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Rebuilt engine, now low oil pressure, advice?

Ninja007

New member
Joined
Mar 5, 2009
Location
Lynnwood WA
I recently rebuilt a B230FT for my Volvo 1990 760. The oil pressure light comes on at low RPM <2500, i've driven the car probably 100 miles since the rebuild. I am fairly sure the lights been on for the majority of those miles.

During the rebuild I installed a magnetic plug in the oil pan, which I just drained and found quite a lot of metal deposits stuck to the magnet.

The Engine was a donor out of a 93' 940, had ~100k and supposedly ran like a champ, then sat for a year before I got to it.

Rebuild included: Oil Squirters (thanks John V), complete clean of everything, light cylinder hone to remove glazing, new rings, New rod bearings, reused main bearings (still had shiny surface), new seals throughout. All rings were measured in cylinder according to green book and are within spec. Didn't measure crank or cylinders.

Heads got a light port with gasket matching, lapped valves. All shims measured and are within spec. Also Rebuilt turbo and AW71 transmission.

This was an ambitious project for me considering I've never rebuilt any of the above and it took about 6 months. The joy I got from starting it up for the first time and having everything work was an amazing feeling. I'm really worried the engine is eating itself. Looking for some advice, whats the next step?
 
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Most likely problem is o-rings on the oil pipe.
Build up the ring on the pipe with JB Weld to hold the o-ring in place or use a washer on the pipe.
 
I read this somewhere else too, its the o-ring on the oil pump pipe that dislodges frequently after a rebuild correct?
 
Don't know about the low oil pressure, but if the magnetic drain plug came from Groton, they have had issues with the chrome peeling off the magnet and freaking people (AMHIK) out that their motor is eating itself.
 
Dropped the oil pan today. Pretty sure oil pump O-rings are not to blame. Pictures:

Here's the leftover oil in the pan, there's a fair amount of metal in there. Not sure if thats a normal amount after a rebuild. I did get that Magnetic plug from FCP Groton and yes the chrome did come off.

4792479556_9069b24876_b.jpg


Here's the bottom end

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Close up of the bottom end

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I'm slightly worried there is oil leaking out around the pads for the oil squirters, not sure if there could be enough leaking out to cause low oil pressure though:

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I dont think the oil pump gaskets are to blame. The pump side is perfect, the block side does have a little kink in it, but it looks like it was still doing its job without impeding oil flow.

4792479984_be9551564b_b.jpg


I'm open to opinions, not sure where to go from here
 
I'd hazard a guess that it IS the transfer tube seals. A nick in it like that wouldn't impede flow....it would allow flow out of the seals. As in pressurized oil making its way past there.

As for the oil squirters.....are there copper washers on them? And they're tight?
 
All of the Squirters are tight, i'm pretty sure I put washers under them. I will pull one and double check tomorrow. The O-ring was very difficult to take a picture of, here's the best I could manage, it shows the other side.

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i cant say for sure, cause it MAY have been ok....but any kind of deformation on installation of those oil pump seals can cause them to allow pressurized oil past them.
and even if they ARENT deformed, they can push past the lump in the tube doing the same thing.


if i were to bet money, i'd say its the seal (o-ring) in question.
 
First off, that o-ring is screwed. No way that was holding pressure.

Hopefully repairing that will cure it, but that isn't a "normal" amount of metal in the pan, either. Did you wash down the cylinder with hot soapy water and scrub them with a plastic brush? It looks like the cylinders weren't cleaned well enough, if I had to guess.

I would pull a rod cap and just make sure the rod bearings aren't wiped. f they look ok then fix the o-ring and let er rip.

If they are wiped, i'd be worried about the mains as well and it's a can of worms...
 
metal flakes. but on first start on a fully rebuilt engine it is somewhat common to have some very small metalic flakes. everythings wearing in, thats why they advise changing oil alot during breakin. some say after the 1st 20 minutes, then 500 miles, then 1500, then 3000.
 
is there a dealer near you? the OEM seals are red...not sure, but both times i've re-done them, i used red seals....

dunno if it'll make a difference, but never know.
only unfortunate part is it takes a day to get things like that from their parts house.

and check into the jb-weld/washer reinforcement trick to keep them from pushing out ever.
 
Your not trippin out. The oil is mixed with some really tiny particles of metal. I think some of that is normal after taking the dingleberryball to the cylinder and putting new rings in. But since I've never done that before now, I dont really know for sure.

The picture didn't turn out great, most of the chunky stuff on the left is just your usual oil pan crud.
 
Good to know about the O-ring, I have a Volvo dealer a few miles from my house, I will go pick up the red O-rings tomorrow. I don't understand the JB weld mod to the transfer tube, Do you make the hump wider, or do you extend it up toward the block?

I will also pull a rod bearing tomorrow to see how they look and post a picture up.

As for cleaning, I toothbrushed the crank case until I could see the metal. The cylinders... I sprayed with the pressurized soap out of can and hosed them down. Then oiled them down with a rag, I may have also done a solvent wash before I oiled them. If I had to do it over I would have toothbrushed them too.
 
My low oil pressure was caused by a sticky relief spring. Totally different setup than a B230 pump, but it still contains a relief spring.

Yep, start with Volvo orange seals and see how it goes. Are those Volvo squirters? I heard they arent supposed to open until a higher oil pressure. Maybe those are sticky.
 
Most likely problem is o-rings on the oil pipe.
Build up the ring on the pipe with JB Weld to hold the o-ring in place or use a washer on the pipe.

I had this problem on my 780 and it was the oil delivery pipe to block seal that had split. I replaced it with a harder compound similarly sized toyota seal that seemed to stick in there much better. After replacing it oil pressure light stayed off.

It is kind of a bitch to replace, volvo recommends removing the motor but it is not necessary. It took me about an hour and a half on a 4 post with air tools. You can avoid removing the motor by removing the top bolts to both motor mounts and jacking up the powertrain by behind the bell housing. Then take all the oil pan bolts off, fish your hands in there, remove the pump, and then the pan can come out. You have to install the oil pump with the pan in place as well.
 
I'd hazard a guess that it IS the transfer tube seals. A nick in it like that wouldn't impede flow....it would allow flow out of the seals. As in pressurized oil making its way past there.

As for the oil squirters.....are there copper washers on them? And they're tight?

washers? yikes, no one told me about washers when i installed my oil squirters so im not using any...no oil pressure problems though...

and i used black o-rings for my oil pump, its what fcp provides...
 
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