mattfranklin

I have a 2002 Accord F23A4 with 147k miles that we bought new. It has had reasonable maintenance, but several years ago started using oil about 600 miles per quart. I just shifted to a heavier grade of oil and that seemed to stretch it to 1200 miles per quart. Never any puddles at all. I think it's burning it. Kind of a hassle, but not a disaster. It seemed to be sluggish and down on power, but still holds up fine at 80mph+ on the freeway.

I mentioned the excessive oil consumption the Honda dealer and they seemed more interested in doing a tune-up and flushing the brake fluid.

Anyway, about a month or so ago it started throwing trouble codes. There seemed like a slightly rougher idle to me, too. OBDII codes were mostly for misfire in *several* of the cylinders. The manual said this might be caused by valve adjustment so I checked and opened up clearance on a few of them. None were overly tight or loose, though.

While I was that far into it I decded to change plugs and check compression. The plugs all had some white fluffy deposit on them and cyl#3 had a lot more than the others. When it came around to the compresion test, all of the cylinders had around 195 +/-5 psi, except for cyl#3 which had 115psi dry and 145 psi wet. That seems really bad to me.

So last week I bought a leakdown tester to further isolate things. #3cyl showed 80% leakage. Direct numbers were 75psi supply and 15 psi in the cylinder, and my 2hp compressor could not keep up with it. I didn't hear anything through the intake or exhaust systems, but there was a pretty good *flow* coming out of the PCV port. I made sure and plugged the fresh air side of the crankcase ventilation with a pencil so the only legit outlet would be the PCV port. I actually slopped some pipe leak detector on my gloves, stuck my finger loosely in the PCV port and looked for bubbles. The flow was too fast to form bubbles, and mostly just sputtered and sprayed the fluid past my finger.

So, now, what to do?

I need to state up front that whatever I do has to fit within a 2-3 day weekend, because we need two commuter cars going in different directions come Monday. It doesn't seem urgent as it still drives ok. I just need to plan so that it gets completely done within the weekend I plan to do it.

With leakage and oil consumption that bad could it just be a stuck ring or is it likely that there is more damage: broken ring, broken ring-land, or other? My normal driving is pretty aggressive, redlining it multiple times a day on the on-ramps to the freeway. So I'm kind of doubting that it's a stuck ring, but I'm not that familiar with that side of things and can be persuaded.

OPTIONS
1) I'll probably try one of those top end overnight solvent treatments (maybe GM TOP ENGINE CLEANER, or equivalent) first.
2) Then, if that doesn't help the leakage, I'm considsering a JDM *replacement* F23A long-block. I have seen those locally for $475. Autozone and Rock Auto had rebuilt long-blocks for $1100-3200, but those are too much for me given the value of the car.
3) A buddy from work recommended re-ringing it after running a ball-hone (Flex-Hone) through it. The problem with that option, is that I don't want to be stuck with no transportation at the end of the weekend if I run into problems. I like the challenge and fun of this option, but I don't want to risk being stuck.

Any ideas? Do I have more options? Anything I'm overlooking?

MAD_MIKE

#1 and #2A(JDM) would be your easiest options.


#2B I don't trust their common Chevy 'remanufactured' engines, let alone something that takes some actual thinking to put together(Honda)
#3 might work, but if the hone/ring job doesn't work or the piston is screwed up, you will be out of a car and a weekend.

accordturb96

Funny I just read the same issue about a similar car, cylinder three was low on compression. It's obvious answer, if your getting a high flow rate from your PVC valve,it's flying past the rings and back up to the head and out the vent. For ***** try hand cranking the engine Into different points, tdc, bdc and right in the middle. If you get the same results it's more than likely a n issue in the cylinder. You can inspect the valves with the valve cover off to see of the air flow is coming from them. Let us know what you find.

mattfranklin

I'm doing this step today. With the new GM "Upper Engine Cleaner." I've heard it is not quite as potent cold and straight out of the can as the old classic GM "Top Engine Cleaner." But UEC it is phenomenal and outperforms everything on the market, including old TEC, IF the engine is hot. Heat is a big deal for this one. The engine must be warm for it to work. And, as an added bonus, it meets the new VOC specs for California.

Here's the link again for their "Saturn" procedure:
http://www.saturnfans.com/forums/sho...0&page=1&pp=20

I based mine on that, but here is a step-by-step of what I did...
Hot engine.
Cylinders at half stroke
2oz per cylinder
2 hours soak
Sucked out what I could what the Mityvac (about 1 oz. per cylinder)
Spun it over with rags covering plug holes
Rags were dry as far as I could tell
Put plugs back in
Started it and revved it
It smoked a bit
Warmed it up
Drained oil and changed oil to Pennzoil 5W20
Drove it like I stole it for 30 to 45 minutes
Between 100 and 200 WOT 10-35 mph launches in 1-2 gear
Hitting 6500rpm redline almost every time
Changed oil again, Mobil 1 5W20 this time

Checked compression again
190psi+/- on all (just like before) except for #3, which was 160 (up from 115).
BIG IMPROVEMENT

mattfranklin

It was kind of fun trashing it back and forth on Pinehurst.
I must have given it a hundred or two 10-45 mph WOT blasts.
I noticed that the iternal rev limiter lets it go to 6500 rpm before it starts cutting out rather than the 6200 redline shown by the tach.
BTW, the fresh oil was really dark after that.

