no oil pressure after rebuild
 

I've tried searching for over an hour, but can't find any info/suggestions to this:

I've done a rebuild on my 1.6 AVO turbo, got everything back together, but tried cranking it over without plugs (as per Haynes manual), and there is ZERO oil pressure. I triple checked to make sure we put oil in, and it reads full. I had a running system before winter, so the pan was already tapped, so a knick in the pickup tube is not the culprit.

I suspected a bad oil pressure gauge, so I tried unhooking the oil feed line to the turbo to see if there was any flow, but there is nothing. Taking it a step further, I took the oil filter off and cranked it over, expecting some oil to at least dribble or squirt out -- but nothing. (I'm guessing the oil system flow doesn't have to be "closed", per se, to get pressure)

Is the next step to pull the engine and remove that pan to see what the pickup is doing? (or alternately, drop the subframe)

The battery was a little weak, so it wasn't cranking over at full speed. It was cranking at a fairly good rpm (IMHO)...could this be the problem?

The other possibility is a bad oil pump. I’m “assuming” it’s good, since it is brand new and OEM. I’ll be certainly pissed if this is the problem.

Any other suggestions??

It will be 0 psig until the system is primed. How long did you try turning it over?

Turbos only need a few drops of oil at idle. I say hand prime the turbo and start it up for a second. Either you'll see a rise or you won't. As long as you put a little oil in the turbo it should be fine, they barely spin or don't spin at all at idle.

shouldn't I at least get oil flowing/squirting out the oil filter nipple if it is removed though?

I tried cranking over without spark plugs on and off for probably 10 mins, maybe more. I'm scared of doing too much because I just rebuilt with Wiseco/Carillo/ARP bottom end and Supertech topend.

You must pre-lube the oil pump and I presume this step was skipped.
You can accomplish it now with a pre lube device. Ask someone that builds spec Miata engines...they'll know.
Sometimes you can pressurize the crankcase using compressed air through an oil fitting and force oil into the pump.

i just took a 21mm socket on a drill and turned to motor over for a few seconds till i got OP on my mechanical gauge.

I've packed the pump with petroleum jelly- but more recenlty used a preluber made from an old propane tank, plumbing valve, brass fittings and a tire valve. Pre lubers are cool. :bigtu:

What about those little aerosol prelubbers sold at autoparts stores?

never heard of "mini" prelubers - but that sounds like the thing to do. Just hook it up to the port on the oil pump- intake side (pictured). The only thing to resolve on the bp is the attachment. On the F the pump boss is already threaded.

Is it possible the sender for the oil pressure isn't hooked up? Have you tried playing around with the resistance on the sender to see if it's OK?

What about swapping in another oil pressure gauge?

Priming the system, sounds like a good solution though....

Dave,

if you are talking about the dashboard gauge, if the Oil pump was packed with prelube (i used assembly grease last time) it took me about 20 seconds of cranking over to see pressure, not sure how long if you dont pack the pump first

agreed- on a fresh rebuild it DOES take some serious cranking to get pressure IF the pump is primed.

ok, so sounds like priming the pump is the way to go. I DIDN'T do that step...haven't read anything about that (in the Haynes manual and I just didn't see it??)

Thanks for the tips, cjernigan and m2cupcar! I'm going to have to take a look at my engine to figure out where that fitting is...what normally goes there? Is there something already in that port (plug?), I don't remember attaching anything there?

there should be- they usually have a tapered plug that's pressed in. If it's flush, you'll probably need to partially drill the center and use a bolt remover to get it out. Then just tap it back in after priming.

m2cupcar: I think that's the plug for the oil dipstick when the engine is in the 323. It's on the exhaust side though, if it's the plug I'm thinking of...is your picture possibly reversed/mirror image?

That's on the intake side of the pump- and actually goes into the pump vs. passing through. Though the photo is of the F pump, the B pumps are the same.

the port is on the intake side. It took me a little bit of cranking before i saw OP on my motor with no prelube.

OK, I just checked out an old oil pump at my buddies place, and I see where the plug is now. Thanks for all the help. I'll try it tonight...cross your fingers!

Thanks to everyone for their input (esp. M2cupcar for the pic). I tried removing the plug on the intake side of the oil pump, but couldn't bust it loose (ended up rounding out the allen key socket). So, I removed the filter, stuck in a length of clear vinyl hose with a funnel on the end and filled up the pump as much as possible.

Woohoo! It only took about 20 secs of cranking and we got oil pressure, and you could hear within a few seconds when the oil starting getting squirted into the cylinders.

To anyone installing /re-installing their oil pump: make sure you prime the pump by filling it with oil or by packing with petroleum jelly. Note: the Haynes manual talks about the petroleum jelly in the "Inspection" section of the oil pump re & re, NOT in the "Installation" section. I only read the installation section because I bought a new pump and didn't think I needed to inspect it...duh! wrong!

I used a Haynes manual to rebuild the top end of a KLv6. Got everything back together and it wouldn't run. Rechecked everything by the book. Sounded like spark, so I manually rotated the crank to check the spark order. The Haynes book was had the wrong spark order for the wires! :doh: