First post and figure to post so it may help someone else. Learning a lot about the K-Series engines...

Well my wife's 2005 CRV has 260K miles and was throwing the P0341 code. Her car is also consuming a quart of 5W20 every 200-300 miles. This car has always had oil changes between 4K and 5K miles. (I had review here service receipts). Was original using Mobile 1 5W20 Synthetic. But since oil consumption dropped below 1000 per quart, she switch to using Pennzoil 5W20. The car does not have the power like it use to have.

The CRV is now a backup vehicle so start working on various issues.

* P0341 - CamPositionSensor
* P0442 & P0456 Evap Emissions - Small leak/Very small leak detected
* P0420 Catalyst System Efficiency below threshold
* VSA light stays 'On' - Check ABS wheel sensors
* Check external oil leak frt crank seal & frt of block

First was the timing chain. Found it had jump one tooth and slack in chain between the cam gears. With valve cover off, found intake cam has erosion on peak of the lobes and the exhaust lobes had sever pitting and lost of metal. Pulled plugs which were replaced about a year ago: #1 had black oily soot - #2-3-4 where white/grey deposits. Looking down spark plug hole - had carbon build up and wet looking.

Pulled head cylinder head confirmed the top of the piston heavy encrusted carbon. Pulled PVC valve and found it was all coked up with carbon. The cylinder bores did not show much wear other than the ring of carbon around the top of each bore.

Dropped the pan, relative clean, no sludge any where. Plastic-gauge each rod journal and all bearing clearance within spec and no signs of wear. Push all the rod/piston out relatively easy by hand.

All the piston's oil control rings were stuck by all the carbon build up. The compression rings where clean and free. These rings are consider low-tension with compression ring only 1.2mm thick and the oil control ring being 2mm thick.

Have cleaned up and prep the cylinder bores. Will install new piston/ring and rod bearings. Having the cylinder head reconditioned. Put in a new timing chain/tensioner.

From what I have seen - Hard to say what was the primary cause. The vehicle was always using good oil. The oil level regularly checked and had regular scheduled oil changes. It's like the chicken and the egg - which came first. All said - I believe that the piston ring where never seated. Unfortunately my wife did not document every time she put a quart of one in.

Right now located a good used intake cam (#14110-PPA-010) on ebay for $30 but having a hell of time locating a good used exhaust cam (#14120-PPA-010). Found I can get a new one from Japan for $320 or a Honda #14120-RAH-H00 for $135 used in Eur/Russian engine. Also deciding if go with aftermarket piston/rings since this CRV is going to just be stock - Looking at NPR, EngineTech, Safety, etc brands.

Appreciate any insight.

Bob G.

 

I recall that back in the day there used to be a service where you'd ship your camshafts in, they would powder weld them up and grind them back to the spec. But I remember too much sometimes.

 

Thanks for the quick reply.

Yeah today we are in a through away world. At least the material is recyclable. Around here machine shops are far and few. Got a call from the machine shop in Harrisburg VA which is an hour away, that my head is ready for $250. It was dropped off Monday.

 

A quick google search shows that there are still a few camshaft grinders still around but the cost could be prohibitive.

Oregon Camshaft
Cam Grinders
there may be more.

 

For the evap leak, after inspecting the cap seal, I would suggest removing the plastic shield around the fuel filler neck in the driver's rear wheel well and inspecting the pipe for corrosion/leakage. In all likelihood it is filled with wet gravel and the pipe has rotted out at the elbow.

Front crank seal is actually quite easy - remove front passenger tire, remove accessory belt, remove crank pulley (19mm), pulley is not an transition fit - I removed my easily by hand. Crank seal is now accessible. It actually seals against the crank pulley.

Other leak on that side of the engine block is probably the VTC solenoid O-ring. This one is a little tougher because the solenoid is installed into a post-filter oil passage, so you can't touch anything when reinstalling it (think: Operation!). Its buried in the side of the cylinder head and it took me a dozen tries to get it. The O-ring is not a standard AS568 -1xx or -2xx ring - I haven't figured out what it is yet, but it isn't those.

I've used NPR ring kits before, wasn't disappointed. Not likely you'll get another 260k out of her, so why put something at an OEM price point back in?

 

Thanks for the respsose Ryan,

The MIL has been on for a while now. My wife's shop had replace first the gas cap and then I believe the filler. Since we have mice problems here in the winter, plan to blow smoke through out the evap system to locate the leak. Will recheck the filler area.

Yeah - It is even easier when the timing cover is off. ;<) Right now I have block still in the car but removed timing chain, intake/exhaust manifolds, cylinder head, pan, balancer/pump, pistons, starter, etc.

The list right now is to installing new piston/rings, repl both camshafts, recon valve/seats, repl timing chain/tensioner, recon starter. The alternator and water pump where repl not to long age.

