The Stovebolt Site Forums The Shop Area Engine Shop Lost oil pressure!! ARRGGGH!!

By now the regulars here are familiar with my '54 Chevy. I fixed the heater this weekend, so I figured I'd drive it to the superbowl party last night.
Well, I drive the 10 miles to my buddy Gary's house to pick him up. Watch the gauges the whole way, everything's fine. Right when I turn the key off I noticed that the oil pressure gauge was already on "zero". Naww, I thought, Im hallucinating.
Gary comes out, I start the car. Oil pressure comes back up to 35 PSI. So we hit the interstate and go north on 55 about 15 miles. Gauges are fine, car runs great. I take the exit, and as I come to a stop at the end of the off-ramp, the oil pressure zeros out again. So I immediately shut her down, wait a minute and crank her back up. No oil pressure. So I quickly limp off the road and coast into parking lot & shut down. Check oil, check for leaks, check for loose parts or lines, everything looks good. We wait a few minutes & try again. Car runs for about 8 seconds and doesn't build pressure, so I shut her down. Gauge in dash and backup gauge under hood both say "zero". Motor is making no wierd noises, starts right up and runs smooth, but no oil pressure.

What the hell is this? I think either the distributor shaft sheared (mini HEI), or the new Melling oil pump failed. This motor has 125 miles on a complete rebuild.

Is this engine ruined? I'm soooo not happy. :o

Chip. I realize that you know much more then I do about these things but I got lucky one time with a similar problem ,had a loose wire on the sending unit not staying tight, just a thought,,,,Fred

Well chipster, man, what a bummer! Any chance the pickup tube came loose or came off the pump? Lose all your oil somewhere? Mabey it is time to dump it? Put it on ebay for $500 no-reserve. It'll be gone in no time and you can buy that used Honda civic you have always wanted. :p (never hurts to keep your sense of humor)

Are both guages mechanical?
-
I would be all for pulling the distributor and attaching a drill to drive the oil pump.

Yup, both gauges mechanical. Oil pump pickup was screwed into pump w/loctite & height from pan floor was checked. Full of Castrol 30 wt oil, still clean. No oil filter. Ran car easy, between 2,500 & 3,000 RPM always. We towed car to friend's house where I can check it out tonight.

I read one footnote in shop manual about overtightening oil pump can cause distributor shaft to shear. But I was careful installing the oil pump, & HEI was working fine in my old motor.

If this motor is shot, I'll have to sell the car, cuz Im just not building this motor again.

chip :mad:

Well I am hoping that you find out it is something simple. I would pull the valve cover, Then pull the dist and run a drill in the pump. If the pump is working you will get oil to the rockers then check gauge. If you get oil to the rockers and no pressure at the gauge then I would disconect the oil tube line to the gauge(disconect at the gauge). Place the (now open) end into a clear jar and fire up the drill. You should get a steady stream of oil. I suspect that you have a blockage and no oil is getting to the gauge. If you have no flow or only a trickle replace the oil line and then fire up the drill, check gauge hopefully you will now have preasure and all will be well. Man I hope I am right! Sending you all the good vibes I can!

Consider this an omen. Swap out that junk engine and put in a new big block. Time for that ol Chevy to fly.

I just spent 3,500 on this junk engine! The only way I can afford to make this car fly is as little chunks of metal out of the shredder. :mad: But keep the ideas comin', maybe its something simple.

chip

When my high mileage engine gets warm and I get off the freeway I am lucky to get 15psi at idle while normally it is always over 30psi. I figure the looseness in the bearings etc are causing this low pressure. Your problem might be similar and go away once the engine get properly broken in and the tolerances are a little tighter.

Chip,
I don't think that there is any way that the engine is ruined. Obviously there is soemthing wrong but your choice in shutting her down was an excellent one. The drill in the oil pump idea sounds like a good place to start.

Tony M
clearances do not get tighter after breakin. If anything, they get larger.

Well I doubt if you hurt the engine, because they can take a bit of abuse. but, you do appear to be on the correct track on the no oil pressure. I would just check every dang thing related to oil pressure. It is something simple I am certain.

hmmm

Hey Ken,

Did you ever live in Tacoma? I'm starting to wonder if I know you.

Couple of questions:

How long can a 235 run under no or light load with no oil pressure before damage? I had to drive it about 200 feet in 1st to get it out of traffic.

If the oil pump or distributor shaft broke, should I worry about metal shavings in my oiling passages? How much bearing damage could occur from a fragged oil pump?

