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I was sure I'd get at least 200k out of my 98 Forester. I've had missfire codes on 3 & 4 since I lightened the flywheel, figured that's what it was from, I never feel any missfires and they only set when coasting. I took it in to our local dealer for routine timing belt replacement, they called and told me that I had missfires recorded on all 4 cylinders and a cat low effeciency code was current. I could get them both done at emplyee rate for around 1200$, including the timing belt stuff. I just don't see putting that money into a 194k engine. I told them not to do anything. Ive had it back for a few weeks and have scanned it a few times. The only thing that comes up is the same old 3 & 4 miss. No cat codes. I don't think it can even run the cat test as long as missfire dtc's are set. There's something going on though because I have higher hydrocarbon levels in my coolant overflow bottle than a model t has at the tailpipe. Any idears out there? Do both head gaskets sound logical or is there a common quirk nobody is sharing with me? Thanks

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I agree with cookie.

 

But also i am not convinced you need HGs. Have you been complaing of fluid loss? Also if you have, and its not a huge amount of fluid (ocassionally topping off) i would live with it.

 

I get very suspicous when a car goes in with no real complaints and they find something major.

 

Missfire can be wires, plugs, injectors or coil towers. First try moving the ignition wires around and see if the problem moves. If it doesnt spray the engine with a water bottle while its running and look for arcing.

 

Cat effeciency at almost 200K would be the front o2 sensor. It can even be the rear one at that mileage.

 

nipper

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[...]There's something going on though because I have higher hydrocarbon levels in my coolant overflow bottle than a model t has at the tailpipe.[...]

There's nothing good that causes significant HC levels in the coolant :eek: . However, if you're not blowing coolant out of the recovery tank, you might not need to rush to HG replacement.

 

Keep in mind that cylinders 3 and 4 are paired in the wasted spark arrangement. A bad coil in the pack or even just one bad ignition cable could cause misfire on both cylinders. That the codes set only while coasting (how do you know that, is it when the CEL lights?) is "interesting", and makes me wonder if the misfire is unrelated to ignition. Coasting is a time of high intake vacuum, so I'm thinking about possible A/F mixture issues, possibly related to vacuum leaks or EGR problems. What is the idle like, both in terms of speed and quality?

 

Of course, small HG leaks can cause subtle problems...

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I haven't noticed any temp gauge fluctuation at all. I get whiffs of coolant after I get out and can smell the exhaust in the overflow. In 3000 miles it just emptied the overflow, radiator level was fine. My engine light is a constant companion, I figure it records the misses on decels because that's when the light flashes. As soon as I tip into the throttle, the lamp steadies. I've replaced the ignition coil, plugs, and wires, still the same. Thanks for the input.

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I haven't noticed any temp gauge fluctuation at all. I get whiffs of coolant after I get out and can smell the exhaust in the overflow. In 3000 miles it just emptied the overflow, radiator level was fine.
The exhaust smell combined with emptying the recovery tank (even if it took 3000 miles) is a sign that at least one HG is significantly leaking.

 

 

My engine light is a constant companion, I figure it records the misses on decels because that's when the light flashes. As soon as I tip into the throttle, the lamp steadies. I've replaced the ignition coil, plugs, and wires, still the same.
So, as I mentioned, it would seem that the trouble probably isn't related to ignition. However, you didn't answer my question about idle speed (RPM) and quality (smooth/rough/loping/etc.), which can be a clue to other possibilites.

 

 

Thanks for the input.
You're welcome.
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Some of them leak at high temps only for quite a while. The exhaust gas in the coolant would be the killer for me and I would be scouring the local cragslist and junkyards for a good 2.2.

It seems to me that most of the rest of the engine would be too tired to invest in head gaskets and a smiilar 2.5 would be likly to have the same problem a bit later.

if it was a cherry car and I had the bucks I'd contact CCR for a rebuilt, or is that Credence Clearwater Revival? Oh well, those guys in Colorado.

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I haven't noticed anything unusual about the idle other than the fact that if I rev it at idle, it seems to hang awhile before dropping down. What say ye?

I say thou art answering specific questions with generalizations. :) However...

 

Let's assume that when you "lightened the flywheel", you didn't somehow affect the crank reluctors or sensor (the degree of engine loading might cause their physical relationship to change enough to momentarily lower sensor output, if there's sufficient play).

