Jump to content
SAU Community

Recommended Posts

guys i was driving down the freeway the other day not thrashing the car or anything doing aroun 120km/h and put my foot down in 5th to overtake slow car in front and all i got was this whomp whomp whomp through the exhaust but no compression revs up to 2500rpm nothing past there I had to putt putt all the way to nth syd from gosford at 70-80km/h and not got past 2500rpm or the whole car would shudder and now tonight I had to drive it back home and even worse getting less and less compression taking it to the mechanic in the morning but I need to ask you any ideas!!?? Just so the bugger can't rip me off!

I turn the car off and back on and it is ok as soon as I get going same thing happens again?

Also what is the HICAS light and will that have anything to do with it?...

Please help guys!

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/
Share on other sites

If the car starts and idles ok then it's probably your AFM. Check for a loose plug for a start, that is hopefully all it is. I had the same symptoms when I accidentally yanked out my S-AFC wiring loom, thus causing the AFM to become disconnected.

Not sure if the HICAS has anything to do with it, mine never came on when I had this problem.

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-572089
Share on other sites

I had a search through the threads last night and it sounds exactly like this except mine shudders and ****ters when i put my fot down

"HELP !- losing a cylinder in the rain :D

As topic states:

losing cylinder(s) when parked outside in the current Sydney weather for 6 hours on an otherwise stock ECR33. after a while (quite a while) & some heat it comes good. The plugs are newish and the Datto has never missed a beat.

Are S1 RB25's prone to this ??

has anyone else experienced this ??

It's kinda spooked me... "

Yup, adam's spot on. it'll sound like a WRX just off idle & runs about as bad as an engine can without stalling !

Swapping the pos of the coils on the alloy mount... well I'm dead certain the moisture was between the coil & mount and that by simply removing/inspecting/cleaning/silicone spraying/replacing (with sighted good ones) the known faulty ones came good !!

Also I eyeballed the sus coils arcing (up to 12mm !!) to the alloy mount from their bases which was a bit of a giveaway.

I reckon seeing is believing, & there's been a lot of threads about coil pack testing involving swapping coils and tossing the failing ones. So how many perfectly good ones get tossed !!

Using the "Crank & Eyeball" test, if the coil is good you should see a spark, but NOT necessarily at the plug electrode !

If no spark do the GraemeW test. Many have questioned the validity of this test, but if it fails it's well & truly dead. I know from searching these forums that other members coils' have passed the resistance test but got binned anyway, consequently the rumour exists that this test is unreliable - methinks not !!

P.S. I gapped the plugs to .75mm and no more miss under load @4500rpm above 8-9 PSI with stock ECU. Jay95 posted about this in another thread & I give it the full thumbs up.. gap 'em down with confidence.

so do you think it could be the coil packs?

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-572109
Share on other sites

Yep definitely could be coil packs, it's just hard to understand exactly what the problem is going off a written description which is why I suggested AFM. Also I just noticed you said it's getting worse, if it's AFM then it's all or nothing (ie it won't get any worse). Check your coil packs too.

Worst case it's your rings or something, in which case you should probably look at your state of tune because they probably shouldn't just go like that with regular driving.

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-572115
Share on other sites

Well, if it all happens at 2500rpm, I am tending to agree with JimX's first impression - AFM.

Generally the cut is at 2500rpm from limp home mode.

Check for loose wires and try giving the AFM a clean, but first, have you tried doing an ECU diagnostics?

Like all things car though, you can never be 100% certain what it is until you have tried eliminating the possibilities:)

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-572286
Share on other sites

Sorry mate extreme newbie here as far as maintaining the car myself always goto a mechaninc... AFM? Air Fuel Meter? and how would i try doing any ECU diagnostics?

I took it too the mechanics today left it there all day and the bloody thing did not play up once and he can not see anything wrong I drove it home and around the coast for bout 1hr and no probs... could it have something to do with the rain i was driving in?... I don't see how has never been a prob b4.

What loose wires would i be looking for? thanks for your suggestions so far guys please help me out more if you can! thanks!!!

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-573049
Share on other sites

If the problem has fixed itself then your engine is definitely fine :D It sounds like an intermittent contact in your AFM (Air Flow Meter). This is the thing just behind your air box, it measures how much air is going into your engine. Unplug the small wiring connectors and spray with some electrical contact cleaner (get it from Jaycar), plug it back in and try again. Also spray the AFM filament with the contact cleaner. Do a search on cleaning the AFM for more detailed instructions.

