Bad Misfires

G

Gee-Lanty

Member
Hi guys,

I have a problem with misfires some mornings. What is going on here?

[youtube]T-SKNJWF8Fo[/youtube]

As it only happens in the mornings I thought I may possibly have a leaking injector, however I have noticed the upper intake boot gasket ring is deformed and not sealing properly in to the air filter, also the lower intake has cracks in the small hose. I’ve ordered replacements but wondering if anyone has experienced something like this…

Car runs quite smooth after startup though I have experienced the RPM’s fluctuate when I take my foot off the gas from time to time.
 
Definitely change any dodgy looking rubber boots etc. Have you got a code reader ? That would tell you a lot. Check your MAF also, that would throw up a code. Is the oil filler cap on tight ? What state is the CCV in ? :thumbsup:
 
patriot66 said:
Definitely change any dodgy looking rubber boots etc. Have you got a code reader ? That would tell you a lot. Check your MAF also, that would throw up a code. Is the oil filler cap on tight ? What state is the CCV in ? :thumbsup:
Click to expand...

Cheers mate, I just took the upper and lower intake boots off and the lower one was in a sorry state, so I taped it a bit (much!) better than the previous owner until I receive the new parts from BMW. Also checked the DISA, and found it had no resistance what so ever…NADDA!!! Think that may be contributing to the performance issues.

Must say when I started the car it ran like a dream and I could barely hear the engine, though it was still warm, it rarely settles so smoothly so instantly. Real test will be in the morning…

Think the CCV is way beyond my comfort zone at this point.

This is my first car, bought it knowing full well it would need a lot of work, but never, ever imagined I’d be the one doing it all. Just expected to throw money at people to do it for me but everyone can tell I’m a Londoner and they’re all extracting the urine and I can’t abide it!!! I was quoted £250 for a non oem thermostat, not including the labour!!! I’m not having it!!! :headbang:

Have also invested in an obd scanner but will have to wait a number of weeks for it to arrive.

Thanks for your help! :D
 
The irregular slamming sound in your video, which I did not recognize as misfire. But if you have solved it already, let us know.
 
To be more precise: A worn timing chain is characterized by a rattling noise that can be heard. The noise will be heard when starting the engine and idling. I thought to hear this in your video?
 
WouterZZZZ said:
The irregular slamming sound in your video, which I did not recognize as misfire. But if you have solved it already, let us know.
Click to expand...


Hmmmm…you got me thinking now! I had noticed a tapping and tried to convince myself it was likely the DISA valve, which I found out today the pedal is loose, but I think watching the video again, I heard what you heard too!

Here’s two more videos of startups…

[youtube]jL3yBCE9U6A[/youtube]

[youtube]Okovvwv8NRE[/youtube]

Thoughts?!
 
WouterZZZZ said:
The irregular slamming sound in your video, which I did not recognize as misfire. But if you have solved it already, let us know.
Click to expand...
Just sounds like popping and banging to me caused by fuel:air ratio being way out. At the same time the rpms stumbles by approx 1000rpm and then recovers. Looks like it's only done 73,000 miles. Timing chain on an M54 should be fine at that mileage :thumbsup:
 
Can you turn the DISA flap against the spring pressure and does it return quickly when you let go ? Does it stay in open position when you put your finger over the small hole on the side of the unit ?
 
patriot66 said:
Can you turn the DISA flap against the spring pressure and does it return quickly when you let go ? Does it stay in open position when you put your finger over the small hole on the side of the unit ?
Click to expand...

No and no. The paddle moves freely with no resistance what so ever, no vacuum is held when placing my hand over the hole. The pin is secured in place but the valve has definitely failed. I’m going to order one of the aluminium rebuild kits which I’m hoping will solve it. 🙏🏼
 
Gee-Lanty said:
patriot66 said:
Can you turn the DISA flap against the spring pressure and does it return quickly when you let go ? Does it stay in open position when you put your finger over the small hole on the side of the unit ?
Click to expand...

No and no. The paddle moves freely with no resistance what so ever, no vacuum is held when placing my hand over the hole. The pin is secured in place but the valve has definitely failed. I’m going to order one of the aluminium rebuild kits which I’m hoping will solve it. 🙏🏼
Click to expand...
The flap is just a flap. The vacuum is generated by a rubber 'plunger' affair inside the round end of the unit. Read this : https://www.bimmerfest.com/threads/disa-autopsy.572199/
20220307_150322.jpgAs part of my supercharger install last March I fitted a new Febi Bilstein DISA valve, just over £100. Top quality :thumbsup:
 
patriot66 said:
The flap is just a flap. The vacuum is generated by a rubber 'plunger' affair inside the round end of the unit. Read this : https://www.bimmerfest.com/threads/disa-autopsy.572199/
20220307_150322.jpgAs part of my supercharger install last March I fitted a new Febi Bilstein DISA valve, just over £100. Top quality :thumbsup:
Click to expand...

Thanks for the link. I kinda understand but as the flap moves freely to the open and closed positions I’m not sure how I could test if it’s holding vacuum or whether it even matters given the flap is definitely malfunctioning.

I’ll take your advice and buy the Bilstein. Would prefer a new unit with new seals etc anyways… :thumbsup:
 
Gee-Lanty said:
patriot66 said:
The flap is just a flap. The vacuum is generated by a rubber 'plunger' affair inside the round end of the unit. Read this : https://www.bimmerfest.com/threads/disa-autopsy.572199/
20220307_150322.jpgAs part of my supercharger install last March I fitted a new Febi Bilstein DISA valve, just over £100. Top quality :thumbsup:
Click to expand...

Thanks for the link. I kinda understand but as the flap moves freely to the open and closed positions I’m not sure how I could test if it’s holding vacuum or whether it even matters given the flap is definitely malfunctioning.

I’ll take your advice and buy the Bilstein. Would prefer a new unit with new seals etc anyways… :thumbsup:
Click to expand...
Wise move and will eliminate the DISA from the equation :thumbsup:
 
I’ve yet to receive the OBD scanner I ordered and this coughing fit my engine experiences every other cold start is really bothering me, and it’s a little embarrassing!

I paid a mechanic to hook my car up to his OBD device yesterday and these are the codes I had…

FE89E468-848B-49A8-87B7-E86A613D6D6B.jpeg

Just 3!!!!🙏🏼

Could the code for the MAF be related to the DISA fault which I know to be malfunctioning as the flapper paddle thing moves freely? Hope I don’t need a new MAF!!!

When I let off the gas after accelerating the RPM’s “pulse” slightly, going up and down in small increments, hoping the new DISA will fix that too!

Also noticed there were no codes for the airbag light I have constantly on, which I assume is to do with the passenger occupancy sensor. Is this normal or do I need to connect to INPA for a more thorough diagnosis?!
 
281E is variable intake fault, i.e DISA
2783 is MAF fault
278C is intake temperature fault
Personally I'd just fit a new DISA and a new MAF. I can recommend Febi Bilstein and Hella respectively having fitted both in the last few months :thumbsup:
 
With BMW diesels, unplugging the MAF to see if it runs better without it was always a thing. Can't remember if that applies to petrol tho
 
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