10 replies to this topic

[Jake Didsbury]

Hi all, so recently fitted the engine back into my Mpi afterna gearbox rebuild but having some strange oil pressure issues that weren't there before.
The only thing in the oil system changed is a new pump and oil filter
The engine hasn't been touched and wasn't having this issue before:
The first day of running the engine after lifting it back in had no problems but the other night came to move to the car in front of the house and the oil pressure light wouldn't go out so I turned the engine off immediately waited a second or two and then tried another 3 times without luck to get the light to go out so I was at this point worried sick so decided to fit a gauge to see of the pressure sensor was faulty so I did that the following day.
After having fitted the gauge and adaptor so I can have the sensor in aswell started the engine and the light was on again and the gauge at 0 but then it came alive and went to nearly 100 on tick over now I know this is too high but a tee driving IT abit it has settled down to about 55 on tick over and about 80 at about 70mph
But the strange thing is the light has been going out almost instantly now after starting butnthe gauge is still showing 0 for a good 10 seconds before going up to 55 wondered if this was because of the pipe being 5ft long
But it's changed again now because the pressure light has started flicking now before the gauge builds up all this is making me think the relief valve is playing silly buggers possibly working and not working just a little concerning
It's actually a very good engine and I have looked after it regular oil and filter changes of castrol 20/50 with a can of winns too
The engine has just shy of 115,000 miles on it
Also ginna try a new oil pressure sensor aswell as cleaning the relief valve plunger

Edited by Jake Didsbury, 04 October 2015 - 07:03 PM.

[minidaves]

oil pumps can be bit meh these days 

[Jake Didsbury]

That's true I am always worried about oil pimp quality this one is an auto pumps one UK made it looked pretty good to be honest but looks can be deceptive I suppose

[Jake Didsbury]

The oil pressure is actually really good once the reading comes alive on the gauge but it's the time it's taking to build the pressure that's concerning me it wasn't doing this before the engine came out going to check the relief valve anyway

[Jake Didsbury]

The oil pressure is actually really good once the reading comes alive on the gauge but it's the time it's taking to build the pressure that's concerning me it wasn't doing this before the engine came out going to check the relief valve anyway

[Spider]

Sounds like the Oil is draining back fairly easy. I'm just wondering if the Oil Pump gasket isn't sealing and / or the bolts for the Oil Pump as a whisker too long?  Given that once you get pressure, everything sounds normal, I'd not be so sure that it's the relief valve, but as that's easy to get at. sure, check that first, as if it is jamming, it will also allow for drain back, only much much slower.

[Jake Didsbury]

Thanks for the reply that did cross my mind I wondered if the oil pump wasn't sealed right, I did use a good gasket and the original bolts from the engine, I sure hope it's sealed otherwise it's engine back out
Yeah I'll check the relief valve I think I'm just wanting it to be that so it puts my mind at ease as it is worrying me

[spiguy]

you say it wasn't doing it before, but did you have a gauge before? I got the impression that you only fitted the gauge recently in light of the problem you are having. If that is the case, then as the light is going out (only means there is a few psi - think standard switch is 7psi) you could have had this problem all along and not known.

[Jake Didsbury]

Yeah that's true and a fair point but I have actually had a look right at the start of the pipe for the gauge where it goes into the block, and on the occasions when the light is stuck on there also isn't any oil in the gauge pipe soon as the oil comes up the pipe the light goes out so its doing its job, but sometimes it's taking what I think is way too long to build up, before the light always went out everytime within a second and sometimes it does that now and sometimes it stays on I have proven to myself it's not the oil switch because it goes out when the pipe fills up for the gauge so something must be different INhabent yet had chance to investigate it properly

[gazza82]

I'd remove the oil pressure pipe and t-piece and go back to just using the pressure switch and see if it goes back to what it was before. Then try re-fitting the t-piece and pressure gauge again but this time try and pre-fill the gauge feed-pipe as much as you can to remove air-locks, etc.

 

I had one on an old Austin inline engine and never had an issue and once the pipe was primed with as much oil as we could get in it as far as I could tell it never leaked back into the oilways ... it was semi-transparent so you could see the oil in the pipe.

[Jake Didsbury]

I'll give it a try I'm going toneet anything now I'm so fed up with it, had the pressure release valve out and that's fine so if doing what the last post suggested doesn't bring anything up looks like I'm going to have to pull the bloody engine out again and see of it's the pump, it's asif its sucking air at first before it gets oil to it like it's draining back to the sump or something's not sealed right I don't know but I'm at my whits end with it