So I took the car out to dinner tonight and did a 3rd gear WOT pull, fell on it's face. Figured out the motor wasn't engaging vtec.. Narrowed it down to my oil pressure. It seems like the checkball that normally engages at 80PSI is opening at 45-50 psi. Is the pump done or should i try to change the oil and filter? I just got back from a drag event revving the motor to 9,000-9,200 rpm.

It's a stock bolt-on k20a2. TIA

What could've caused this?

 

165 views and no suggestions?. sheesh. i was hoping to find a quick solution!

Dipstick shows the motor is full of oil.

 

the oil pump captivates at 8,600 rpm. Could captivating it cause something?

 

Yes... oil starvation and bearing failure.

It doesnt go above 40-50psi at any rpm?
Whats the pressure at idle?

It sounds like bearing issues if it used to be in the 80 range and now its half. The goods is if you caught it before it spun a bearing you can likely reuse most of the parts.

 

Cavitates!

 

When I look at the oil pressure gauge it pegs at 50 psi like it used to at 80 (because of the check ball) pressure at idle is about 20-23

 

my friends vtec was having problems just recently. have you noticed it is burning oil? , my thought is, maybe your cylinoid which enguages vtec could be worn out, or has a loose wire. my buddys had a loose wire, but it still isnt even noticable :/ , another thought is a clump of sludge or dirt mightve worked its way into one of the narrow passaged needed to help enguage it. im no expert thats for sure.

 

Is the gauge faulty?

 

No sir, motor won't engage vtec either.

 

My buddies car did something similar felt like the car was falling on its face and when he looked at his oil pressure gauge low oil pressure, unfortunatly it was to late spun bearings

 

Inspect oil pump?

 

option 1 is something upstream of your gauge and the vtc prs switch has restricted flow (unlikely but possible). option 2 (most likely) the pump is not putting out like she should, whether it's failed or the check valve has. final option (but much less likely than two) is something downstream has opened up flow, and oil is taking the road of least resistance.

im not you, but if things happened to me in such a manner as exactly you've described without any other symptoms or warnings.. i'd be dissecting my oil filter looking for oil pump guts. filters are cheap, and can be an excellent indicator. next, i'd inspect the pump. then, but risky because we know the engine is thirsty, i'd hook a known-good manual gauge to the oil pump and see what the pressure was, and again to the head. now i'd know whether or not i have to hang my do-not-disturb-or-else sign on the garage and clean up everything in prep to tear the motor down.

hopefully it's the pump, as 30lbs of pressure should mean your car is ok as you didn't ride around WOT for days like that. but typically when they go, they go. as in, no more pressure. the check valve could've stuck.. but they are a pretty fool/fail-proof design so then one has to wonder.. what stuck it and where did it come from?

good luck, such a captivating problem such as this will have me checking back often for updates.

 

^^ that's a perfect answer. i appreciate yoru effort in trying to resolve this. How would I hookup a manual PSI gauge to the head and oil pump?.

I will try and pull the oil filter when i get home tonight and see what spills out of it. Will i need to cut it in half and go over it with a magnet? or is stuff inside the oil pump not metal?

 

If you open the filter up like stab it with a screwdriver and Peel. Cutting it with a blade will deposit stuff that could be mistaken or hide bad stuff you're looking for. Oil pump shavings are metal and by the time they got to the filter probably look like metal sand or thin tiny strands. Bearing debris will look similar but have copper or brass layered on them and typically when things go wrong with them you'll have engine noise. But usually anything along these lines ends in catastrophic engine failure.

Have you asked on that k20 site? I know k20s have a lot of quirks I myself have never had the displeasure of working with. (Hydraulic chain tensioners, etc..)

EDIT: just saw 9200 on a stock motor.. wut?

 

Well then how will i find out what's on the inside of the filter?. And yes, 9000-9200. 22" slicks at the track don't have very good MPH. . can ran fine for a couple of weeks after the IFO events then magically one day not as much oil pressure!

 

where the hell did you come up with that BS. we run stock pumps 11k+ and have never seen pump cavitation or pressure drop.

 

like i said, stab it and peel.

but knowing what i know now, i'll bet you've spun a bearing. look for metal flakes in your oil and filter.

 

From ERL's website and a few other sources. Now is it a marketing tool they use to sell their pumps? Not too sure, A few local race buddies use stock oil pumps on their race motors with no problems. WHy badluck with?

 

Finally drained the oil. i know it's been a month lol. and no metal at all! Oil is super old though i think it has close to 10k on it. Mobile 1. I'm wayy past the 3-5k mark


You think how old the oil is and how much it thinned out could cause the oil pump to operate incorrectly?

 

you shoul have taken it to 10k to finish it off. then build it to take it to that RPM.

 

An oil change cant hurt anything. Make sure you dissect the old oil filter and look for small particles. If the pressure is still low I would pull the oil pump and inspect it. If the pump specs out good then you have bearing issues. If the pump is bad then you replace the pump, and since it didnt completely lose pressure the bearings should be ok.

 

Okie doke, do you have any experience with k20's? i'm wondering if i can change the pump with the motor in the car