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boynamedsue 03-09-2013 02:01 PM

More Questions....
97 lgt 5spd wagon. My rpms seem to be high when driving on the freeway. At 70mph, it's running at 3400rpm, that seems high to me. Is this normal? This is the only lgt I've driven, so I have nothing to compare to. Also, when cold, the rpms are very slow to recede. Is this normal?

What kind of distance are people seeing between fill ups?

One more thing, I recently purchased heated mirrors and was thinking about just wiring them to my rear window defroster, has anyone done this? Also is it possible to make it to where the rear defroster is timed like the 98/99s? You have to manually shut the rear defroster off in the 97s and sometimes I forget.

Thanks again in advance.

InsertEnigmaHere 03-09-2013 02:42 PM

I'm usually around 3200 rpm this time of year and I thought that was kinda high. Sounds to me like there might be a throttle cable adjustment issue with the sticky cold revs, I used to have a similar issue.

I commute about 2x a month ~350 miles between NH and NY, so yeah about 375 highway miles to a tank for me I'd say, but last weekend I learned the hard way weekend that I shouldn't over-trust the gas light in my car, and I ran out at a little under 400 miles I think, haha.

boynamedsue 03-09-2013 03:30 PM

Man, I haven't seen 250 miles per tank yet. But I haven't taken any long road trips yet with it. Just mostly city driving.

Kennyfvholla 03-09-2013 04:43 PM

3400 RPM at 70 mph seems very far off.

Doing the math (3400x24.88)/(340x4.11x0.780) yields about 77/78 mph.

My 98 LGT wagon 5MT would be at just about 3050 RPM at 70 mph.

You might have a car with an Outback 5MT installed. They have a shorter 5th gear ratio. It's 0.871 instead of 0.780 ratio. Doing the math with that figure in place, shows that you are right on the money for having an OB transmission installed.

3400 = RPM
24.88 = OD of tires

340 = constant figure
4.11 = differential ratio
0.871/0.870 = 5th gear ratios (non-OB/OB)

YES, the engine RPM's are slower to recede until the motor warms up. No throttle adjustment issues are at fault here whatsoever.

Around town, you shouldn't really get less than 280 miles to the tank worst case scenario... You do have a problem of some sort there...

snederhiser 03-09-2013 10:52 PM

What transmission do you have? If it is a manual, then you clutch is slipping. Auto trans will slip a bit to warm up the fluid, this is winter so on short hops the trans never warms up enough. Steven.

Kennyfvholla 03-10-2013 07:30 AM


Originally Posted by snederhiser (Post 4332265)
What transmission do you have? If it is a manual, then you clutch is slipping. Auto trans will slip a bit to warm up the fluid, this is winter so on short hops the trans never warms up enough. Steven.

He has a manual. It says that in his user icon area and at the top of this thread in his original post.

The clutch is not slipping. I've had a clutch go on my 5MT LGT. I know what happens when it's first starting to slip and what it's like when it's just about done. This is not what happens. At 70 mph, you're not pressing the throttle down enough to force it to slip.

Bassnectar 03-10-2013 11:39 AM

really bad gas mileage? check your spark plugs, fuel filter and air filter. Clean your Maf.

Your idle air control valve controls how your car warm's up, it sounds like that is working as RPMS won't recede until temperature come's up in the block (causes higher compression in the cylinders and more vacuum pressure inside the engine) but you can clean that if it is stuck open a bit your car will dump fuel to keep things running smoothly. same deal with a dirty throttle body

Check all the rubber hoses connecting your intake, these are 16 year old and if they have a leak they will be adding air to the engine that the MAF does not see. your 02 sensor will see that and will force your car to add fuel to reach a more stoichiometric burn.
(you can spray carb cleaner on the hoses, Listen to a increase in RPM while spraying if the idle changes, the hose has sucked up some carb cleaner which is a fuel caused the rpms to change... then its simply replacing rubber with silicone hoses, I reccomend buying some small zip ties to get everything as tight as possible.)

it doesn't make sense that your 3400 @ 70mph and other are at 3050. I would compression check the engine at the same time as checking the spark plugs to rule out any major headaches right away.

snederhiser 03-10-2013 05:03 PM

Sorry that I do not know every transmission and engine combo in Subaru's. Yes a clutch will cause this. As you change into a higher gear more torque is placed on a clutch. What might not slip in first gear can exhibit a creep in higher gears. The coupling in the tranfer case could also be going south causing a higher rpm. Steven.

boynamedsue 03-10-2013 08:59 PM

First off I want to thank everybody for the responses. It makes me love my car more and more, the more I understand and know about my car. Thank you everyone for helping me.

So anyway, that was one thing I was planning on doing anyway, was changing the plugs, wires, and do the msd ignition. The wires on there now look new but I want to put the optimum wires and plugs in so I can get the best performance from my ignition. I'll have to look up other posts to see what everybody likes.

As far as airfilter goes, I just put in a new ebay cold air intake, so the filter is clean. I know I'll get some flack for it, but I wasn't going for hp. From what I understand, we aren't ever going to get track performance out of the cars, so I just did the cai for the intake noise. I like it and am already married soi don't care that my wife doesn't like it. It keeps her from driving it, lol.

I haven't cleaned the throttle body yet or done the fuel filter either. So I will do those along with the rubber intake hoses very soon.

As far as the clutch goes, I've replaced clutches before. I know what slipping does. Unless there are other signs of the clutch going south, it isn't slipping. It just chatter a tiny bit when its cold, but I figured that was due to the rpms not comming down fast enough.

Thank you all again. If you guys wrre all local I'd buy you all a beverage of yer choosing.

Kennyfvholla 03-10-2013 10:26 PM


Originally Posted by snederhiser (Post 4332919)
Yes a clutch will cause this. As you change into a higher gear more torque is placed on a clutch. What might not slip in first gear can exhibit a creep in higher gears

Buddy, it really won't. I drove my car with the clutch going to the brink of failure. It was at the point where any throttle input beyond 1/8th would cause it to slip, no matter what the gear. Slippage with these transmissions is VERY noticeable when it happens. The motor is not making enough torque while cruising at 70 to make it slip. Yes, it's more likely to slip in higher gear, but not by much, especially while cruising. It's most noticeable while accelerating..

Just trying to make sure everything is straight here... I mean, if it was going to slip at 70 mph in this car it wouldn't, because the car probably wouldn't even be able to get there if it was bad enough to slip by a couple of hundred RPM at that speed.

snederhiser 03-11-2013 07:49 AM

So why the hi rpm? Transfer case clutch? Crappy mileage? Magic? Steven.

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