Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: IrishCJ6 on September 18, 2011, 06:56:25 PM

Title: Oil pressure - or lack there of
Post by: IrishCJ6 on September 18, 2011, 06:56:25 PM

My test electric oil pressure gauge shat itself the other day and instead of unpacking my nice new mechanical one I was so eager to get it running I said to hell with it and I'll just start it up (no harm done)

So everythings ok, but today I thought I better just check, so I installed the new gauge and would you believe it no pressure,

Now this doesn't make sense to me cause the pressure switch turns itself off imediatley on start up (ok so maybe 5PSI) but still pressure, there is no knocking in the engine, no sticking or noisy lifters, no black smoke and the engine temperature is good (80 degC constant) and sounds good, with good response through the rev range.

So my theroy is that if the engine had no oil pressure then after my 10-20min run ups the engine would have seized??

So I'm thinking my gauge/capilary tube might be at fault? I'm going to buy another electric test gauge and just double check, but has anyone else got any bright ideas?

Title: Re: Oil pressure - or lack there of
Post by: Panic mechanic! on September 18, 2011, 07:00:46 PM

I think you have a blockage somewhere along the line, capillary can take a few mins to read the correct presure and are not the best way of doing it.
Have you got an airlock in the capillary tube?

Title: Re: Oil pressure - or lack there of
Post by: IrishCJ6 on September 18, 2011, 07:32:12 PM

Not sure, I disconnected the tube from the gauge but only got a very small drip, I checked the tube and I can't see any kinks, its almost like the tube has an obstruction internally?

Title: Re: Oil pressure - or lack there of
Post by: dieselj20 on September 18, 2011, 07:42:48 PM

is it a small nylon tube with brass olives very easy to over tighten and crush the tube

Title: Re: Oil pressure - or lack there of
Post by: IrishCJ6 on September 18, 2011, 08:06:38 PM

No its a 1 piece copper 1 with soldered olives, I didn't swing on them either, always though a mechanical gauge was better and more accurate than the electric but maybe that assumption is not true

Title: Re: Oil pressure - or lack there of
Post by: dieselj20 on September 18, 2011, 08:13:21 PM

i usually find electric gages tell lie,s mechanical are better

Title: Re: Oil pressure - or lack there of
Post by: Panic mechanic! on September 18, 2011, 08:52:36 PM

mechanical are more accurate but they can take a while to register a sudden drop in pressure and electrical can be probematic and give false readings but they are not wildly out.

Title: Re: Oil pressure - or lack there of
Post by: dieselj20 on September 18, 2011, 08:58:45 PM

that's why it pays to run an idiot light as well you will notice the light first

Title: Re: Oil pressure - or lack there of
Post by: IrishCJ6 on September 18, 2011, 09:14:14 PM

I'm going to get an electric gauge to check, I'm also going to disconnect the tube a the tee piece in the mean time and turn it over and see if oil sqirts out, I won't know the pressure but at least I'll no the pump is pushing something, I'm pretty sure its working as the oil filter was hot which would suggest oil is circulating to this at least, is there any other easy access points for oil delivery?

Title: Re: Oil pressure - or lack there of
Post by: Dave69 on September 19, 2011, 06:45:58 PM

have you bled air out of the capilary tube? if not you will have an air lock which could cause response issues.

electric ones are not that bad it all depends on where you take the reading, plus they are easier to route the cables.

Title: Re: Oil pressure - or lack there of
Post by: IrishCJ6 on September 19, 2011, 08:32:21 PM

Ok some news,

was talking to the mechanics at work today and they all said if I had no oil pressure the engine would have seized by now and would not run as well as it does, so we think the tube has a blockage (the copper tubing has a minute hole in it and could easily have a bit of crap in it) so I borrowed a test kit and will try and set it up tomorrow and recheck. I have also got a new tube and will then use this. Finger crossed all the assumptions are correct.

Title: Re: Oil pressure - or lack there of
Post by: IrishCJ6 on September 21, 2011, 06:44:17 PM

Crisis over, turned out to be a blockage in the tube, I have plenty of pressure now :ace:

Title: Re: Oil pressure - or lack there of
Post by: Bulldog67 on September 21, 2011, 06:53:02 PM

phew :13:

Title: Re: Oil pressure - or lack there of
Post by: bigjeepzj on September 21, 2011, 06:55:19 PM

wow hoo  :clap: :clap: :13: