I was hoping to get some ideas on a tricky problem I'm having on my '98 Subaru Legacy GT Limited (AT, 2.5L). Maybe someone has had something similar happen?
I bought this car back in August after it had not been driven for about a year, and before that, driven by a girl who did no maintenance on the car whatsoever. It has 160k miles.
Here’s my problem:
- Lacks power going up hills and when accelerating
- Occasionally car has bursts up to normal power when in “crippled” mode
Let me explain in detail… Going up larger hills (I live in the mountains) sometimes takes the petal to the floor to get up. Sometimes when going up these hills in “crippled” mode I will get a second or so “burst of power” during which the RPMs will raise slightly. This will repeat maybe once or several times in a row rapidly. The problem is much more noticeable when it’s cold outside (considerably worse when it’s 30 F or below), but also when the car itself is cold. It seems to have okay power in lower gears (1st / 2nd) when climbing hills, but if ever I am in anything higher, it’s like I’m towing a boat behind me. During this time the gas petal seems largely unresponsive throughout ¾ of its range (ie…pressing it ¼ or ¾ of the way down does not seem to change anything where normally it would cause a downshift). That’s basically it.
Here’s what I’ve done:
- Cleaned throttle body
- New fuel filter
- Clean air filter
- Throttle body position sensor (was bad…new one adjusted by Subaru)
- Also throttle stopper screw adjusted by Subaru
- Cleaned Mass Air Flow sensor
- New spark plugs (using NGK BKR5EGP 7090)…these are same specs as the recommended plugs but are the “platinum” version instead of the “double platinum” version
- New timing belt (old one was installed backwards…doh!)
- Can of seafoam in gas…several times.
- New oil change
- New shifter cable and neutral safety switch (had bad old one)
Can anyone verify if the spark plugs are definitely causing this? Recommended part number is: NGK PFR5B-11 if you want to check the specs and compare.
Another possibly related issue is that the engine has a tick noise on one of the cylinders/valves. A lot of Subarus have this I think but usually it goes away after it warms up (but not with mine).
I am up for any suggestions and thoughts! Let me know if I can clarify anything… Thanks guys!