Please help

My exhaust(sports) on my 98 forester is making a lot of popping sounds

The spark plugs are brand new and the exhaust has been checked and that's not the problem...

The sound mainly happens when i softly push the accellarater down and when i let go it lets of a pop or two..

I also have noticed that since the problem has started that my fuel isn't lasting.

The car is also hitting 200,000km mark. i think that's about 120,000miles

 

Could this problem be related to the fact that my speedo doesn't work and my engine light is on..

 

 

any help would be much be appreciated

Thanks, Michael

Please help

My exhaust(sports) on my 98 forester is making a lot of popping sounds

The spark plugs are brand new and the exhaust has been checked and that's not the problem...

The sound mainly happens when i softly push the accellarater down and when i let go it lets of a pop or two..

I also have noticed that since the problem has started that my fuel isn't lasting.

The car is also hitting 200,000km mark. i think that's about 120,000miles

 

Could this problem be related to the fact that my speedo doesn't work and my engine light is on..

 

 

any help would be much be appreciated

Thanks, Michael

 

My car backfires like that too,I can't really answer your question though.

Sounds like backfiring - A sign the engine is running rich. I'd maybe also change the engine coolant temperature sensor. Could be feeding it too much gas.

 

 

 

My car backfires like that too,I can't really answer your question though.

Thanks

would answer why the catr smells rich.

Bloody mechanic tryed to tell me that was normal for a subaru..ha....

Thanks again:D

this popping sound can happen when the engine is too lean on the bottom end. partially clogged injectors may be the problem. a rich engine won;t pop on deceleration

this popping sound can happen when the engine is too lean on the bottom end. partially clogged injectors may be the problem. a rich engine won;t pop on deceleration

 

It doesn't really bother me,it must sound mean,people's heads snap to look all the time.

Backfire. BACK fire. That's when cumbustion flames reach backwards up through the intake manifold.

 

Exhaust popping is not the same as backfiring.

 

 

Back to the point: A slightly rich mixture will encourage "overrun" popping, so replacing the temp sensor is a good place to start.

 

The popping could also stem from valve problems. Like a burned valved not sealing and letting combustion flames escape.

Backfire. BACK fire. That's when cumbustion flames reach backwards up through the intake manifold.

 

Exhaust popping is not the same as backfiring.

 

 

Back to the point: A slightly rich mixture will encourage "overrun" popping, so replacing the temp sensor is a good place to start.

 

The popping could also stem from valve problems. Like a burned valved not sealing and letting combustion flames escape.

 

My first inclination was to mention valves, but I didn't feel confident enough. Your idea of an over-rich mixture could lead to excessive carbon buildup too. That could prevent a valve from closing completely. Might be interesting to pull the plugs to examine general condition and for comparison with each other. maybe a 'Seafoam' type treatment and , as you suggested, a coolant temp sensor or other air/fuel sensor replacemnt is in order.

 

edit; wait, you need to read or have the ECU code read. The CEL light may point to an emmissions sensor that is bad. Autozone or a 'friendly' mechanic will have a scanner to read that.

Backfire. BACK fire. That's when cumbustion flames reach backwards up through the intake manifold.

 

Exhaust popping is not the same as backfiring.

 

 

Back to the point: A slightly rich mixture will encourage "overrun" popping, so replacing the temp sensor is a good place to start.

 

The popping could also stem from valve problems. Like a burned valved not sealing and letting combustion flames escape.

 

I appreciate you clearing that up, I always thought it was from the exhaust. I suppose this makes much more sense though.

In the states, at least my whole life, we always used the term 'backfire' for 'explosions' taking place in the exhaust system as heard from the tailpipe. We would qualify the term as 'backfire through the carburetor' for - well - that type of situation. When I was much younger, I had a '51 Chevy while driving to night school. A section of the trip called for going through a tunnel under the airport runway. I would switch off the ignition for a second or so and switch it back on creating a very loud POW! . I stopped after I saw someone swerve vary badly and nearly crash. Lucky also I never destroyed the muffler/exhaust system!

your mechanic might have apoint saying that thats normal, if you have a free flowing exhaust, the car makes a lot more noises than it does stock. i have headers and a larger catback with a non restrictive muffler, my impreza pops, burbles, and such wehn decelerating and if i just tap the gas when slowing down. every ejXX ive seen with a performance exhaust does that to an extent.

 

now if you have a factory exhaust and its making popping noises, you might want to get the internals looked at and get your air fuel ratios checked.

Well the exhaust is modified but i have had the exhaust modified two years ago and only in the past two months it has been popping... i understand what you mean.... I have just replaced my battery yesturday with a high performance battery and the car's popping has halved....Weird:brow: ...

 

I am planning on taking the car to the mechanic in a couple of weeks when he returns from his honeymoon....

 

the last mechanic was a joke:mad:

 

Thanks guys and gals, i will be mentioning this to the mechanic....

With all this info hopefully it will save me some money..

Battery: Not strange, your ECU will have reset itself to more conservative ignition timing. The pops will come back