oil pressure

[droy]

I just installed a new rocker arm assembly. Previous to that, my pressure was below 20lbs at idle, and the oil geysered from the rocker arms. After installing the new one...actually re-built by Rocker Arm Specialists...very well done and came recommended. The oil is no longer geysering and the pressure held at 22lbs at idle...for a while. It has now dipped below 20...15-18lbs. What else could be causing the pressure drop?

Could it be the oil pump? Any ideas or suggestions would be welcome.

Don

 

[Blonde Healey Girl]

What weight oil are you running? Also, what type of filter do you have? (Original cartridge insert or have you converted to a spin on type)
I'm having similiar symtoms on my BT-7 except I don't have geysers and have not rebuilt my rocker assembly. Recently installed a spin on filter which helped a little, then went to 20W50 which helped a little more!! Will read this post with great interest, as I'm sure this is an easy one for the Healey Masters.....Mr. Goodwrench? Ha.... he has not a clue about LBC's

 

[Dave Russell]

Don,

I debated whether to confuse the issue by bringing in another thread, it's not directly related to your problem but maybe it will help you to understand the oil pressure issue.
https://www.britishcarforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=5&t=000448

Back to your problem: First are you sure that your gage is reasonably accurate? The only way to be sure is to temporarily attach a known good gage at the engine connection in place of the present gage.

I don't know your engine condition, miles run, compression test results etc.

Twenty psi idle is pretty low but within reason for a worn engine. Thirty would be better. If it comes up to 40 or more at 3000 rpm things are not too bad & the engine will probably last quite a while.

As mentioned in the ref. thread, there are a dozen places in the engine where the clearances could be greater than desired. Worn bearings, worn oil pump will all contribute to reduced oil pressure.

A good 20-50 oil may help but a general rebuild might be in order if the low pressure really bothers you.

I think that I would just let it go for a while & see how the engine does in the future.
D

 

[Randy Forbes]

Ten PSI per thousand RPM is adequate (15/1500, 60/6000).
Unless you just feel like rebuiling your engine.

 

[John Loftus]

Hi Don,

15lbs @ idle is considered low ... time to rebuild. (as Dave said, check the gauge first ... use a test gauge)

What is your oil pressure reading at 3000 rpm?

-John

 

[Healey 100]

I've driven my 100 for years with an idle oil pressure around 10 psi or even less when really hot. At higher RPM speed on a very hot day, she sits around 25 to 30 psi. I use 20-50 weight oil, that does keep the pressure up a few psi when hot.

You've really gotten the low hanging fruit by rebuilding the rocker shaft. The next step (oil pump and bearings) is quite a bit more work and I would not do it unless the engine had other symptoms indicating that a complete engine rebuild is needed. Such symptoms include high oil consumption, low compression, bearing knocks, etc. The oil pump isn't too hard to replace, but personally I have never seen much wear in an oil pump and I seriously doubt if it is the source of your low pressur

Bill

 

[Gary Pope]

I installed a spin on adapter and my oil pressure is very low on idle about 12psi. It used to idle ate 55psi with the old type filter.
Seams like the filter is absorbing all the pressure.

 

[Dave Russell]

Gary,

A correctly installed spin on filter should not have any affect on oil pressure. Something is wrong. I don't think that I would run it until the problem is corrected. It sounds like something is obstructing the oil flow.

Possibilities are;

The adapter is wrong for your engine (holes in the wrong place) or adapter installed upside down.

The gasket between adapter & engine has the wrong holes or is installed wrong.

The filter itself is the wrong type.
D

 

[Dave Russell]

Hi Gary,

Pretty strange situation. Other than the filter can for some reason, I can't think of anything related to the filter.

Your car does have a oil pressure relief valve, doesn't it? Maybe a coincidence that some dirt or whatever has gotton caught under the valve plunger & is holding the relief valve open. Or the plunger is hanging up in it's bore & not fully seating. Just a guess on what to check. I am very curious to know what you find. I guess that putting the original filter back on might shed some light on this.
D

[ 03-31-2003: Message edited by: Dave Russell ]</p>

 

[droy]

I did install a spin on filter adapter. It didn't really affect the pressure from the original. At 3000 rpm it runs steady at over 40lbs pressure. I will try the 20w50 oil. I have been running 10w40. It doesn't burn too much oil but I will watch it and keep a record. how much is too much? I'm not sure about the mileage. The odometer has frozen at 64,000. The guy I bought it from who had it for 12 years did not drive it much. (thats a whole nother story). He estimates there is 80k on the engine. The rod bearings were replaced in 2001.

 

[Dave Russell]

Hi Don,

If you click on the "pencil & paper" icon in your message header, it will take you to a message edit panel. In the header of the "edit" panel there is a "delete post?" check box which will remove the extra post.
D

 

[droy]

Thanks for all your help Dave.

Don

 

[droy]

Blonde Healey Girl,
Thanks for the suggestion. I changed the oil, went to 20w50 and pressure is steady now at 22lbs at idle. I'm driving her to work tomorrow to celebrate...woo-hoo.

Don

 

[Gary Pope]

Hi Dave,

The only way to get a spin on adapter installed on a TR6 is to have it angled at a seven o clock position otherwise the filter impedes on the clutch slave. So the filter doesn't sit exactly verticle.

The gasket is an o-ring in the center and a large o-ring on the outer rim. The kit did come with 2 different thickness o-rings for the center, I just used the first one the thicker of the two.

I have ordered an oil filter from Moss just incase the Fram I have on is a problem. Other than that there isn't a lot to it.

 

[ThomP]

If the bearings have been replaced and the rocker shaft is OK, I'd say the oil pump is the next "low hanging" item.

I rebuilt my engine in 1998 and, at the time, I checked the oil pump. It looked OK, not like new, but within tolerances. Once the engine was back together, I was concerned that my oil pressure dipped below 20 PSI at idle (no way to treat a brand new engine). I bought and installed the new oil pump and the pressure is over 28 PSI at idle, even after long runs down the highway. I use 20w50 oil and have a spin on filter and adaptor.