Honda / Acura K20a K24a Engine Forum banner
1 - 20 of 128 Posts

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #1 ·
Long story short, oil light turned on at idle and on the way home, I heard a bit of rod knock at idle. Haven't driven the car since. I pulled the oil pan to inspect the bottom end. Crank rod journals look

great, rod bearings look great (220k mi). Then I took the oil pump apart. All clearances are in spec, however, the relief valve and where it sits in the pump have some scoring. I had to tap pretty gingerly on the pump for the valve to fall out. Could this have been the source of my symptoms? Do I need to get a whole new pump? Could I polish out the scoring on the pump/valve with any sort of success? Worried about sourcing an oil pump since everyone gets one for their swap... Need some advise please.

Thanks in advance

Automotive wheel system Bicycle part Rim Nickel Auto part
Vehicle brake Rim Automotive exhaust Bicycle part Automotive wheel system
Green Household hardware Nickel Cylinder Auto part
Font Urban design Pattern Parallel Map
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #3 ·
I wouldn’t risk it. Lots of dealers have new oem oil pumps in stock currently. Around $200. I would replace it for safety if it was my engine.
OEM Pump ordered. Do you suspect this was the cause of my low oil pressure? Also i noticed the new part has a replacement part #. Any idea what the change was?
 

·
Registered
96 civic HX K24a
Joined
·
2,530 Posts
OEM Pump ordered. Do you suspect this was the cause of my low oil pressure? Also i noticed the new part has a replacement part #. Any idea what the change was?
It’s hard to say for sure , if it’s the original pump at 200k+ miles then that’s a strong possibility. You could hook up a mechanical gauge with the new pump installed. The oem light usually comes on at 3-5psi or something like that , very low lol.
 

·
Super Moderator
2002 DC5 Type S
Joined
·
1,561 Posts
What's up @yaggs

The scoring inside of the relief valve piston's housing may reduce oil pressure even if you replace it & the spring.

The outer housing does not have damage meeting with the gear, then ok. I had a rod bearing failure on #3 because the outer housing and gear didn't spin for well.

Like Kbuilt said they are $200 and in stock.

Also you said the clearance tests passed. However the three tests for movement in the oil pump gear & outer housing, the area where they do not touch each other, warping of the two-piece unit etc.
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #6 ·
I love this forum. Such a step up from crsx. Thank you both for your input. So nice to have information delivered in an intelligent and well articulated manor. Seriously guys, its greatly appreciated and should not be overlooked.

Purchased a sandwich plate and digital oil pressure guage with my new pump. Very glad those were on the shelf. Seems more and more items are discontinued\backordered by the day.

Thanks again for your help!
 

·
Super Moderator
2002 DC5 Type S
Joined
·
1,561 Posts
I love this forum. Such a step up from crsx. Thank you both for your input. So nice to have information delivered in an intelligent and well articulated manor. Seriously guys, its greatly appreciated and should not be overlooked.

Purchased a sandwich plate and digital oil pressure guage with my new pump. Very glad those were on the shelf. Seems more and more items are discontinued\backordered by the day.

Thanks again for your help!
We are glad you love the forum. Tell your fellow friends to come here and register. We are working on improving the forum with some exciting ideas.
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #9 · (Edited)
If you have any other questions feel free to make a new thread tagging us, keep this one going or send a PM. 👍
@Them Witches @KBuilt

It’s rather a sad day for me. I got the car put back together & fired it up. It’s 40 degrees out and I’m using Castrol Edge 5w-30… oil pressure steadily decreased from 35 down to 3 when coolant temp reached 180. Just so everyone knows: the dummy light comes on at 3 psi (according to my digital pressure gauge). I replaced the oil pump and changed all the rod bearings but obviously wasn’t the cause of my low oil pressure. My only conclusion is that it’s worn out main bearings. I don’t suppose cam wear could cause this? I will say that when I adjusted the valve lash yesterday, 12 out of 16 were too tight (30k since redone head and last lash set). A few things running through my mind… please advise

