What's wrong with my car?
January 19, 2008 8:13 AM   Subscribe

Two mechanics have given up. Help me diagnose my car.

I drive a 94 Honda Accord with about 194,000 miles. I have a problem with it going dead while I am driving. For the past three weeks it will, at random times (when driving, when stopped, when going very slowly or going 45 mph, uphill, downhill, even grade, and sometimes not at all for days), cut off: the check engine light comes on and the engine dies. There is no spluttering or anything, and I can start it up again easily, although lately it's been taking a little longer to start. The first mechanic found an oil leak around where the spark plugs are and changed the gasket and plugs, but this did not correct the problem. He said he couldn't find anything else wrong. Took it to the second shop for a diagnostic, and they called me back a few hours later and said they also could find nothing wrong and I could come pick it up. The mechanic there said it could be something with the distributor, but he didn't advise me to get any work done in that area because it would be a lot of money and could very easily not be it at all. He said I would most likely have to just keep driving the car until it gave out all together and then someone could find the problem. It is perhaps unnecessary for me to say that I found this suggestion to be neither convenient nor safe. What should I do? Just start changing one component at a time until I hit upon the right one?
posted by frobozz to Travel & Transportation (19 answers total) 2 users marked this as a favorite
I had a similair problem with my car (96 Primera) a while back. Turned out there was a crack in the distributor cap, which was letting moisture in. I looked around in breakers sites online for parts and managed to pick a used distributor up for about £40 and had that put in and it's been fine ever since.

The fact that you can start yours when it happens makes me wonder though, it took at least half an hour of waiting to get mine to start when it happened, and there were a few times it took days...

I can't tell you exactly what but I'm pretty sure my mechanic managed to diagnose it from the electrical system on my car, but it may have been because it was a slightly unusual setup which led pinned it down to it being one of a couple of possible parts.
If there's any way you can be more sure it's the distributor and find a second hand one cheap, you could try that, but for a car of that age (as I well know) it gets to the point where it's as easy to get something slightly younger. I'm never sure when I get mine fixed whether it will survive long enough for it to be worthwhile.
posted by opsin at 8:30 AM on January 19, 2008

Could be a flakey ignition switch. Do you have a large key ring? Try taking the ignition key off your ring and using just that.

You can also read the codes right after if happens. From Yahoo answers

On a '94 Civic you need a "jumper" to retrieved stored codes in the ecu. There is a blue connector under the glove box that is "jumped" to read out the code(s) in the form of blinks via the "check engine light". You need to be able to read those flashes to properly determine what code or codes are causing the engine light to come on. You cannot use a scanner.
posted by IronSurfer at 8:42 AM on January 19, 2008

I'd have to say that the distributor is the best place to look for a fault of this type. I'd also try to run a few bottles of fuel injector cleaner through it, or have your mechanic clean the throttle body.

If it's some other intermittent electrical short, it may be very expensive to trace.
posted by kuujjuarapik at 8:43 AM on January 19, 2008

It was never going to be the spark plugs, that's for sure. Not in a million years are those symptoms evidence of a spark plug or gasket problem. He got some money for old rope there - scratch him off your list for starters! I'd certainly give a thumbs up to the second mechanic for his advice and add him to my 'people I trust' list. Not only did he admit he didn't find anything, but also advised against spending any work unless he was sure of where to start. In case there is any ambiguity, this is a good thing.

As to the car itself, without actually poking and touching it there is very little else that we can help with, other than give the second mechanic some ideas he's probably thought of. Anyone that pretends to diagnose it here will also be guessing, and any answers should be given no more than equal merit as 'possibiities' - even anecdotally similar events. There simply isn't enough to go one without more information or having the car in front of you to do anything other than speculate.

It is perhaps unnecessary for me to say that I found this suggestion to be neither convenient nor safe.

As I've said already recently about intermittent faults, this may be the only way to find the fault without randomly replacing parts on hunches. This will be extremely expensive. The most expedient way of finding the fault is to try and make it do it, or establish a pattern. It sounds like you have tried this, but are perhaps discounting things that don't occur to you as being relevant.

