Solved: How to fix your BMW M235i misfiring
Is your car misfiring? It’s not a nice feeling when you start your vehicle and hear the engine misfire. And it’s worse when you get the warning light on your dashboard.
When Mr H brought his BMW M235i to RM Motors, his vehicle was intermittently misfiring.
While his car still worked, it’s not an issue you want to ignore, as it can worsen, leaving you with significant engine damage. Not to mention the costly repair bill.
Mr H had already visited another garage to have his spark plugs, ignition coils, and injectors replaced, but the problem persisted.
Luckily, he chose to visit our BMW experts at RM Motors for a solution to his car’s problem.
What we found
During the initial inspection, our BMW specialists used their decades of experience and BMW manufacturer information to identify the root cause of the problem.
As your local BMW specialist, we have access to the same technical information as the main BMW dealership. You get a dealership-level service for better-than-dealership value.
It was clear some of the BMW’s parts had been replaced, confirming what Mr H had stated.
Our BMW experts had a suspicion of what was causing the M235i to misfire but wanted to ensure they covered all the bases first.
Diagnosing the problem
Our BMW experts test-drove Mr H’s car to see the issue first-hand. During this test, we found the vehicle’s misfire occurred during a cold start-up and when placed under load.
Once back at the garage, the next step was to run a full body scan of the vehicle to see if any fault codes returned.
Several fault codes appeared on our system:
- P0300 – Random multiple misfires.
- P0304 – Misfire cylinder 4.
- P0306 – Misfire cylinder 6.
Confused? It’s ok; these fault codes won’t mean much to you. But to our experts at RM Motors, they point them in the right direction.
When our BMW specialists had confirmed the issues and their fault codes, we tested the M235i’s mechanical integrity using an oscilloscope to monitor the misfires as and when they occurred. An oscilloscope is an instrument that graphically displays electrical signals and shows how those signals change over time and it’s something more usually found in hospitals or a science lab rather than a garage!
Using an oscilloscope is not something even the leading BMW dealership would have done. It allows us to identify faults quickly and effectively, ruling out common causes. By doing so, we solve your car’s problem fast, saving you time and money.
At RM Motors, our specialists use a multi-step diagnostic process to resolve any issue. We guarantee a quality first-time fix, saving you time, stress, and money spent on repeat repairs.
Our multi-step diagnostic process digs deep into your vehicle, identifying any faults before they worsen.
Using the multi-step diagnostic process, fault codes, and rigorous testing procedures, our specialist technicians discovered the cause of the misfiring.
It was the new spark plugs installed on his BMW by the previous garage!
When looked at closely, the spark plugs were low quality and weren’t cut out for the job, causing his vehicle to misfire.
Poor quality car parts can cause a wide range of issues inside your vehicle, often leaving you wishing you’d spent a little more on high-quality components.
It’s one of the reasons why we only use genuine BMW or high-quality equivalent parts for all of our repairs, maintenance and servicing. You get the quality your vehicle needs to run optimally.
Fixing the BMW
Now our BMW experts knew the cause of the issue, we informed Mr H of our findings and how he’d like us to proceed.
At RM Motors, you’re always in complete control. We only begin working on your vehicle once you’ve given us the go-ahead.
Mr H was shocked that his new spark plugs were causing the issue. However, he was pleased we’d identified the root cause of the problem.
He agreed to our recommended repairs, and our BMW specialist technicians got to work sourcing and replacing the necessary parts.
Once the low-quality spark plugs had been replaced with BMW-branded spark plugs, his M235i ran like new with no misfiring or error messages on his dashboard.
Our BMW experts were pleased to hand Mr H his keys, and he was over the moon to have his vehicle back in top working condition.
Mr H saved time and stress while getting better-than-dealership value.
Summary
Mr H’s BMW M235i had been misfiring for a while, and he’d had several parts replaced at other garages to try and solve the problem.
Unfortunately for him, the misfiring persisted.
Luckily, he brought his car to our expert BMW technicians at RM Motors.
After rigorous testing, using BMW manufacturer information and our multi-step diagnostic process, we identified the cause of the fault. Mr H’s BMW has been fitted with poor-quality spark plugs (by another garage).
Fortunately, our experts spotted the issue and replaced the poor-quality parts with BMW-approved spark plugs.
Once the replacement had taken place, Mr H’s car ran like new with no misfiring.
Mr H was pleased to have his M235i back in peak condition. And he was even happier when he saw the bill, which was cheaper than the leading BMW dealership.
If your BMW is misfiring, call our specialists at RM Motors for a quality first-time fix.
Call us on 01924 456666 and book your BMW check-up without paying dealership prices.
