Mazda - Exhaustsystems - Miata :: Backfires On Downshifting
Mar 1, 2011
My car often backfires on downshifts. It happens as I?m decelerating in gear, and then blip the throttle to match the higher rpm of the lower gear. The car runs well and is well maintained. The spark plugs, MAF sensor, O2 sensors, and cat are all in good order. I?m confident the air/fuel mixture is working as intended by Mazda (at least under normal driving), so I?m not looking for a mechanical culprit. I?m sure it?s my style and frequency of downshift/rev matching which causes the backfires.
It happens anywhere from 1-2 times a week to 1-2 times a day depending on my driving, or on something like 2-5% of all downshifts. Personally, I rather like excitement of the backfires and the exhaust burble which accompanies them, it makes me feel like I'm in a race car. My question is whether frequent backfiring is going to drastically reduce the life of my catalytic converter and O2 sensors.
I don't mind replacing the cat 5 years from now instead of say 10, but I don?t want to have to replace it within the next 10,000 miles or less. My Miata is a 1999 model with 130,000 miles on it. The exhaust system uses stock manifold and muffler but with an AEM performance intake and monsterflow catalytic converter.
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So, something odd happened to me today while driving. I was getting off a highway after about 250 miles of driving, downshifted from 5th to 4th, and when I hit the gas pedal after shifting, nothing. No acceleration. I shift back to 5th. Still nothing. Try revving in neutral, also nothing. I come to a stop on the exit ramp and try to start the car up. It starts up, hits about 1k rpm and stalls. Gas pedal does nothing still. What's up with this? I had it towed to my shop.
Couple tidbits of info: just had the oil changed three days ago. Checked the oil and it seems fine. I have an aftermarket he's unit in the car and lately, it's been a little wonky. When I put use my automatic windows, sometimes the volume will mute for a sec.
My car is a 2006 Mazda Miata base model. 5 speed manual. Power windows but not locks. No traction control. No cruise control. 40,000 miles. Oil changed regularly with full synthetic.
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Last week the shift got stuck in Park. I used the emergency release button to get into Drive. After this happened several times I took it to the mechanic who said the shift needed replacing. Got a new shift. The problem persists. I get stuck in Park about 1 in 6 times.
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Problem: car cranks but doesn't start then randomly it will start. 2 different shops...first thought maybe battery (no it cranks) but said these cars are notorious for cam sensor problems they didn't have software to diagnose. Brought to dealership again battery (we were finally beat down and replaced battery) ...then brought home if car sat for a few days totally dead needed jumpstart....brought back to dealer they replaced cam sensor and timing belt...went to pick it up and you guessed it....cranked but didn't start....mechanic came out and it started....so after replacing several parts we are back to the same problem intermittent crank without start...
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I have this vehicle, which keeps blowing out the catalytic converter, its been replaced 3 times in the last month, and the mechanic doesnt know why, he refuses to put another one on it, until he figures this out.
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I have a Mazda Miata 2001, 152,000 miles. It's developed a metallic scrape from the right rear wheel. When I'm driving about 20 mph it sounds like a scritch every half-a-second or so, and if I'm going faster it just blurs into a metallic scrape. When I tap the brakes, it usually stops, and then it'll come back a little bit later (maybe when I hit a bump?) It comes and goes, but it seems to be more persistent now (or maybe I'm just always listening for it).
I took the wheel off and sprayed brake cleaner everywhere and I thought that had fixed it, but it came back again after a week maybe.
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I have a 1990 Mazda Miata, and the AC is not working. It has been switched over to R134a. I took it to a mechanic to have it recharged a few weeks ago. He said that one of the o-rings was cracked and so it was leaking around that. He filled it up and put some stop leak in it and for awhile it seemed to work fine. Then it stopped blowing cold air. I took it to a jiffy lube just to have the level of coolant (correct term?) checked. The person there told me that it was very low and was leaking around the valve stems. I tightened the valve stems and re-filled it. After 24 hours it had stopped blowing cold air again. I got a price quote on a new compressor and it is about $500.
