Oil pump warning
Turbo Mini Forums

Some of the pepole that look at may have seen my thread about my oil pressure problems I’ve been having with my new 998 motor.


It now seems like we have an answer but it is a little conserving as it could affect a lot of people. After all the testing we did it left no other real option but to be a defective oil pump Now there are not too many things to go wrong in one as they are a very simple devise, in case people dont know what is inside one.



The problem looks to be that the input shaft that is driven from the camshaft is slipping on the ‘impeller gear’ that creates the pressure as it rotates Now there is no way in any shape or form that this joint should slip.

We have looked at four oil pumps two old, two new and this is what we found:
The new one that I had in the motor when I was having problems when put in a vice you could slip the impeller on the shaft with a shifter at room temp.



The second new one was no better if not worse, the second one was out the packet hadnt been in a motor yet. We tried this with a worn STD rover item out of a old A+ 998 and there was no way in the world you could turn in, even leaning into it with two hands on a 12” shifter. And the last pump was a three or four year old pump out of my last motor and that was a lot tighter then the brand new ones but not as good as the STD rover item.

So we decided to take a look at the shaft to work out if we could pin it someway. So we pressed them out and found something that explains it a bit more.


The STD A+ Rover item has splines on the shaft to ‘lock’ the impeller on were as the aftermarket pumps are just a smooth shaft. Now I do appreciate that if done correctly a shrunk fit item like that should hold no problems but I think the proof that it can be turned by hand shows that it’s not tight enough and to be a bit of a concern.

Even if this is not the cures behind my oil pressure problems I can’t see it helping anything being like that when you think of the force that needs to be transmitted through that shaft to make the oil pressure.

In the end we pressed the Rover shaft into the new impeller with some locktight just to make sure. I’m really hoping that this and the new modified centre oil pick up with fix my oil problem

Not sure if anyone has seem this before? Thanks Nathan.

Edited by Slo998 on 6th Aug, 2009.

well done mate good reserch and interresting indeed.

just goes to show rover at times did get things right unlike the aftermarket crap.


bit like the layshafts, you are better of using a good second hand item than a new aftermarket one,

always looking for them bigger bunches of bannanas

Which aftermarket one is it ???

Sourced in the UK or over in your part of the world ???

Schrödinger's cat - so which one am I ???

Out of the two new ones I got one was from Swiftune there “OE spec high flow oil pump for a 998” and one was from a local supplier as the same discription.

Both pumps were identical.

Edited by Slo998 on 6th Aug, 2009.

Worrying because that suggests the wholesale source is the same, just going in different bags and boxes.....

(edit, typo)

Edited by Rod S on 6th Aug, 2009.

Schrödinger's cat - so which one am I ???

have you told Swifty? they are the first that should know! I have been using swiftune sourced pumps in two of my engines lately (big bore engines), luckily I seem to have okay pressure.

I specilifcally bought the Swiftune 998 pump for my engine, assuming it was of good quality. Luckily I decided to modify an Avonbar turbo oil pump for the 1098 instead.

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

The state of new parts lately is not at their best.. all I seem to be doing is replacing new parts that have only been on the car a year or so.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

I have let swiftune know and they said they had not heard of it happing but agreed it was possibly.

They asked if I could send the pump back to look at. I will see what the outcome is from the one I got locally as they are testing that one for themselves. As it look to be the same supplier anyway.

I know of a high up racing man over here having the same symptoms as mine but in a big bore but has not pulled it apart yet so that could be intresting.

How much work is involved in converting to a metro turbo steel back pump in a small bore?

Is it just drilling and tapping for the mounting bolt and a spacer plate?

Excellent I will look into it next time it is apart

If you look in the thread that I posted from Ausmini you will see the pics of how my oil pump gasket was sealing, which is what we throat the problem was the first time I lost oil pressure. What do you think?
Is it normal to have that little sealing surface?