Oil Pump

[Chris28]

So while swapping a new KA in last weekend I got to thinking why my old KA failed. I'm almost positive I put the rods back in not only the wrong way, but also with the wrong end caps on them.

What seems odd to me is that I got rod knock so quickly on brand new bearings, not to mention I know I torqued everything down to spec.

Also, the turbo was knocking/hitting the compressor housing. When I took the engine out I felt the turbo, and there is maybe a mm at most of side to side shaft play, nothing in and out. Turbos don't just knock like that, something had to be wrong...maybe it wasn't being lubricated.

Let's say the oil pump was defective. That means the rod bearings weren't getting any oil, as well as the turbo not getting any oil, resulting in both "knocking." I didn't have my oil pressure gauge hooked up so I don't know exactly what was going on, but it seems really odd that the 2 things that need oil seemed to fail, and it was a brand new oil pump that I didn't know worked. I know my old stock one worked because the engine ran well with it.

Do oil pumps need to be primed? I'm just wondering if maybe it was something else other than me putting it back together wrong.

I know this seems like beating a dead horse, but I'm starting to wonder if maybe it wasn't totally my fault for a crappy rebuild.

[480sx]

Hate to break this to you man, but if you put the rod caps on the wrong rods it was almost certainly completely your fault.

Next bit of hard news.. Your turbo. This was again, almost certainly caused by all the metal coming from your rod bearings being pushed through your turbo. This is why i run a pre filter from my oil feed to my turbo to avoid this from happening.

Oil pumps dont really need to be primed. A gear driven pump will overpower the vacuum of having no oil inside it. They say to coat the gears in a light coating of oil, thats it. I always prime the pump/system anyway, but its not mission critical just prevents a little possible wear. Most of the time that wear is negligible because of engine assembly lube.

As far as a pump being defective, thats really not a possibility. The only way that a pump can really go 'defective' is if the oil relief valve sticks open. This is VERY easy to check for and if you want to make sure that it wasnt your oil pump that smoked your motor just check to see if the oil relief valve/piston moves freely in its cylinder. You can also have a worn out pump, but generally the pump will outlast the motor. If the pump fails naturally, the motor is most likely already smoked.

[SX APPEAL]

thats seems logical. I've heard of plenty of people who start up a new engine without priming the pump and everything works fine though, since it should only run dry for a second or two. What one of my tech school instructors said to do was prime the pump with vasoline. Sounds funny, but its petroleum based and its a gel so it'll stay in the pump as you install it, and it'll all be washed out by the first oil change anyway. I'd try that next time for sure.

[480sx]

The vasiline thing i dont think is a good idea. While it might be P based, its nothing like oil. I can just see that crap getting stuck in the engine galleys and staying there forever.

Just follow the FSM directions and lightly coat the oil pump with engine oil.

[SX APPEAL]

How is it going to get stuck? its a gel being forced through smooth passages at 80psi. All its doing is taking the place of the air that would normally be in the pump right when you first start it up. Either way, I think we both agree that starting the pump dry has little to no effect anyway so I guess it doesn't really matter.

[480sx]

Well think about it this way. Its not designed at all for high temp applications. When it shoots through the bearings god only knows what its going to do. Its also sticky by nature, its nothing close to a fluid.

Idk iv heard people using Vaseline before for this, but id just stick with the FSM. Or use engine assembly lube if your super paranoid, not something designed as a skin moisturizer.

[eazye2000]

On my oil pump, I used some of that Lucas oil stabilizer in it. Pretty thick stuff, and it coated it pretty well. Let that drain out as much as gravity could.On critical parts, I use Permatex engine assembly lube. It's kinda blood red, and sticky as all hell.Just some info for ya'. Hope the next build works out good for you.

[Chris28]

Haha I know putting the rod caps back wrong was my fault, but was that enough to cause failure? The turbo started making noises basically right on startup, whereas the rod knock happened about 30 minutes after that.

I realize it's my fault, it's just when I boost my new engine I want to make sure it wasn't a combination of things that made the old engine fail. I don't want this happening again haha.

Thanks for the info though.

[480sx]

Yes, putting the rod caps on the wrong rods will destroy the bearings and damage the crank in most situations unless your unbelievably lucky.

However, the fact that your turbo made noise right on startup doesnt make much sense. What kind of turbo did you use? Your turbo failing should have been after rod knock.Are you sure you turbo was getting oil? Was your oil line new and did you check to make sure it was crap free? I try to crank the engine with the feed line D/Cd to make sure oil sprays out of the line before i crank and engine up wi/ a turbo for the first time.

You might have had a combination of failures, lol.

[Chris28]

Haha I think you're right about the combination of failures. Turbo was a Garett T25 from an SR, practically no shaft play. After I realized my engine was shot I did take off the feed line and turn it over by hand to see if it was getting oil, and it was kind of getting oil. I turned the engine over 2 complete times and got maybe a drop of oil...seems like a kind of small amount.

Brand new JGS oil lines with a .063" restrictor.

[480sx]

Well turning it over by hand isnt going to tell you much. You didnt need to run an oil restrictor to a garrett t25 tho.

[slipnfall]

It's pretty easy to 'prime' a KA prior to startup. This assumes the block was assembled with 'lube.

Relieve fuel pressure (shouldn't be any...), remove fuel pump fuse. Attach oil pressure gauge in place of sending unit (picked mine up cheap from eBay..)

Fill block about 1/2-1qt shy of oil, then, with timing cover off, pour the remaining over cams and into front cover. Loosely replace cover, and bump the turn engine over a few times until you see oil pressure rise. It only took about 1-2seconds to see nearly full cold pressure.

[480sx]

Or.. You could just unplug your injectors and crank the engine.. Same could be done by taking out the FP fuse i suppose.

[SX APPEAL]

They always say to take out the FP fuse and crank the engine to relieve fuel pressure, but now that you mention it unplugging the injectors sounds like a better idea. Since you would still have full fuel pressure in the rail, it would start right back up again when you reconnected them instead of having to repressurize the whole system like when you take out the pump fuse. Just a thought.

[slipnfall]

Unless you took the motor out without disconnecting fuel lines to begin with, you won't have any fuel pressure.

[SX APPEAL]

True enough lol, didn't quite think that one all the way through. I was thinking of other operations when relieving the fuel pressure is necessary, replacing fuel pump and what not.