• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

No oil pressure

Share this page

Michael Oritt

Michael Oritt

Yoda
Silver
Country flag
Offline
This morning I drained my old engine oil on my 100 and replaced the oil filter, then refilled the sump to the correct level and restarted the engine to check for oil pressure.

After several seconds I became concerned when the oil pressure gauge needle stayed pegged. I also have a low oil pressure warning light, the sender for which is mounted to the block at the point where the flex hose normally attaches and it is staying lit.

By this time I had run the engine for at least 30 seconds and was becoming very concered, so I shut it down, removed the valve cover and disconnected the banjo bolt going to the rocker shaft, then restarted the engine--no oil is coming out of the oil line.

Thinking that perhaps the oil pump lost prime I removed the flex hose from the coiled copper pipe gong to the oil pressure gauge and back-fed some engine oil, then reattached the hose to the line but on restarting again nothing has changed.

Though this has never happened before I have heard of oil pumps not repriming themselves and/or taking a while to do so after an oil change. I have already run the engine for at least a minute in the several restarts and am frankly concerned that serious damage may have already happened. BTW the engine ran just fine with normal oil pressure of 45-50 psi during the ride I took earlier this morning to get the oil warm prior to draining sump and changing filter.

Any thoughts or suggestions will be appreciated.
 
Last edited:
John--

I did not mention that I use a spin-on oil filter (K&N 2009) which mounts to the engine laterally--that is, the filter body is horizontal. Prior to installing the filter i partially filled it with fresh oil to lessen the size of the slug of air the pump had to "inhale". In any case a mechanic friend of mine made a similar comment--that the filter might in some way be blocked or improperly assembled, etc.

I decided to let things set for the day and see if the situation changes overnight (stranger things have happened in the world of Healeys) but tomorrow I will probably back the filter off a couple of turns so that the gasket is clear of its seat and see what happens when I crank the engine over with the plug wires disconnected. If no oil comes out from the filter base it would probably mean either a broken pump or drive spindle. If oil does come out I will be contacting K&N!
 
Michael, I think you are on the right track - not unheard of for filters to be wonky. I prefer a remote filter where it's hanging down simply because you can completely fill the filter before installing, but obviously you did the best you can with the horizontal positioning.
The overnight wait may help - if there is an air pocket in the pump, it may well slowly fill with oil (burp sort of).... perhaps wishful thinking but seems possible.
Another thought, since you have run it for a minute or so without pressure, consider pulling the plugs and using the starter. It should be possible to get pressure spinning on the starter and there is a lot less potential to harm rod bearings. Obviously being careful not to overheat the starter in the process.
Good luck.
Dave
 
Hi Michael,

Did you run the engine to warm the oil prior to changing? If so, how was the oil pressure then?

Also, after checking out your filter (I also agree the most probable cause), if the low pressure light sensor is mounted in series with the gauge line (I am not familiar with this unit), I would remove the sensor and reconnect the gauge line to see if flow returns to the gauge.

A while back I experienced a low pressure due an air block in the gauge line and eliminated it by loosening and bleeding the line. Although it is common for this line to drain after the engine is shut down, after this bleed, I never experienced this pressure loss again.

Good luck,
Ray(64BJ8P1)
 
Last edited:
Try another filter not a K&N and prime it with something goopy like Bardahl or STP oil treatment that will hold/stay in the filter while its on its side . It may help if it a pump priming issue and save making a mess spewing oil out with the filter backed off .
 
I doubt this is a problem with the oil filter; I've used spin-ons for many years in many cars and never had a problem, and K&N is a reputable company. There is a known issue--at least according to Denis Welch--with the solid copper pipe from the pump to the block (they are supposedly prone to cracking due to heat/work hardening). DW sells a flexible, stainless steel sleeved pipe to replace the solid copper one. We installed one in our BN2 based on that information. If that has indeed separated or even cracked I think you would lose considerable pressure; perhaps all. Michael, it can't hurt to try another filter, but if the problem persists I think it's time to drop the pan.
 
All-

Thanks for your responses and suggestions. I am going to jump on this in the morning and i hope I can get some sleep tonight.

I too doubt that it is the filter though it would be a convenient fix. I replaced the original copper oil line that Bob refers to with a DW braided line many years ago so that is definitely not the problem. Bottom line if loosening the filter does not quickly solve the issue the pan comes off. If nothing appears broken perhaps packing the oil pump with vaseline will do the trick.
 
The same happened to me last month during an oil change. I let the car sit for a couple of days when I drained it before I refilled. I was so used to not having this issue that I probably ran the car for 25 seconds and even pumped the pedal a couple of times before I looked at the oil pressure gage and freaked out. I just figured it was either OK or it wasn't. A couple of other shorter attempts and no luck. So I pulled all the plugs to make cranking faster and easier and pulled the spin on filter off, took a big syringe and pumped a bunch of oil through the adapter back towards the oil pump. I cranked it with the remote button and voila!! Happy day, oil poured out. Took it for a spin and everything seemed normal except now I have a door rattle. I'm pretty sure that's not related but who knows :smile:. From now on I'll try and fill it at the same time I am draining it (good trick that would be). I think I will always just clean and gap the plugs at any oil change so I can do the little procedure as SOP.
 
Hi Jon,

Although I have not experienced this condition as my common process is to drain and refill as one short process (with new original filter setup), but if Michael's experience turns out to be caused by drain-down, then it can happen even during a short cycle. I have heard the loss of pressure happening before but the issue has often been reconciled by the correct fitting of a spin-on filter adaptor.

