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no oil pressure


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I was heading to work in the morning and I started hearing some noise from

the engine. I looked at the oil pressure gauge and it read 0. :shock:

 

I took the next exit off the freeway and pulled into a shopping center. My wife

came to get me and I left the car in the parking lot. After work, I went back

with my trailer and towed the car home. Here's what I found when I pulled

the oil pan...

 

oil_pump.jpg

 

I'm going to put on a new oil pump and pick-up and hope for the best.

Ah, the joys of driving a HybridZ. :D

 

:cheers:

Don

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Don,

It doesn't sound good if the engine was making noise before you discovered the pressure loss. Of course you can hope that the noise was only the result of the OP pickup rattling around the oil pan. Was there sufficient clearance between the pick-up and the bottom of the OP? Did something hit the OP that could cause the pick-up to separate from the pump? Hope the pump is the extent of your damage.

Hanns

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What the heck's going on?

 

I recently pulled my oil pan to fix a small leak where the oil pan and timing cover seal together, and found this in the pan:

pic%20014S.jpg

 

The screen had obviously cracked and then vibrated around a good bit, since some of the edges were worn shiny and smooth. I cut open the oil filter and found some metal shavings there. Further disassembly found scarred mains and light scars on the crank. The crank polished out OK and I just finished freshening the short block. I replaced the Melling pickup shown with a Milodon one that looks exactly like dmanzo57's. It bolts to the pump cover and I thought that would solve the problem. Now I'm wondering.

 

dmanzo, even with the screen broken off, the pump should pick up oil fine thru the tube, if it wasn't low on oil. If you lost oil pressure I bet you're motor's hurt. I was extremely lucky to find mine before the shavings did any more damage. Cut your oil filter open and see what's there.

 

But, what's causing this? My motor's balanced and runs smoothly, other than the normal idle roughness associated with a 242/248 @ 50 solid roller. The oil pickup was 3/16 of the bottom of the pan when the motor was freshened last time, about a year ago. There is no evidence of the oil pan hitting anything and damaging the pickup. I though it was the cheap pickup until I saw this, now I'm wondering if there are other problems I need to address.

 

John

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oil_pump.jpg

pic%20014S.jpg

 

 

 

the damage was caused by vibration, heres a pump brace. but not a pickup brace, this helps limit the pickup vibration,

 

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1735&prmenbr=361

 

you should also weld a sheet metal brace to the pump pickup that bolts to the lower pump housing made from 1/16"-1/8" sheet metal

this will tend to prevent those pickups from breaking loose, dont forget that brazing the pickup to the pump housing helps also, just be sure that the pickup is mounted 1/2" of the oil pan floor when the pans installed before brazing or welding it to its final position, another thing comonly done is to weld a 1/2" thick NUT to the bottom of the oil pump pickup that maintains the pickup to oil pan floor distance clearance

something similar but stronger than this, many high quality pickups come with braces ALL oil pump PICKUPS should have them

 

18311.gif

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My pickup originaly had a brace, but it wouldn't line up with any of the bolts

on the oil pump, so I cut it off. :oops:

 

I pulled the rear main cap and the bearing looked OK. I'll pull a rod cap and

check a rod bearing before deciding what to do.

 

Thanks, guys.

 

:cheers:

Don

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I normally braze a 1/8" thick and 1" wide steel strap from the pickup to the pump body, with a twin set of holes matching two holes in the pump body,and I braze the pickup to the pump body and carefully braze the pickup tube to the screened pickup.

I also tend to favor the 5 bolt big block style pumps, with thier twin 12 tooth gears rather than the twin 7 tooth gears sbc standard pumps that are not nearly as smooth running use, WHEN THE APPLICATION ALLOWS,(some oil pans just dont have the space)

I have seen dozens of similar pickup failures, or pickups that showed signs they were vibrating or coming loose, over the last 35 years or so ,but Ive never had one YET!

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I got under the car with a drop light and found that the two rear most rod

bearings are toast. The rod caps and crank journal are black with burned oil. :(

The bearings didn't spin, so maybe the crank and rods can be saved.

 

I see this as an opportunity to put in a hyd. roller cam and a 2800 RPM stall. :D

 

:cheers:

Don

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Don: Sorry for the bad news. Hopefully the damage isn't too extreme, and it's great you can have a positive attitude about it.

 

I was just plain lucky. The last time I drove my car was at a 2 day track event at CMP. Probably 3 1/2 hrs WOT running, hitting the 6800 chip 4 times a lap. Excellent opportunity for a catastropic failure. I'm really glad I decided to fix the oil leak and found the damage. I usually cut my filter open when I change oil, but not always. There was enough metal in the filter to indicate a problem.

 

This is what the mains looked like:

picS.jpg

 

They look a little worse than the pic shows, due to my crappy photo skills. The oil pump and cam bearings were also shot, but the rod bearings still looked great, apparently none of the metal made it that far. Oil was Mobil One 15-50.

 

This is what I went back with:

pic%20011S.jpg

 

A Milodon 18307. You can see the brace, and it's spot welded to the pump cover, but you can't see the weld in the pic. I'm debating tearing it back down and adding the brace Grumpy suggests. That pickup is a work of art, some beautiful tig work there.

 

John

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John,

 

It sounds like your persistence in fixing that oil leak really paid off. That

new pickup doesn't look like it's going anywhere.

 

Mine was a bit more than one quart low on oil when it started making noise.

I've got the engine out of the car and on a stand.

 

:cheers:

Don

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Guest E.Murray

I probably shouldn't introduce myself to the forum with a story of how dumb I am...oh well. I just bought my 260Z with a 350/TH350 last week in Nashville (about 300 miles from home) and drove it home. My oil pressure started out about 50 psi...then 40... then 35... then 25... then about 18. I finally gave up about 70 miles out and called for reinforcements. When we finally got in at 2 the next morning, I was feeling pretty miserable about my new toy. The next day, I pulled the pan to make sure it wasn't just a gummed up screen or loose pickup tube or something. Guess how much oil came out when I drained it... 1 1/2 quarts INCLUDING the filter. Funny part is that I had just checked the level about 100 times on the way home and it read full. Know what that means? Wrong stupid dipstick. The dipstick I bought it from neglected to mention this piece of information. SO, I ran at 3500 RPM for hours on end with virtually no oil. Nice. Once I put in the right amount of oil, it has been fine (although I doubt I did it any favors). I'm feeling MUCH better now, although it's in serious need of ball joints or wheel bearings (I'm tearing it down tonight). Really looking forward to learning a lot from this forum and having a blast with the new Z. Thanks much.

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