does my CRV need a ring job at 90k?

[Dr. Jerryrigger]

It’s a 2002 CRV with the 2.4l engine (I think that’s the only thing they put in them, at least in the US). Yesterday I put in new spark plugs and did a compression test while I was at it. 175,175,143,164. Wet test on #3 was 180psi (I only wet tested #3 and #2 for comparison).
This seems crazy for a Honda with so few miles. It doesn’t eat oil and runs okay. How long might it have before it becomes a problem? Should I trade it in now and not look back?
Thank You

PS, I’m sure I did the test correctly.

Topic

[Lorrin Barth]

I’d suggest testing it again before jumping to conclusions. I’ve seen cylinders that were low one day be okay the next. If the results are the same then it is not a good sign. Even Honda can make a bad engine.

[college man]

If the wet test did increase that would indicate rings.
see if compression comes up on and #4 wet

[Dr. Jerryrigger]

Thanks guys. I’ll give it another test when I get around to it, but I’m not hopeful. I had some suspicions before I did the test.
Is this something I can live with for a while or is it likely to get worse fast?

[Bryan Carter]

[quote=”Dr. Jerryrigger” post=110987]Is this something I can live with for a while or is it likely to get worse fast?[/quote]

The depends on why the compression is low. If it’s due to uneven wear in that particular cylinder bore, then you can probably milk it along for quite some time. On the flip side, if it’s due to some sort of physical ring damage, then it could stay this way forever or fail completely tomorrow.

[Ingvar]

Before going nuts on this, run a can of Seafoam through engine oil. For maybe a thousand miles, then do oil change. See, Seafom is good about dissolving gunk. Anywhere it goes. And oil does go to piston rings.
Just FYI, I had Seafoam in my Ranger engine for 2500 miles, out of curiosity.

[Dr. Jerryrigger]

I would guess due the the low mileage that there is some defect in something rather than the wall and ring being warn (unless the first owner put 70k on it all in first gear).

I don’t see how sea foam would help. If anything gunk would help compression in this case. Unless there was a major shortage of oil going to this one cylinder, but even then; given the test results, major damage has been done (or there is a different underlying problem).

[Lorrin Barth]

Maybe check out Eric’s leakdown video.

[Glenn]

One more suggestion here… Try a different compression gauge. I almost condemned a good engine once, when getting bad readings from the gauge. It’s best to be sure…

[Dr. Jerryrigger]

[quote=”tomatofarmer1″ post=111008]One more suggestion here… Try a different compression gauge. I almost condemned a good engine once, when getting bad readings from the gauge. It’s best to be sure…[/quote]

Good idea, but I’m pretty sure of the tool. I went back through each cylinder and got within 2psi of the first test.

[Dr. Jerryrigger]

[quote=”barneyb” post=111007]Maybe check out Eric’s leakdown video.[/quote]
I saw that when it first came out. Unfortunately I don’t have an air compressor….

[Rereonehundred]

I think compression tests are over-rated as a diagnostic. Big differences are surely meaningful, but difference of 25 psi or so never concern me.

Keep in mind that some compression testing equipment is poorly designed, hard to use, and dysfunctional.

Also, compression tests are meaningless for ring condition inferences unless all your valves are known to be perfectly sealing.

And the “gas dynamics” (air flow into and out of the engine)are very very different at cranking speed versus running speed.

And hot versus cold engine can be really important if some rings are cold stuck but not hot stuck.

If the engine runs reasonably well with close to its expected efficiency (fuel mileage), then just run it and don’t let compression variances worry you.

[Mantas]

Is idle silky smooth? If it’s still under warranty, then let the dealer fix it. If not – sell it

[Joeseph Mama]

I vote for the suggested leak-down test. Early diagnosis of why cylinder #3 is losing compression might save you money in the long run.

Maybe you just need a valve adjustment.. or a valve guide seal, burnt valve, valve spring, blocked oil passage, or maybe early signs of a head gasket failure.. or maybe it’s rings.. or EGR…. or a PCV problem.. or cylinder out-of round.

Q: Has this engine ever overheated? I wonder if you could give us a little history here (collision(s), auto-racing, nitro upgrade, teenage driver, flood damage, etc.)

Since you don’t have an air compressor, I’d take it down to the shop and spend a couple of bucks and have a mechanic perform the leak-down for ye’. Having someone else corroborate your findings will also increase the validity your rest results. Furthermore, I wouldn’t even let the technician know what cylinder you suspect is at fault… let him come to you with his findings. An opinion from Eric the Honda Guru might also prove useful here.

While you’re in the shop, an additional test you could ask for could be a relative compression test.

You have the advantage of your pro-active and early diagnostic.. I’d hate for you waste this opportunity to get ahead of something before it gets worse.

[Dr. Jerryrigger]

Thanks you all for the replies!
I’m planning on testing it again because why not? I had planned on adjusting valve lash this weekend, but I’m thinking I’ll just do #3 for um… Science.
I guess it could be a stuck ring, so opening the oil plug and dumping a can of sea foam into that cylinder might help…but has anyone ever had a ring stuck in the piston? Ever? Maybe on something that hasn’t been driven in 20 years, maybe. My concern with that is crud could be making to compression better, and if I want to unload this thing…

Ratchet Face,
Very good point. Paying for an hour of work is well worth the price. Also I’ve only been to a pro twice;it’s a fear I need to work on now that I have a child and a job that pays okay.

[EricTheCarGuy]

I’ll start by saying that I don’t think the Seafoam is going to do anything. It can’t hurt, but based on the problem you’re describing, I feel it will have absolutely no effect.

As suggested the leak down will tell you how much of an issue the low compression is, but to be honest, I’ve seen plenty of engines with one cylinder down slightly on compression and it didn’t cause an issue. You may be overreacting a little on this.

As for engine wear, it really depends on how it was taken care of. The more neglect, the more wear. With Honda engines, they last a good long time, even if they’re damaged in some way. In short, I wouldn’t loose sleep over this.

Lastly, be cautious with your valve adjustment. I’ve seen more engines damaged by novice valve adjustments than I care to count. If the valves aren’t noisy, I would leave them alone.

Good luck and keep us posted on your progress.

[Author]

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