Series 1 3.8 low oil pressure after fresh engine build..Help!

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abouttownman
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#1 Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sun Jan 20, 2019 1:48 pm

Hi All

Just before I go on to ask for specific advice, I just wanted to thank all the moderators and contributors on this site for all the helpful advice I have gained in aiding my rebuild of my beloved Series 1 E-Type.
I appreciate this topic has been raised in several previous threads having sifted through a few dozen this morning!
Just wondering if there were any fresh takes on it ??
I have just completed the engine rebuild and instal on my 64 3.8 OTS
All internals have been replaced or reconditioned where possible. The crankshaft has been reground with new shells fitted.
Having installed the engine,added fluids including priming of the original oil pump, which was checked for clearances and seemed perfectly serviceable,added a small drop of oil down the bores.. I cranked over the engine with ignition disabled in order to check compressions which were all in the 170lbs region.
I decided to fire up the engine which started in an instant
I immediately checked oil pressure gauge which was barely showing 20lbs pressure where I would of expected at least 60lbs
I shut down the engine after only perhaps running for a minute to investigate. I checked the OP gauge by earthing out the WB wire on the sender unit and it sends gauge to the top. I tried a wet test pressure gauge which on crank produced no reading at all..concerning!
Before further attempts to start the engine I decided to remove the oil filter housing to re-check the PRV and balance valve which again seem to be in order with plenty of pressure on the new spring and no debris found. Reluctantly I then decided to remove the sump which as you will be aware is no easy feat.
With the sump down I removed the oil pump and pick up pipes.
Upon stripping, I discovered the green ‘o’ ring fitted to the pick up feed pipe had been split and thus the seal of the pipe was fairly loose. The supply pipe seemed fine. The oil pump works even when turned by hand.
My question is. Could this be the cause of such a drastic loss of oil pressure?
My train of thought was always to believe that the pump does not actually produce oil pressure but the fitment of the internal parts, i.e crankshaft bearings does. As my bearings are all new I can’t see this being the case but not ruling it out at this stage.
I would be most grateful for any advice on this and my second question is..before having to strip the block again, if necessary can this be achieved from under the car with engine in place without removing the head?
Thank you in advance for any feedback!

Regards

Mike
Mike
64 S1 3.8 OTS

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Tom W
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#2 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by Tom W » Sun Jan 20, 2019 2:20 pm

Have you tried running the engine with the mechanical gauge fitted, or just cranking, and if only cranking, was it with the plugs out to get maximum cranking RPM?

How badly split was the o-ring? I suppose if the pump is drawing air in as well as oil, you’d get aerated oil coming out of the pressure side of the pump. This could reduce your oil pressure.
Tom
1970 S2 FHC

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Moeregaard
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#3 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by Moeregaard » Sun Jan 20, 2019 3:20 pm

Tom makes a good point. If the O-rings on the pickup tube are missing or damaged, any amount of air drawn in will aerate the oil as it enters the pump. Fortunately, you had 20 psi, so there was most likely no bearing damage. There is the possibility that your oil-pressure relief valve is malfunctioning, so I would have a look there first. It's easily accessed and qualifies as "low-hanging fruit" in my book. A final possibility would be excessive bearing clearances, but you most likely would have heard some knocking on initial startup. I will keep my fingers crossed that this isn't the case.

Regarding oil-pressure gauges, I permanently installed a small, liquid-filled gauge directly on the oil gallery immediately behind the filter assembly. They're designed for high-vibration environments at are available through industrial suppliers.
Mark (Moe) Shipley
Former owner '66FHC, #1E32208
Former owner '65FHC, #1E30036

Planning on getting E-Type No. 3 as soon as possible....

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Mich7920
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#4 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by Mich7920 » Sun Jan 20, 2019 5:30 pm

Agree with Tom and Mark
But why re use the original oil pump if you rebuilt the engine ?
It's a so important part. Change it with new O ring. It's not really easy to fit these O ring, take your time.
The pump produce pressure and the inner or outer O ring cut give you less pressure
Michel
1963 E Type OTS - Angus Restoration
1965 E Type FHC - On the road at last !

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abouttownman
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#5 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sun Jan 20, 2019 9:24 pm

