Riick

If I let my '93 civic sit for more than 24 hours it does the following:
-stalls at intersections
-"bucks" on the highway
-sputters a lot when idling
-has coolant displaced by air

These symptoms eventually go away after a lot of driving, only to return if I don't drive frequently enough.

Any ideas on what's going on?

kellogg6316

check the computer for trouble codes. Jump the 2-pin connector underneath the glovebox. Count the blinks of the check engine light with key at On position.

Stock 99

You mean your coolant reservoir is overflowing? Check for failed head gasket.

Riick

No blinks. (Check engine light just stays on when I jump the connector.) Not too surprising perhaps since check engine light does not come on when I drive.

Riick

Chemical testing showed no head gasket problem (no traces of exhaust detected in coolant).

Riick

New information:
1) The stalling and bucking begins once the engine is warm - after the temperature gauge has stopped rising.
2) After a stall I sometimes have to floor the gas for it to restart. (Then it sputters and coughs for several seconds before suddenly roaring to full throttle.)

To recap:
If the car has been sitting a few days it will stall at intersections and buck on the highway, but only when the engine is fully warmed up. When it stalls it often refuses to restart unless I'm flooring the gas. The problem goes away after I have driven the car a lot (an hour or two), but it comes back any time I let the car sit for a few days. There is also disappearing coolant and occasional air pockets in the coolant system.

Stock 99

LOL, After 4 weeks I'd figured you'd probably solved this by now. I didn't even notice it was an old post until I had posted the other day.

I'd be trying to figure out where the coolant is going check it hard for external leaks. Apparently there is some sort of UV dye you can put in your coolant that will help to visually see the leak. I don't know I've never done that but I've read about it lots on this forum. Once your 100% sure there are no leaks then the only other place it can be going is into your combustion camber and being burnt out the exhaust. I know you say you tested for that but that does sound like what's going on to me. ie. water/coolant in the pistons is making it run crappy.

Riick

I did find some coolant seeping out of a cracked hose feeding the intake valve. (The Honda parts websites ID it as "HOSE, WAX IN.")
Could a coolant leak in this location cause stalling? (Like by lowering the coolant's temperature so the intake valve is positioned wrong?)

Nah- 4 weeks is nothing-- with my luck I still won't know what's going on 4 months from now!

Riick

I think Stock 99 may be correct. I taped a bit of paper towel to a dowel (securely) and the #1 piston is slightly damp. Also there is some dark gray sludge in the coolant. But coolant getting into the cylinder can't be the full story. Here's why:
1) The engine always runs smooth while it's still cool - yet this is when there should be the most coolant in the cylinder.
2) The problem persists for several DAYS afterward - yet the coolant should burn off in just a few minutes.
(Even if you assume more coolant is spraying into the cylinder when it's hot, why would this stop after a few days of use?)

So... is it possible that the sludge in the coolant is settling firmly on something while the car sits (temperature sensor perhaps) and then takes several days to wash off?

It would be helpful for me to know; I am looking for a solution (flushing the coolant?) which might buy me a couple weeks while I look into head gaskets or new a car.

Stock 99

Hmm, when the car comes up to temperature the tstat opens and starts circulating coolant through the block. As well, the cooling system won't be pressurized when it's cold. That maybe why it's doing it while its hot. Have you checked to see if your oil level is going up or your oil looks 'milkshakey'? If so then the coolant is getting into your oil. Here's a DIY on probably a different model civic engine then yours but it'll give you an idea what's involved. Look at the pics towards the bottom with the HG off and it'll give you a better idea of how the coolant is flowing around the cylinders.


http://hondaswap.com/general-tech-ar...ts-pics-71528/

Riick

OK, but this should also be true even if the car has been driven every day. Yet I have few troubles then. That's what puzzles me. It seems unlikely that frequent driving could cause the hole to plug itself up. Any ideas? [/quote]

Oil is dark but neither cloudy nor frothy. I'll check the level tomorrow.

Great link! Any other do-it-yourself head gasket links you know of? How do I find specs on torque and such? (I think I feel a project coming on... )

Stock 99

Yeah, I was just putting that out there. Tstat/coolant pressure being the major differences when it's warmed up. I don't know how the sitting for days factors in. The only thing I can think of is the gasket is still in early stages of failure. Generally the compression of the engine pushes into the cooling system and causes your coolant to overflow from the reservoir.

It would be helpful to know what model your engine is. Figure that out and get a FSM (Factory Service Manual) it will answer alot of questions for you.

I don't know if the 5th gens are stamped with the engine model # in the same place but this is where it is on the 6th gen...

https://www.civicforums.com/forums/1...vic-motor.html


This is a shot of my FSM with the exploded view of the headgasket. Cylinder bolts are torqued to 49 ft-lbs on my D16Y7

lazlong

Try having the coolant system flushed. With the "sludge" you may have a clog in the coolant system.

Riick

After a drive with bucking problems I always find a bubble in the cooling system, but it's never big enough to push coolant all the way out of the reservoir.
I do go through a lot of coolant (1gal/400 miles?), yet there is only a tiny bit of moisture on the cracked hose. Given the steady drip of water out the tailpipe (only when the engine is running poorly), the dampness in the #1 cylinder, the sludge in the coolant, and the occasional coolant bubble, am I correct in assuming the headgasket is DEFINITELY leaking? Or could the cracked hose and sludge account for all of this?

That Field Service Manual looks fantastic. I'll check for my engine model number tomorrow.

Riick

Would that cause these symptoms?

Whatever it is it's getting worse. Now it won't stay running for more than a minute, and the engine speed is all over the place (it's not just cycling - it sounds like someone is doing random things with the gas pedal.) It used to run smoothly until it warmed up fully; now it only runs smoothly for the first ten seconds.

