[N/A] Car not Accelerating After Stop.

I have no Subaru experience, but when Rich mentioned Saturns, it tripped a memory of my kid's Saturn doing a similar behavior. That engine would carbon up the EGR valve, which would then stick open and cause a stumble on acceleration, but also die at idle. So, don't know if that helps at all.
 
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Popping is not good. And I'll say probably not a knock sensor. Bummer.

Does your OBD-II reader do real-time? That'd tell if "the port is bad". No data, not working. My harbor freight cheapie will read real-time sensor data while the car is on.
Popping under acceleration is bad. Mine pops everytime I drive it between shifts and on decel.
 
A bad knock sensor won't cause a missfire or popping. When the computer sees noise from knock sensor it pulls timing until it sees no noise. A failed sensor with lots of noise will pull so timing the car will have no power and feel laggy, but no missfire or hesitation.
 
If the car runs, and the "worth a try" things are easy and free (or cheap) to try, then why not? It's not like there are an abundance of good automotive diagnosticians out there. It's easier to find a good brain surgeon than it is to find a car mechanic who actually knows something about diagnostics. I have to drive almost 50 miles to find one who's merely competent; and if I want a true scientist, the car had better be up to a three hour-plus trip to College Point, because that's where his shop is.

Most mechanics nowadays just throw parts at a problem in the hope that they'll stumble upon the fix -- and that's assuming that they have codes to work with. If the problem doesn't throw a code, all they can do is stand around with their thumbs up their asses. It's pretty pathetic, actually.

My favorite example used to be when Saturn S-Series engines would throw P0340 or P0341 codes, and so-called "mechanics" would spend hours and hours searching for the Camshaft Position Sensor so they could swap it out. The only problem was that the S-Series engines didn't have Camshaft Position Sensors. P0340 / P0341 codes could be caused by a variety of problems with the ignition system, but 95 percent of the time it was bad spark plug wires, which used to cost about $15.00 - $25.00 depending on quality; or a corroded ground to the DIS, which cost nothing to fix.

But that didn't stop countless mechanics from spending countless billable hours searching for a part that didn't exist. That was all they knew how to do.

Rich

If a mechanic makes an obvious guess, he doesn't get paid for "diagnostic" time that has not occurred.

The Saturn CMP codes are well known, and anyone who hangs a shingle and hasn't heard about that needs another line of work. The spark plug wires aren't that cheap, though. The first thing to do is remove the two coil packs and sandpaper the engine block grounds. Takes 15 minutes, counting the coffee break. Then run the engine in the dark to see if it arcs.

I strongly discourage going to an auto parts store for codes, because it's very much in their interest to read a code and encourage you to jump to conclusions and buy an expensive sensor right there. Though it IS fun to watch some of those dweebs try to find a Saturn cam sensor to sell you.... Generic OBD2 code readers are cheap, and doing it at home encourages further investigation before condemnation, which is how one does this competently. You can very easily spend thousands of dollars replacing good parts without that step.
 
If a mechanic makes an obvious guess, he doesn't get paid for "diagnostic" time that has not occurred.

The Saturn CMP codes are well known, and anyone who hangs a shingle and hasn't heard about that needs another line of work. The spark plug wires aren't that cheap, though. The first thing to do is remove the two coil packs and sandpaper the engine block grounds. Takes 15 minutes, counting the coffee break. Then run the engine in the dark to see if it arcs.

I strongly discourage going to an auto parts store for codes, because it's very much in their interest to read a code and encourage you to jump to conclusions and buy an expensive sensor right there. Though it IS fun to watch some of those dweebs try to find a Saturn cam sensor to sell you.... Generic OBD2 code readers are cheap, and doing it at home encourages further investigation before condemnation, which is how one does this competently. You can very easily spend thousands of dollars replacing good parts without that step.

You mean Subaru? ;)
 
If the engine light is coming on and flashing it should be setting a code. Bring it to a mechanic, or if you want to do it yourself, get an OBD reader that will give you real time data.
 
Oh ok. Thought you were commenting on the OPs problem.

No, it was just an example of the difficulty of finding qualified auto diagnosticians. It's a common-enough thing to happen that you'd think any professional mechanic would know about it (or at least quickly learn about it). But alas, that's not always the case.

Rich
 
I'm guessing valve cover gaskets are leaking oil into spark plug holes shorting out the wires, causing the misfire. without codes it's hard diag.

