My car! My precious car!
February 11, 2010 11:54 AM   Subscribe

I'm having car trouble. I know about computers not cars. I feel stupid. Can you help?

So my check engine light came on about three days ago and I ignored it because everything seemed OK.

I took it in this morning to my usual guy, and I just got the call back.

Apparently the diagnostic code indicated a problem with cylinder #3 on my engine. After a number of tests, it was found that it was only at 60 psi whereas the rest of my cylinders were at 120 psi.

I guess this is bad.

I asked him if he could fix it, and he said that as it was an internal problem the best fix he could suggest was that he could call around and try to find a used engine. Haha. Hahahaha.

Ha, Ha.

I asked him, as the car had been running fine (more or less), what consequences I risked by continuing to ignore the issue, and he gave some menacing grumbling about how the engine might shake apart or something and I might explode.

So, question #1, knowing that you are not my engineer or my mechanic or anybody, what reasonable consequence could I expect if I continue to drive this car with this issue?

Secondarily - I also had requested my regular oil change. He said he could not change the oil, because the dip stick wasn't registering any oil and that meant that it was probably a quart low or so. He said that, given the condition with the engine and the low oil already present, he had no desire to change the oil because if the engine seized, he would then be liable. He suggested I just take it to a JiffyLube style place, because they don't give a shit and they'll just change the fucking oil.

Question #2 - does that make sense?

Thanks, and feel free to send me money.
posted by kbanas to Travel & Transportation (28 answers total) 2 users marked this as a favorite
i know next to nothing about cars, but if my mechanic told me all those things about a car that i felt was running fine, i'd find a second mechanic for another opinion. you can also get check engine light codes checked at autozone/o'reillys for free.
posted by nadawi at 12:04 PM on February 11, 2010

Compression being low in one cylinder means that one or more of the seals that keep combustion gasses in the cylinder and engine oil out of the cylinder are broken; either a valve is damaged, or the rings are shot. Either is expensive to fix. The cylinder may stop working at all, in which case you'll have little power (poor acceleration, low top speed) and vibration. Your mechanic is assuming the engine is on borrowed time. If it fails suddenly on the freeway then, well, you could suddenly be stranded in the middle of the freeway. Which would be bad. Which he doesn't want to be liable for.

Yes, #2 makes sense. You've got significant internal engine problems, and he doesn't want to be involved unless you plan to actually fix them.
posted by jon1270 at 12:06 PM on February 11, 2010

Sorry to say this but yes it does make sense. Engines VERY carefully balance. One of the rings around your pistons could've lost it's seal but that's just one of many possibilities. I've replaced the rings on small engines, like a lawnmower but an engine rebuild on a car is extremely costly.

As far as him not wanting to change your oil, I don't blame him. Like he said if it's about to seize and he just changed your oil that would not look good on his behalf. Also, if it's not even registering on the dipstick you were, like he said, AT LEAST a quart low on oil. This is not good. Engines need the oil to stay lubricated and keep everything running smoothly. When it isn't, it starts to get hot and thats when things can bend, warp, and just get ruined all around.
posted by no bueno at 12:07 PM on February 11, 2010

IANAM, but a compression problem in a cylinder is fixed by either a valve- or ring-job, which is probably why he suggested a replacement of the engine, as opposed to a simple overhaul. It could be fixed, but would probably wind up being cheaper (in terms of time) just to replace. As to the long term effects, I suspect that you'll begin losing power and 'missing' while the engine is running. The cylinder needs a tight seal to compress the fuel/air mixture before the spark is fired, so without that, you get less bang, ergo, less power. Your mileage will probably start to suffer.

Could it shake apart? I'm not so sure about that. It'll certainly be running at less than optimum efficiency and would probably cause you to fail an emissions test.

As to number 2 - IANAL, but telling you to slink off somewhere else where it'll be 'someone else's problem' seems a bit on the sketchy side. Why wouldn't JiffyLube be just as liable for a problem? Usenet is something of a wasteland in most areas these days, but for car issues, I've had very good luck on the newsgroup as well as the manufacturer-specific groups for Toyota and Honda-related questions.

