`95 Legacy engine miss

[Bradley Walker]

Hello all,

I was driving my mom's `95 Legacy L on Friday and noticed what appeared to
be an engine miss. When I started the engine I could hear this very
noticeable miss that was very constitent and rhymic. When leaving the
engine in idle and applying the accelerator, the rate of the missing
increased equal in ratio with that of the engine rpms. There doesn't seem
to be hardly any speed/performance loss, however gas mileage has went WAY
DOWN in the past few days. In fact I put $10 worth of gas in the car when
the tank was near empty on Friday. I drove it 76 miles to pick my mom up
from work and come home. The tank when filling it up was a 2-3 'dots' below
half. By the time we got home, it was 2-3 dots above empty.

My initial reaction was that it was an ignition miss, but when I noticed the
miss increasing in frequency in ratio to a revved up engine, I got to
wondering if it was a valve going bad / tapping? I had an explorer once
that blew out two valves and symptoms were rhymic 'tapping' or misses, along
with major dropping in gas mileage. Although that vehicle had major
performance losses due to it's weight and the engine virtually running on 5
cyclenders.

Any thoughts and ideas? I'm having her take it to the shop in the next two
days to have a mechanic look at it. I"m beginning to lean towards a
possible bad valve. Or am I off and it's an ignition misfire that is
causing the miles per gallon drop off? As I said above, there has been
maybe a hair of a performance drop off, but it still drives just fine like
it has.

Brad

 

[Carl 1 Lucky Texan]

Hello all,

I was driving my mom's `95 Legacy L on Friday and noticed what appeared to
be an engine miss. When I started the engine I could hear this very
noticeable miss that was very constitent and rhymic. When leaving the
engine in idle and applying the accelerator, the rate of the missing
increased equal in ratio with that of the engine rpms. There doesn't seem
to be hardly any speed/performance loss, however gas mileage has went WAY
DOWN in the past few days. In fact I put $10 worth of gas in the car when
the tank was near empty on Friday. I drove it 76 miles to pick my mom up
from work and come home. The tank when filling it up was a 2-3 'dots' below
half. By the time we got home, it was 2-3 dots above empty.

My initial reaction was that it was an ignition miss, but when I noticed the
miss increasing in frequency in ratio to a revved up engine, I got to
wondering if it was a valve going bad / tapping? I had an explorer once
that blew out two valves and symptoms were rhymic 'tapping' or misses, along
with major dropping in gas mileage. Although that vehicle had major
performance losses due to it's weight and the engine virtually running on 5
cyclenders.

Any thoughts and ideas? I'm having her take it to the shop in the next two
days to have a mechanic look at it. I"m beginning to lean towards a
possible bad valve. Or am I off and it's an ignition misfire that is
causing the miles per gallon drop off? As I said above, there has been
maybe a hair of a performance drop off, but it still drives just fine like
it has.

Brad

Hard to say. Possible exhaust leak too I guess - they will hiss
sometimes like that. Did the check engine light come on? If there are
codes stored that would help diagnose the car - even if by elimination.

good luck

Carl

 

[Bradley Walker]

I had thought of an exhaust leak, but does an exhaust leak cause gas mileage
to drop like 20-30 miles per tankfull?

 

[strchild]

If your car has a turbo, and the exhaust leak happens to be before the
turbo, sure! Whether or not your car in question has a turbo, and whether
or not an exhaust leak matters to fuel mileage otherwise, I don't know, but
I can't imagine offhand why it would. (-; I would think it could decrease
the efficiency of your catalytic convertor(s) and also decrease backpressure
in the exhaust system coming off of the engine, maybe making a normally
aspirated engine a tiny bit more efficient?

~Brian