But I guarantee it's not water in gas or old gas. That stuff doesn't matter any more in modern fuel injection strategies. Get Me some codes and we can go farther with it
Your guarantee ain't worth a ****. Two bottles of "Heat" took care of that exact symptom in my modern fuel injected car. Start with the least expensive fix first.
 
If a mechanic makes an obvious guess, he doesn't get paid for "diagnostic" time that has not occurred.

The Saturn CMP codes are well known, and anyone who hangs a shingle and hasn't heard about that needs another line of work. The spark plug wires aren't that cheap, though. The first thing to do is remove the two coil packs and sandpaper the engine block grounds. Takes 15 minutes, counting the coffee break. Then run the engine in the dark to see if it arcs.

I strongly discourage going to an auto parts store for codes, because it's very much in their interest to read a code and encourage you to jump to conclusions and buy an expensive sensor right there. Though it IS fun to watch some of those dweebs try to find a Saturn cam sensor to sell you.... Generic OBD2 code readers are cheap, and doing it at home encourages further investigation before condemnation, which is how one does this competently. You can very easily spend thousands of dollars replacing good parts without that step.

Seriously. You can get serviceable readers for twenty bucks or less on eBay or Amazon; or you can get full-featured, real-time scanners for Android or iOS for six bucks plus the cost of the BT OBD2 interface. Any serious gearhead or shadetree mechanic should invest in one. They're so cheap that there's no reason not to anymore.

Rich
 
Your guarantee ain't worth a ****. Two bottles of "Heat" took care of that exact symptom in my modern fuel injected car. Start with the least expensive fix first.
So you had frozen fuel lines in Ohio?
Or you can diag it right the first time and not have to spend extra money.
 
So you had frozen fuel lines in Ohio?
Or you can diag it right the first time and not have to spend extra money.
You've obviously never read what's printed on those bottles. Nope, it was summer and I had just gotten gas at a little out of the way station just before it started. I stopped at another station and "Heat" was the only product they had. But, it worked.
 
You've obviously never read what's printed on those bottles. Nope, it was summer and I had just gotten gas at a little out of the way station just before it started. I stopped at another station and "Heat" was the only product they had. But, it worked.
Your right I've never read a label on those bottles, I don't use them so I haven't a clue. I guess a gas station in the middle of nowhere could have water, still a rare occurrence and even rarer accurrence that it would pose a problem is a Subaru. Whats the make amen model of car?
 
You've obviously never read what's printed on those bottles. Nope, it was summer and I had just gotten gas at a little out of the way station just before it started. I stopped at another station and "Heat" was the only product they had. But, it worked.

HEET's not a bad choice. It'll correct a variety of "bad gas" conditions as long as they're not too severe. It absorbs water, which is what it's marketed to do. It'll also raise the octane a bit if the gas is borderline stale and the lighter hydrocarbons that they use as antiknock additives have started to evaporate. The methanol component also reacts with some of the hydrocarbons to form azeotropes, which increase the RVP of the gasoline, making for easier starting (especially in the winter). So it's really not a horrible choice if a station is only going to carry one gas-drying product.

Where I live, stale gas and wet gas are recurring problems in between the tourist seasons. The stations have big tanks to deal with the short but busy tourist seasons, but that means that the gas also tends to get a bit stale and sometimes wet during the slow seasons in between. In fact, both stations had to have their tanks completely replaced within the past three years because of rust, and a third station a few miles north was shut down entirely for the same reason.

Once in a while I get a tank of gas from a low-volume station that's so far gone that the car immediately starts running like ****, followed by an intermittent MIL and P032x codes, with detonation and PCM compensation for same when the engine's under load. I can surmise that it's the gas causing the problem because the symptoms will start about a mile or so after I fill up.

I suspect that what's happening in these cases is that the lighter hydrocarbons in the gasoline have evaporated, lowering the effective octane of what remains. I suspect that because adding literally any additive that increases the octane helps tame the problem until I can run the tank down. Usually it will at least extinguish the CEL and demote the code to "pending" after a few drive cycles. Running the tank down a quarter to halfway and filling up with 92 or higher octane gas from a high-volume station in one of the nearby "cities" also works.

But burning through the tank and filling up with known-good gas is the cure. There are other things that start happening when gas gets old that won't be solved by raising the octane.

One time several years ago, I got such a bad tank of gas that I wound up siphoning it into cans and taking it down to the county waste management facility to get rid of it. It really was that bad. I wouldn't even use it in the lawnmower.