 

"Good" engine operation requires a free-flowing exhaust, a free-flowing intake that can be throttled as needed, and well-sealing valves and rings so it can pump efficiently. Bad head gaskets can throw some of that out of balance. If you snap the throttle shut after revving, the closed throttle should cut off most air (which indirectly should cause most fuel to also be cut), and the engine revs should drop rapidly while the intake vacuum jumps up. Slow response to a rapidly-closed throttle could indicate a vacuum leak, or leaks at the injectors, etc.

 

A vacuum gauge (and the knowledge to use it and interpret readings correctly) might help quite a bit in resolving things. On the other hand, so might a new engine. :)

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There is one more thing that can be done by a shop to discover if the leak is external. Usually the engine is cleaned, then a dye that illuminates with a black light is put in the coolant. This way if the leak is external, it can be traced.

 

I would like to see a compression test, both wet and dry to see how the engine is.

 

This can just be a tired engine. I am never a fan of lightnening flywheels in stock subarus, as it seems to be very dependent on the shop knowing what they are doing, and not just removing mass.

 

I am not ready to condem on the basis of the overflow, but i am starting to wonder myself if you have bad HG, or some other leak where the cooling system is near an intake passage way. Usually the fluid in the overflow is never ever changed, so the plastic can hold 200,000 miles worth of odor.

 

Subarus tend to smell like antifreeze. My 97 OBW smeeled like that with no leaks. My freinds 2004 forester, the same, and a 2006 OBW I rented also had a hint of that smell.

 

A compression test would help.

 

nipper

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I say thou art answering specific questions with generalizations. :) However...

 

Let's assume that when you "lightened the flywheel", you didn't somehow affect the crank reluctors or sensor (the degree of engine loading might cause their physical relationship to change enough to momentarily lower sensor output, if there's sufficient play).

 

"Good" engine operation requires a free-flowing exhaust, a free-flowing intake that can be throttled as needed, and well-sealing valves and rings so it can pump efficiently. Bad head gaskets can throw some of that out of balance. If you snap the throttle shut after revving, the closed throttle should cut off most air (which indirectly should cause most fuel to also be cut), and the engine revs should drop rapidly while the intake vacuum jumps up. Slow response to a rapidly-closed throttle could indicate a vacuum leak, or leaks at the injectors, etc.

 

A vacuum gauge (and the knowledge to use it and interpret readings correctly) might help quite a bit in resolving things. On the other hand, so might a new engine. :)

The WRX's come with new engines don't they? Blasphemous, considering I work at a Chevy shop. I do have limited mechanical abilities of my own, but I can borrow a vac gauge for the weekend. The injectors are super easy to get out. Someone on here awhile back suggested my 3&4 missfire records may be a result of resurfacing my flywheel. They started coming on almost immediately after we did the clutch here. He said the flywheel may spin too fast on a decel, throwing off the crank sensor readings. Nothing sounds too far fetched to me anymore with OBD2 stuff.
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yes, all new subaru's come with new engines and warranties, that should take care of your problems for awhile!

 

you said you replaced the plugs and wires. with what? OEM or non OEM parts? the EJ series engines are very sensitive to ignition components, non OEM (NGK plugs and Subaru wires) are very likely to cause mis-fire readings. i've seen brand new ones out of the box do it.

 

the engine had to come out for flywheel work, which means the wires were likely touched at least. i'd swap wires and ignition coil pack right away and see what happens.

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The WRX's come with new engines don't they? Blasphemous, considering I work at a Chevy shop.
One assumes they're new.:lol:

 

 

I do have limited mechanical abilities of my own, but I can borrow a vac gauge for the weekend.
Now I'm having a hard time separating sarcasm and self-deprecating humor from fact ;). Either way, put a warmed engine through its paces. These links cover most of the useful engine tests using a vacuum gauge:

http://www.international-auto.com/index.cfm?fa=ad&aid=47

http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm

Be sure to include the non-idle-speed testing; the results of both slowly and rapidly revving to about 2000-2500 RPM and closing the throttle can be very revealing. Of course, if there are concerns over things like rings or valves, a compression and/or leakdown test (wet and dry, as Nipper mentioned) would be useful. I like to start with a vacuum gauge because it can tell a lot, and is easier to do than pulling plugs, especially on (ahem) certain engines :rolleyes: .

 

 

The injectors are super easy to get out. Someone on here awhile back suggested my 3&4 missfire records may be a result of resurfacing my flywheel. They started coming on almost immediately after we did the clutch here. He said the flywheel may spin too fast on a decel, throwing off the crank sensor readings. Nothing sounds too far fetched to me anymore with OBD2 stuff.
I've seen too many weird circumstances to ever say "never".
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