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Need help lost oil pressure a 2nd time, more pics added.
https://www.ausmini.com/forums/viewtopic.php?f=2&t=54835		 Page 1 of 2
Author:  Slo998 [ Sat Jul 04, 2009 2:35 am ]
Post subject:  Need help lost oil pressure a 2nd time, more pics added.
Well you may of read some of the problems I’ve been having with my 998 build in my build thread well today has hit a new low!

Was out driving throw the hills with it trying to get some Kays on it before racing it on Sunday, ive been about 100km so far with it without a problem and running really well and noticed the oil presser started to drop a bit from say 60PSI to 40PSI so throt it may of just got hot. Started taking it really ease and it started droping more and more, I pulled over as soon as I could because I couldn’t stop were I was at the time, when I pulled over it still had just over 10PSI oil presser and did not change at all with RPM :?

Switched it off and cheeked: the oil level, it was just above max. Looked for leak everywhere, just around in general, oil gallery plug on the timing end, on the back of the gear box were the oil pick up in the gearbox goes. All looked good. Throat I would quickly start it and see what it was doing was down to about 7PSI on the gauge, switched it off. Disconnected the coil so it wouldn’t start, then disconnected the oil presser gauge so it was just an open hose and turned the motor over the oil belay trickled out.

Then pulled the oil bypass valve out to see if it was stuck, it’s a ball bearing one and seemed free. So that was all the stuff I could think to test for on the side of Greenhill road, so organised it to get picked up on a car trailer and take it back to my house.

Took the motor out the car, drained the oil, flywheel off, transfer case off, oil pump out in just over an hour and a half. :lol: It looks like the gasket behind the oil pump not sealing proply.

Should the cam bearing be flush with the block face between the oil pump and block? Because it is just inside to the motor a bit, and should there be a chamfered edged between the block and where the bearing starts, as in there it a gap between the block and bearing? All the other block I have at home are square to the bearing.

Would that be enough for it to loss its presser?
I will put pics up in the moring of what i mean to make it clearer, iv been up sine 6.30AM and its just to turn 2AM and am totally gutted ATM :evil: :x :cry: so sleep time.

Thanks for any input you may have Nathan.
Author:  drmini in aust [ Sat Jul 04, 2009 7:22 am ]
Post subject: 
Your motor is still OK, sleep easy. :lol:
A common problem when using a ball.
The ball setup needs a bit of steel rod inside the spring. Otherwise when you give it a rev and the ball lifts a bit, the spring slips round the side of the ball. This stops the ball seating properly. You get 10-20psi as you have found.
Cut a bit of 5/16" plain steel rod 40mm long and put it inside the spring.
Put the best end of the spring (if it's been cut) against the ball. Problem solved.
I have done about 12 motors like this.
With the 40mm long rod in, there is room for the ball to lift 6mm, it will never lift this much.

8)
Author:  Wombat [ Sat Jul 04, 2009 7:47 am ]
Post subject: 
Cut a bit of 5/16" plain steel rod 40mm long and put it inside the spring

TIP: get a long 5/16" bolt and cut off the smooth shaft above the thread
Author:  Slo998 [ Sat Jul 04, 2009 9:07 am ]
Post subject: 
When we put it on the trailer in the rain, we had to drive it up. The 10 or so seconds of doing that make it lose pretty much all of the oil preasure. Also when we had no gauge on the oil line even at 10PSI the oil should flow out steady?

Here are some pics when you look at them the pump is just barely sealing agents the block, its more where the cam bearing is. I've broken the gaskit away in the pics to see how close it was it wasnt like that :oops:

Image

Image

Image

Image

Thanks for your input, Nathan.
Author:  drmini in aust [ Sat Jul 04, 2009 9:13 am ]
Post subject: 
Pretty lousy gasket sealing there, what brand is the pump?? (so I don't buy one) :lol:
I would still add a bit of steel rod inside the relief valve spring. Otherwise... pressure drop can happen.
Author:  Fiji [ Sat Jul 04, 2009 11:31 am ]
Post subject: 
whateva happens man gl with it ..... i'd be pretty guttered too.
Author:  Super-mini [ Sat Jul 04, 2009 2:30 pm ]
Post subject: 
SW-10 :)

hope you can get it sorted
Author:  Slo998 [ Sun Jul 05, 2009 12:51 am ]
Post subject: 
Iv got it fixed turns out the pickup was partly blocked, it looked like some gaskit. I had washed the gear box out before assembly, must of been behind the diff or who knows :?