The stale gas problem is one of the reasons why I'm pretty happy that the local Hess station has become a Speedway station. They have an extremely generous rewards plan, so they're attracting more business from the surrounding area. It's actually the talk of the town. (Obviously, we don't have a hell of a lot to talk about here.) The reason I like Speedway's reward plan, other than saving money, is that more turnover means fresher gas.

The other thing I learned shortly after moving up here from The City was that STA-BIL is a wonderful thing. It won't do anything for gas that's already stale, but it will help prevent borderline gas from getting any worse after you buy it. It's also a pretty decent fuel system cleaner and helps prevent ethanol-related nasties. One ounce of the marine flavor per 10 gallons of gas is what the locals swear by.

Rich
 
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I'm guessing valve cover gaskets are leaking oil into spark plug holes shorting out the wires, causing the misfire. without codes it's hard diag.

But I guarantee it's not water in gas or old gas. That stuff doesn't matter any more in modern fuel injection strategies. Get Me some codes and we can go farther with it

Actually that makes the most sense! They said, when I had my axles replaced, a few months ago that I might have a leak either from the valve gaskets or the axles. They couldn't tell from all the grease when my boot blew. I haven't noticed an oil loss beyond normal and the oil didn't look bad when I changed it a few weeks ago. So it didn't register until now.

I dropped the car off at my mechanic. They'll call in the morning. If its that I'll have them replace the gaskets and I'll buy a new set of spark plug and put them in this weekend. might splurge and get new wires.

I tried to pull the codes this afternoon on my drive to the shop. It still showed nothing. My mechanic said that was odd.
 
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Just learned what is wrong with the car. The spark plugs and the coil are shot. They are also going to fix the oil leak. Which is a cam seal.
 
Just learned what is wrong with the car. The spark plugs and the coil are shot. They are also going to fix the oil leak. Which is a cam seal.
Not a bad deal, hope it fixes it, sounds right to me though.
 
Actually that makes the most sense! They said, when I had my axles replaced, a few months ago that I might have a leak either from the valve gaskets or the axles. They couldn't tell from all the grease when my boot blew. I haven't noticed an oil loss beyond normal and the oil didn't look bad when I changed it a few weeks ago. So it didn't register until now.

I dropped the car off at my mechanic. They'll call in the morning. If its that I'll have them replace the gaskets and I'll buy a new set of spark plug and put them in this weekend. might splurge and get new wires.

I tried to pull the codes this afternoon on my drive to the shop. It still showed nothing. My mechanic said that was odd.

Yep i do this same repair 2 or 3 times a month. Doesn't matter year or model. All the subarus do it eventually. Most pocket code readers will only show current codes, if it stopped missfireing it will move it to stored codes and you'll have snapshot of what all the sensors where doing at the time.
 
Just learned what is wrong with the car. The spark plugs and the coil are shot. They are also going to fix the oil leak. Which is a cam seal.
Is there only one coil on this vehicle? That's kinda rare in the last 20 years.
 
Sounds like it may be a fuel filter almost plugged off. When you apply the throttle for rapid acceleration the volume flow is enough to stir up the sediment, but if you go easy on it it doesn't plug it completely. Same when you need to open the throttle wider for more fuel flow to climb a hill.
:yeahthat:

Older GM cars had a fail-safe fuel filter that when partially clogged, would only pass enough fuel for low power operations. Dunno if they still do or if your car has something similar.

Check the engine codes.

:yeahthat:

-Skip
 
Yep i do this same repair 2 or 3 times a month. Doesn't matter year or model. All the subarus do it eventually. Most pocket code readers will only show current codes, if it stopped missfireing it will move it to stored codes and you'll have snapshot of what all the sensors where doing at the time.

Yep. I did mention waaaay back up there that my Subaru specialty shop (couple of Russian brothers, they're a trip...) has that deal where they do timing belt and gaskets all together because they're the "must do" Achilles heels of that engine.

They hate having a vehicle in and doing one and then it comes back in a few months for the other "common problems" so they offer a discounted "one price we do it all" service at every 90,000 miles. Keeps from wasting their time and downtime for the customer. As I recall they do plugs and plug wires in that deal too.
 
Just learned what is wrong with the car. The spark plugs and the coil are shot. They are also going to fix the oil leak. Which is a cam seal.
Good deal! I got a check engine light when my spark plugs went south with 116k miles on them... but the engine ran fine. Love my '08 Ford Escape.
 
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