When oil is drained for internal parts replacement or as part of a restoration rebuild, process are acknowledged to develop oil pressure prior to initial operation. These procedures are thought to be unnecessary during a simple oil and filter change and rarely cause an issue. In Michaels situation, if I have read correctly, there was no significant time delay between drain and refill...unless there was? Additionally, as I first misread, Michael pulled the oil line feed from the banjo to find no oil flow after his initial oil/filter replacement. What would cause a pump's prime to be lost within such a short time .... especially if their was no obvious issues prior (like low oil pressure due to internal leaks or a failing pump)? Other then pulling the pan, is there a process that could be followed to find if the pump is working?

Just some thoughts,
Ray(64BJ8P1)
 
Just now I pulled off the K&N, removed the spark plugs and spun the motor over. After about 15-20 seconds of cranking I could see a good stream of oil coming out of the port in the oil filter adapter and the needle came of the peg. I put a new filter on, reinstalled the plugs and VOILA--oil pressure! Collective wisdom is that with an engine that has some miles on it no damage should have been done to bearing surfaces, rings and bores, etc. during the minute or so of running without oil pressure yesterday and I certainly hope that will be borne out in real life.

As I said in an earlier post I have heard of oil pumps losing prime when they have sat for a while without oil in them. However no more than 30 minutes elapsed between the time I drained the oil and went to restart yesterday and I am quite surprised by the oil pump's inability to reprime itself. I have probably changed the oil and filter in the same manner 10-15 times over the years and while there is always a first time for everything I believe the message is that the lower end of the engine and pump need to be closely inspected for clearances and new parts installed as necessary. I performed the oil/filter change yesterday because in about ten days my wife and I plan on taking a trip down to the North Carolina Outer Banks and then on to Wilmington NC to celebrate our second anniversary. So I'll hope for a successful and uneventful trip and for sure the car will be up on stands immediately upon my return.

Thanks to all of you for the good advice and patience. This forum continues to be a great resource!
 
red57 said:
consider pulling the plugs and using the starter. Dave
Click to expand...

I'm with Dave on this one, that is how I primed my engine after the rebuild - granted I had some engine building lube on all the bearings, but there again you must have had some oil on the bearings, it may not be that bad. If you do drop the pan have a look at the big ends at the same time.

:cheers:

Bob
 
Ray--

Sorry, I did not read your post before putting up mine just a few minutes ago.

I agree with everything you say and while no more than 30 minutes elapsed between my having drained the engine and the attempted restart loss of prime to the oil pump must definitely have occurred. My guess is that some wear within the pump has occurred and there was not a sufficient film of oil to create the vacuum needed to draw oil up from the sump, through the pickup and into the pump, etc. As I said in my post it has been my intention to go through the bottom end anyway as oil pressure is not what it used to be so maybe this was simply the engine's way of getting my attention.

In any case both the engine and myself are breathing easier again--go up two post for the details. Thanks again to all for their suggestions and experience.
 
Last edited:
I concur that no amount a damage was done during the little bit of running without oil pressure. There should've still been enough of an oil film at idling-no load revs.

As long as you're still reading adequate oil pressure after your trip (Congratulation, btw!) I wouldn't be in to much hurry to o/h the bottom end. Unless you just need something to do, but I expect you have enough other car projects already on the list.

Glad that (oil pressure) order was restored. :cheers:
 
Glad it worked out, and thanks for the post-problem report.

Question for those who know the insides of these engines more than I do: When the engine has stopped and oil has drained into the pan, it the oil pump submerged?
 
Having never experienced this issue (or even worried about it until now), I'm wondering whether this is more of a problem with the four cylinder in a 100-4 than with a 100-6 or 3000. Any experiences or opinions?
 
Last edited:
This is a good thread. My engine hasn't run for several years now due to a seemingly never ending restoration. I had the oil pan off to get the dents taken out so it is 100% dry. I was considering taking the plugs out and spinning it over to build pressure first, now I definitely will. Thanks for all the info and taking the time Michael.

I don't want to start a firestorm but will just mention this since the brand of oil filter was mentioned. Most all my friends use K&N oil filters on their (Hinckley) Triumph motorcycles. A couple years ago many had problems with them. The problems were not with the internals or anti-drainback valve but with the spot welded nut thing on the bottom. It would either just snap off at very low torque or leak oil because the welds burned through the shell. Take this for what it's worth, but those failures somewhat coincided with the time K&N moved the oil filter production overseas. IIRC, the automotive filters are now made in China or Korea and the motorcycle filters in Taiwan.
 
fyi I experienced the same effect the first time I changed the oil and filter after converting to a spin on filter. I quickly stopped the engine and removed the filter. It was completely empty. Managed to get the engine pumping after priming it by squirting oil back from the adaptor to the pump. Never had a problem like this with the old original cartridge type filter.

The first time I installed the spin on adapter it came up to pressure just fine. Not sure why it acted up when I changed the oil the next time. It has been OK since.
 
To Walt's post about K&N's: I use them on all of my cars and since I almost always change filters and oil on my race cars after each event I go through a lot of filters (and oil) during the course of a season. I have never had a problem with them and cannot speak to the welded nut breaking off as I generally use an oil filter wrench--the kind that goes around the body of the filter--rather than a 1" socket to install and remove them.

I once purchased a Royal Purple oil filter and because I cut open all used filters and examine the media for any particles, bearing material, etc. I can tell you that the RP filter material is a definite step up at least in terms of toughness--it seemed like fiberglass reinforced mesh and it was difficult to get through it even with a fresh razor knife.

As to my initial problem with the engine's not producing oil pressure I believe this was not due to any problem in the filter but rather to resistance created by the anti-drainback material which prevented the oil pump from drawing oil up from the sump. Though this was a first it was nevertheless a lesson and it would not be difficult to spin the engine over till oil is produced at the filter base before mounting the filter or fully tightening it.
 
Last edited:
Back
Top