E36 320i Hollow Knock at Idle
Discussion
Hi All,
I've a 1993 320i Coupé with the M50 engine. Anyway, I know the engines are known to have slightly noisey tappets on cold start for a couple of seconds which mine has.
However, once the car has any heat in it, there seems a slightly hollow top-end knock from the bulkhead end of the block. It only happens at idle and once the revs increase it dies away and the engine revs completely smoothly.
It's very strange and my local mechanic after passing a quick ear over it thought it odd too.
Does anyone have any words of wisdom on the subject?
Thanks all,
Nick
I've a 1993 320i Coupé with the M50 engine. Anyway, I know the engines are known to have slightly noisey tappets on cold start for a couple of seconds which mine has.
However, once the car has any heat in it, there seems a slightly hollow top-end knock from the bulkhead end of the block. It only happens at idle and once the revs increase it dies away and the engine revs completely smoothly.
It's very strange and my local mechanic after passing a quick ear over it thought it odd too.
Does anyone have any words of wisdom on the subject?
Thanks all,
Nick
Fire99 said:
TheEnd said:
A full service i guess? new filters, plugs, oil?
No new plugs on this one but filters & oil. And had new Rear Suspension bushes but they don't play much of a part in this issue. 
check the plugs to see if the rear one is loose. I had exactly the same, a hollow "tok-tok-tok" knocking from the top, which was from either 5 or 6 cyl having a loose plug.
Well Mr End, or can I call you THE? 
Checked Cylinders 5 and 6. No 6, though not loose in the normal sense did take turns alot easier than 5. Nipped it up a turn or so and Put it all back together.
Took it for a road test and it appears that Tock Tock has gone gone. Excellent work. Thanks mate!
It does appear that using normal pro socket sets, No 6 with the body overhang could do with a socket extension bigger than the standard short one but shorter than the standard long one. Maybe that's a factor.
Anyway, thanks again. Now just wish that little M50 engine had another 100 hp or so.
Checked Cylinders 5 and 6. No 6, though not loose in the normal sense did take turns alot easier than 5. Nipped it up a turn or so and Put it all back together.
Took it for a road test and it appears that Tock Tock has gone gone. Excellent work. Thanks mate!
It does appear that using normal pro socket sets, No 6 with the body overhang could do with a socket extension bigger than the standard short one but shorter than the standard long one. Maybe that's a factor.
Anyway, thanks again. Now just wish that little M50 engine had another 100 hp or so.
Fire99 said:
Well Mr End, or can I call you THE?
Checked Cylinders 5 and 6. No 6, though not loose in the normal sense did take turns alot easier than 5. Nipped it up a turn or so and Put it all back together.
Took it for a road test and it appears that Tock Tock has gone gone. Excellent work. Thanks mate!
It does appear that using normal pro socket sets, No 6 with the body overhang could do with a socket extension bigger than the standard short one but shorter than the standard long one. Maybe that's a factor.
Anyway, thanks again. Now just wish that little M50 engine had another 100 hp or so.
If you want more horsepower, check the throttle cable for adjustment too, mine was off for about 2 years, opening to only 65%, knocking the power down to about 170 (on a 325) and as a result, it was always operating on the economic part throttle maps, rather than the full fat Wide Open Throttle map. Checked Cylinders 5 and 6. No 6, though not loose in the normal sense did take turns alot easier than 5. Nipped it up a turn or so and Put it all back together.
Took it for a road test and it appears that Tock Tock has gone gone. Excellent work. Thanks mate!
It does appear that using normal pro socket sets, No 6 with the body overhang could do with a socket extension bigger than the standard short one but shorter than the standard long one. Maybe that's a factor.
Anyway, thanks again. Now just wish that little M50 engine had another 100 hp or so.
The day I found that out was a nice one!
PS, Daisy is gutted...
TheEnd said:
If you want more horsepower, check the throttle cable for adjustment too, mine was off for about 2 years, opening to only 65%, knocking the power down to about 170 (on a 325) and as a result, it was always operating on the economic part throttle maps, rather than the full fat Wide Open Throttle map.
The day I found that out was a nice one!
PS, Daisy is gutted...
I'll do that. But i'm not expecting great things from the little 320. It only starts with 150bhp on a good day. Well if I sniff too much horlicks I may one day drop a 328 in with 325 inlet etc. Or just buy a faster car. The day I found that out was a nice one!
PS, Daisy is gutted...
Poor ol Daisy. We'll have a second of silence for her...... and that moment has passed.
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