Hi Guys

Thank you for all your responses.. much appreciated!
Just a brief back ground, before this rebuild the car was running beautifully with several continental tours under her belt without issues. It began a as cosmetic restoration which quickly spiralled into a nut and bolt rebuild!
The reasons however, I did not change the oil pump were one that replacement 3.8 pumps are no longer available, I ordered a new 4.2 pump which requires adaptors to fit the narrower bore 3.8 feed pipes. Two being, that having inspected the new pump, I didn’t think it was manufactured as well as the original which I had stripped and checked all the clearances which were well within the green Jaguar service manual specifications and as mentioned above was working fine before. The only other option was an uprated pump but at a staggering £1800 cost!
One of my objectives in this restoration was to try and retain as many of the cars original parts as possible and the Bourdon Eaton pump seemed perfectly serviceable, as mentioned it pumps oil even when turned by hand.
The ‘o’ ring I discovered that was damaged was completed severed with small piece missing, this must have been done when the pipes were installed.As you have mentioned it is not an easy job to get these fitted and of course once the pipe goes goes on you have no way of knowing if you damaged the ‘o’ ring. I have already replaced the pick up feed pipe ‘o’ ring with another I found to be a tighter fit and now the pipe seems fairly well sealed. Unfortunately I could not find another ‘o’ ring to fit the supply end of the pump which I will try and source tomorrow.
Im beginning to wonder if the green ‘o’ rings which are supplied with the complete gasket kit are infact not for a 4.2 pump? This would make sense as they were a much looser fit.
The wet gauge I used to test OP was of a type that had a fairly long pipe attached. Perhaps I was being over cautious in not cranking it over long enough to allow oil to flow to the gauge?
I will try and source a gauge that fits directly to the block if anyone has any suggestions for one?
With regard the PRV, the spring was replaced, I’m not really sure what else to look for with it. Perhaps I should just order a new one and eliminate it?
Yes I hope the crank bearings are not the culprit here as the engine is looking so pretty in the car .. it would be a shame to have to take it out again.. especially difficult trying not to scratch any of the fresh paintwork!
I will keep you posted
Thanks again for all your suggestions!
Mike
64 S1 3.8 OTS

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#6 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abowie » Mon Jan 21, 2019 4:23 am

abouttownman wrote:
Sun Jan 20, 2019 1:48 pm

The supply pipe seemed fine. The oil pump works even when turned by hand.
My question is. Could this be the cause of such a drastic loss of oil pressure?
Yes I reckon it could.

Fitting the pipes into the O rings is tricky, especially as you get a fun selection of orings in a bottom gasket set, most of which don't fit.

I've just (yesterday) popped the sump on a 3.8 I'm rebuilding. Because the motor was incomplete I've ended up using a new 4.2 pump and oil feed pipe. I can tell you that the O ring for that pipe is 1" OD, 0.75" ID and 1/8" cross section. I routinely wire wheel the end of the pipe to smooth it and then linish it to chamfer the end then insert it using grease on the o ring. I still managed to wreck one oring doing it. It should be a snug fit.

I do not know what the correct O ring is for the narrower 3.8 pipe. Given the low cost of a new pump and 4.2 oil feed pipe I'd think seriously about replacing yours. If you do make sure you get the correct 2 bolt flange on the pipe end rather than the 3 bolt one.
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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christopher storey
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#7 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by christopher storey » Mon Jan 21, 2019 10:55 am

Any leak on the suction side of the pump will cause a loss of both flow and pressure because the pump then compresses the air in preference to the incompressible oil . I doubt that you have done any damage by running it, but IMHO it is essential to change the rubber/neoprene seals for new ( and correct ) ones . BTW, worries about damage to a freshly rebuilt engine can be minimised by coating the bearing surfaces with Graphogen when reassembling

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#8 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by Geoff Green » Mon Jan 21, 2019 3:12 pm

Just a note on oil bearing clearance and oil pump pipe size.

I check bearing clearances on all engines with a dry assembly and plastic gauge because little math is needed. I have acquired an inside mic set and will try with both plastic and mic to check my increased math skill level using mics. :bigrin:

Also because the 3.8 oil pump is not available new and the 4.2 pump is used they are of different size and you need a matching pipe:

https://xks.com/i-6912974-jaguar-oil-pu ... -0215.html

Original 3.8-liter oil pumps had 3/4" oil suction and delivery ports and associated pipes. A new, higher-capacity, oil pump was fitted to 4.2-liter engines with a 7/8" suction port and associated pipe. (The pressure, or delivery, port and pipe remained at 3/4".) Soon, all replacement oil pumps were of the later type and a sleeve was fitted to account for the difference in port sizes.

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#9 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sat Jan 26, 2019 5:08 pm

Hi Guys

So just to update, I replaced the oil pump and ‘o’ ring seals with new parts supplied by SNG making sure they were a snug fit in both pick up and delivery pipes. I checked the pump flow on a bench using two oil pans and it pumps well even when turned by hand. So I installed it and refitted the sump. I replaced the pressure relief valve with a new one as well as another new spring in the filter housing even though I could see no issue with the original ones, but just trying to eliminate everything now. Re- filled the engine with 20/50 oil and fired her up. The oil pressure gauge instantly shot up and off the scale and I’m thinking hey presto when suddenly oil started pouring out of the oil filter canister front seal. I immediately shut it off and began cleaning up.
Having replaced the seal and retightened the canister added more oil I tried again, now no leaks but sadly only 10lbs pressure showing on the gauge?? The motor sounds fine with no bottom or top end rumbling so I’m hoping I can eliminate the crankshaft now but alas back to drawing board! Any thoughts chaps??

