End of the road for my Civic HX? (Update, HX fixed!)

[Jim-Bob]

I am rebuilding a 1992 Metro with a burnt exhaust valve that is in far worse shape than your car. I am using the opportunity to make it better on gas with modifications to the engine and a swap to a 5 speed transmission with a taller final drive than stock. Your problem is simple by comparison. Plus, I don't even have a job that pays all that well ( I deliver pizza) but I will still get it done.

[pumafeet10]

I have been feeling my hx has been performing sub par and had a cel and it was a mis fire that i cured with a new set of plugs since the cylinder 3 was fouled. I still seem to have a dead spot in the lower power band.

I have done a compression check and the same cylinder is down, next thing to check is leak down.

It will be much cheaper and way more eco-friendly as others have said to fix the engine.

you can buy parts from the dealer and have new piston rings put in as im sure the rods,crank and pistons are fine, but even if they aren't it still can be rebuilt relatively inexpensively with factory replacement parts.

i say keep it and fix it!

[NHRABill]

That kind of difference in cylinder pressure then you more than likely have one of a couple problems My guess would be valve seals or rings. how many miles on the car has it been properly maintained through its life?

there is too much pressure to be a hole in the piston and both of these are common on a engine with a lot of miles or one not maintained . Not sure of the parts prices for a Honda but on a American V8 that is really a cheap easy fix.

If it were me i would remove the head and if you don't know what you are doing get it tested at a machine shop It is probably just a valve seal $2 a pop or something else like a weak spring that needs to be replaced. Rebuilding a head is much better than sourcing a junkyard model which may have same issue. Replacing the motor for the unknown is never a solution unless you get new. You may be happy with a "fixed" car and not a new unknown or a unknown replacement. I like to fix stuff and not throw out for something new.

if it is a valve seal and you have head rebuilt it will cost a couple hundred to have someone do the head work you do the removal and reinstall + you add in new gaskets + fluids replace and you have a great gas mileage car again and it runs like new.

If it is a bad ring you need to pull motor take bottom end apart replace ring put it back together and done much more expensive if you have someone do it. Sorry to say you Honda guys get ripped off constantly for the work they do

Best of luck on your ride hope you figure it out.

[brucepick]

Thanks all.

To answer NHRABill's questions re. mileage and prior care:

I bought the car at 150K miles and it's now at 218K. When I got it the oil was dirty and even after a change it would be blackish again within a couple hundred miles. Also it would take 1-2 hours for oil to drain into crankcase so I could get a consistent dipstick reading. I deduced the drain passages were pretty well clogged.

I used at least three things in the oil at different times to clean the innards and now it drains within moments. Any oil added in the top shows up immediately on the stick, not as before. Also the oil doesn't go blackish with use, but it does darken normally after 2-3 thousand miles.

So my mechanic friend reports:

Lousy compression in Cyl. #2, which does NOT improve when adding oil via spark plug hole. So there's a head/valve problem.

The shop has a small video camera on a long gooseneck that can be used to observe the interior of the cylinder. Slick, huh!! One valve (underside) showed heavy whitish deposits from oil coming down the valve stem and burning while oil was coated onto valve. That would be a burned valve. Top (seat) side of valve isn't really visible but the damage is there. One of the four valves was invisible due to the cylinder configuration. But it's pretty wild you can see anything in there without taking it apart!

The remaining question is, are there also bad rings or are they OK? I don't think we want to do a whole rebuild but wifey might go for a top end rebuild. I'm going to have to pay somebody, I'm not up to the job.

For the rings: This weekend I plan to test for weak rings by putting a few ounces of light oil in each via spark plug hole. Note crankshaft position and measure depth of oil in each with a straw for a dipstick. Make notes of the depths. Then later, check all cylinders for draindown. If any are really bad I should see some differences between cylinders. I can also crank the engine with a wrench to work the rings a bit. Not like running the engine but I should see some differences between cylinders if any have really bad rings. If there are bad rings I might have to ditch the whole thing. Not worth our $$ to replace the whole engine with a questionable used one.

That's my story and I'm sticking to it. I'll post again after I complete the proposed rings draindown test.

[pumafeet10]

my thinking for buying the extra motor so that he would not have to deal with any down time, since i am guess this is his dd

[brucepick]

It is indeed my dd, but I still have my Volvo 240 which I can use while the Civic is down.

[Zerohour]

If you know what the problem is, the parts can be ordered, and the car can be back on the road within a week, especially if it is at a shop. You could always get a rental car as well. Booking them for a week is pretty cheap, especially if you're older than 25!

[NHRABill]

That is good news Brucepick,

A bad valve seal will really chew up your oil and lose compression. It sounds like you have a good shop you are working with many mechanics don't go through the trouble to scope. you can do the straw test but i think you have already found your answer.

have the head rebuilt new valves, seals, springs and valve guides whatever the shop thinks you need. It well cost a few bucks but you will have a nice running motor again with all new gaskets to boot.

Best of luck in getting her running again, It is sweet driving a car after it is properly fixed you feel all that you originally liked about it.

[Jim-Bob]

Given the history of poor maintenance the car has seen, I would seek out a JDM engine from one of the many salvage engine importers and go with that. You will want to vet it properly before purchase though. After installation, be sure to pull the plugs and spin it over until the oil light goes out. Otherwise, you will likely spin a bearing because of how long the salvage engines typically sit. The only other choice would be a full rebuild as the bearings and rings are likely shot at this point too.

[comptiger5000]

If the compression on the other cylinders is fine, and adding oil didn't help at all on that one, the rings are likely fine. The chances of them being more than a little off from the others wear-wise isn't enough to worry about.