318i engine rattle.

Need technical Q/A then you're in the right place

Moderator: martauto

jmc330i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6621
Joined: Mon Jan 10, 2005 11:00 pm
Location: Somerset

Post Sun Apr 23, 2006 10:39 pm

Driving home from work on Friday morning, I noticed a faint 'rattle/tapping/knocking' coming from the engine. Didnt do it all the time, only on light throttle between 2.5k and 3k rpm. When idling it was fine and also under load, until just before 3k rpm when it came back and got louder with higher revs (didnt take it over 4k).

Went out this afternoon and the noise was still there, no different to before. Driving home this evening the engine cut out on me and wouldnt restart - wouldnt even turn over. After leaving it a couple mins it started fine, but the faint rattle had got a lot worse - engine rattle seems a bit of of tame description now :(

I was only 2 mins from home so I drove it back very slowly, not going over 2k rpm. The engine seemed to be down on power (I didnt push it, but it didnt seem very eager) and would surge under load just below 2k rpm.

Ive got a vid taken on my phone of it idling and with a few revs, its a bit crappy but it gets the noise across. The bonnet is up so the knocking is loud - Click me please

About 20 seconds into the vid, the noise stops and the engine is idling fine until I rev it again. It doesnt always do this, but it will still (occasionally) idle normally without any knocking and then will start knocking again even when it isnt reved.

I got the rocker cover off before it got dark, and everything seems fine there. All the rockers, cam lobes etc all there and in one piece.

Any suggestions what I go look for tomorrow?
James
'91 325i Sport
'93 318i touring 16v
Top
smithy318i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 5797
Joined: Thu Apr 28, 2005 11:00 pm
Location: Tyne & Wear

Post Sun Apr 23, 2006 10:45 pm

FEK ME !

sounds like one of the piston rods is broken?
Image
Top
jmc330i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6621
Joined: Mon Jan 10, 2005 11:00 pm
Location: Somerset

Post Sun Apr 23, 2006 10:52 pm

smithy318i wrote:FEK ME !
Thats what I thought 8O
sounds like one of the cylinders is hitting your valves. Check cams/rockers etc.
Thought that as well. The cam and rockers seem ok - nothing obvious anyway. At first I thought one of the rockers had snapped or something, but it will still run ok, and then starts knocking.

Looks like the head is coming off then :evil: :cry:
James
'91 325i Sport
'93 318i touring 16v
Top
jmc330i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6621
Joined: Mon Jan 10, 2005 11:00 pm
Location: Somerset

Post Sun Apr 23, 2006 10:56 pm

smithy318i wrote:sounds like one of the piston rods is broken?
I dont think its that, it will still run and sometimes absolutely fine - as smooth as an M40 can be anyway.
James
'91 325i Sport
'93 318i touring 16v
Top
Dan318-is
Married to the E30 Zone
Married to the E30 Zone
Posts: 8006
Joined: Wed Jul 06, 2005 11:00 pm
Location: Surrey/London

Post Sun Apr 23, 2006 11:05 pm

jmc330i wrote:
smithy318i wrote:sounds like one of the piston rods is broken?
I dont think its that, it will still run and sometimes absolutely fine - as smooth as an M40 can be anyway.
Possibly a seized ring job; although this would not explain its reluctancy to start would it?

possibly a crankshaft/shell problem?
Top
Martinaston
E30 Zone Addict
E30 Zone Addict
Posts: 3749
Joined: Mon Mar 14, 2005 11:00 pm
Location: London

Post Mon Apr 24, 2006 12:24 am

Got any oil in it ? 8O
There is NO nucleus.
Top
User avatar
stevetigger
E30 Zone Addict
E30 Zone Addict
Posts: 4659
Joined: Thu Feb 24, 2005 11:00 pm

Post Mon Apr 24, 2006 1:54 am

Sump off first before head! Check in the sump first! Sounds like the shells.
Top
jmc330i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6621
Joined: Mon Jan 10, 2005 11:00 pm
Location: Somerset

Post Mon Apr 24, 2006 9:49 am

Martinaston wrote:Got any oil in it ? 8O
Yup, plenty. It wasnt smoking or burning oil over the last couple weeks (Ive only just bought the car :( ) and it still isnt. The oil level hasnt changed in the few weeks Ive had the car (I always check this daily on a newly acquired car) and its been running 100% spot on. Not using water and no temp problems.

Although I dont know the history of the car, its really quite unexpected considering how well the car has been running since I got it.

As Steve said and as there wasnt any cam/rocker damage, I will drain the oil, drop the sump off and have a look see.

TBH, Im thinking its the end of my 4 pot time - all 2 weeks of it :?
James
'91 325i Sport
'93 318i touring 16v
Top
User avatar
stevetigger
E30 Zone Addict
E30 Zone Addict
Posts: 4659
Joined: Thu Feb 24, 2005 11:00 pm

Post Mon Apr 24, 2006 2:56 pm

Yep, Time for an M50 in it! :mad:
Top
Martinaston
E30 Zone Addict
E30 Zone Addict
Posts: 3749
Joined: Mon Mar 14, 2005 11:00 pm
Location: London

Post Mon Apr 24, 2006 4:25 pm

Have a look to see if someone's had a play with it before, they could have just bodged it to get a sale, Although i've never come across it i've heard the oil pumps don't last as long as the M20.
There is NO nucleus.
Top
jmc330i
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6621
Joined: Mon Jan 10, 2005 11:00 pm
Location: Somerset

Post Mon Apr 24, 2006 7:16 pm

Could be the oil pump I guess - but wouldnt the oil pressure light have come on??

I didnt get chance to look at it today and Ive got nothing to drain the oil into anyway - after a clearout of the garage last month, i cant find my high tech oil catch device (read half barrel) so its time to make another.
stevetigger wrote:Yep, Time for an M50 in it! :mad:
Not sure I can stretch to that just yet - and I need to finish the S50 before I start another conversion :roll:
James
'91 325i Sport
'93 318i touring 16v
Top
gcorky
Boost Junkie
Posts: 2009
Joined: Tue Jul 12, 2005 11:00 pm
Location: n.e england

Post Mon Apr 24, 2006 8:43 pm

sounds like a little end to me,unplug each ht lead in turn and try it will miss but the knock should go away if it does ,engine or overhaul time.


remove the four spark plugs -what they look like?
Image

525 sport
Top

Return to “E30 Technical Help”