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1500 Oil Pressue Issues

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boxfullofyertoys

boxfullofyertoys

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Hey everyone...had to move the car to the new house a week ago and noticed that the oil pressure was really low after she warmed up...probably in the 5-10psi range at idle. I did some searching on the forum, but wanted to see if I'm missing anything from my "order of operations" list:

In order from easy to difficult:

- Oil/Filter change (it's probably due anyway)
- Check for blockages on pressure line to oil gauge
- Check/replace pressure relief valve
- Replace rod bearings
- Replace oil pump

Full disclosure: I haven't done any work/inspected the bottom end of the motor since I bought the car over 2 years ago, as she's been running pretty well and nothing until now has given me pause about it. I do already have a replacement pan gasket waiting to go on, so maybe this is a sign...

Is there anything else I should be looking at?

Thanks!
 
IIWM, I'd change rods,mains and thrust bearings. Check pump clerances and change if out of spec. Polish crank, put back together. Straigh 50w in summer w/ Lucas. This advice if all you are concerned about is getting it up and running and usable. If you have the time and $$$ and aren't worried about laying it up, go through it and fix it right. Mine was HORRIBLE and knocked for 7 years (10K) on a cold start up. .002 out of round still and 10K later and still going w/ bottom end frshened up. It all depends on your needs/wants/goals for the car. I have no idea what my pressure is at a hot idle and I don't want to know. I pulled the motor and was glad I did as there was lots of flak in the oil passages. Then again, if you pull the motor go ahead and go through it right. I would have but didn't want to lay the car up that long. I find it is important on the 1500 to build oil pressure BEFORE you light it off. If you d/c the choke it's easy.
 
That's a really tough call. My honest goal for the car is something I can enjoy. It doesn't have to be perfect, but I would like it look nice, function correctly, run well, and have a bit more punch than it did when it was stock (high compression pistons, and fuel injection at some point).

I'm now at the bodywork vs. motor debate as everything else is pretty much as done as it can be leading up to getting the body done. In a perfect world I'd yank the motor/trans and work on that while someone else is doing the body.

There's little point to pulling the motor just to slap a bandage on it and have to pull it again.

Taking it off the road is a rather depressing thought though, as I've had very little drive time and I'm really itching for more...
 
It would feel better if you had higher oil pressure at idle, but you are definitely in the bottom end of functional range where you are. Especially if your pressure is good when you are at cruise.
 
I would find a another/different gauge to verify your gauge before i did anything else..

m
 
I trust the gauge, as I replaced the old stock one with a dual water temp/oil pressure gauge about a year ago. What I don't fully trust is the plumbing going into it. I'll probably pick up a tester gauge, change the oil, and then start there. The oil pressure on the car was fine last summer (from what I can remember anyway), so I'm hoping the car just has a case of "It's being British".
 
Replacing the rod bearing will buy you some time, later you can built it properly, which could inlcude a crank grind, mosre than likely a cylinder boring and oversized pistons, and most definately would include resizing the big ends on the connecting rods. As Kelly mention it, a good time to rpalce the thrust bearin as well, you can check the main bearing, but they wear at much slower rate since they are at the begining of te oil pressure feed, it won't hurt peeking at a couple of them anyway. If you continus as is, you'll most likely have a bottom end failure, and be spending alot more money.
 
A total rebuild is definitely on the list. For now, due to time/budget constraints, I'll probably just do the rod and thrust bearings after a little investigation with the plumbing for the gauge to make sure I'm not making a mountain out of a molehill.

Thanks for the advice everyone, as always it's greatly appreciated!
 
Change rod bolts too. Check the center main, IIRC that one wears more. If you change the mains, do ONE at a time. Don't break them all loose at once. You'll have to roll the crank some and you need the other two to support the crank or else you may damage/crack your 30+ year old oil seals and it'll leak like a stuck pig. Never stuck a pig before but I hear they leak like an LBC with bad seals. :jester:
 
My old TR3 developed real low oil pressure one time. Long story short, the center main bearing had come loose. Tightened it down and all was well.
 
I hope this doesn't come off as dumb as it sounds, but I'm about to order a bunch of other stuff, and I figured I'd ask before I dropped more money on the bearings/thrust washers...

Is it better to plastigauge the bearings first, and then go to a larger size if the rod bearings are that far out of spec? Or will the stock sizes suffice?

I guess it might be a moot point anyway since I'm not sure if the bottom end of the engine has ever been rebuilt...judging from my experience with the top of the motor, I doubt it has been...

Better safe than sorry, or in the return line :p

Thanks again for all the help!
 
It won't be worn enough to put an oversize bearing in w/o machining it first. IIWM, I'd put back whatever size came out. Polish the crank first and make sure it's cleaned well afterwards.
 
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