(on preview, what jon and no bueno said)
posted by jquinby at 12:08 PM on February 11, 2010

Also on the oil issue, it sounds likely that the rings on that piston are shot, and you're burning away engine oil as it leaks into the combustion chamber. As this worsens you will use oil progressively faster. You don't need to have a mechanic top it off; ask the mechanic what weight oil he suggests, then buy some yourself and dump it in, checking the level with the dipstick. It hardly sounds as if having an oil change done is worthwhile at this point.
posted by jon1270 at 12:10 PM on February 11, 2010

By the by, have you noticed any bluish smoke coming from the tailpipe? That's your dead giveaway that you're burning that oil off (because it's getting past the (shot) ring and into the cylinder.
posted by jquinby at 12:13 PM on February 11, 2010

Look, at least put some oil in there, ok? Driving around a quart low isn't going to help with anything.
posted by mr_roboto at 12:16 PM on February 11, 2010

Response by poster: Yeah, oil is the top priority.
posted by kbanas at 12:17 PM on February 11, 2010

Why wouldn't JiffyLube be just as liable for a problem?

Well, the mechanic doesn't care if JiffyLube is liable, just so long as he isn't liable. And JL isn't going to check compression before doing the oil change.
posted by mr_roboto at 12:20 PM on February 11, 2010

What make/model/year car are we talking about here? How many miles?

I doubt your mechanic would be so dishonest as to lie about something like this. Your engine is almost definitely on borrowed time here. You can either schedule some pain, or you can wait for some pain to come at any moment. Either way, this one WILL hurt.
posted by paanta at 12:20 PM on February 11, 2010

Response by poster: It's a 2004 Dodge Neon which was gifted to me by the estate of my grandparents after they died.

I kind of liked it because it was completely paid off.

Oh well. All things...
posted by kbanas at 12:26 PM on February 11, 2010

It's possible the low oil problem caused the piston skirt to break, also. Any way you look at it, very bad things are in your automotive future. Buy oil, check/top off the level every time you drive the car and add towing coverage to your insurance. The question is not if, but when the engine implodes and strands you somewhere. For future reference, engine fluid levels are both the easiest & most important engine service items to take care of.
posted by torquemaniac at 12:27 PM on February 11, 2010

Why wouldn't JiffyLube be just as liable for a problem?

Well, the mechanic doesn't care if JiffyLube is liable, just so long as he isn't liable. And JL isn't going to check compression before doing the oil change.

2nd this. I bought lots of cars/engines for claimants when I was an auto insurance claims rep and WhateverLube was my insured.

all kinds of stuff - they left the fill cap off, left bolts off, drained the oil and didn't put any in, you name it, I bought it.

now, all of the above were WhateverLube's fault, but I also paid stuff that may/may not have been WhateverLube's fault, on the condition that it happened reasonably quickly after the service was performed and could reasonably be construed as being the fault of WhateverLube.

furthermore, WhateverLube doesn't seem to care that much about the outcome of their garage liability claims either (in my experience). it's better for their PR to pay all but the stupidest, most egregious claims.

last but not least, paying the going rate for a commercial oil change at industry recommended intervals over the life of the original engine can actually cost more than the value of a new engine (based on personal observations of some of my friends). furthermore, a first-time oil change near the end-of-life of an engine whose oil has never been changed is pretty much the coup de gras for that machine.

bottom line, don't change the oil (if that's the situation you're in), just keep adding fresh and drive it til it dies.
posted by toodleydoodley at 12:49 PM on February 11, 2010

Are you sure the engine isnt covered under warranty?

My 04 corolla is covered under warranty till 75k miles.

I would bring it into the dodge dealer it was bought from and see if the engine is still covered.
posted by majortom1981 at 12:51 PM on February 11, 2010

Are you sure the engine isnt covered under warranty?

I never would have guessed it, but this site says that the OP's car is still under powertrain warranty unless it was delivered prior to today's date in 2003 or has more than 70,000 miles on it. You might be prepared for a fight if you can't demonstrate regular oil changes and other maintenance, though.

My 04 corolla is covered under warranty till 75k miles.

Sadly, the same site says that your Corolla is out of factory warranty.
posted by iknowizbirfmark at 1:06 PM on February 11, 2010

Ergh, On ebay, neon 2.0l engines go for $400 to $600 bucks. Figure $1000 to $1500 to have it installed and you're out the door for under $2K. Of course, blue book on the car is probably about $2000.


I am so sorry for your loss.
posted by paanta at 1:07 PM on February 11, 2010

Find a mechanic who can perform a leakdown test, which can help diagnose why one cylinder has lost compression. If it's due to a bad valve, you just have to replace the cylinder head rather than replace/rebuild the entire engine. Not cheap, but less expensive than replacing/rebuilding the entire engine.