Stock 99

LOL, are you kidding? You'd think if it was leaking that much it would be easy to see. Your cooling system only holds around 1 gal so I guess you're kinda of flushing it as you drive.

02civicsi02

If its leaking that much its leaking somewhere, so look everywhere on top and under. What anti freeze are you using cause you should only use hondas cause others can cause problems. Are you making sure you bleed it good cause it usually takes 10 mins or more to bleed it if putting a gallon in at a time. Plus with the bucking and stalling sounds like its getting into the cylinders or something, check your o2 sensors for it to be like white I think for coolant burning.

Riick

1) Cracked hose connecting to the air intake valve. Not dripping, just has a spec of coolant sometimes.
2) Sometimes a drop of coolant hangs where the radiator intake hose connects to the engine.
3) The #1 cylinder is damp; just moist on top of the piston sometimes. And when the engine is behaving poorly water drips out the exhaust; not sure whether that is from poor combustion or from coolant.

Never heard that before! Can you point me to a website where this is discussed? I know orange dex-cool can damage cars not designed for it, but I'm skeptical that the brand makes much difference. Mine is the traditional green kind but I seriously doubt it's the Honda brand.

I put in about 1/4 cup each time I drive. Bleeding is kind of pointless because air ends up back in the system no matter how well it is bled.

Good suggestion, but I think I'd need an o2 sensor wrench so that's going to have to wait.

Riick

I agree! I did find some leaks (see previous post) but can they account for this much loss? Based on what I've said in this thread, do you think I can DEFINITELY assume the head gasket is leaking?

Stock 99

Instead of checking your O2 sensor just check your plugs. Pic below was a plug taken from a car burning coolant.

I'm always hesitant to say 'yes DEFINITELY' because I'm just some dick sitting at a computer on the other side of the continent in another country from where your car is located. Maybe there's some information I don't have that would lead to another conclusion but like I said before if your absolutely sure it's not leaking then it has to be burning coolant. Fix your leaks and see if there's a difference. It's possible that it's leaking on to your exhaust and evaporating off so it's hard to see. You can try putting a piece of cardboard underneath your engine after driving and see if coolant is leaking somewhere you haven't noticed as well. I would exhaust all my options before I started tearing an engine apart.

lazlong

FYI: An O2 sensor wrench is less than $10 and is available at any auto parts or tool store.

Riick

Mine definitely aren't furry like that. But the #1 was actually moist after a particularly large amount of bucking.

Yes exactly. Unfortunately, I suspect that after doing all the tests under the sun I'm still not going to have any definitive answers.

My performance problems are eerily similar to what happens with low fuel pressure. I will probably get a fuel pressure gauge (and attachment) before committing to a head gasket repair.

Riick

That is less than I expected. Problem is it will be a few days before anyone can drive me to the auto parts store.

Stock 99

Well, if you take coolant loss out of the equation. Then you might want to check your PGM-FI main relay as well


http://www.tegger.com/hondafaq/mainrelay.html

Riick

Never heard of the three click test; I'll do that and also test the ignition switch test tomorrow. Looks like I also should consider testing my igniter and my coil. That tegger site is pretty nice.

Riick

Status:
1) Car does not start at all now.
2) Main relay - passes first two tests, but third click is drowned out by starter motor so I can't hear it.
3) Ignition switch - passes all tests.
4) Plugs - Looks like there are white crystals on #1 after all (see pics).

Conclusion: Will keep testing spark/fuel problems... I don't think a slow coolant leak can prevent starting.

dstroman

Fix your coolant problems before checking relays. the problems didn't start with electrical it sounds like it was mechanical to begin with. A warped head is going to change shape when it gets up to temperature. not sure how it wouldn't go back to crap after the head cooled. And now car doesn't run. check Spark compression and Fuel. if you have no compression the car isn't really gonna run. likewise with the spark and fuel

Riick

Seems I have a bad coil. Spark was weak and orange, coil has rainbow scorch marks (see pic), and positive-secondary resistance was too low- should be 13200 to 19800 ohms but it was 10000. A bad coil would explain the bucking/stalling when warm as well as the soot on the #2 and #3 spark plugs. It will be a few days until the new coil arrives...

As for the coolant, I will replace the cracked hose, backflush really well, and also flush with sodium citrate. Then I can see whether the sludge comes back and tell how quickly coolant is going into the engine. Is there any chance the sodium citrate could increase the head leak or cause a heater leak?

dstroman

i wouldn't flush it with anything. chemical will only make a leaky gasket worse. just drain and fill. Strange it was only acting up on a couple cylinders. i would have just tried a used dizzy i guess instead of replacing the coil but if the resistance is off then thats probably your best bet for bucking issues. (and yeah ur spark should be like a bright blue color). coolant issue doesn't sound good.
i had 2 cars that u had to add coolant everytime you drove it and i know the 1 car for sure had a bad head gasket so adding the coolant everytime isn't a good sign but you should still be able to drive it (the second car with the problem i still have and i drove it for about 6 months adding coolant every time i drove) hopefully the coil will fix the first 2 problems then u have something to drive at least until u can replace the head gasket. i know somebody will probably yell at me for saying u can probably drive it but i never said it wont hurt it, coolant is not something you want getting into the combustion chamber because when it burns it leaves behind residue that will clog and interfere with injectors and o2 sensor

Riick

I'm sure all four were affected. The soot is just more visible on 2&3 because they don't have additional problems confusing matters like 1&4 do. You can see what I'm talking about if you look at my pics of the spark plugs a few posts back...

Thanks for the tips on chemical flush and on driving with a leak. I'll post again after the parts come and I've had a chance to see if they helped.