If the check engine light alwayscomes on when it stalls (and it doesn't when the car otherwise stops running - can you check this? Is it a manual gearbox/stick?) then it suggests to me that the ECU is somehow losing a signal and so can't keep the car running. My gut feeling is that it will be a fairly fundamental part, or it'd lope/hesitate/otherwise try and use a default map in there to keep the car running. But this is blind guesswork. Things that I would check initially are for dirty earth connections or broken wires on the battery and engine earthing points. I'd also check the crank position sensor wires, as this may be losing the signal. I'd then check anything that the ECU relies on constant monitoring of to keep the engine running. But seriously, this could be absolutely anything in your electrical/air intake system, or even fuel system, as there isn't enough to go on with the detail we have here. We'd be completely shooting in the dark.

First: If it is a manual gearbox, try stalling the car against the brakes. Does the check engine light come on? If it does, then that element is not helpful as it means that light comes on every time the engine stops without using the key. Then all bets are off with the above, although you coudl still be looking for a loose connection/broken wire, it's just the ECU won't help as a starting point.

I think the key is to make it do it. Do you have tow coverage? My suggestion would be to take some time where you don't need to be anywhere, drive it around in favourable conditions where you don't endanger yourself when it fails (ie not on the freeway) and when it stalls, don't try and restart it (tell the tow truck guy that!) and get a diagnostic computer hooked up and find the fault code as to why the engine stopped. Restarting it will clear that code, so that has to be a no-no.

You may even be able to do this with the mechanic's help - drive within a few mile of his shop around and around and call him when it stops. He could perhaps come out and diagnose it on the spot when it has failed. Just an idea, as he may not be willing, of course, but until it fails in front of him, he has nothing to go on.

Just start changing one component at a time until I hit upon the right one?

Absolutely not, for summary. You could be there for days, spend hundreds and not find it. You need more information and to find more evidence. Without getting you to try various things and report back, this is as far as any useful advice will go here. Search any Honda forums for idea and similar symptoms to get to your mechanic (the second one, the first one doesn't sound too sharp to me) as a starting point.
posted by Brockles at 8:45 AM on January 19, 2008 [2 favorites]

I had a '92 Subaru SVX that liked to die on me for no reason. The culprit was a bad O2 sensor. They're relatively inexpensive, so you might want to look into those.
posted by BiffSlamkovich at 8:46 AM on January 19, 2008

I had the ignition switch changed a couple of years ago; didn't seem like exactly the same symptoms then. Put in a couple of bottles of fuel injector cleaner back when it first started.

Brockles, thanks for that answer. It never occurred to me not to try to start it again (but then I didn't know about the codes...). I'll call the second mechanic and run the idea by him of trying to get it to stop in the vicinity of his shop.

Oh, and yes, the check engine light always comes on simultaneously with the engine going dead. It goes off when it starts up again. (When it takes a few tries to start, the light stays on until it's started.) It's not a manual so I can't try stalling it.

posted by frobozz at 9:20 AM on January 19, 2008

I have a 92 civic with 170,000 miles on it and it does a similar thing. Mine is manual transmission, and when I drive it short distances it's fine. When I drive for more than 20 minutes or so, it has trouble holding the idle at the correct rpm. I would press on the gas pedal to increase the rpm, because without doing that, it would die.

I'm a DIY-we and I like to try and fix or figure things out on my own. I read hundreds of boards, looking for someone to have my exact same problem - and I came away with a list of diagnosis from the o2 sensor, the distributor cap, wiring... Finally I took it in to the Honda dealer for a diagnosis-only
service. $65 later, they tell me they believe I have a blown head gasket, and that fixing it is not a fun process because you have to leave your car at a shop for 2+days, its labor intensive and mecanics don't really like to do it because they've got to tear the engine apart and tie up a bay while they send your gasket to a machinist who does some sort of test to look for cracks. At the dealer, the repair would cost $800 and they could not guarentee that it wouldn't blow again after getting it repaired. I went home and researched symptoms of a blown head gasket and they sound just about right, although I don't want to do the repair because it seems like throwing $$$ away since the repair is tenuious. I did learn about many sealing fluids that promise all kinds of things - including resealing the thing perfectly. Steelseal seemed like the best one to try, although I haven't yet. The process involves draining your coolant, putting fresh back in along with the sealant, and revving the engine at a certain rpm for 20 mind or so. Its too cold now to do all this outside where I live. My temporary solution has been to switch cars with my boyfriend, who graciously let's me drive his car on my 25min highway commute. He drives my car or rides a bike the 5 minute distance to his work. I feel lucky to not have to deal with it right now, but eventually, in the spring, I'm going to try the sealer because it can't hurt it anymore than its already performing.