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-573105
Share on other sites

I got a bit enthusiastic cleaning the engine bay and a day later the barge started dropping cylinders under load. Fine off boost and stumbling at idle so I whipped out the coil packs and water had filled in 3 of the plug wells and was seeping past the rubber weather seals. Even so the damage was done and a serious coating of baked on crap is right up the ceramic insulator on a few of the plugs. I tried to clean most of it off but was still dropping a cylinder so a new set of 7 heat range standard plugs gapped to 0.8mm has solved the problem and it's delivering more power than ever. And I was worryng it would be a coil pack.

I leave the plug cover off with the copper plugs so i can clean and gap them every time it starts to get rough under load....about 5000km but the power is better than the platinums.

Sounds like [some of] your plugs got water around them and were not firing in some cylinders. After 18 years of racing cars, swinging spanners for a living and getting a mechanical engineering degree I still find that plugs are the number one culprit for lost power and misfires.

Link to comment
https://www.sau.com.au/forums/topic/27175-big-problem-help/#findComment-573191
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • f**kin' yikes! That insulation is the shittest stuff I have ever seen. You need to do an insurance job on that f**ker, pronto. WRT to the washer cover, I would have said that there'd have to be some at a wrecker, then remembered that it's a BMW, and reasoned that every single wrecked one would have been tailgating and so the front end would be trashed.
    • Oh and I lost my headlight washer jet cover!
    • Ok, so I got myself some X1 wheels really cheap to try out, they're a bit different and I like them but they're really narrow (18x8) they are available in staggered 18x8/9 also but really hard to find.  I kinda dig them, but not as much as the F10 19's I usually run, so these go into the wheel pile.         As I mentioned in another thread, I got a new exhaust. It's an off-the-shelf stainless one that fits OH-KAY. I don't love the tips size and how far they come out the back, I think I might cut the tips off and replace with some smaller (~3") ones that don't extend as far. It sounds really good though, I'm not sure if its just in my head but the car feels a little quicker, more responsive.      I fitted an eBay special front lip. Surprisingly it fit perfectly and all holes lined up. Its a little rickety but I haven't put any double sided tape on yet, I want to clean the front bar up where it has scraped the road a lot and fil in the number plate holes (or, get body coloured wrap to cover them - is this a thing?  I'm not sure if I'll leave it gloss or pain it matte. I really like it though, I don't particularly like the front bar without it, I don't really like the M-Sport and to get anything else is just too expensive. That said, I might need a new one now anyway as I dropped the car onto the jack after forgetting to put ramps under the front wheels. It bent a lot and while it did go back to normal after I got the car off the jack, I do fear I have not done it any favours.    Lastly, my headlights died. Different problems in each. They have gotten much dimmer over the past year or so, I put new (uber expensive) OSRAM bulbs in them but to no avail. One of them pointed at the ground and the other just kinda did its own thing with light working sometimes. Yeah, check this 18 year old BMW headlight wire. I reckon I know why they were stuffed.            BTW, the yellow and black is the power to the Xenons. Yikes. I hunted around an researched my options here. I would have loved to just get a replacement harness but not a thing. My car has adaptive headlights, that is they rotate left and right with the steering wheel. Good condition used adaptive xenons were over $700 each, non adaptive were around $400 each, but I couldn't help but think that they're all around 18 years old now, surely they'd have the same problems. So I looked at newer LCI headlights but they were even more expensive and I couldn't confirm that they'd be plug and play with lots of people having lots of opinions so not worth the risk.  I ended up getting brand new Chinese headlights from MARS. They're very close to OEM with only the angel eyes being a bit different. I didnt want crazy turn signals or sharp DRL's or anything. Not my bag.  They're not adaptive, I thought thats a feature I wouldn't really miss. So I coded that out.  The lights are awesome, they look so nice and they take so many years off the car. The angel eyes look great and the headlight brightness is ridiculous. I was so used to the old ones, I didn't realise just how bad they were. The new ones use the OEM bulbs, Xenon ballast and leveller motor which I was happier with. The only issue with them is that the rear cover is held on by SEVEN screws. This will be a nightmare to get to and open when I need to change bulbs.   
    • Now that you mention it I can see those too. More subtle. The lighting and low resolution makes it hard to assess super well what's going on but what is visible is bad enough to pull the motor.
    • I feel like this is due an update
×
×
  • Create New...