Ha - removing the the crank belt pulley - Boy did I under estimated this one for something that is torqued 180 lb/ft.

Any suggestions on aftermarket pistons? NPR, Safety, EngineTech, etc

 

Thanks for sharing. Any pictures? Is the car doing slot of short trips?
you are right throw away world. Easier but no level of satisfaction

 

For crank belt pulley you probably need the Honda 50mm hex tool to hold if it is anything like my Pilot's.
I just did TB on my Pilot and used that and a 3 1/2' 3/4" drive cheater bar.
The bolt budged easily with a little squeak. That cheater bar is the best tool I ever invested into. Helped to open the notorious transmission filler plug effortlessly too.

 

I Here is how I broke crank bolt loose ‘Pure Torque’ , galled exhaust camshaft and timing chain tensioner..

 

Ditto!

 

ok - here is cylinder removal.

 

#1

#1

#1

#1

 

Yikes! These deposits are horrible. I see lots of blow-by and inefficient rings.
Honda's become such a... But their timing chain tensioner seems to be a better design than the self-destructing, bio-degradable Nissan's.

Did it blow head gasket?

Did you ever try to run 2x cans of Seafoam per 40l / 8 gal of gas once a year? I follow this schedule religiously and the cars run like a top.

 

Did not blow head gasket - actually the HG looks pretty good. Have dipped two of piston twice and they cleanup to like new. After two days of soaking, the oil control ring drain holes still rock hard with carbon. Had to use a drill bit to get the carbon out.

This engine does not have what I would call “sludge” . For 260K miles, it is fair clean inside except where oil coked up.

Miked the cylinder bore - basically out of round at top of ring travel 0.0015 to 0.0025” wear. Checked ring gap with old ring 0.038” P2W was roughly 0.0030 to 0.0035” Was hoping to install new pistons / rings and call it a day...

Guess will need to drop the sub frame to pull the block out and get it bored.

Does YCP make 0.020” stock OS pistons for Honda K24A1 engines? If so, who sells them?

 

Just curious what kind of trips were done with this vehicle? Synthetic oil used?

 

Well we live in the county about 8 miles from nearest town and 30 miles to towns with stores. Make numerous trips from Virginia to central Texas, Indiana and Montana cruising 70-80 mph. This is my wife vehicle but when I drive I am alway looking for sixth gear. Engine is turning 3500-4000 rpm. Seem like my 2 cycle chain saw.

First post covers the history. But adding to this I found out recently on another forum that ‘Mobile 1 Synthetic’ is sold in six different packages (different additives) with OCI rating ranging from 3000 to 15,000 miles.

With my 260K mile 1998 VW Jetta TDI using Rotella T6 5W40 oil, I only need a 1/2 to 1 quart of oil per my 7,500 mile OCI .

 

I have found this chart helpful when looking on eBay and Honda online parts to see what works for with K24A1



Honda K-Series Component Cross-Reference Chart

 

Well - Dropped engine/transmission and subframe so to get the block bored for new pistons.

Bought from Rock Auto a set of EngineTech 0.50mm OS pistons and rings. According to NPR of America, they distribute to EngineTech.

- Piston Set# P4833(4) 02-06 Dish top. 1.165" CH. Hyper. Coated skirt

- Piston Ring# S87124 02-06 Premium. Steel top. 1.2 / 1.2 / 2.0mm.

Will see what the quality is. Will upload photos when they come in this week.

 

OK - Thought I had already uploaded pictures of the EngineTech 0.50mm OS pistons and rings...





Here is ET vs OEM side by side...





Have block/pistons bored 0.5mm oversize and crank to be polished.

Bob G.

 

They look like excellent reproductions. I was a little worried after looking at the first picture because they are clearly sand cast, and I'm used to seeing billet or forged pistons...but I guess if its good enough for OEM, they should be fine. Do both pistons have that coating on the skirt? Are they the same weight as OEM?

 

Yes both pistons have coated skirits. The OEM piston coating was mostly worn off. When get home and block back from the machine shop, will see about weighing them up.

By the way, the ET pistons pins are full floating where the OEM is semi-floating.