The dealer said the concept of the head gasket keeps the pressure between the coolant and the engine block even. With a leaky head gasket,the engine can't maintain proper pressure. With mine, he said it may have happened because I hadn't flushed my coolant in a looonngg time. Winterize, is what the shops call it. He said coolant can turn acidic and eat the seal, which looks to be some sort of hard rubber.

Good luck figuring your own auto mystery out! I do recommend the dealer analysis, although you have to go on knowing 1) every service they recommed is going to have a large pricetag and 2) they will pressure you to get it fixed there. I was very clear from the moment I walked in that I was there for the diagnostic service. I had to hold firm and repeat it three or four times, but I never came across blown head gasket in all my forum searching - and I looked for weeks. Let us know what happens!
posted by nyoki at 9:55 AM on January 19, 2008

As Brockles said, for the engine to stop rather than just hiccup and change performance , that signifies something fairly fundamental.

If it stops dead as if you had just turned it off, it's most likely something electrical like the spark control computer. It is failing or losing power. Or it's losing the engine position signal. The car Will Not Run if it doesn't know when to send the spark. Probably a Hall effect switch in the distributor, or could be a crank/cam position sensor. Or the wiring to the ignition coil is loose/corroded/shorting.

If it sputters a little and hiccups and then dies, consider the fuel pump, especially the wiring to it. Or a relay that controls it.

Seals, gaskets, sparkplugs, spark wires, alternator, battery- all these things would either leave the car completely dead, or merely lower performance.

If you're adventurous, start the car and start jiggling things in the engine compartment to see if anything causes it to die. Don't touch the spark plug wires- the can kill you, or worse give you a shock that will make you wish you were dead.
posted by gjc at 10:13 AM on January 19, 2008

Nyoki: Your problem sounds entirely unrelated to me. Also 'sending the head gasket off to a machinist' is bullshit*. You just replace head gaskets as they have 'one use only' compression seals in them. Any workshop can do it, but it can be a long job. 2 days is utter crap, mind you - I've replaced a head gasket on a VW Golf in under an hour (between lectures at Uni!) and while the Civic is more complicated, it is NOT a 16 hour job. It should be in and out in one day easily. I think your dealer can't be bothered to do it.

I've never known a 'sealer' that works on head gaskets, and your example assumes it is a coolant part of the gasket that has been blown, not (say) between pistons, or between pistons and oil system. You'd need more information before that was even worth trying - it may do absolutely nothing - although I am assuming the dealer has some evidence in assuming that was where the issue was. Either way, if the cylinder is leaking into the water system (as opposed to the water system leaking to outside the engine) you have no chance of any sealant resisting the forces and pressure involved long enough to set and seal it.

Incidentally, either he explained his reasoning badly, or he doesn't know what he's talking about, or you are not remembering clearly, as his reasoning for the gasket's purpose and failure is somewhere between warped and untrue. The gasket is to keep the two systems entirely separate, not balance them in any way. Also, unless the engine has been overheated through loss of water (do you check you water level regularly?) there is no reason to suspect that the head gasket replacement won't work perfectly well if done properly.

Head gaskets are not usually (purely for reference) made of any rubber compound.

Perhaps you either need a separate askme question if you want to pursue this and analyse your options further, or just go and get a head gasket replacement priced at your local (non-dealer) shop.

*It has just occurred to me he may have meant "Send the head off for pressure checking at a machinists" rather than the gasket. On a 1992 car, that is 'belt and braces' and most likely unnecessary. The chances of the head itself being faulty is much lower than the head gasket failing. I'd get the gasket done and if it fails again, it just tells you the engine is junk, as it is then likely that the head (top quarter of the engine as you look at it) has failed internally. This is usually not fixable and a car of that mileage and age will mean a new head is not a cost effective repair and a reconditioned head won't help any other issues with the 170,000 mile bottom 3/4 of the engine. The car is then either scrap, or you get a reconditioned engine.
posted by Brockles at 10:20 AM on January 19, 2008

gjc: no sputtering at all - in fact, I had a friend driving it a couple of days ago and he didn't even realize the engine had shut off until I told him after we had been coasting for a couple of seconds (it's normally a very quiet running car).
posted by frobozz at 10:33 AM on January 19, 2008

Sounds like a faulty igniter to me. Common problem on the Hondas.
posted by ninjew at 10:40 AM on January 19, 2008

wow - thanks. Yes, I'm probably explaining the situation badly and I am not an engine expert, so please excuse my naive ways. I guess I was sharing what I thought was an analysis of a situation that I had not read in other forums. I wasn't probing for an answer, but I'm interested in what you said. Thanks!

