Can I replace the oil pump without pulling the engine?

[JohnB27]

My '66 4.2 FHC is showing low oil pressure, about 15 psi at idle, 20 psi at 2,000 rpm, but it doesn't really climb higher than that. I go by the old 10psi per 1,000 rpm guideline, so I would like to see at least 40 psi, if not 60 at high rpm. Assuming it was a bad sender, I checked the pressure with a mechanical gauge and to my dismay, it showed the same 20psi and would not go higher. I changed the oil to Castrol 20-50 non-synthetic dinosaur oil, and added a 1/4" shim to the spring in the relief valve, but it's still just 20 psi. So now I'm thinking I should replace the oil pump. It looks like I could drop the sump and replace the oil pump without removing the engine. Is that possible? Has anyone here done this?

Best,

John B

[chrisfell]

Yup been there. Done that. Biggest issue, once I got the sump loose was the oil feed pipe, both when getting the sump off and when putting it on. It was in the way.

And I had to loosen the engine mounts and supports and gearbox mount and raise the engine quite a bit to remove the sump.

I have to say that unless you find the pump was definitely at fault (measurably worn or damaged) it is at least as likely, if not more, that the low oil pressure reading is caused by something else.

[Sprytly]

Currently, I run a 3.8, but I've previously had a Series 1 4.2 that I had gone through completely. If I had your symptoms I would pull the center main bearing cap and check the condition of that first. That is, if you are going to go to the bother of dropping the sump. I hope its a simple fix.

[E600]

Sorry to say it sounds more like General wear, it is possible to change mains and big end shells in situ, I don't think the pump can be changed without removing the crank, if this is the case then timing chains would be an issue. If the car is a keeper its looking like engine rebuild time.

Best of luck
Pat

[christopher storey]

Contrary to what has been said in the immediately preceding post there is no difficulty in removing the pump with the sump off - it bolts to the front main bearing cap. Indeed, it is about the first thing which has to come off in order to reach the crank. However, unless there is significant damage/wear ( which is very easy to assess merely by taking the pump cover off and measuring the clearance with feelers ) to the pump , then , as has already been said , the likely culprit is bearing wear. The cheerful news is that these engines will run almost for ever even when well worn, and I well recall a Mark VIII of my Father's which ran a big end at about 3 years old and 100,000 miles. When sent back to Jaguar at Brown's Lane - which in those days still had a service department - back it came with a bill for new shells and a note that the crank would still be passed as fit for installation in a brand new car!

[NickJ]

It is very easy to remove the oil pump but it's the process before this that's the problem. I now have had 2 engine failures from the same so called professional builder. The last one involved low oil pressure again and something going through the oil pump before the first 250 mile filter and oil change! No way am I going back to him. Therefore went for the pump removal option in the interim and was staggered by the damage when I took it to pieces. You've got to slacken off the torsion bars by dropping the front suspension and remove the reaction plate as getting up into the rear sump bolts is not easy. Piece of cake getting the pump out. Hopefully firing her up tonight so fingers crossed that the filter caught everything.
Not sure what the Forum's policy is on "naming and shaming" suppliers/companies but this guy was dreadful
NickJ

[Gfhug]

Not sure what the Forum's policy is on "naming and shaming" suppliers/companies but this guy was dreadful
NickJ

Without wishing to put another task onto our headmaster (or caretaker as he prefers to regard himself) would it be appropriate to let David (Heuer) know some details?
He may be aware of other problems with certain companies that could help you know if you are the exception or the rule?

Do admonish me, David, if you so wish

Geoff

[Heuer]

The rule is simple - throw sugar or bouquets as much as you want but when it comes to criticism of vendors or suppliers please do so in private otherwise the Forum could get closed down in this increasingly litigious world. If you see that someone is heading towards treacherous waters simply add a post to the thread on the lines of "Please PM me regarding this garage/vendor/company/person/matter as I have some information that may be of interest".

[NickJ]

Agree entirely about naming and shaming. This is not what the Forum is about. Just back in from the garage and am delighted to say that all appears fine. Cranked it up for a minute or two with no plugs in and coil disconnected. No pressure showed on the gauge. Realised that I had not connected the sender. Idiot! Refitted plugs, connected sender and one quick jab and she fired up. Gauge sped round to just under 60 at tick over and on half choke. Switched off and tomorrow the road beckons so will add on some careful miles before I am 100% confident.
I only went to this particular engine builder because he had a 3.8 E engine. My car had languished in a barn for some 16 years with tap water in the block - obvious what happened. A 3.8 block from a Mark 10 was subsequently fitted but I felt it important to get a proper E engine. This guy had one which he "rebuilt" for me. I would add that he is not one of the excellent companies who advertises in the E Type,Club magazine
NickJ
62 FHC 860541

[E600]

Thanks for clarifying oil pump removal, I recall the issue I had was with the drive gear. If I remember correctly the front main bearing cap has a cut out to accommodate the driven gear.

[JohnB27]

Actually, with the change to Castrol 20-50 and the helper shim in the spring relief valve, I'm seeing 30-35 psi now.

[PeterCrespin]

"..and was staggered by the damage when I took it to pieces. "

What sort of damage and in which components?