 

Well the bad news...
Miked up all the new pistons at the skirt. Three where 3.4441" diameter and one was 3.4440". Impressive since the box label said +- 0.00025". Did not weight them yet.
Drop my block off a week ago to have it bored to 3.4455 which would give me the Piston 2 Wall clearance of 0.0014". When pick the block on Friday, asked the person who actual did the bore/hone what the piston clearance was. He said after a brief hesitation that it was 0.002" then said to 0.0025". Did not blow up - took block home. Saturday set my dial bore gauge to zero extactly to 3.4450". This what Wiseco piston site said as bore size. Checked all the bores dimensions and added 3.4450" to give me the actual bore diameters then subtract the piston skirt dimension to give me the actual P2W clearance. Here is the result

Bore #1: MaxBore Taper/OoR= 0.0003" P2W= 0.0029" to 0.0032"
Bore #2: MaxBore Taper/OoR= 0.0002" P2W= 0.0026" to 0.0028"
Bore #3: MaxBore Taper/OoR= 0.0006" P2W= 0.0030" to 0.0036"
Bore #4: MaxBore Taper/OoR= 0.0004" P2W= 0.0029" to 0.0033"

I talked to the "machinist today. He though the engine was going to be used in racing environment. Were going to try sourcing a set of .75mm (0.030") O/S piston & rings and hone the block out another 0.008" if possible.

When talking to him about the bore dimension for example '0.0029"' as 29 10,000th of an inch. Sensing his frustration over the phone, I then referred to as 2.9 thousandth. I am not used to working at this level of precision. Is there a proper way to converse these 10,000th" measurements?

But the good news is I received an excellent condition exhaust camshaft from Dubai in four days after purchasing on eBay for $77 + $30 shipping last week.

 

Question:

The 2005 Honda CRV K24A1 engine has these specs...

Model Number: K24A1 (2002–2006 Honda CR-V)
Displacement: 2.4 L; 143.6 cu in (2,354 cc)
Cylinder Bore: 87 mm (3.425 in)
Piston Stroke: 99 mm (3.898 in)
Valve Train: DOHC
CompressionRatio: 9.6:1
Power: 160 hp (119 kW) @ 6000 RPM
Torque: 162 lb⋅ft (220 N⋅m) @ 3600 RPM
RedLine: 6500 RPM
RevLimit: 7000 RPM

According to the component chart above - this Honda CRV K24A1 engine is the only one to use the 'PPA' pistons for 9.6 to 1 compression ratio.

Notice that most of the components in the same vintage Honda Accords K24A4 enginges are interchangeable except the block, head, piston (C/R?) and manifolds.

Assume engineers where conservative with the K24A1 engine since it being used in a SUV carrying more constant load compare to regular passenger car.

Notice the difference between Honda CRV 'PPA' crater piston and the Accord 'RAA' slight dome piston is probably a higher C/R. So would there be any issue using 'RAA' pistons in a K24A1 engine?

Just wondering...

 

When talking about those small numbers, I tend to talk about "half a thou" for 0.0005. or "four point seven thou" for 0.0047 or "point two eight thou" for 0.00028 . I walked over to one of our machinists and asked him how he would call a number I had written on a piece of paper "0.0029"... he said "two point nine thou". These are pretty small numbers, I would think the 10,000ths position would be eaten up by a tolerance pretty quickly and specifying it aside from nominally and then expressing a tolerance isn't very important. You wanted about 1.5 thou P/B clearance and you go closer to 3.

My theory is the relatively low power level on the K24A1 started back at vehicle inception... the power level matches what the vehicle was meant to be, which matches similar body styles in the market at the time (2002 Forester was 165hp, Rav 4 w/ 2.4L was 158hp, the list goes on). The target market isn't looking for a high HP unit - they want steady, predictable, reliable. No sense in putting in 200hp "just because you can" - it does more harm than good. Not designing for that extra 40hp means you can make everything lighter, more cost effective, and it will take more miles and abuse. This vehicle design was done before the huge push for fuel economy that caused DI gasoline engines, high power density small units (1.3L turbo Cruze) etc. I'm not actually sure why they didn't put the 2.0L powerplant in the CRV - it might have just been marketing pressure (Forester was 2.5L, Rav 4 was 2.4L, who would want the dinky 2.0L Honda). It also looks like peak torque on the 2.4L is about 15% higher than the 2.0L, which is useful in a small-intended SUV.


I've seen lots of threads on part interchangeability, but haven't memorized them. I suspect you can mix and match all you want, but I'd be careful unless you want to tune it after - I expect jumping 25% in power is enough to move outside of the ECU's allowable fuel compensations. Changing C/R drastically will change what the motor expects for preignition/detonation behavior as well.

 

Thanks Ryan for insight with talking the numbers. Back 25 years ago it was one thousand, one and halve thousand, two thousand, etc.

Regarding the difference between ‘PPA’ and ‘RAA’ pistons is because there is really good chance I will not find a 0.030 OS pistons to get this block together within spec. Called NPR of America to see availability of a 0.030 piston. The reply was only std and 0.020” where offered due to low demands due to K24A1 used in 2003-2006 CRV’s.

Looked at K24A4 engine specs for the Accord and they were very close to the k24a1. The CR only difference between the two is 9.6 to 1 and 9.7 to 1.

Do you think .0025” to .0035” piston to cylinder wall excessive? Am I over think this? Thanks