This could just be my imagination, but I can swear, if I drive slow and easy (is that possible) you know, cruising speed not exceeding 3k rpm not accel fast, this car loads up on me. How do I know? I travel home from the office on about a 5 mile road fairly strait, 45mph...the last 1/4 mile before my turn-off jumps to 65. Well of course I go for it. Usually downshift to 3rd, puts me arround 3400, 3500 revs, and then gas it. Now here's the wierd part, (pop pang ting cough) and then like a carnie at church, "im outta there". Now, what the heck is with the hack and cough? Bad gas? Need a fuel system cleaner?
[Car history: New 2002, Bought it about a month and a half ago with 99 miles on it. Now has 1700 (good miles)(coastal trips) I changed my oil at 1250 because of the cars age, and the time it sat on the lot. Never exceeded 3k rpm during break in while in my possestion, who knows about those first 99. Elevation 500ft. Rains here all the time. Temp 45-60 deg]
Any thoughts?
Ukla
Knocks, bad gas, lower octane. Put 93 Octane in it all the time! Octane boosters are a joke they raise it a few points (tenths). 4100-4250 is the peak torque range and is where most knocks happen. Do you feel a vibration from the engine and is your car complete stock. Let me know and I can give you more feedback.
The car is totally stock at this point. I always run 93 at the pump. No I don't feel any vibrations. I really only hear and feel a hesitation breifly. This really only happens once. If I head out for a drive a while later, all seems well, so basically only once a day I will experience this.
Your engine is knocking... unfortunatelly there isn't an easy way to fix this. It's most likely because of the Ron/Mon rating in your gas where you live. Around here 93 octane sucks (I have to retard timing a lot to run high boost) while if I fill up in NC or SC I get great gas. If your planning on modding your car I would simply get a UTEC (http://www.turboxs.com [direct] or http://home.att.net/~teaguesauto/ecuwrx.htm [great NC shop]) you can make your fuel a little richer and retard your TDC degrees on your timing. You shouldn't be knocking with stock boost unless your gas is really bad, I didn't until 14.5psi (1 lbs above stock). If you aren't planning on upgrading your Scooby, you can get a MBC (manual boost controller) provided you have a boost gauge installed (stock will work for this). Trim the boost down 1/2pound or maybe 1 full pound (.0 1/3 kPa-.0 2/3kPa).
Hope this helps. (Plus with the Utec you can see what the injectors/knock sensors are seeing when this happens)
you could test that and see if you knock, however Octane per se isn't the problem. Octane is made up of RON + MON / 2. RON is the low temp knock rating, while MON is the high temp knock rating. Becuase its just the average of the two, some places with 93 octane have a lot less MON and more RON, which doesn't help for turbo charged cars (high temp). However a 100 octane run should help, but wouldn't be a sure fire way to rule out engine det/knock (unless it went away with 100 octane, if it stayed it could still be knock).
So UTEC is definitly the place to start. How does that work when you dig down into the warranty? Service departments get pissed off, or do they even notice?
depends on what they are doing, but they will notice if they look at the passenger floor board, it moves the back stand back 2", but it takes 15 minutes to remove, (if you have a big service), but its the place to start.
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