Hello,

I am new to the forum site, but have been reading some of your posts and must say very informative information coming from some of you experineced Olds, owners. I have a bit of a big problem and are hoping you guys can provide some light in to ny situation.


Ok I recently over the last 3 years restored a 71 CS, 455cui, car.
Over this last summer I just threw the motor in the car and recently had it running, about a month ago.

I have a couple of different situations and will do the best to explain them.

This 455, is stock as a rock, just so everyone knows. w/ 5pt oil pan.

When she first fired over, we did the engine tests and timed the motor correctly, unfortunatley she almost over heated according to my raly pack gauge, so we had to start the car 2-3 times to get the engine tests right.
She only ran for 20 mins and most, then we dumped that oil, as it was the first time this rebuilt motor had run. Had 5w-30 with a ZDDP additive from Yearone, in it. As far as we know it had good oil pressure according to the gauge.

Now a week or two later, we fired it up again and finnaly got the radiator to keep the motor cool, we also replaced the thermostat with a 160, vs 190, to give us better reading on the guage and keep the motor cooler.
Again as far as we know the car had oil pressure. 5w-30

For its first drive out according to our guages we had oil pressure not sure if we drove it long enought to test it but did some driving in it. 25 miles...
At this point we started to notice that the oil pressure was realy low, on an idle, rev it up and she came back to normal., no knocking or banging noise from the motor, infact all my car buddies said she sounded healthy.

So I replaced the oils sending unit from a 80 psi to 60 psi, when she fired up now on 10w-30, she had about over 3/4 oil pressure, but when she warmed up the guge would bounce with the motro revolutions, from L, to the 1/4 mark. We then looked at the wiring and found faulty wiring, and replaced it once replaced we got the gauge once warm, only to read L, when it was idle, and only about 1/4 a litte over that but not 1/2, oil pressure when she was running down the road, again, did not sound bad, at all, Now running 20w-50 VR1 oil.

So all of a sudden we started hearing a knocking noise after she warms up, and we determine its the 39 yr old powersteering pump, and its got a knocking like no tomorrow, a mechanic other than my self checks the bottom and top of motor and claims to hear no knoking, except the pump.
At this time we repalce all stupid guages with a direct reading guage, and found at cold she is 38psi, and when warm and in gear, 0, and in idle 0, but when reved up she wahs about 20psi. 20w-50 VR1, oil.

So let the test begin, if you take off the oilsending unti rig a hose start the motor oil poors like a mad man from the oil sending port back into the oil fill tube, rev up, oil gets stronger, but is solid, so we have flowage, but still no oil pressure. Took off the distributor and me and another guy, beilive it has absolutly no oil pressure and we are hosed.

Block History, the block I am using was professionally rebored, and rebuilt, however the block was orginally blown up and damaged, it was not a runing car when i got it, but the machinist said it was fixable.

Please anyone have any ideas out there what could be my issue? Why do I have flowage, yet no oil prssure? tried everything I and another mechanic can thing of, need serious help. The block can be stripped and taken out, but really was hoping not to do that. Any Ideas what I am in for, or what maybe causing this?

I know I am new and asking alot, but I would really appreciate anyones time and consideration in helping me with a possible solution.
Need more information please let me know.
Thanks You
Jason

 

Welcome aboard

I gonna let the engine Guru's chime in. It just took me 5 months to get my hood off.

 

Take off the valve cover why its turned off if the rockers are wet then your getting oil to the top which means you have pressure. Need to make sure bearing clearance was checked if you have to much clearance it will cause you not to have oil pressure at low idle. Oil pressure should be 60-40 cold, 40-30 warm, 15-25 when in gear at idle when warm.

 

I took off both valve covers, and yes I am getting oil to the top of the push rods, and in the valve covers. I have oil flowing I have proven that, what I dont get is why I dont have pressure??

I think I may have either too much clearance somewhere, or a crack in my oil galley, internally and leaking somehow back in to the oil pan, becuase I have a full oil reading on the dipstick.

And I have good oil pressure 40psi, when it is cold, its when its warm I have 0 in gear, and 0 in idle, but about 20 psi when reved up or moving at about 60mph. Yet I dont here knocking coming from the motor, or at least I dont think, and is sounds good. Shouldn't something more be off, tellign me I have an oil pressure problem?

And is fixing it, pulling the block? checking for cracks, and or clearance issues?

 

Welcome to the site.

 

I moved this thread to the big block forum You'll get more response there to your problem. I'll check back in later today

 

Citcapp, thanks for helping with the thread

1ATony, thanks

 

removed engine, dropped oil pan, found big chips in the pan, removed oil pump, looks like a rock crusher, still looking for smoking gun.

 

yikes.

 

You have serious issues. Did you have the motor rebuilt by a machine shop? If so have you talked to them? Give us some background on the engines history.

 

Yes the block was professionally rebuit by a machine shop.
Apparently, a piece of metal went throught the oil pump, and tore is up, and then went into the cam, and tore up the bearings, that is why my oil is silvery color.

Not sure what, or where the piece came from, but how did it get past the oil screen?
The Piece looks bigger than the oil screen will allow. Any ideas?

The oil pumps has lots of wear marks and nics in the gears. so that is why I dont have oil pressure. Becuase the oil had a metallic look, I am going to have to strip it to the bare block, and fluch the whole motor plus, the rods, and new bearings all around.