  • Find a k20a2 block and refresh everything and drive another 200k (I love revving out to 8.5k)
  • Find a k24 block and do the frank install. (I have literally no idea what parts would be needed and cost for said parts. Also… what is a safe redline for k20a2 head w/ k24 block? I have kpro 4 for my type s ecu btw)
  • For either option, I’m not looking to “build” the car. I’m not changing my stock exhaust, I don’t want new cams, pistons, rods, etc. I’m not looking to make power on FI. This is my daily driver. I just want it to last as long as possible.
  • What is my next step for right now? Do I even bother checking the cams? Do I just start ripping it all apart? Should I wait to buy a bottom end until I discover the culprit for my low OP?
Please don’t suggest power making parts unless it maintains reliability and is cost-effective

You input is greatly valued. Thanks
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #12 ·
Damn, I am sorry to hear that. That dummy light isn’t worth much at 3psi. I’ll be the first to say it’s over my head as to what could be causing this. @Lotus @LotusElise may have some insight.
I'm gonna drop the motor and take out the crank to assess damages. I looked more closely at the oil drained at first symptom. Gold flakes after only 200 miles on the oil change. Im strongly suspecting main bearings at this point. Just need to see if the crank\block are too damaged. I'm going to attempt to drop the engine from the bottom, as per helms manual. I will first take off the head to give me more room to clear the body. Stella will live again!!! I will update as i can. Thanks to everyone for the help!
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,690 Posts
Welcome to K20a.org @yaggs. I am sorry to read about the engine issues you suffered.

It’s 40 degrees out and I’m using Castrol Edge 5w-30… oil pressure steadily decreased from 35 down to 3 when coolant temp reached 180.
As a general suggestion. First, I never would use Castrol oil, neither non- nor synthetic, even not for the first installation lubrication. It has a low capacity to build up a stable oil film compared to the top dogs in the field of engine oils. High revving engines need a proper and stable oil film. Second, anytime an immediate oil pressure pressure drop happens, the oil filter check, oil level check, oil leak check are causing obligation. And 3rd, anytime a part of the oil system has signs of seizure oil was missing already there.

For your specific case. The seizure of the relief valve shows already signs of missed oil flow, which means an insufficient sucking or pressuring of oil flow. What would happen it that valve was always open? Oil pressure on lower engine speeds up to around 3000 rpm would be lower then normal. What would happen if it was always closed? Oil pressure would have been increased over 5 bar at higher engine speeds and the efficiency of the oil sucking would have decreased. The possibility of insufficient oil supply to bearings would have been dramatically increased at higher engine speeds.

For me it is not clarified where the relief valve stuck, either in the open or closed position. The symptoms you have described would indicate finally it has been stuck in the open position, means oil pressure was to low at higher engine speeds, what would match those lately observations you have described. But it is not for sure, I would like to see if there are also signs of seizure in the fully open position of the oil pump housing. The seizure signs in the pictures above show only closed stuck position, which contradicts the observations you have described. My conclusion, both sticking positions might have had happen.

On the journal bearings there are signs of pitting on the cap side and little scratches on the rod side.
  1. pitting on the cap side: lack of scratches on the cap indicates more a oil driven then particle driven pitting, lack of oil flow or insufficient thermal stability of the oil film
  2. wear on the rod side egdes: all bearings show one-sided wear on the low load areas, which may are signs of out of spec or excessive engine spinning under worn axial washer issues
  3. scratches on the rod side: the lack of wear in combination with scratches indicates those scratches can't be to old, what would be also a possibility for 1.
I have no history of that engine and no live observations of the issue (sound, feeling, signal trends, ...), just a stomach feeling of what is behind the gathered above. That tells me something caused the relief valve to seizure and this caused the stucking of the relief valve in both position and drove finally the damages of this engine. A lack of oil level? Or a low level and hard cornering? Or a low level of oil niveau and excessive engine speed? @yaggs maybe you have some ideas on that?

