Rebuild, now no oil pressure

[tazgn]

OK, once again I'm at my witts end!!! I just got done with a rebuild and started the car up yesterday. Well, I only had 10 psi of oil pressure at all RPM's. Then it would slowly go down. I could rev the car up to 3K RPM and get 40 psi of oil pressure but then it would rapidly drop off to 10 psi. Now I can get any pressure at all. With high RPM's I can get some oil out of the rockers, but none at idle. I've repacked the oil pump twice. I took the oil pan down and made sure the pickup was on tight (took it off, put new gaskets in and sealed it up). Still the same results. I even bypassed my remote oil filter and oil cooler. Nothing helps. I'm not getting any oil at the turbo either.

Tomorrow I'm going to take the timing cover off to make sure I somehow didn't block the oil passages. But has this happened to anyone else???? Anyone have ANY ideas???? To make matters worse, I think through all this I've wiped another bearing!!

Please, ANY suggestions????????

Thanks,
Derrick

 

[StageII86]

Oil pump spring in?

 

[Russ Merritt]

Didn't you prime it on the stand? I prime every engine on the stand before I even put it in. If I don't get 60+ PSI with the drill, I'd know somethings wrong. Was it assembled for you? I've seen a guy once tape/paint the front cover then install it with tape over the pick-up hole, hence no oil press. He was a big shot engine builder too so I guess it can happen to anyone. Gotta be somethin stupid. I gotta go plow snow, good luck!

 

[TurboDave]

Sounds more like a clearance problem, not a taped hole. He at least had some pressure at first (up to 40#).

I would have to ask specifically, what were the cam, mains and rod clearances when you started the assembly?

How confident were you of the block's internall cleanlyness.

 

[malibuick231]

Remote oil filter you may have a filter with a check valve.If so you may have your lines backwards.Seen this happen to a friend scared the crap out if him.

 

[Chuck Leeper]

LO PSI

I feel your pain!
I bought a "ported and clearanced" ft cover from some joker that claimed to be an "expert" on these engines.
The problem was the pump cover was "ported" so far off, that the pressure side from the remote oil filter bypassed right back into the inlet side. Cold, pressure was great! Drove it less than 3 miles and the engine got noisey, lifters rattled, engine was trashed.....We had to look VERY close at the gasket. The telltale sign was that in one place the gasket had no impression in it from the cover/body.

A $3000 rebuild, paid out of MY pocket, and a "I put the cover on my personal car, and it's run for 2 weeks" bull$hit reply from this clown, and I was back on the road!! No more pressure problems.

Another I've seen on a car brought to my shop was the ft cover was not drilled all the way thru on the passages. This was a "made in Hong kong" POS. This problem has been seen around the country, also.
Other ideas:
Plug came out of the cam galley, ft end.
Plug in too far, blocking the main oil passage.
Cam brgs spun and are on the way out.
Excessive end play on the pump gears..some psi [oil cold].. none hot.


There are enough possibilities to fill a book. If it were mine, it would come out and COMPLETELY apart. Being run w/o oil has likely killed the brgs, cam, etc.

BTW, the genius that did me for 3k is still around. PM me for details.....

 

[tazgn]

I do have the same front cover that I had before the rebuild. All I had the machine shop do was dip the block and install new cam bearings. They may very well have screwed up the cam bearing install. My clearances were all great, around .008 on the mains with .006 thrust clearance. Rods were all in spec as well. The crank was also ground 10/10 this rebuild. Is there a diagram somehwere showing how the oil flows? I thought the oil flowed from the pump up to the 1st cam bearing, but the oil pressure was sensed before it got there (the turbo feed line port). Is this right?

Also, I didn't specifically check to see if the plug in the cam galley was in. They may have removed it during the dip and never put it back in. That would really tick me off!!!

Derrick

 

[Russ Merritt]

.008 on the mains? Supposed to be .002. Good luck

 

[Chuck Leeper]

Originally posted by tazgn
I do have the same front cover that I had before the rebuild. All I had the machine shop do was dip the block and install new cam bearings. They may very well have screwed up the cam bearing install. My clearances were all great, around .008 on the mains with .006 thrust clearance. Rods were all in spec as well. The crank was also ground 10/10 this rebuild. Is there a diagram somehwere showing how the oil flows? I thought the oil flowed from the pump up to the 1st cam bearing, but the oil pressure was sensed before it got there (the turbo feed line port). Is this right?