Not Fun.

Any ideas how this could of happened?

The Engine was originnaly blown, but when I got the block becuase it was original, so I had it professionally looked at and restored to working condition. Its a shame becuase I hope there is no other damage to the motor given the metallic oil and the pieces of metal that went throught the cam, and bearings.

 

LOL!! You can make him a list of parts, though!! Very helpful!!


Yeah, what he said!!! That's terrible! Welcome to the site by the way!

 

Did you weld the pick up tube to the oil pump?

I always take apart new oil pumps to see if there is any debris before I use them.

There could have been a piece of metal in there.

If you ran the car with very low oil pressure, then there is a good chance that the bearings are worn out. The extra clearance will cause the oil pressure to be low.

Other reasons for low oil pressure: Pick up tube not seated on the pump, oil galley plugs left out, excess bearing clearances.

I had a Milodon oil pump pick up fall off the tube due to faulty welding. 45 seconds on low oil pressure wiped out my cam, lifters, and bearings. Cost me $4,000 to repair.

 

almost sounds like there was a chunk of metal in the pump to start with, or if the block wasn't seriously cleaned there could have been metal in the oil galleries since the engine was blown.... the silvery stuff sounds like bearing particles maybe the clearance on the bearings was too tight to begin with, olds bb motors have huge main bearings. a minimum of three thou. on the first four mains and around four thou. on the rear bearing is a must. like everybody said make sure the pump pickup is fully welded on. I always blue print my oil pumps. my motor right now runs about 75 psi cold start with 10/30 and a hot idle of around 55 psi. I want all that pressure 'cause i'm spinning the motor a little more than most and want those huge mains to get the oil..

 

I would take it back to the machine shop since it sounds like it's there fault. I had a friend that had Fisher machine shop rebuild his engine it was bad after a month of driving. The trust bearing was bad he had to take them to court to make them fix it. My brother-in-law had them turn a 350 olds crank 25 years ago it couldn't even turn the crank in the engine had to take it out and have turn it again. I just saying because it's a professional machine shop doesn't mean they know what there doing. I would have them fix mainly since you know that its not your fault. You haven't even had a chance to enjoy it.

 

I agree, take it back to the machine shop. They will question why you kept driving it when it had no pressure. Think about how to present you case, you don't want to sink your own ship at the get go. Keep you cool, a honest machine shop will step up to the plate to resolve the problem. Good luck

 

get a nice engine and rebuild that one ...

 

Well guys, it looks like my tiny piece of metal destroyed everything but the cam. The main bearings are shot, the crank will have to be turned again, new piston bearings, maybe rods, and new oil pump\screen. Just about the whole motor. Question for you guys???

My cranks was waering almost 10 thousands more on one side of main cap 3, than the other? What does this suggest? Was it not machined properly the first time, or did somethin shift? The crank was already trune 10 thouands, and will have to be turned another 20-30, becuase the bearings are shot and the crank need to cleaned up as well.

Other than the fact we do have small metal shavings and metallic oil thanks to our shiny copper bearings , Nothing tells us wear it may have come from? Although we did notice on cylinder 3, that there is damage to the very top of the cylinder, and the piston is scratched to no end, it was the worst one. Is it possible that that piece of the block\cylinger wall broke off and caused this whole mess?

Appreciate all the help, How can I prevent this from happening again, do any of you reccommned going with a different machine shop, or telling him he origainally messed up to begine with?

My crank is already turned 10, over, do you reccommend going ot 30-40- or 50, for main bearings, or is it just better to get a new crank?

Please help, as I do not want to go throught this again, its no fun, especially when time and money are down the drain.

Thanks for the oil tip, I will tack weldthe screen in place, and the pick up tube as well? is that right?

 

Your failure could have been caused by some trash left in the block after final cleaning. I've seen a new build ruined from a few glass beads...sounds like you might need another crank core.
Any chance we could see some pics, especially of the #3 piston, and rod and main bearings??

 

Yeah it deffinitley was debris from something, either its from the cylinder in the block that is chipped, #3, at the top, which I find odd, or its becuase metal chips from the oil pump that I found inside it, and tore up the gears, could have chipped that one cylider #3. Its a deffinite mystery, but I would like to figure out at least how it happend.

Yes, I can upload some pictures and well as maybe a video so you guys can see what I am taking about.

Appreciate all the help and feed back, it really sucks sitting in the situation I am in. I tore the block apart, and after seeing the distruction, I just kind of sat there lifeless, becuase to us, its just devistation, a horrible site to see such site, most people dont get it, but we do...

 

is this a stick car or an automatic? the bearing wear on the thrust sounds like the tranny torque converter/clutch was in wrong almost. how do the rings on the piston look? are the cast pistons? usually if the rings butt it'll pop the top of the piston, but ya never know... did something possibly get down the intake while you were working on the motor? it kind of sounds like you sucked something in there.

 

Sorry have not had time to get pictures up here yet, but I will answer your last questions. The car is an automatic TH400, we are a bit concerned over the torque converter. The piston rings some are ok others are not. Yes they are cast.
Not sure as of now, but we were very careful not to get anything down the intake, kept it blocked off at all times. So.

I will post pictures soon to let you all see the damage.