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Oil Pressure Oddness

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I really really do not want to start this thing until I know I have some life from the oil pump...

Following some phone advice from Barry (thanks!) I'm finding that spinning the engine for a few seconds allows the 12v pump to push in more oil via the sender port. I've now pumped in probably 1.5 litres in total and the sump level hasn't changed so I can only assume it's topping up and maybe moving along air in the system somewhere on its way to the pump?

The battery is on charge just now, then I'll give it a proper spin over and see if I can get any out flow.

Beyond that I'm starting to worry that I've got something fundamentally wrong with the oil pump rebuild. But what? New inner and outer annulus from SJ, assembled as per the manual, using 2 gaskets as advised because it didn't spin freely with 1.

 

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I'd be a little concerned with the extra gasket moving the front cover too far away from the pump, allowing oil and vacuum to bypass the rotor. 

Not that I'm familiar with the setup, but it doesn't sound right. 

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The manual and PNM site (I think) was quite clear that if the pump doesn't spin freely with 1 gasket (which mine didn't with the new rotors) it is necessary to fit a second gasket.

Logically if I don't get anywhere back priming it then the oil pump will be my first port of call when I can bring myself to strip it off again ☹️☹️


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I’m perplexed by the additional gasket.

Not sure what the implications of that are exactly .....looking at the diagrams it looks like it could mover the location of the main body’s and annulus - and this could well affect the pumping ability - but I just don’t know for sure. Who said to fit the second gasket

The annulus is the correct way round isn’t it ??


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5 minutes ago, Barrykearley said:

I’m perplexed by the additional gasket.

Not sure what the implications of that are exactly .....looking at the diagrams it looks like it could mover the location of the main body’s and annulus - and this could well affect the pumping ability - but I just don’t know for sure. Who said to fit the second gasket

The annulus is the correct way round isn’t it ??

The right way round?? 


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Yes - it is orientated one way or the other - it’ll either pump or suck depending on that. 

I had this issue with the abs pump when I stripped and rebuilt that 🤣

2881EBFC-2FDE-4996-B26D-80B7514B94DA.thumb.jpeg.1baa0a0e4ab4e4fbf0efe312a2ec82d9.jpeg


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Sh*t. My Lotus manual doesn't show that at all, just says to fit the annulus to the shaft!

Presumably that means both inner and outer parts have to be a specific way round? How would I even know which is the right way just by looking at them? I recall that one part had a dimple on one side (the inner I think) but there was nothing on the other part I'm sure so I though it couldn't be related to matching up their orientation!

Assuming (perhaps) they're not oriented properly, am I likely to have damaged them turning the engine over with them the wrong way round or opposed (if they are a matched pair)? Or am I safe to strip, re-orient them and go again?

Feeling like a right muppet if this is the problem...😐


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I’ve never stripped one of these pumps. It maybe they’ve only stated that due to the meshing to the rotor - I don’t know and wouldn’t without physically seeing it.

depends on how it picks the oil up and passes it on. 

@CHANGES - any guidance here chap??

Better off ensuring this is correct before feeling like a skint muppet with a pile of broken parts 👍


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Looking at pictures on the web - I can’t identify any obvious holes or differences between these things.... 


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Now seen a photo of a stripped one. It’s a simple pump unit - and doesn’t look to be configurable like the abs pump setup. So it should always pump depending on turning the rotor the correct way of course. 

Id be more concerned that gasket has added a clear path to bypass the rotor like @Steve V8 mentioned.

however - all this confusion aside - where’s that bloody oil going !! Maybe it’s just filling up the coolers and maybe there’s no issue at all. Have another go with the battery pump


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I've just looked at the 4 pot notes, it says to insure the rotor and annulus are the right way around but doesn't say how or why you would know. However this may be neither here nor there, but I've recently done a Mazda pump and both rotor and annulus have dimples which face the front cover, that would imply if you have a dimple there is probably a right or wrong orientation. 

Also no mention of an extra gasket in the Lotus service notes.

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I'm positive that only one part of the SJ 'set' I received had a dimple on it, which is why I discounted it being anything to do with orientation. That and the original parts aren't marked at all (I checked then and just double checked now).

Interesting that the SJ website shows a dimple on one side of both parts, which would have led me to realise there was a right and wrong way round to fit them. Mine deffo only had a dimple on one because I puzzled for a while why that would be in case it meant they were a 'matched' pair and needed to both be fitted the same way round. I even called SJ but it was the last day before Christmas and nobody would pick up the phone...

