In 2014 i bought a 1972 240z that carried an upgraded L24 engine as shown in the picture. However i have been struggling with the car in order to get it stable under stop and accelerate idle traffic conditions and it was not until today that my mechanic found out that the oil pressure in the car was very low and it only went up to the middle when you accelerate real fast. Once in traffic it starts dropping back. He argued that it was quite posible that the company that rebuilt the engine did not change the old oil pump during the process and that it is not pushing enough process to cover all the parts of the engine when its warm. The oil gauge has never kept the oil marker in the middle.

We will try and drain the oil using 5 bottles of Castrol 20 50W engine oil and a new filter. If this does not change, ill guess ill need a High Capacity oil pump and hope that any of the engine parts were damaged

http://www.thezstore.com/page/TZS/PROD/17-8021

Does the oil pressure really affects the driveability of the car?

 

The first "Item #10" (Block painted in genuine Nissan blue) on the rebuild list you showed is probably the only thing that you can be sure was done.  The fact that there's a second "Item #10" on the sheet should be a clue to the quality and thoroughness of the seller.  Who, if I remember correctly, had/has a sketchy reputation.

Dennis

 

 

Edited January 30, 20187 yr by psdenno

So should i sue this company or disassemble the full block? I thought you could provide something more.

Edited January 30, 20187 yr by jalexquijano

First verify that the oil pressure is in fact low by installing a mechanical oil pressure gauge in the port where the stock sender is located. The stock gauge should not be trusted. Normal idle oil pressure can be as low as 10-15 psi and should top out around 60 psi above 3000 RPM. 

Oil pressure is determined primarily by bearing clearances. If the clearance is too large, then the pressure can drop. This normally happens with an old engine. No excuse with a new one.

What Zkars said ^^^^

Verify first. the gauge is just a guideline.

Also I don't think low oil pressure is gonna affect drive-ability. When it does, you'll know it and the engine will die shortly after!

Just my opinion on a couple things:

1)  I doubt that the oil pressure is the problem with the accelerate and idle problems.  Sounds like carb adjustment to me.  Also, could be fuel vapor lock issue.

2)  I don't really trust the oil gauge value on the 240Z gauges.  You would probably want a direct pressure gauge to the block oil port to measure real values.

3)  If I did contact the seller, I would ask what rings and bearings were installed. Does he have the receipts.  these parts are as important as the head items if not more.

4) probably not worth the time and effort to sue if you do not have direct oil pressure data

5)  Not sure what disassembling block would do for you.  Just change out the oil pump if you are concerned about it's integrity. Much cheaper and easier.

How many miles have you driven it with possible low oil pressure?  I agree with previous comments - verify pressure with an independent gauge, not the dash gauge.  Basically, when LOW oil pressure becomes NO oil pressure, the engine will lock and need to be rebuilt.

Dennis

2 hours ago, jalexquijano said:

 my mechanic found out that the oil pressure in the car was very low and it only went up to the middle when you accelerate real fast. Once in traffic it starts dropping back.

Does the oil pressure really affects the driveability of the car?

Oil pressure in these engines always runs on the low side at low RPM.  And the oil pressure senders are known to be inaccurate.  You can't really decide on what to do about it until you get an accurate a gauge and record real numbers.

Oil pressure won't affect driveability until right before the engine seizes up.

It never goes over half of the gauge. At idle it goes to1/4

2 minutes ago, jalexquijano said:

It never goes over half of the gauge. At idle it goes to1/4

Either verify with a mechanical gauge or not! At least 4 people have told you, the gauge is not accurate...

The advise is free, but from the sounds of it, it has more value than what you have to pay your mechanic. The people on these forums know these cars many times better than almost any mechanic!

Reading that paper makes me sick. It is filled with fluff, bs, and poor grammar/English.

They are too dumb to even be successful crooks.

Im buying 5 quarts of castrol 20 50w oil and a new filter as per the mechanic request. He will then measure the oil pressure with another gauge and get back to me.