Depending on what's wrong with your engine, it could either die a sudden death or just progressively run worse and lose power.
posted by zombiedance at 1:12 PM on February 11, 2010

Take a look at your air filter. I'm guessing it's gotten soaked with oil mist blowing by a damaged ring seal, which means your engine is dying.
posted by TrialByMedia at 1:13 PM on February 11, 2010

Before you have the engine replaced, consider other problems the car may have, and how much those problems + the engine replacement may cost you in, say, the next few years. I say this because Neons of that vintage don't have the most reliable transmissions, either.

So a new car might be $280 a month for five years, if you put nothing down on a $16,000 car with a 0.9% financing deal. Your new engine might be $1,500, which covers nearly half a year of new car payments. A new transmission for $1,000 makes your total potential outlay on that "free" car equivalent to nine months' payments on a new one.

You may look at those numbers and think that makes a great case for keeping it, or a great case for ditching it; your choice. Obviously those numbers don't factor in your insurance (I don' t know if you have liability or full coverage currently.) Whatever the solution you choose, we know that the cost of a good engine and transmission still won't come anywhere near the cost of a new car, even if it does require you to put in a lot more than the car's worth to someone other than you.
posted by davejay at 1:28 PM on February 11, 2010

Do you know what code the mechanic read to determine there was a problem? The OBD system typically only has codes for electrical or sensor issues, and I'm having a hard time figuring out the path from an electrical code to a cylinder ring failure. Can any shadetree mechanics answer to this?
posted by Big_B at 1:33 PM on February 11, 2010

I am also a computer guy, and not a car guy. So take the following for what it's worth.

I once had a piston problem in my Accord's 4-banger engine. Apparently one of the rings got stuck, and oil was pouring into the combustion chamber. The result was that no gasoline ignition was really happening in that chamber, my car vibrated heavily when driven, and would often stall and shut off when the gas pedal was not being pressed. Obviously it was not working like a car should.

I took it to a mechanic who diagnosed the problem, and was able to do some kind of temporary fix, but couldn't solve the root problem of the ring. He recommended engine replacement.

I was pleasantly surprised though, to find that engine replacement was not as big of a deal as I thought. I called a local Honda dealership and asked for advice. They did all the legwork for me, calling around to scrapyards and such to see what engines were available. In the end, I got an engine that was 2 years newer than my car (from a comparable model Accord), and had only 5000 miles on it, and came with a 1 year warranty. The engine cost me $900, and the dealer charged me $1200 to install it. In total, $2100 got me a much newer engine.

Yes, $2100 certainly isn't nothing, but it wasn't nearly as bad as I thought it would be. Much less than buying an equivalently used car. If you have a credit card with that kind of room on it, you might just be able to charge it and make monthly payments. Otherwise, you might be able to refinance your car and roll the repair costs into it. Yes, it's a little known fact, but you can refinance your car, even though it's paid off.

As others have said, your car might be under factory warranty. The shop might want to see records of your oil changes though, to make sure this isn't a self-inflicted problem. Failure to perform maintenance can result in warranty claims getting denied.

Hope that helps.
posted by Vorteks at 1:40 PM on February 11, 2010

Amazingly enough a friend of mine had a 1986 Toyota Camry LS with pretty much the same problem. It was a 4 cylinder, and one cylinder had low psi and he was going through oil at a pretty good rate. The mechanic told him: engine replacement is the only economic thing to do. "How long will it last otherwise?" "No way to know, it could collapse at any moment". Well, that was back in 1998. He drove it - unfixed - for the next 11 years, and finally sold it last year for $600. Caveat: he used it only a few times a week, and never drove more than 100 miles at a time; plus the damn thing couldn't be taken on the freeway, and had a hard time with hills.

Moral of the story: there is no way to know how long your car will last.
posted by VikingSword at 1:46 PM on February 11, 2010

OK, lets not go overboard here.

1. Get some oil in there - fast.

2. Closely monitor the oil level, until you get a better idea of the consumption rate. After each trip to start with, then every day, then every week ... you get the idea.

3. Obviously, keep driving the thing. Low compression in one cylinder won't kill anything, but low/no oil will. And check the coolant level regularly too.

Millions of cars are out there with low compression, doing just fine - the owners have learnt to watch the oil level (and the water/coolant), it's a pita but that is life with an old car.

Your car could last along time yet, IF you keep the oil and coolant levels within limits. If you can't do this, find a friend or neighbor to show you.

However, if it starts to sound like a heavy mechanical knocking sound, the end is nigh, imminent even. With a bit of luck, and the attention you will now give the poor beast, it should last quite a while (years even) ...

Good luck!
posted by GeeEmm at 2:00 PM on February 11, 2010

ee could call around and try to find a used engine. Haha. Hahahaha.

