Idling car vibrates, plus loss of power

[redlotus]

Wondering if I could get an opinion on this. Few days back, my car couldn't be started up( can still be cranked, so I dont think its a simple battery issue, which was replaced couple months back), thought the fuel pump could be the problem. Anyways called up and went over to Naidu ( he thought it was a fuel pump issue too) and brought over a mechanic. Replaced the fuel pump (located at right rear passenger seat) and after that no problem. Now however, whenever I start my car up, there's a jerky vibrating feel while idling. And while driving I can feel the subtle loss of power, and that I need to rev harder to reach a higher rpm, speed of the car now taking slightly longer to accelerate. Thoughts on this could possibly include a) Vanos seals need to be seen to and replacedb) clogged cat converters c) ignition coils d) Camshaft sensors To be sure, I'll be heading to Optimum tomm morning to get a diagnostic check. All I see on the OBD is "check brakelight" . One question though, if more than one thing is faulty in the car, will the OBD able to show all of it. Coz in spite of all this, I'm still wondering why there is no check engine light coming on. Even the icons arent lighting i.e. no Christmas tree yet... ( someone once described the icons lighting up in his car like a bad ominous Christmas tree haha!)

 

[jarance]

Try with the simple things first and then work to the complicate thing if cannot work.

1. fuel filter
2. spark plug
3. clean the MAF
4. check air filter.

BTW, what is the engine spec and year?

 

[zib]

I am pretty sure it is the one of the ignition coils. There are 6 of them ,so 1 could be faulty.

Test one by one when the engine is running and unplug each coil in sequence. The one that does not make the engine vibrate worse than the current situation is the culprit.

replace only that one. And off you go again.

Hope that helps.

Cheers..

btw the coil pack costs ca.RM115 each IIRC and the brand would either be Bremi or BMW.

 

[huskar3399]

don't be like me. i changed so many started with all 6 ignition coils, then maf, then both o2 sensors and unfortunately the symptoms like u mention above still occur. last thing i did was clean the icv. and surprisingly it works. symptoms all gone however the cel still illuminates.

 

[redlotus]

Thanks guys!

 

[redlotus]

Try with the simple things first and then work to the complicate thing if cannot work.

1. fuel filter
2. spark plug
3. clean the MAF
4. check air filter.

BTW, what is the engine spec and year?

Thanks bro Jarance, will check up on these. Btw, the car is a 2002 M54 520i.

 

[redlotus]

Got the issue sorted out this morning. Took the car to Optimum and had a diagnostics check done. Yeah cylinder 1 was misfiring, so changed the ignition coil for that one, and the ride got back to a pleasing normal !!

 

[alantiong]

if one coil is bad.. the rest comes very fast.. i will suggest change all.. if the firing efficiency differs from one coil to another.. it creates what we call a firing capaciting which it draw more current from the better coils.. trying to balance out the sparks.. in the end your new coil also rosak.. i believe many forummer here also have experience that.. change one coil.. another few comes like in a row.

 

[zib]

if one coil is bad.. the rest comes very fast.. i will suggest change all.. if the firing efficiency differs from one coil to another.. it creates what we call a firing capaciting which it draw more current from the better coils.. trying to balance out the sparks.. in the end your new coil also rosak.. i believe many forummer here also have experience that.. change one coil.. another few comes like in a row.

Well alan, I beg to differ.

I still recommend change as necessary and required. Save your money for other important things.

I changed mine last year and the rest are still running ok.....

...well one might go south tmrw but heck I am not worried, I will only change the faulty one I am a happy man.