SantaFeSubi Posted June 3, 2011 Share Posted June 3, 2011 95 legacy wagon 2.2 At..... Hello Subi world I'm in need of help! I have a 95 legacy wagon that's having a jumping problem at 50+mph! It feels like a bad wire/spark plug... I've put new plugs,tried different wires,coil pack,check all fuses,fuel filter,getting a constant flow of gas from the fuel pump,MAF seems to be working,knock sensor is new,air filter,new ball joints,hubs,& sway bar links. Front struts good, new rear struts,good tires..... I've pulled a few other sensors, one under the alternator,& another on near the driver belt the same color orange. They seemed to be ok, the one under the alternator had a small dent on the bottom? Idk what's going on but if feels like a huge miss at 50mph+ ??? Jumping stuttering sputtering & continues after that even at lower speeds??? Seems to do this once the engine is warm? Any suggestions would be great, I'm stumped & my mechanic charges 75$ hrs for subarus..... Link to comment Share on other sites More sharing options...
heartless Posted June 4, 2011 Share Posted June 4, 2011 do you have a check engine light either all the time, or when it starts acting up??? if you do, then you need to get the codes out - that should give you a lead on what the problem is. Many of the larger chain parts stores (advance, autozone, etc) will read codes for you and give you a printout of what is found - for FREE. just taking a stab in the dark - sounds kind of like O2 sensor - but to know for sure, get your codes read. Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 4, 2011 Share Posted June 4, 2011 If it's a misfire you'l have a check engine light. Make sure the CEL works during the bulb test when you turn the key on. When you start the engine it should go out after a few seconds. If it doesn't light up at all the bulb is burned out. You'll want to get the codes read to see what faults the ECU has recorded. Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 6, 2011 Author Share Posted June 6, 2011 Ok so I don't have a check engine light?300K Used motor @ 150K So I was told from the previous owner... she only seems to act weird at high rpm/speeds. I've checked everything listed 3-4 times just to make sure. I'm renting a crows foot tomarrow to replace the front O2 Sensor with a used one from another Subi with half the miles on it! It's really weird my cars never done this before, just recently she started acting up! I haven't had an alignment in a good while? I have good tires 185/70/14 Front -185/75/14 In the rear I had put on a week ago... Link to comment Share on other sites More sharing options...
Olnick Posted June 6, 2011 Share Posted June 6, 2011 I have good tires 185/70/14 Front -185/75/14 In the rear I had put on a week ago... YIKES! Get them off! All 4 tires MUST be the same circumference, within 1/4" difference max. Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 6, 2011 Author Share Posted June 6, 2011 YIKES! Get them off! All 4 tires MUST be the same circumference, within 1/4" difference max. WOW I didn't know that! I thought it just ment the tire was Wider? Ive been told you need all the same size tires before! I would've never thought being .5 wider would make a huge difference.... Link to comment Share on other sites More sharing options...
Olnick Posted June 6, 2011 Share Posted June 6, 2011 Sidewall height is shown as a ratio of tire width--thats the 70 and 75 numbers. Your rear tire circumference is actually 2.3 inches more than the front tires, totally out of range for an AWD vehicle! As mentioned, 1/4" is the maximum acceptable difference. Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 6, 2011 Author Share Posted June 6, 2011 Ok so could this have something to do with the shake as well? I will have them replaced tomarrow hopefully along with a alignment..... Link to comment Share on other sites More sharing options...
johnceggleston Posted June 6, 2011 Share Posted June 6, 2011 assuming your car is AWD and not FWD, yes you need to get matching tires all around. as a stop gap measure, you could run the larger ones on the left and the smaller ones on the right and not cause any more damage, but long term this too may cause trouble for your front and rear carriers. but i doubt that this is causing your shudder at 55 mph. does it do it at the same rpm / speed in '3' instead of 'D' ? Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 6, 2011 Author Share Posted June 6, 2011 She only starts stuttering/jumping/shaking at 50 mph+? I've tried down shifting with the car in D, but I havent tried down shifting into 3'd.... it feels like a old spark plug or wire, but I've replaced both along with another coil pack! She responded the same! Link to comment Share on other sites More sharing options...
Olnick Posted June 6, 2011 Share Posted June 6, 2011 it feels like a old spark plug or wire, but I've replaced both along with another coil pack! She responded the same! What brand plugs and wires did you use? Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 6, 2011 Author Share Posted June 6, 2011 Bosch platinum plus.... I had NGK'S before Link to comment Share on other sites More sharing options...