Took the lay gear out of the gear box, centre oil pick up, cleaned it all, new gaskets back on the motor. We ended up making a aluminum shim to go behind the oil pump to seal over the cam bearing, a 1.6mm verson of the automatic to manual adaptor plate in case it was the partly to blame as well.

Star to put it all back in the car at 7.50pm, first test drive 11.15pm, packed up and on the car tralier by 12pm now bed by 12.30pm. Get up and load tools at 6am! get to the track by 8am, scruteneering by 9am :lol: :roll: . By the first corner it will make it all worth while :twisted:

Thanks Nathan
Author:  simon k [ Sun Jul 05, 2009 10:50 am ]
Post subject: 
whew!

hope you had a good day ;)
Author:  Slo998 [ Tue Jul 07, 2009 11:38 pm ]
Post subject: 
Well I don’t have oil pressure again. After all the work that went in to it over Friday and Saturday getting it running again to go out on Sunday and get a lap of practise and notice one wheel bearing a little lose :oops: so came in tightened that up went out for the first sprint and got a lap and a half in and the oil pressure dropped again. I switched it off at 20PSI put my left indicator on and costed safely to the side of the track and had to get towed in. :cry: :evil: :x

When we started it up it again it had about 20PSI pressure at idle and pretty much stayed the same with revs, so we throat relief valve. Pulled it out and cleaned it and didn’t make much differents. We have taken the ball bearing out of the relief vale and tried two STD slides, one brand new one and no differents. Then something a bit weird, instead of the pressure staying the same with revs it now drops as revs increase :? After lots of stuffing around with it not getting any scene out of it, it went back on the trailer.

Just to make things that much better we had to do all this in the rain at the track :roll: :P

The first time I’m sure it was just the blocked pick up, this time it’s very different. Last time I had no pressure at the end this time I still do but it drops with revs, when the motor is cold it has less pressure 10-15PSI at idle and halves with revs. I’m pretty confident with the relief vale is working as it should I’m thinking pump.

Any help would be really good, I think it will need to come out again and pulled down and looked at again.

Thanks as always Nathan. :)
Author:  Mick [ Tue Jul 07, 2009 11:49 pm ]
Post subject: 
Just a thought, have you proven the pressure gauge is fine...?
Author:  Slo998 [ Wed Jul 08, 2009 12:07 am ]
Post subject: 
Mick wrote:
Just a thought, have you proven the pressure gauge is fine...?


Yes have tryed a brand new one in and its the same. Iv also disconected the oil cooler, put the STD copper line back on. still the same. Now that i had two gauges i drilled and taped (not on the car) one of them in to the banjo bolt to see if there was a pressure dorp between the to and it pritty mutch the same.

With the banjo bolt completly bloked just with the gauge in there and it only gets to about 50PSI were it should get to the 70ish PSI the the relief vale should take over.

Nathan.
Author:  superSeven [ Wed Jul 08, 2009 5:37 am ]
Post subject: 
sounds like:
http://www.ausmini.com/forums/viewtopic ... l+pressure

looks like:
http://www.ausmini.com/forums/viewtopic ... l+pressure

:?:
Author:  Wombat [ Wed Jul 08, 2009 8:08 am ]
Post subject: 
Did you put the rod in the relief valve spring as suggested by the Doc?
Author:  Slo998 [ Wed Jul 08, 2009 2:55 pm ]
Post subject: 
superSeven wrote:
sounds like:
http://www.ausmini.com/forums/viewtopic ... l+pressure

looks like:
http://www.ausmini.com/forums/viewtopic ... l+pressure

:?:


Yes sound the same but this is a new build, the bearing were fine when I pulled it all down on Saturday afternoon. And even with the motor disconnected from the oil system (so no flow into the filter or anywhere bar the pressure relief valve), so the pump is only pumping agents itself, the gauge I have in the banjo bolt and the pressure relief valve is doesn’t get to the relief pressure. So I’m very confident that it’s not to do with the motor side, it’s got to be the pump, pump gasket or the pickup again but there is lots of oil flow under no pressure and the pump should still make pressure even if it can’t pickup that much flow.

Wombat wrote:
Did you put the rod in the relief valve spring as suggested by the Doc?


Slo998 wrote:
We have taken the ball bearing out of the relief vale and tried two STD slides, one brand new one and no differents.


Thanks for the help the more question the better, what do we all think about this cam bearing not being flush with the block face between the oil pump and block? Would this make a differents?

Thanks Nathan trying to hold his chin up. :)
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