I don't understand your haha. Used engines are cheap, plentiful, and replacing a blown engine is a common practice.

the engine might shake apart or something and I might explode.

check out 2:02 in this video. When an engine throws a rod, it can take punch holes in metal.
posted by nomisxid at 2:38 PM on February 11, 2010

"So, question #1, knowing that you are not my engineer or my mechanic or anybody, what reasonable consequence could I expect if I continue to drive this car with this issue?"

Absolute worst case is a piston seizes and a rod makes a violent exit out of the block. Pretty unlikely though; more usually the blow by gets worse to the point that either the engine won't run or it's using so much oil and gas it's costing more to run than replace. Definitely top your oil up and keep a quart in your car so you can maintain levels. Check every time you fill the tank (good practice anyways). Watch you mileage so you can keep track of when the point of no return is coming.

kbanas writes "It's a 2004 Dodge Neon which was gifted to me by the estate of my grandparents after they died."

This family of engines is bad for eating head gaskets which can in some cases cause localized low compression. On a non turbo car replacement is very straight forward and fairly cheap; maybe a few hundred dollars.
posted by Mitheral at 4:04 PM on February 11, 2010 [2 favorites]

I am a mechanic. I'm a motorcycle mechanic, but 4-stroke engines are all the same.

GeeEmm nailed it. I've driven literally over a hundred thousand miles between two cars that had low compression and/or burned oil (60k on an 86 toyota celica and 40k on a 94 ford ranger) and both were running fine when I got rid of them. Most people don't understand how much abuse modern engines can take.

The other thing to do is see if the car is still under warranty. If it is get it checked out by the dealer.

Also you can easily verify the compression yourself. Buy a cheap compression tester and follow the instructions in this video. He seems to explain things very well.
posted by thekiltedwonder at 4:11 PM on February 11, 2010

In your case, it's likely not rings or valves causing your low compression. The Dodge Neon motors (and later, the first gen New Mini Cooper motors) are notorious for having head gasket problems, like Mitheral says.

A couple simple test can be performed to rule out rings or valves. For instance, measuring peaks in crankcakse pressure can confirm or disconfirm blow rings. Observing the pattern of intake manifold pressure can help determine a valve problem. More testing is certainly required before condemning the whole engine.

You could be loosing oil through the headgasket, potentially.
See, the engine is made of, basically, two main assemblies. The Head, containing the valves and camshafts on your engine, and The Block which contains the pistons and crankshaft. When the head is bolted to the top of the engine, the seal between them is critical since not only does oil and coolant pass through both assemblies, but their mating also creates the combustion chamber where fuel and air ignite to make power in the engine.
When the headgasket fails, not only does the high-compression required for combustion leak out, but the seals between the oil and coolant passages also break down, which can result in the oiling and cooling systems mixing with each other of those fluids being drawn into the combustion chamber and burned. Nasty smoke out the tailpipe can be an indication of this, especially white, sickly sweet smelling smoke.
So, if there's no smoke out the tailpipe, where's your oil going? With the engine cold (please) open the radiator cap and examine the coolant. It should be green and clean. If it's oily, sludgy, or smells REALLY BAD, there could be getting oil and combustion gasses finding their way into the coolant via a blown out headgasket.

If you were to bring this problem into my shop, I certainly wouldn't tell you to take it somewhere else to change the oil. I'd still do it, but both your copy and my copy of the repair order would have the results of my engine diagnosis written clearly on it as well as a warning about potential engine damage unrelated to the oil change.
Additionally, as part of this diagnosis, I probably would have drained the oil anyway, to check its condition and see if there's any water mixed in with it from the cooling system leaking through the headgasket.

I would take your car to another mechanic for a second opinion. A new headgasket is much cheaper than putting another engine in the car. It's only a 2004. Don't treat this like an old, worthless beater. Get it fixed right. You'll be happy you did.
posted by Jon-o at 4:34 AM on February 12, 2010

For future reference, an OBD-II reader will help you avoid the "everything seems fine, I'll ignore the Check Engine light" trap. They cost about $30-50, and it's the exact same device your mechanic uses to find out what triggered the light. The device spits back a code, and there are many websites you can search to find out if the code is something you need to take it in for immediately or not.

As an example, I had a Check Engine light triggered by something related to emissions. It wasn't vital, and I had no cash, so I just waited. I had to get the problem fixed before my next emissions inspection, but I was able to wait until I had the money to fix it. I love my OBD-II reader!
posted by etoile at 2:42 PM on February 12, 2010 [1 favorite]

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