEAR OF FAN / BELTS ), and undo bleedscrew to let out air. STOP ENGINE. Refill coolant to mark with antifreeze mix.

If this soes not solve problem, it could be more serious - either blocked matrix or if you only find steam regularly - it's a head gasket problem - requiring replacement.