So I found the cause of that shocking misfire! I took the rocker cover off today to find that on cylinder 2 (from the front of the car) the end of the rocker has snapped clean off...
This happend a few weeks after I had the valve clearances adjusted due to lots of tappet noise. The tapping very quickly returned!
The car is an M20 325i...
Now I wondered if you could advise what the likely extent of the damage is i.e. could the valve have hit the piston etc...
my initial thoughts are get another rocker arm... fit and see what happens...
any advice welcomed...
cheers,
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Snapped Rocker!!! - Likely Damage? Advice appreciated!
Moderator: martauto
Exactly same thing happened to me last year, I adjusted the tappets sounded all good, then a couple of days later a rocker snapped... it's now a trendy key ring.
What you can do rather then removing the head is take out the rad and anything in the way, then pull out the support bar they're on through it and replace it. I'm sure someone is able to give you a more thorough description because I couldn't be bothered to replace my one and just changed the whole engine
What you can do rather then removing the head is take out the rad and anything in the way, then pull out the support bar they're on through it and replace it. I'm sure someone is able to give you a more thorough description because I couldn't be bothered to replace my one and just changed the whole engine
I dont know if the same thing has happened to mine, however the symptons sound the same!
Did your engine refuse to start? Mine seems to be missing and not idling, backfiring and all sorts! However I thought this was because of a 'mechanic' screwing my AFM up!
Did your engine refuse to start? Mine seems to be missing and not idling, backfiring and all sorts! However I thought this was because of a 'mechanic' screwing my AFM up!
I dont know if the same thing has happened to mine, however the symptons sound the same!
Did your engine refuse to start? Mine seems to be missing and not idling, backfiring and all sorts! However I thought this was because of a 'mechanic' screwing my AFM up!
Did your engine refuse to start? Mine seems to be missing and not idling, backfiring and all sorts! However I thought this was because of a 'mechanic' screwing my AFM up!
cheers... thinking new engine but may try that just to see...
mine was starting fine but just missfiring badly and I had narrowed it down to piston 2 by removing leads singularly to listen for ay cange in engine sound... if no change on one then that is certainly going to be one of your issues to investigate furter!
mine was starting fine but just missfiring badly and I had narrowed it down to piston 2 by removing leads singularly to listen for ay cange in engine sound... if no change on one then that is certainly going to be one of your issues to investigate furter!
cheers fella going to give thi a whirl... if anyone has some spares give me a shout! been a bad news day... the head gasketwent on one of my polo G40's too! prettyexcited to getmy E30 back on the road though and get some progess underway on the improvemen/mods front!
The rocker probably snapped because the valve hit the piston so you probably have a bent valve and maybe some piston damage. 
You could try your luck and just replace the rocker first and see how that works.
You could try your luck and just replace the rocker first and see how that works.
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B7
- E30 Zone Team Member
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What a load of rubbish! m20s snap rockers regularly if the clearances are wrong or cheap after market rockers are used. As said remove the rad and fan, jack the engine up and slide the shafts out the front. 1 new febi bilstien rocker later and i'll bet the jobs a goodun.Billwill wrote:The rocker probably snapped because the valve hit the piston so you probably have a bent valve and maybe some piston damage.
You could try your luck and just replace the rocker first and see how that works.
B7's Motto. "If it's French, BURN IT!!!!!!"
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Simon13
- The longest resto in the world !
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this all bollocks imo. It snapped because the cam is f**ked and the rockers are worn. It needs a top end rebuild. End of. New spraybar - this is why the valve gear is shot, so a new cam and rockers.
By replacing one you are buying a little time until the next one snaps. Which will happen. A load of aggro for zero gain really.
Guys if its still running with a snapped rocker it will run very rough shaking the whole car to death nearly, smoke, zero fuel economy and no power it will sound fucked, its a very obvious thing! I've driven 50 miles on one, not funny.
By replacing one you are buying a little time until the next one snaps. Which will happen. A load of aggro for zero gain really.
Guys if its still running with a snapped rocker it will run very rough shaking the whole car to death nearly, smoke, zero fuel economy and no power it will sound fucked, its a very obvious thing! I've driven 50 miles on one, not funny.