I read somewhere several months ago about Melling oil pumps failing in V8s. What are my warranty options if the pump called it a day? I bought all the internal parts from Patrick's, the HEI from Stovebolt engine Co.

thanks guys... You know how much work I put into this car.

chip

Good morning Chip,

I'm with Oly. I don't think you ruined your engine. You saw the oil pressure at zero, but after that you again had 35 pounds. I don't think you would get that result if either the distributor shaft sheared (mini HEI), or the new Melling oil pump failed.

.02

P.S. How do you spend $3500.00 dollars on that engine? Is that a normal amount for that engine, or did you do a lot of fancy things to it?
Good luck with it. Keep us posted.

JYF- Yup, all new parts & 4bbl clifford intake, holley 390 4bbl, fenton duals, HEI, electric fan, short shaft water pump, alternator & bracket, smittys, new clutch, ring gear, starter rebuild, etc. I was careful and thorough while selecting parts and building the engine, so this is very frustrating and leading to much self-doubt.

Just had another thought- Would an improperly installed oil galley plug cause this? Could it blow out and vent the oil pressure inside the motor?

chip

chip, wouldn't the engine be somewhat noisy if you actual lost oil pressure. I lost an oil pump in a dodge truck and I heard it real quick''good luck ...Fred

May be of no use to anyone, but I lost oil pressure one day when I was warming up the juggernaut, shut it down, popped the hood. Oil everywhere! The copper tube for the oil pressure gauge broke (I guess I had accidentally crimped it) and I sprayed 2.5 quarts of oil out a small hole under 50-60 lbs. pressure. Quite a mess.

No ill effects on the engine. I suspect you caught the problem before any damage was done, but I like the idea of spinning the oil pump to see if the right areas get wet.

The lesson here, I guess, is watch your gauges, they're there for a reason. :p

Aw Chip, not again. An engine under light load can run quite a while with no oil pressure.I would bet on the HEI shaft is too short or you didn't have the distributer all the way down before tightning the pinch bolt Or the previously suggested overtightning of the oil pump pointy retaining bolt, that may certainly cause a pump shaft siezure.BUT...the distrubuter drive gear pin would shear ,shutting down the ignition.The oil pick is screwed in so its unlikely that's the problem unless it's cracked severely.The oil galley plugs are on the outside of the block,loss of them would produce an Exon Valdez class oil spill.Good luck, hope its just a easy to fix problem.

I do have to agree with Tony. Low revs, light load and oil will stay in the bearings for quite a while, possibly up to an hour. Pull the buzzer box, spin the pump and go from there. You might end up dropping the pan to check the plumbing, but that's not that bad. You're beating yourself up too much before you know the facts. Time to sip a cold one and puff on a ceegar.

Chiphead,

I agree with truckernix. I would try the drill driving the oil pump (ask for clarification, if you want instructions) and I would take off the valve cover. Drill-drive the oil pump and check the oil gauge and check for oil coming out of the rocker shaft/arms. This will give you a better idea of what works and what does not work (and where/what to check next).

Good luck,

Tim

I too doubt any damage. I lost pressure probably 1/2 dozen times before I figured out my problem. It only lasted a few seconds each time. My problem was no baffle in the oil pan. Changed pans no further problem. Mine gave noticable clanging as the pistons flopped around. No noticeable damage on mine so yours should be fine. Just broken in a bit quicker than you might have planned. I think the cool brew is the right place to start on this one!

seems to me Chiphead that if you sheared the distributor shaft, the moment that happened you would have immediately lost power (and ignition). And you car certainly would not have restarted.

You can most definitely remove that one.

-ftyler

One step at a time.

If you have a strong battery, just pull the coil wire and the rocker cover and crank it and see if it's lubing the top end or if nothing is coming up. It will be fairly obvious if it's working or not. If yes, check the guage and see if you can find the source of the problem there.

Either way, I don't think you could have done much damage from lack of lubrication. Especially since nothing it rapping or slapping too bad. You're ok.

Cheer up. Things will get worse.

OK guys, thanks for the reassurance thus far. I went over to Tim's house last night to check the car out. I lined the motor up on #1 TDC & pulled the distributor. Distributor is fine, no signs of shearing or damage. I did see a few slivers of metal clinging to the oil pump drive tang.