... Now back to our regularly scheduled program ...
posted by nyoki at 10:41 AM on January 19, 2008

Call car talk. You missed this week's show, but that's ok because I'm pretty sure it takes people a few weeks to make it on the air. For all that they're really silly guys, they have good ideas (and if they're stumped, they go onto their forums and ask the other people who hang out there the question. Good luck!
posted by arnicae at 10:52 AM on January 19, 2008

This sounds a little bit like when my fuel pump failed. The key to diagnosing it was to have the mechanic keep it for a day or two and drive it around and let it run (30 minutes plus, usually) to let it fail in their presence.

Hope you find an answer for cheap.
posted by Riverine at 11:00 AM on January 19, 2008

I'd second Riverine's suggestion - a dying fuel pump will easily cause this sort of problem. But yeah, before you replace it, give the car to your mechanic for a few days, most good mechs will do this. Although it probably means their parts runner will beat the hell out of your car for a day.
posted by M.C. Lo-Carb! at 11:22 AM on January 19, 2008

a dying fuel pump will easily cause this sort of problem

So could any of the following:
a bad distributor cap.
A bad rotor arm/pickup
ECU dry joint internally
Poor earth to ECU
Poor main earth
Poor earth to fuel pump
Poor earth to any one of the following sensors: O2, crank position, Air flow meter, knock sensor, fuel pressure sender (if fitted)
Any faulty wire of some kind to any of the above.
Debris in the fuel tank
A collapsed/otherwise blocked fuel filter
internally cracked spark coil/coils
etc., etc

There is nothing like enough information to discount any of those, or probably some more I could come up with. Wild, internet stabs in the dark (even from Car Talk) will likely cost you more money than sticking to basics - try and find more parameters of the failure and/or make it repeatable. Then make the problem happen in front of someone who knows what they are doing.

'My car just stops running' is impossible to diagnose, even with the car in front of you, unless it shows evidence of the problem. Guessing as to specifics is as likely to be just as unhelpful as it is to replace items randomly. They aren't helping, and "it happened to my car" is no real use to anyone.
posted by Brockles at 11:45 AM on January 19, 2008

I had a similar problem in a 1994 Jetta. Long story short, it was a faulty relay (I think it was the one for the engine computer). The relays are usually mounted near the fuse box underneath the dash. Tap around on them while the engine is running and see if any of them cause the engine to die.
posted by Brian James at 12:58 PM on January 19, 2008

Frobozz: The oil leak is not your problem, as others have mentioned--and it could be several things at this point, also as others have mentioned.

You mention it's been happening for about three weeks, and it looks like your local temperature dipped around that time, too. That could slightly tilt the balance toward more electrical-type problems, as the expansion/contraction of temperature extremes probably affect electrical connections (and, incidentally, vacuum leaks) more than fuel pump issues.

Nyoki: I wouldn't trust that dealer; my experience is that the symptoms you list are not generally caused by a head gasket (in my car it would be most commonly a vacuum (or manifold) leak or (maybe?) a carburetor in need of a rebuild. In fact-- I have that problem right now and it's probably a cracked manifold.
posted by RikiTikiTavi at 11:59 PM on January 19, 2008

Sounds a lot like the problem I was having with my '93 Civic (94K miles). When I'd stop it would cut out intermittently. And later I began having trouble starting the car. After trying a number of things over the years (yes, I drove it like this for years), my mechanic finally replaced the distributor and it's been great since. (Cost me about $300 if I remember correctly.) Unfortunately now the engine light is always on and his diagnostic equipment can't figure that out.

I'm thinking I'll have to donate the thing to a worthy non-profit because I wouldn't get a decent trade value for it and I wouldn't feel right selling it to someone.
posted by booth at 9:26 AM on January 20, 2008

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