So - my question is this - should I just put a new compressor in or is there something cheaper I could try first?
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Car recently acted like it was running on two or three cylinders and cel came on and continued to flash. The shop that did the repairs is no longer a Mazda dealer, but has a factoy trained tech. Don't know the code #, but was told that there was a low voltage code, and a misfire code. The battery was replaced, throttle body cleaned and a new fuel filter installed. The cel came back on about 25 miles later. They rechecked the codes. Said it could be the converter, and cleared the code again. After about 150 miles, the cel came on again but the car ran normal. Talked to the shop again and was told the the converter problem would have to be serviced at a Mazda dealer. The engine did the running on three cylinder thing again. Since then, it seems to run ok but the light is still flashing. If the OEM converters are fragile are there better options for replacement? The car has 30,000 miles.
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I have a 2007 Mazda Miata that I just found standing water under the passenger seat. Took it to dealership the drain is plugged if I had brought the car in when under warranty they would have done the retrofit it needs to fix their lousy design problem for free. I am trying to talk to Mazda and the dealership about them fixing the problem for free. They issued a in house service bulletin but not to the public.
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I've got a '94 Mazda miata which is in good shape, with among other things a fair number of suspension upgrades. It drives really well, other than the clunk. On the occasional bump it clunks as if something is loose on the driver's side rear. I've checked the shocks, springs, jacked it up and inspected everything I can think of. I'm looking for wisdom from your decades of experience (in your terms wasted time) on what it might be.
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My Miata stalls out on the highway but not on residential streets. If I open the gas tank ,it starts up again. This has happened with a full tank, 1/2 tank and 1/4 tank. How can I fix this?
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I have a 91 Miata Auto. I bought it from someone that (I think!) never drain auto trans fluid during its 145K mile life. So last year I replaced all the gaskets/filters and tuned up the car. It runs fine except shifting harsh in cold weather. I have to mention that it seem to have no power and goes very slow on first few minutes.I used a pump to suck trans fluid out. It was so dark (even I dropped the trans pan and replaced filter/gasket). Then I pumped Lucas trans fix fluid in and it seem to improve. What should I do more to reduce the harsh shift condition in cold weather? Or is there a booster module need to be replaced?
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I have a 2001 Miata. It's been over 100 degrees daily lately. The AC will blow sort of cold for about 30 minutes and the temp gauge will move towards the H hashmarks. If I turn the AC off, the gauge will slowly drop. I've also noticed that the amount of cold air is decreasing as time passes. In fact, the other day, the system was blowing air hotter than the outside temperature after about an hour drive.
The viewing glass has bubbling stuff flowing thru it. The recently flushed radiator is full as is the overflow reservoir.
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So i was cleaning my 2007 mazda miata and i noticed one wheel has some fairly deep scratched grooves inside of it. I inspected all the other tires and the other front tire has similar marks but they are way way more of a surface/barely there scratches. The rear wheels are not scratched. I am also hearing a rotational noise when i drive. It gets faster as I accelerate and slower when I brake. I don't know anything about cars.
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2006 Subaru Outback. It has around 121000. I bought it at 113,000 last October since my previous 1998 Subaru made it to 240,000. So far I've taken it in for all new wiring and a tune up. And I was assured by the car salesman that the timing belt had been changed prior to my purchase. Anyway, since August I've had a rattly/whirring sound that I am experiencing over 15 mph. It seems to be coming from the back of my vehicle. It sounded like I had a hole in the muffler because it was reminiscent of when I lost my muffler on the highway with my 1998 subaru a few years ago, but this sound is definitely not as loud. The sound does increase in volume at high speeds on the highway but has so far not been as loud as my previous experience. (and the muffler is still there when i look under the car)
When I took my car in to get the oil changed a couple months ago, I asked the mechanic to check and see if he saw anything while under there. They told me it was my heat shield.
