New Oil Pump

[Brit-Car-Nut]

ALL manuals offered are from other sources. I just host the site (with approval from Lotus,UK) where they can be available for everyone.

There is an index on page 1 (left side).
Select Engine (EC)
Scroll down 38 pages.
The next 4 are the instructions for examining.

I have attached those pages only:

Oil Pump Service.pdf

My web pages were created in MS FrontPage over 10 years ago and don't support tablet or phone use without a struggle.
If anyone wants to re-write the pages, they are more than welcome to do so.

I will eventually have to stop hosting things as I am becoming less and less able to maintain them. My health and eyesight are both failing faster than the medical world can cope.

[simonbuk]

Thank you for doing that.

Does anybody know if you can remove the oil pump with the engine in situ ? Is it easy to get at after a wheel has been removed ?

[Brit-Car-Nut]

According to the Service Manual, the pump can be removed without removing the engine, but it requires removing the oil pan (sump), removing the crankshaft timing belt cover, belt and sprocket among other items.

If you decide to do it this way, you should first line up the cam gears like you would doing a timing belt replacement. Using the two valve cover bolts to secure the camshafts will make it easier to reassemble when you are finished with the oil pump project. You might want to consider changing the cam belt while you are in there.

All of that info starts on page 38 of the Engine Section of the V6 Service Manual. If you need me to send the entire section as a PDF, let me know your email address and I will send it that way as it might exceed the file size limit on LEC.

[simonbuk]

Damn, last thing I did was have the sump off for a visual inspection of the bottom end.

If the oil pressure relief valve sticks/fails - what are the symptoms ?

Not getting up to normal pressure ? Or making oil pressure far too high ?

[Brit-Car-Nut]

Why don't you tell us what has you worrying about the pump in the first place?

Let us know ALL of the symptoms you are experiencing. There are other components that will give an odd oil pressure reading...

[simonbuk]

It's simply my long standing noisy engine issue !! Various people have looked/listened and come up with lots of different answers - oil pressure was good at the time.
Thought it was noisy head so head got swapped but still same noise.
Last time we looked I took it to an M100 guru who was also stumped as to what it was but did take the top off to reveal a very dry head. Oil pressure had dropped. He simply said to pull the engine to get it inspected.

I have purchased a short motor and got it rebuilt, about to pick up another head this week and get it inspected.

So I may not get to use my car again this summer. So just thinking if the pump or valve is causing a problem with the oil to the head it might be a relatively easy fix to get it running for the remainder of the summer.

The new engine can be swapped over winter.

[TorqueHorse]

Figured it would be easier to append to this thread, as it already has some good info in it.

As part of my current engine tear down/rebuild I was going to inspect my stock, DOHC turbo oil pump (OPG-006), when I also happened to see the other, similar SOHC oil pump (OPG-004) for sale for $15 bucks, so I figured it was worth picking up and doing a side by side tear down to see what the actual differences are.

Similarities:
The exterior castings and bolt hole patterns are exactly the same
They both fit onto our crankshaft the same
The relief valves appear to have the same spring & resistance (didn't measure exactly though)

Differences:
The annulus rotors are different in diameter, thickness, and number of teeth
The interior casting depth and diameter is different to accommodate the different annulus rotor size
The backing plates are slightly different, but the bolt patterns are the same

Both side by side with gears in place

006 on left, 004 on right


Subtle differences in the castings interior


Differences in thickness/depth


Differences in Diameter and Teeth

006 on bottom, 004 on top, both


So for future folks looking for a replacement oil pump and you wonder if you could just settle for the SOHC, OPG-004 version, it will fit on your car, but it presumably won't be creating as much oil flow due to the smaller annulus rotors.

Since I couldn't find specs on the actual oil flow rate for either, or any info on the actual rotors, here is what I measured on my OPG-006 (in-case someone wants to mill-out an 004 casting and/or get new 006 version type rotors machined for a replacement).
77.86mm outside diameter of outside annulus
7.96mm thickness for the main annulus rotors
12.96mm thickness at the driving dog/central connection collar to crankshaft
9 teeth on the inner annulus
10 teeth on the outer annulus

[Simon_P]

Thanks, useful information.
I understood from a few years back that the Impulse pump is different to the Elan - have you identified that the pump is 006 or are you going by what was written previously?
I have a vague reccolection that something on the casting is different.

[TorqueHorse]

Just going by what was written previously and inference. My original pump has AISIN 1K cast on the outside of it, and from looking at their catalog, the only other pump that I can see that has the exact same outside shape (and inlet and outlet locations) is the 006. Combined with the fact that when the PO had the car, the original/correct parts were still available, so I'm assuming it is correct.

As to the different casting part for another Isuzu engine...If you look at the service manual section EC 38-41, in a lot of their illustrations, they are actually depicting OPG-001. It looks similar, but the relief valve and inlet locations are not in the same place. Good enough for conveying the concepts they were trying to illustrate, but not helpful if you are trying to match parts exactly to it