Suzam Posted June 7, 2011 Share Posted June 7, 2011 (edited) FIND THE FWD FUSE HOLDER UNDER THE HOOD ON THE PASSENGER SIDE AND PUT ANY SIZE FUSE IN IT A.S.A.P.!!!! This will disable the AWD and keep you from damaging the transfer case. It may also prove that mismatched tires are causing your other problem. KEEP THE FUSE IN UNTIL YOU GET ALL 4 MATCHING TIRES. The fuse holder is a small black flat box marked FWD on the cap. It's near the firewall and strut tower on the passenger side. Edited June 7, 2011 by Suzam Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 7, 2011 Share Posted June 7, 2011 FIND THE FWD FUSE HOLDER UNDER THE HOOD ON THE PASSENGER SIDE AND PUT ANY SIZE FUSE IN IT A.S.A.P.!!!! This will disable the AWD and keep you from damaging the transfer case. It may also prove that mismatched tires are causing your other problem. KEEP THE FUSE IN UNTIL YOU GET ALL 4 MATCHING TIRES. The fuse holder is a small black flat box marked FWD on the cap. It's near the firewall and strut tower on the passenger side. DO THIS^ ^ ^ Link to comment Share on other sites More sharing options...
Olnick Posted June 7, 2011 Share Posted June 7, 2011 Bosch platinum plus.... I had NGK'S before NGK plugs and OEM wires are highly recommended for Subarus. Bosch plugs and aftermarket wires might work for awhile but . . . ! Link to comment Share on other sites More sharing options...
heartless Posted June 7, 2011 Share Posted June 7, 2011 FSM lists 3 spark plug brands and Bosch is NOT one of them. First and preferred - NGK 2nd - Nippondenso 3rd and only if you cannot get either of the other 2 - Champion. proper gap is a must. Good quality wires also a must Yes - if car is AWD, tires MUST be of matching size and wear all around to avoid damage to the AWD system - not quite as critical on a FWD... Ok so I don't have a check engine light?So you are saying that when you turn the key to the "on" position (without starting it) that the "check engine" light does not light up? if that is the case you need to get a new bulb in there and try again - betting that there are stored codes that would love to be read....but you need a functioning light to do so. Link to comment Share on other sites More sharing options...
SantaFeSubi Posted June 9, 2011 Author Share Posted June 9, 2011 Alright 7mm supermag silicone wires,My Bosch platinum spark plugs seem to be working fine. I also ran my car in FWD today it seemed to run a lot better even though I had the incorrect tire sizes in the rear! I put some Goodyear tires the correct size in the rear 185/70/14 this evening & she's running 10 times better!!! No stutter,or jump! A front tire balance & front end alignment will be needed asap, I'm sure this is causing the remaing vibration in the front... This is also making me wonder if I should still replace the O2 sensor? She ran fine till I had some idiot put the wrong size tires on the rear?!?! Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 9, 2011 Share Posted June 9, 2011 (edited) I also ran my car in FWD today it seemed to run a lot better even though I had the incorrect tire sizes in the rear! Yes that's about right. What you have is a rear axle that is trying to spin slower than the front axle. Larger tire circumference means fewer revolutions per mile. Your front tire size is turning about 835 revolutions per mile, the rears only about 810. Now at 15 mph that's not that much of a difference, but when you're moving a mile a minute (60mph) that's an extra 25 revolutions the front wheels are making. The two ends meet at the center transfer unit in the transmission. This causes the clutches in the unit to slip past each other. The ECU detects the difference in speed between front and rear axles and determines the front is slipping so it tells the TCU to lock down the clutches in the transfer unit. Now your front and rear axles are essentially locked together, and you have a tug of war between front and rear. You end up with a major case of torque bind, causing the wheels to skip and drag along if they can. The transfer unit will usually slip if the wheels can't which burns the clutches and wears out the unit. As the clutches slip you have a transition between binding and slipping which relieves the stress in the drivetrain temporarily. The clutches grab again, loads the drivetrain, and the process repeats over and over. You'll feel it as a shimmy, shake, shudder, lurching around. It's your wheels basically wobbling fore and aft in opposite directions under the car. When you put the fuse in the FWD holder, the AWD system is disabled, so the transfer clutches don't lock down. The rear axle just free-wheels and doesn't put any power to the road, so no more binding. Edited June 9, 2011 by Fairtax4me Link to comment Share on other sites More sharing options...
Olnick Posted June 9, 2011 Share Posted June 9, 2011 I put some Goodyear tires the correct size in the rear 185/70/14 this evening & she's running 10 times better!!! You'd be very wise to get a piece of string and measure the circumference of all 4 of your tires, even though they may be marked as the same size. Otherwise do what Fairtax said put a fuse in the FWD holder. Link to comment Share on other sites More sharing options...
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