VW Oil Pump Part Number? Confusion Explained

Hello.
Regarding my problem with the oil pressure (Jetta TD 1987, engine code JR), I inquired at VW today about the price and part number for the oil pump. According to AKTE, the part number is: 028.115.105.G

I was just working on the oil pan and taking a closer look at my oil pump, but it has the part number: 049.115.153.B.

Can someone explain this to me? Did the previous owner have something installed incorrectly? (The car is from the first owner, and the previous owner was over 70, so I'm not assuming any malicious intent!)

Maybe someone could look up that number and tell me where it actually belongs.
-My engine has insufficient oil pressure.

Regards,

Hendrik.

What does "Jetta 1987" mean?

More data would be needed, as the model update occurred in 8/87, and from that point on, the "028" number is correct.

Check if you have an "H" or a "J" in your registration number.

J is MJ 88 and then 028...

H is still a 1987 model, and then there's the 068 115 105.

The part number for your old pump is no longer available.

Sure, here is the translation of the text from German to English:

"m" translates to "male" in English.

Thank you for the information.
There is a 'J' in the FGN number.

Is there any information about what changes have been made to the pump?
The oil pressure is just a little low, and I'm wondering if a new oil pump could make a difference.

Regards,
Hendrik.

euro wrote:

The oil pressure is just a little too low, and I'm wondering if a new oil pump could change that?

The pressure is initially the result of the pump's flow rate and the "backflow" through the bearings, superimposed by the current viscosity of the oil -> temperature!

As mileage and wear increase, the bearing clearance expands, leading to increased leakage and lower oil pressure. A similar process occurs within the pump itself.

To prevent excessively high pressures, especially when the oil is cold, a pressure relief valve is used. This valve typically opens a passage between the pump outlet and the inlet, allowing the pump to recirculate a portion of the oil internally once the maximum pressure is reached.

If your maximum pressure is too low, it's likely due to the aforementioned pressure relief valve, which, as far as I know, is located in the pump -> replacing the pump will solve the problem.

If your tire pressure is too low or fails to reach the specified limit, it's likely due to general wear and tear (mileage?).
Then, at best, a new pump will bring about a small/partial improvement by reducing internal "leakage losses."
Possibly an alternative: Using a thicker oil can also increase the "unregulated" pressure .

What kind of oil are you using?
Older diesel engines with swirl chambers often don't like the new fully synthetic oil (0W-XX or 5W-xx). They tend to react negatively, exhibiting high oil consumption, reduced sealing effectiveness of the crankshaft seals, and low oil pressure when the engine is hot. A semi-synthetic 10W40 or a good quality mineral oil with a viscosity of 15W-40 or 20W-50 would be more suitable in these cases.
What's the condition of the engine like? If the bearings are very worn, even the best oil won't help, because the oil pressure at the bearing surfaces will simply be lost.

Regards,
Jens.

I've already tried several oils.
I'm currently using Castrol RS 10w60 oil. I thought it might help, but unfortunately, it only made a slight improvement.

The engine has only 160,000 kilometers on it. Is there a way to check the bearings?
The oil consumption is extremely low. It always starts immediately and still has plenty of power.

I heard that you can replace the connecting rod bearings without having to disassemble the entire engine, so I think I'll try that next.
Has anyone ever done this before?

Regards,

Hendrik.