Next I put a screwdriver down into the oil pump drive and turned it by hand. It felt kinda weird, a little rougher than usual. So I chucked up a screwdriver shank in my makita drill and drove the oil pump. Tim wasn't there, so nobody could watch the gauges, but I felt resistance in the pump as it started to pick up oil. I could see oil move up the plastic tube to the underhood gauge but I couldn't see the gauge face, so I don't know what the pressure was. But I don't think the gauges are blocked/plugged because the oil moved in the gauge line.

I put a drain pan under the car and drained the oil. It came out the color and thickness of Hershey's syrup- black and thick. Lots of fine silver and bronze colored glitter in the oil. No big pieces or metal ribbons, but I don't know if this is normal.

I pulled all the oil pan bolts and popped the pan loose from the gasket. It got cold before I could drop the pass side exhasust and drop the oil pan off.

Here is what I think happened- I bought the '55-'57 style oil pickup & pan used from Stovebolt engine co. Pickup was really dirty, and the tin piece at the bottom (pickup & screen assy) had a few *serious* dents and kinks in it. I cleaned and straightened it out as good as I could before I installed it. I think the pickup is faulty. I think its sucking air cuz it was beat & bent up and also interfering with the dipstick. I should have listened to my gut, pitched it and found another one.

I think the black oil is from sludge that was stuck in the block or in the pickup and broke loose, contaminating the oil. This motor was a non-detergent baby. When I bought and dissassembled it a few years ago, it had 1/2" of black goo coating its insides. Maybe there was a clod left hiding somewhere. The replacement pickup wasn't much better before I cleaned it.

I don't know what to think about the metal in the oil, but it can't be good.

I'm going to pull the rear main and change the neoprene seal for one of the asbestos NOS seals. Gotta find a 'chinese finger' rear main installer. Assuming the rear main isn't already wiped out. What other bearings should I look at?

Assuming the bearings are OK, I plan on replacing pump and pickup. Anybody got a '55-'57 235 oil pump pickup? I'll PAY for one in great shape.

What do y'all think so far? Engine ruined or not?

chip :o

I'm still betting/guessing/hoping for "not".

Good luck today.

Thanks JYF. If it doesn't rain tonight, I'll get the oilpan off & take a look. I'll borrow the digital camera from work, and post pics of pump, inside of pan and bearing shell(s) for discussion.

The reason I'm paranoid is the original 235 in the car was killed by bearing failure.

Chip,
metal filings in the oil is not normal. You will definitely have to find the source of that.It will probably be pretty obvious when you start to have a really closeup look. Good luck and we will all be waiting.

I thought I was seeing a bunch of metal filings once but when I checked with a magnet they were not metal. You spent so much on this rebuilt, surely the block was flushed? Do you think the black oil could be break in grease?

I pulled the oil pump and pickup last night. You guys are not gonna believe this one! The ONE thing I didn't check during assembly came back to bite me in the a$$.

The HEI distributor drive gear ate into the top of the oil pump. The bottom of the gear ground a perfect circle 1/8" down into the oil pump. Most of the metal in the oil was from the metal removed from the oil pump, and the distributor drive gear is pretty chewed too.

This HEI distributor worked fine in my '54 235. The oil pump in this '60 was mounted & located correctly by the pointy retaining bolt.

Somehow the gear interfered with the top of the oil pump. What dimension do I need to check to see if the distributor, pump, or block
dimension(s) are off?

Oil pan sump was full of clumps of finely shredded oil pump. Say that 3 times fast. :rolleyes:

Pulled the #2 main bearing. It shows some metal contamination, scoring and wiping of the babbit. Not down to the copper though. #2 journal was roughed up a little by all the metal. What other bearings should I check to determine the engine's condition?

Usually I have some good suggestions for others, but this has me at a loss. What happened here? Since the HEI worked in my other 235, I assumed it would be fine in this one.
ARRRRGGGGH. :mad:

chip

I don't know what to tell you about the distributor shaft, hopefully Luke or someone that knows will respond. I would recommend pulling the cam, lifters and crank to clean out the oil passages. A lot of work, but you can leave the engine in the car at least. Dang!

Chip we feel for you. This is a bad deal after all the trouble you have gone through. Don't despair, take a break and fix it.

FredT,
Assuming the worst: Pulling the crank out requires pulling the engine & tranny and complete disassembly of engine. Then it becomes ANOTHER rebuild. I am not going to do that, not so soon, no way . Not to mention that I'd have to tow the car home first.

I need a way to flush the crap out without further disassembly of car or component parts of engine. I can wipe the oil pan and crankcase out with old t-shirts soaked in paint thinner.