Please don’t suggest power making parts unless it maintains reliability and is cost-effective
Buy a good used 86x86 bottom end and go with it. The stock header manifold restriction will stop any worth benefit on intake and exhaust side and cause further budget demand. Just my two cents.

Edit: there is a lot of excessive engine speed indicators, this doesn't mean 9000 rpm or more, it means the system was run faster that it was capable of. If the weakest link is low enough, 6000 rpm could have been that excessive engine speed already, just duration of it would work out the damages.
 

·
Registered
Joined
·
1,162 Posts
but he got a new oil pump for that run, so also new relieve valve. Why should it be stuck open or closed or intermittently both? The previous pump, yes, could be worn or stuck.
I think his main bearings are worn and piss oil left and right and oil pressure drops to next to zero.
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #15 · (Edited)
First off, thank you so much for the detailed response, I am learning alot! Your knowledge and contribution are sincerely valued and appreciated!
High revving engines need a proper and stable oil film
Anny recommendations? Pennzoil? Mobil 1? Would like to keep 5qt jug cost under $35
the oil filter check, oil level check, oil leak check are causing obligation
I immediately check all of the above after shutting down after oil light. zero leaks, 200 mi on new filter and oil. oil filled to top dot.
excessive engine spinning under worn axial washer issues
are these thrust washers?
A lack of oil level? Or a low level and hard cornering? Or a low level of oil niveau and excessive engine speed? @yaggs maybe you have some ideas on that?
I religiously check oil levels every 1000 mi. It's never been below halfway between dots. Oil consumption is less than .5 qt since head rebuild 30k mi ago. I have driven the "tail of the dragon" a few times. Summer tires 225/45-17. I ran that 10 mile stretch a few times pretty spirited but not full out race mode (there are 314 turns, many are switchbacks). Oil starvation potential?
Buy a good used 86x86 bottom end and go with it
Would I need to find a type s bottom end? don't want to rebuild any internals and maintain same/similar CR. if i went with a k24a2, are you saying my header would be a bottleneck?
but he got a new oil pump for that run, so also new relieve valve. Why should it be stuck open or closed or intermittently both? The previous pump, yes, could be worn or stuck.
I think his main bearings are worn and piss oil left and right and oil pressure drops to next to zero.
This was my most recent assessment as well
 

·
Registered
03 Acura RSX Type S, Stock internals, Basic bolt ons, kpro 4
Joined
·
77 Posts
Discussion Starter · #16 ·
If none of the main bearings are spun, could i potentially just replace them? Assuming the crank is ok? All rod journals looked good btw
 

·
Arouse the DAMPFHAMMER!
Joined
·
8,690 Posts
Pennzoil? Mobil 1?
Pennzoil I would row it in the Castrol section. Formula customer had Pennzoil full synthetic in SAE30 quality and had scratches at the liner and the piston side. Mobil1 full synthetic would be great too.

are these thrust washers?
Yes, meant that.

I religiously check oil levels every 1000 mi.
Signs of incredulously :D. I check it almost every time I am going to start the engine. Yeah, for an DD are 1000 miles/check quite good, but think of it, an oil change every 7500 miles would be a good thing, it is an high revving engine and earns only best maintenance.

if i went with a k24a2, are you saying my header would be a bottleneck?
If you start changing the system, issues will began, as you will need some aftermarket support and parts, which has a much lower quality. Most engines I did tune were modified after the modification to be in adequate quality level for the tune. Aftermarket is one of the issues you will suffer. Be aware of that. Second the header and the intake are the biggest power adders. If you add those to your 86x86 engine (assuming you have an 11.0:1 CR engine with performance iVTEC) you won't miss it. Low end torque is nice, but high end torque is much nicer :D.
 

·
Super Moderator
2002 DC5 Type S
Joined
·
1,561 Posts
Dang, I am sorry to hear this horrible news.
I religiously check oil levels every 1000 mi.
Once every 1000 miles is not enough, the service manual suggests checking the oil before each road trip. Yes excessive, but the practice is there to catch a problem before taking off in the car.
 
1 - 20 of 128 Posts
Top