Here are the details cylinder-by-cylinder:
Cyl#1 = 193
Cyl#2 = 192
Cyl#3 = 160
Cyl#4 = 190

I will Repeat the processs right now with the last half of my GM Upper Engine Cleaner bottle.

mattfranklin

BTW, on my second "procedure" I also rotated the engine back and forth maybe 5-10 degrees with a wrench on the power steering pump several times during the 2-hour soak to give the rings an extra chance to flex and rattle around in the grooves.

I don't know about the oil consumption yet, but I'm very, very happy with the responsiveness of the engine. On my morning commute it holds speed much better before having to drop to a lower gear. It also has plenty of torque to climb a particularly steel hill. It's also much more responsive off the line. I had forgotten how this car was when it was new, but the sluggishness is gone and it feels like it did when it was new. BTW, I did give it a little more than a 2x (3x12 oz bottles = 36 oz in a 16 gal tank) dose of TECHRON CONCENTRATE PLUS in the gas tank, too.

Very, very pleased with the results. I just can't say enough good things about GM's Upper Engine Cleaner.

I'll report on oil consumption in a week or two.

accordturb96

So you have gained some comp by cleaning the ring lands with This product? Was the comp test done in similar conditions and weather conditions?

mattfranklin

Probably pretty similar weather. The key is that #3 changed relative to the others, which didn't change much at all.

mattfranklin

Here's the MSDS for GM Upper Engine Cleaner: http://paceperformance.com/attachment/55141-.pdf

mattfranklin

I think the oil consumption is better now.

It used to be ~1000-1200 miles with 20W-50 and 500-600 miles with 10W30.

Now it's ~1000 with 5W-20. Not perfect, but a lot better than it was.

Before my next oil change I'm planning to try the clean-up procedure one or two more times. And I'll check compression before and after that again. Maybe in a month or two I'll have the results.

mattfranklin

Bad News. I just checked the compression again. #3 is bad again. I'm leaning toward valve problems. I put a borescope inside to take a look. There were some scratches in the bore -- a few more in #3 than #2 -- no smoking gun there, though. But the exhaust valves didn't look too good. Hard to say because it was a challenge to get the right angle with the borescope. But in the image I saw the exhaust valve faces were kind of dark.

I had the dealer do another diagnostic to help drill into why #3 was bad. They said #3 had 80% leakdown and the others were about 30%. They said the technician could hear it in the intake.

Now I'm thinking about the following:
1) swapping new valves ($160 + $50 for gaskets)
2) swapping for a rebuilt head ($350 + $50 for gaskets)
3) swapping in a JDM engine ($500)

I would probably be doing this myself, so time is a bigger issue than the differences in these costs. Sure, I'd like to save a few hundred bucks, but if the JDM replacement takes less total time then that's what I want. Trying to figure out what will take less time. And I want to make sure than an F23A is a CARB acceptable replacement for an F23A4,

Any guidance here? I've swapped a few 1970s light truck V-8s and a Jeep 4-cyl, but have not yet done a front-drive car.

Lost Again

Just me but if "time" is the biggest thing, I'd go with option #2

mattfranklin

Good point. I'm thinking I may even pick up a JDM for $475 if they're still available and use just the head from that. That way I can test my disassembly skills once before I tackle a live vehicle.

mattfranklin

It was getting worse, so I wimped out and just had a local shop do all the work. About $2500 for everything. I wish I had the time to do it myself, but the reality of work and family schedules is that I no longer have spare time for fun projects like this. It was a burned exhaust valve.

Runs strong again now.

We'll see what, if any, impact that has on the oil consumption.

mattfranklin

UPDATE:
The head rebuild was good for a few more years -- however it did not take care of the oil consumption issue.
Near the end it was using about a quart of 20W-50 or 15W-40 every ~350 miles.

It finally burned a valve again in Aug of 2018, a little over a year ago.
I've been waffling on what to do with it.
While it would be fun to rebuild myself, I already have another fun project car, a 1998 Civic, in better shape.
So I'll probably sell as-is or donate to the Red Cross or something like that.
My curiosity is killing me though, I'd still like to pull out #3 piston and see if there is anything obviously wrong with the oil rings.
But maybe I'll just have to let that stay a mystery.