Can I remove the valvecover and pour a gallon or two of fresh, cheap oil over the valvetrain and let it run out of the crankcase and into a tub below the car? Then wipe out the crankcase, reassemble the engine and change the oil several times?

But the question remains: How did the distributor gear crash the oil pump in the first place?

thanks guys,

chiphead

Chip, on these engines. the cam rotation pulls the dist down.The distributer shaft must bottom out in pump before the gear grinds metal.The gear must also be located properly as far as the cam gear in concerned. This image is a stock 235 dist, the inch and 11/16 th measurement is reasonably accurate, use your stock one for an accurate comparison.Does your gear look just like this one?You have the mini HEI? which is actually an S10 2.8 modified unit.Carefully check the drive slot in the oil pump, it may be cut to deeply.If the bearings have imbedded debris, a complete disassembly is the only option, sure hope that's not the case,we are all pulling for ya..... Distributer shaft

Thanks Tony! This is a big clue! I noticed that the wear on the dist gear teeth is above the centerline of the gear. I had thought that the distributor body had "pushed" the gear into the pump body like a drill press. I was wondering how the gear ate into the oil pump, but there was no wear marks on the dist body right above the gear.

Are you saying that since the oil pump drive tang didn't bottom out in the pump, the distributor gear sat too low in relation to the cam gear? And then the screwed up gear geometry allowed the camshaft gear to push the distributor gear further into the oil pump body? The result was that the distributor gear ate into the pump body until the tang finally bottomed out?

This is something so crazy that would happen only to me.

Really Stupid Question Time- There is a little white plastic spacer that came with my FelPro gasket kit. Is it supposed to go on the distributor shaft to prevent this???

So I need a pump, a pickup, and a distributor gear.

I plan on cleaning the motor up as best as possible and trying to run it. It may survive. If the oil pressure goes south, I'll know the bearings are ruined.

I'll post pics of dist & pump later today. Think I can get any replacement parts under warranty?

thanks

chip

Wow, bummer,was planning on firing up my 235 this week end for the first time since rebuild, was going to pull the mini-HEI to prime the system any way, but think I'll also check the gear and dimensions. Always good info on the forum, sorry about your luck and I know how fast $$ can add up when you add goodies.
ZEKER6

OOOh, now I put on the reading glasses, the bottom of the distributer gear is worn,so the gear bears down on the the extended portion of the oil pump that pokes through the clamp with the pointy bolt.Check the drive end of the pump for improper machining.

I removed the fuel pump and side cover and lifters/pushrods and flushed the engine down with gallons of diesel after finding some metal around the head area from bent push rods.

You could flush the head first and then work your way down just in case anything made its way up to the head. Probably didnt. I also loosened the oil line under the side cover and blew all that out.

With the lifters and distributor and fuel pump out you will be able to flush the whole cam.

Then reassemble, fill up with oil and start the engine and run it for just a couple of minutes checking for oil pressure. Shut it down and change the oil and filter again. Run the oil through a strainer and look for metal.

I have done this on several engines and eventually the metal works its way out. Only do it if you really don't want to disassemble again. I bet the current bearing scratches are minor. The tolerances are so tight that only very small metal could make it in there. You shut down after a few minutes so shallow scratches would just wear back out.

Chip,
going by the book on the older 235/216, it is possible to lower the crankshaft by about 1/2" to 9/16". This is a procedure used to replace the main bearings. This also means removing the transmission and front cover.This would allow you to flush the block out usuing the oil pump and solvent.

Flushing: I would be flushing with solvent using a new oil pump while the motor is apart. The top can be flushed by pouring on the head. This will ultimately run through the side cover area so it should come off. You can also rotate the crankshaft and blow in compressed air into each main journal hole. The truth is though that to be sure, a complete disassembly is required. You probably would not have to buy a whole lot of new parts, just gaskets.

Talked to both Patrick & Tom L tonight. Both were very helpful and made a few good suggestions. Patrick wants me to ship him the pump and distributor so he can see for himself what happened. He maintains that there is no way for the gear to grind into the oil pump, so he wants to see the parts.

Tom L suggested plastigauging the mains and flushing the engine. He also suggested checking the cam bearings for damage. He doesn't see what would cause a sudden drop in oil pressure unless the pressure relief valve in the pump stuck open from shavings, or a main bearing just totally wiped out. He also suggested taking the motor apart and redoing it.

Looks like I'll have to get the car towed home. This is going to take awhile.

So for your viewing pleasure, here are a few pics of the pump and distributor.

www.PictureTrail.com/gid1640560

I am in hell :o :confused:

chip