The double gasket is mentioned here. With one mine felt a little tight so I put a second on and it turned freely

https://www.thelotuscentreonline.co.uk/epages/sdctukef2v6v.sf/en_GB/?ObjectPath=/Shops/sdctukef2v6v/Products/A910E2659R

So now I'm reluctant to do any more cranking until I'm absolutely sure if the rotors need to be oriented a specific way or not. If they do, I might be able to remove the nose of the aux housing to check which way round they are. Problem is, if only one has a dimple how would I know which way round it is!?

 

 


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The manual is referring to strip and reassembling - so the orientation will be critical if it’s a pair of parts which have spun round for thousands of miles. 


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The suck/ push is determined by the direction of rotation which is governed by the shaft rotation. so, in that sense it doesn't matter which way round the annulus and rotor go, but as Barry says directly above, it would matter if they were used parts being installed together again. I think these are new, so again, no matter there.

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Yes, both new parts and came as a set from SJ. As only one had a dimple on it, even if they were machined as a matched pair (i.e. Both need to be fitted the same way round as machined) how could I know which way round the second part should be?

So are we saying that definitely the orientation of the rotors can't be the problem? If so then I'll persevere tomorrow with priming the pump when the battery is fully charged.

If necessary I can revisit the double gasket thing but I did try it initially with 1 and wasn't happy it was spinning freely. 

One thing I am sure of is that my engine is spinning the right way.

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Gin & tonic aside, I can't offer any solution. But if you do find yourself taking the oil pump out again, I'd advise packing it with Vaseline, which helps oil pickup from new. And I'm inclined to agree with Andy about the rotor and annulus orientation, as they're new parts.


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You should expect the oil pump to need little force to rotate (when not attached to other bits), but not to expect it to carry on turning after you stop. The sort of thing I'd accept would be, you can rotate the pump by pushing your finger against the belt pulley and turning the pulley that way.If you couldn't have done that, then a second gasket as a shim is in order. If you had to forcibly grasp the pulley in order to turn it, then there's too much resistance.

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image1.jpeg.8362ee17cc6e002a1a7dbdcf284cd462.jpeg

Success! Well at least a big step forward. After much priming with a litre and a half of oil and some 1:1 advice from @Barrykearley over the phone my car just produced this from the pipe tapped into the sender port whilst being spun over with the plugs out. About a litre of oil 😀

Its a little grimy so logic says that has come from the cooler pipes (which were never drained), pushed through and into the pump by the oil I've pumped into the gallery today. 

The battery is getting low and it's bloody freezing in the garage now so I've called it a day and left the charger on. I guess I'm ready to go for a start tomorrow now with the manual pressure gauge plumbed in and see what I get?

Big question is, do I need to revisit the pump gasket now or should I leave well alone as long as I have good pressure? It's in the back of my mind now but would mean dropping off the cambelt again and losing the prime on the pump to check the 'feel' according to @andydclements advice above.

Anything else I ought to/not to be doing at this stage??

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Leave it alone - recheck it’s pumping ok by taking some more oil out - keep an eye on the dipstick.

then go for the big start up :animier:

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Yep.

If you pull it apart now, you are tampering with something that you've proven already works, but may or may not have a fault (nothing says it has, nothing says it hasn't). If when you start it for a 2nd, 3rd, 4th time etc, you find it takes ages to get up to pressure, then you may have found that there's a problem, and so warrants investigation.

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It was taking ages before, which is why I stripped it in the first place so if it's still the same I guess I won't be sure if it's the original problem or the gasket. I'll see what I get tomorrow and go from there.

Thanks so much for all the advice here so far. I may well be back for more..!

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Sounds all good then Neil, I was beginning to wonder and look at possible problems, but forget all that now you have pump output.

One thing you may consider though if the initial problem was slow pressure build up after start up. The seal of the non return valve that keeps oil at the pump after shut down, failure here would allow oil to drain back to the sump, on start up it would take a while for the pump to drag the oil back up. And may also have caused the difficulties getting output at the pump after rebuild.

I am just thinking outside the box, no expert.

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I'm open to all ideas @Steve V8

Where exactly is this mysterious seal of which you speak?

Ill see what happens tomorrow but with regard to the original problem, that coincided with the car going back on the road after I replaced the through chassis coolant pipes. Now I know the exact path the oil flow takes (out of the pump to the front cooler before reaching the pressure sender) I wondered if it was more than just coincidence.

Whilst inserting the new pipes I did need to flex and in one case temporarily compress one of the rubber oil cooler pipes to get the ally pipes past. There's no leak or outward damage but could I have inadvertently damaged the hose inside? Could that somehow be retricting the oil flow back to the sender until enough pressure has built up behind it? Or am I just being paranoid...?


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It’s the size of the pick up pipe and the displacement of the pump which is the issue. It takes a fair few seconds for the pump to fill that pick up pipe from cold


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