First time owner, few problems

Hey,

Hope this is not a violation of any rules, but i have checked some of the other threads and it seems alot of the cars here are modified, which mine is not its completely stock, so i didnt want to get any advice mixed up if it didnt apply to me.

I recently bought a 2009 speed 3 and it has a few problems that i need to resolve but am not super car savvy and dont want to be ripped off by any garages.

I bought a code reader and connected it to an app on my phone, even though there is no check engine light at all. Im using the Car Scanner free app at the moment, unsure if this is the best or if there are any other recommended ones.

1 - Randomly under acceleration the car bucks, like its losing power, i assume a misfire, idle is fine and cruising on the motorway is fine with cruise control, but put your foot down to overtake and its pot luck if you can. I have had trips where it happens all the time, and others where it never happens even under the same driving conditions, it also happens in random gears, initially i noticed it in 4/5/6 but then had it happen once in 2/3 aswell. I have been recommended to start with spark plugs and if that doesnt resolve it move onto checking coil packs, is there anything else to check or test first?

2 - The air conditioning does not engage. Randomly the light on the button will be on, then turn itself off when turning the car on. Sometimes i can press the button and the light comes on sometimes it does nothing other than turn the heater onto auto but the AC button light stays off, i do get a beep though. Checking the compressor while the car is running and someone pressing the button, or restarting the car we can see that the magnetic clutch is not engaging. Could this be down to no gas in the system, faulty relay or bad magnetic clutch maybe? Im just not sure where to start diagnosing this, i did see some videos suggesting to swap the horn and the ac relay, but i didnt want to apply too much force in the fuse box but the relays feel like they are screwed in or something?

3 - Groaning sound coming from passengers footwell when turning (again randomly...) i assume this is just a sign of old age and wear and tear, but any ideas what part might be causing this issue that might be worth checking? I have had someone check the suspension and the shock and spring all look good, so do the lower arm bushes and balljoint, they think maybe anti rollbar link maybe?

4 - There is one fault code that shows up on the app from when i connected it last "U0428(62) ABS Control Unit -OBDII: Invalid data received - steering position sensor control module". Without sounding like a total idiot does this mean that sensor is faulty and needs replacing?

If you got this far and can offer any advice thanks in advance, it will be nice to get the car back into good running order to enjoy!

 

Spark plugs. Try recapping first

Probably ac clutch

Probably just the lsd during right turns which isn't a problem but tough to confirm over the internet

Wouldn't worry about it unless it triggers a warning light

 

Thanks for the reply, i think i will get the plugs done first and fingers crossed it will go away, that seems the cheapest option to try first.

 

I would suggest replacing the transmission fluid and checking the Pivot shaft seal to make sure it isn't leaking. low fluid can cause LSD chatter during turning.

Another thing to think about it the power steering system. At full lock a little whine/groan is ok. So repeat the test you're doing in turns at full lock and not fully locked

Welcome to the forums.

 

i'll defer to the guys who are still in the MS3 game, but issue 1 sounds like it could be a fueling issue - specifically losing fuel pressure.

issue 2 - i would make sure the system is charged before doing anything else. you could buy a can of freon with a gauge on it easily enough. if it's low, charge it. if it's good, then start looking elsewhere.

 

Thanks for the replies, sorry it's taken a while to come back, between weather and schedules only managed to get the plugs changed yesterday.

It did sound and feel alot smoother on the drive home yesterday but today will be the first longish run, so fingers crossed but given the gap and state of the old plugs I'm feeling confident.

Hoping to investigate the AC issue further when we change the belt in the next week or so.

 

Hey, looking for some more advice if possible, the car was running fantastic after the plugs, smoother that ever... then the smoke started... randomly white/grey/bluish hard to tell really smoke from the exhaust, randomly, sometimes days with nothing then constantly for a few drives, albeit only for about 1/2 a mile and then it clears.

My dad an ex mechanic thought originally valve seals, but did make a comment when i went over that it smelt like rotten eggs, but we have come to the conclusion its too inconsistant for valve seals and then today on my drive home from work the check engine light came on...

From the research i have done this sensor is after the cat, i did clear the codes once and went for a 8 mile drive and about half way it came back, that drive was also the first time the car smoked this week, for about 1/2 a mile until i hit a bypass and it cleared.

Starting to feel so demotivated as it feels like it just one thing after another... any advice would be really appreciated, i just want to get the car into a good working state as i have quite a few long journeys this year planned and right now i dont feel comfortable driving the car 2 miles to work, let alone several 400 mile round trips...

Cheers again for any advice.

 

If you're burning oil or coolant you can break down the catalytic converter. Causing it to come apart and clog which in turn chokes the engine and causes more smoking or lack of power.

The slow response is because of lack of airflow across the sensor. Remove the catalytic converter and check it for being clogged. Or run it without the front O2 sensor threaded in and see if that makes a difference.

Rear O2 sensor has nothing to do with maintaining the Air Fuel Ratio. It's only purpose is to monitor converter health.

 

Thanks for the reply, although im even more concerned now if this sensor it simply a monitoring sensor, i was hoping it might have been the cause of the smoking...

Any idea what could be causing the smoke? it literally started last saturday which is a week after the plugs were changed. My dad is confident its not valve seals as he said that would be present constantly and not just happen overnight like it appears to have happened. He has mentioned possibly turbo, which terrifies me as it was one of the parts i had a quote from Mazda from while looking to buy a car and it was about £1500 before tax! Im just after some ideas of where and what to check / test before biting the bullet and taking it to either a garage or the dealer.

It the fact its so random when it happens thats puzzling us, goes 3-4 days with nothing then happens for about 1/2 a mile, then nothing, park up go into shops come back and sometimes smoke sometimes nothing... Where if oil was getting into the cylinders for example via valve seals surely it would smoke badly first thing in the morning, but so far its never happened in the morning... so confused.

Just based on what you have said about this sensor, changing it now would only mean the new one getting damaged anyway if the root issue is not fixed.

Please also excuse my lack of experience with this but what does running without the front O2 sensor do?