Recently the noise started being a little bit louder on the highway so I thought maybe it was my tires since they were very due to be replaced. I bought new tires within the last few weeks and there has been no change with the whirring sound on the highway. Yesterday, I noticed a light thunking sound that started happening between the speeds 10-40mph. It seems to be in the front of my car and occurring with the rotation of my wheels. There are no sounds when Idle.
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My 2001 S2000 is a great car, but I'm having trouble getting people to ride with me. It seems that after being driven for awhile the passenger seat gets hot. I did have my dealer check the heat shield and they said it's fine. What's causing this and how to I fix it?
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So my Nissan emits a loud (way louder than normal) "vroom" when I start it up and then idles back. Also, sometimes the tach needle jumps high and then falls, sometimes almost seems like the car might turn off. I have a knock sensor code on and nothing else. I was due for state inspection and the guy told me that my exhaust was warped and said that it was too loud and I will fail the inspection (I think he meant on the noise level as he did not do any diagnostics.
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My exhaust system was replaced on my 2005 Corolla in August. After driving it for just a few days, there was a shaking when the car idled. The mechanic replaced two engine mounts and the idle was much worse! He said it was ok to drive, so I started on my planned trip across the country. In Denver I took it to a mechanic at the Toyota dealer and they adjusted the throttle. It was better for a while, maybe a week and 1,000 miles. Now it is worse than ever! Having gotten two totally different causes from mechanics, I am not sure what to do next.
Also just before the exhaust sytem went, I had the 60,000 mile service done and had the car totally checked out by both Toyota, and an independent mechanic who specilizes in Japanese cars. After a car wash in California, the maintence required light came on.
What is going on?
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Can't get a solution to this nagging odor in my car. the dealership (that I do trust) claims they cannot find a gasoline leak or an exhaust system leak. The check engine light is NOT 'on' and the car runs well for a car w/ 139K on it. I notice it briefly gets worse w/ harder acceleration. I'm driving w/ the windows partially open, which is way 'too' cool to suit me. Could this be an emissions system problem not tripping a sensor for the computer?
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I had an '83 Chevy Malibu Classic that slowly lost power until it was nearly undrivable. I rebuilt or replaced every fuel or spark related item I could think of. I finally had the catalytic converter and O-2 sensor replaced. It ran better, then the problem returned about 8,000 miles later. Disconnecting briefly the exhaust did not work. This suggested that I was sold a new converter for nothing, but the mechanic must have done something to get it to run better. The question is: what was the problem and what did the mechanic do to improve it? (hint: I had indications of coolant contamination in the valve covers, any connection?)
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For the past maybe 10 months, my car has been giving me new AC problems. The AC runs just fine when I'm driving normally or on the highway (basically without stopping for long periods of time and out of traffic). But when I stop for a long time (traffic, drive-thru, long light), my AC begins to run hot. To be more specific, the car actually begins to feel like it is running with more difficulty, as the engine starts running loudly and then I know that it is game over and it begins spitting out hot air. I generally just turn the AC off and put the windows down until I can get moving again, and then the AC is colder when I turn it back on.
Now, about 5-6 months ago I took it to my Mazda guy and he checked it out. Of course, it did not do what I wanted exactly, showing him what really happens when it sits for too long. Anyways, he said that everything seemed to be fine & both fans were working, but that the freon (r134) was low and he charged up the system and added some freon. After this, the AC was running MUCH cooler than it was before and the problem stopped.
That brings me to the last couple months; the problem has returned. This indicates to me, perhaps, that the freon has leaked out at this point, so it needs some more r134, but with dye, so that they can get a sniffer and pick the leak. Additionally, the engine is not overheating or anything of that sort, so I don't think it has to do with the radiator or coolant. I have essentially replaced almost every other part of the AC system in the car within the last 3 years. I have replaced the condenser, one of the fans, the water pump, hoses, everything you could imagine that isn't the compressor or the second fan.
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