Mike
Mike
64 S1 3.8 OTS

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mgcjag
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#10 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by mgcjag » Sat Jan 26, 2019 5:22 pm

Hi Mike have a look at this post....there is another valve in the filter head..have you checked it.....and the gasket between filter housing and block..there are a few different types.....http://forum.etypeuk.com/viewtopic.php? ... ass#p79513 Steve
Steve
1969 S2 2+2 & Building a C type replica

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#11 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by cactusman » Sat Jan 26, 2019 5:29 pm

Hi. The electric oil pressure gauge and sensor is a notoriously unreliable arrangement. Before doing anything else get a mechanical gauge and connect to the engine where the electric sensor goes. If this shows good oil pressure (and very likely it will) then either the sensor ( highly likely) or the gauge or possibly both are not working correctly. Sadly the after market sensors are pretty rubbish too so you have two options. Replace the electric system with a mechanical one.....kits are available. Replace.the sensor and or gauge and get it working even if inaccurate and only worry if the electric.reading suddenly changes.....and even if it does it will probably be a measurement problem not an engine problem unless accompanied by ominous engine sounds and b!ue smoke!
Julian the E-type man
1962 FHC
1966 MGB....fab little car too

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#12 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by lopena » Sat Jan 26, 2019 6:37 pm

+1 on Steve’s suggestion above to make sure you have the correct filter head to engine block gasket...fitting the wrong one is a very easy mistake to make (ask me how I know).

Alan
N.J.

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#13 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sat Jan 26, 2019 8:57 pm

Thanks guys for those reply’s. That’s an interesting link Steve but sadly that’s an S2 which has an entirely different type of filter housing, the S1 does not appear to have any valves other than the pressure relieve valve and the balance valve.. if any one knows exactly how these work I’d be delighted to know. I have seen many references in these threads mentioning these valves being a potential cause of low oil pressure but I can’t see anything wrong with these which are all brand new.
I also have the correct gasket fitted to the filter housing see image attached.. if it incorrect then please let me know. It’s surprising how many different variations of these filter housings there were!
I have another question, most new filter elements are supplied with two seals one slightly thinner than the other..which is the correct one for an S1 3.8?
Cheers

Mike
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Mike
64 S1 3.8 OTS

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#14 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abowie » Sun Jan 27, 2019 2:42 am

abouttownman wrote:
Sat Jan 26, 2019 5:08 pm
Hi Guys
! Any thoughts chaps??

Mike
Has someone left out one of the plugs in the rear of the camshafts?
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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#15 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by mgcjag » Sun Jan 27, 2019 10:04 am

Hi Mike.....yes the filters are supplied with 2 o rings....think its just use the one that fits best.....you mentioned that when you fired up the oil guage went high....is this on mechanical or are you back on the electrical....can you post a photo of the filter side of the housing and where the housing fits on the block....Steve
Steve
1969 S2 2+2 & Building a C type replica

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abouttownman
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#16 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sun Jan 27, 2019 1:35 pm

Hi Steve

On the second start up I was also using the cars electric guage.
If you recall from my original post I was getting just 20lbs pressure on the first start up having just rebuilt the engine where I would have expected at least 40-60lbs
As also mentioned, before this re build the car was running perfectly so I had no reason to suspect the OP gauge has stopped working although this is entirely possible. I am going to try a wet (mechanical) test this week, unfortunately I was unable to get hold of a tester with imperial fittings so will remedy that this week.
What was strange that having remedied the issue with the pump seals and then tried the second start up, the gauge immediately went all the way up before sprouting a leak from the filter. I thought I had cracked it, so obviously disappointed to see even less pressure 5-10lbs on the second start up having cured the leak.. bizarre! Also I was thinking perhaps I should run the engine a little longer to see if pressure increased, do you think this wise with such little pressure showing? As mentioned the engine sounds fine, no horrible noises but it has run for no longer than 30secs.
As I don’t have any direct images of the filter side of the housing to hand,I will attach some images of the block when it was out, where you can just see the filter housing. Hope this helps.
I am not sure what was referred to in the earlier post regarding rear camshaft plugs?
Thanks again for all your comments.
Mike
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Mike
64 S1 3.8 OTS

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#17 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by lopena » Sun Jan 27, 2019 1:37 pm

Mike:

Here’s a photo of the fully functional Tecalemit filter-head on my ‘64 3.8 E-type...it looks virtually identical to yours. The only difference I can spot is in the spring where yours shows about 8 coils and mine shows about six...I doubt that is of any significance.

Alan
N.J.




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#18 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by lopena » Sun Jan 27, 2019 1:44 pm

Mike:

In looking at the photo of your engine block I notice that the disc on the filter-head isn’t the same as mine. Could this be of significance?


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abouttownman
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#19 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by abouttownman » Sun Jan 27, 2019 2:18 pm

Hi Chaps

Yes I have noticed that there seem to be a number of variations to these filter housings, I’m not sure if the number of coils showing on the PRV spring is relevant, mine is all new.
I will try a mechanical wet oil pressure test this week and revert back to you.. fingers crossed it doesn’t all have to come out again!
Mike
Mike
64 S1 3.8 OTS

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#20 Re: Series 1 3.8 low oil pressure after fresh engine build..Help!

Post by mgcjag » Sun Jan 27, 2019 2:49 pm

Hi Mike...have a look at this post.....note your block has 5 bolt holes but your filter head 4....you could contact David Jones (Heuer) to discuss details as the post isnt conclusive Steve http://forum.etypeuk.com/viewtopic.php?t=4770
Steve
1969 S2 2+2 & Building a C type replica

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