Also, I didn't specifically check to see if the plug in the cam galley was in. They may have removed it during the dip and never put it back in. That would really tick me off!!!

Derrick

Don't you mean .0008?? .008 is eight thousandth's.. FAR too much for brg clearance!! AND .0008 is way too tite for a performance engine....

If you have a .010 crank, you did use .010 under brgs, right??
A std brg on that .010 journal could come close to your posted clearance of .008.. [Especially if you checked it w/ plastigage.]

If the shop tanked the block, and did it right, all the plugs were removed from the oil galleys, and the freeze plugs were knocked out too.

Like I said in my first post... Take the engine out and tear it down and find the problem....

 

[Russ Merritt]

Originally posted by TurboDave
Sounds more like a clearance problem, not a taped hole.

No $hit. I was givin him a for instance of it being somethin stupid. He said his clearance was .008 on the mains. If that's true, you were right.

 

[Raymond Bunch]

Man, you guys scare me with this particular topic. I don't think I will ever rebuild my own engine with out a lot of research

Tazgn , good luck and hope you get that bad boy running soon.

Ray

 

[Lee Thompson]

oil psi

Keep us informed.

 

[Russ Merritt]

Originally posted by Raymond Bunch
Man, you guys scare me with this particular topic. I don't think I will ever rebuild my own engine with out a lot of research

Don't let it scare you, it's really not bad. You need a good machine shop and research helps a bunch.

 

[tazgn]

My mistake. Not enough zero's. I had 3 mains at 10 thousands, and one that I called 8 thousands. I used plastigage, so it's kind of a judgement call less than 12 thousands.

But for an update, I pulled the front cover and found the discharge port between the cover and the block about 75% blocked with gasket sealant. I put a new gasket on without any sealant in that area, vaselined the oil pump. I then used a drill with a screwdriver on the end and primed the motor. I got 10psi with the drill bogging down and oil at the rockers. Then I started the car and had 60 psi for about a minute. Then it dropped to zero for about 10 sec. Then back to 60 psi for about 30 sec. Now it's back at 0. This thing is driving me crazy. I think I'm going to get a new lower oil pump plate to get that out of the picture. It does have some gouges in the gear surfaces on the plate. Oh, I also tried a different relief spring and made sure the relief valve moved freely.

I do have a week of leave coming up over the holidays, but I wanted to enjoy the car vice work on the car over that time. Besides, the wife and kids are getting a little impatient with it now too....

Derrick

 

[Razor]

I would never fire a motor that didnt pass the drill test on the oil pump... thats just me.

Too much at risk.

Good luck to..oil can sometimes leak from the most unsuspecting places.

I also am assumming the guage your using is a mechanical one with a nice non kinked line.

 

[hipsi2fly]

did you pack the oil pump w/ vasiline?

 

[Lee Thompson]

oil pressure

I would look for something in the front cover. Something moving around and blocking the oil flow. Lodging and unlodging. I still don/t understand bearing clearance numbers.

 

[gmgearhead]

you have way too much main brg. clearance..!!!
you need to have between .002-.003 at the most,really plastic guage is not a good way to measure.Most home builders this is the only way to do so.
I agree about priming the engine too,if it doesn't make oil pressure with a drill then DO NOT INSTALL,back up and find problem.

 

[tazgn]

I realize that. People were confusing me on where the thousands place was. My bearing clearances were in the .0015 range. Whatever that is in "normal" words terms..

I'm still trying to figure out how to fix this. I'm trying to get a new thrust plate for the oil pump still, since autoparts.com didn't send me what they advertised.... But hopefully NAPA has one here..

Derrick

 

[Six_Silver]

Originally posted by tazgn
I got 10psi with the drill bogging down and oil at the rockers. Then I started the car and had 60 psi for about a minute. Then it dropped to zero for about 10 sec. Then back to 60 psi for about 30 sec. Now it's back at 0.

What kind of oil pressure gauge are you using? Its not an electric gague is it? If you gauge is jumping around like that it almost sounds like an electrical gauge going wacky. Just a thought.