Cylinder Heads!!
Discussion
Well, decided that it was time to investigate that coolant problem (keeps blowing out of expansion tank despite bleeding it uphill and down dale!)on the 350i.
Get out the compression tester, and run tests on the RH bank, all on or just over 170. Great methinks that side looks OK, i'll just clean the plugs and check the gaps - all OK, pop the plugs back in, and fire her up.
Loud metallic clunking coming from the top end of the engine (didn't get time to check which side, as I shut it off PDQ.
Decide to pull LV to coil and turn over again, no clunking!
Put LV back to coil and she fires, intermittant clunking (I can only describe it as something metallic that's loose and bouncing around).
Now I'm sure that I didn't drop anything down the plug holes, and I've taken the plugs out, but I have to admit, the holes are bl00dy small and I can't really see if there's anything in there. I've checked the plugs and they are intact.
So the question to Wedge experts is; Do I really have to strip the engine to find this, or is there any other way to check out if anything dropped into a bore?
I've thought about taking all the plugs out of the engine at once, and giving it a 'right good cranking'.
I guess that now might be a good time to whip the heads off, and clean them up anyway.
All ideas welcomed.
Get out the compression tester, and run tests on the RH bank, all on or just over 170. Great methinks that side looks OK, i'll just clean the plugs and check the gaps - all OK, pop the plugs back in, and fire her up.
Loud metallic clunking coming from the top end of the engine (didn't get time to check which side, as I shut it off PDQ.Decide to pull LV to coil and turn over again, no clunking!
Put LV back to coil and she fires, intermittant clunking (I can only describe it as something metallic that's loose and bouncing around).
Now I'm sure that I didn't drop anything down the plug holes, and I've taken the plugs out, but I have to admit, the holes are bl00dy small and I can't really see if there's anything in there. I've checked the plugs and they are intact.
So the question to Wedge experts is; Do I really have to strip the engine to find this, or is there any other way to check out if anything dropped into a bore?
I've thought about taking all the plugs out of the engine at once, and giving it a 'right good cranking'.
I guess that now might be a good time to whip the heads off, and clean them up anyway.
All ideas welcomed.
convert said:
I've thought about taking all the plugs out of the engine at once, and giving it a 'right good cranking'.
Well you should have done this anyway, for the compression test, not just one bank at a time.My money is on one of the plugs either not done up or damaged, and gas escaping.
Try pulling each lead one at a time and running the engine to home in on the cylinder.
adam quantrill said:
convert said:
I've thought about taking all the plugs out of the engine at once, and giving it a 'right good cranking'.
Well you should have done this anyway, for the compression test, not just one bank at a time.My money is on one of the plugs either not done up or damaged, and gas escaping.
Try pulling each lead one at a time and running the engine to home in on the cylinder.
It's not the manifolds, (unfortunately) as i've had that problem in the past.
The clunking definately sounds like something loose, bouncing around, as it is intermittant, I'm pretty sure it must be something in one of the bores.
Anyway engine has done around 55K so it might be as well that I strip it, clean it (Hmm maybe the excuse I need for a slightly wilder cam') an bolt it back together.
I've had the rocker covers off, and there is nothing broken / loose in there (Nice very light golden brown sheen though
)
The clunking definately sounds like something loose, bouncing around, as it is intermittant, I'm pretty sure it must be something in one of the bores.
Anyway engine has done around 55K so it might be as well that I strip it, clean it (Hmm maybe the excuse I need for a slightly wilder cam') an bolt it back together.
I've had the rocker covers off, and there is nothing broken / loose in there (Nice very light golden brown sheen though
)As Tempus has already said, a telescopic magnet down the spark plug holes should do the trick to see if you have dropped anything down. Other than that, I don't know...

Link to what we mean by telescopic magnets. Well worth the investment, regardless of whether it helps you out now or not.
http://www.eclipsetools.com/ProductPics/Latest%20....


Link to what we mean by telescopic magnets. Well worth the investment, regardless of whether it helps you out now or not.
http://www.eclipsetools.com/ProductPics/Latest%20....
Edited by L33 on Wednesday 7th November 12:23
dickymint said:
May be just coincidence that it has happened now (unlikey as it sounds). Could it be a loose trumpet rattling around?
You could be right, I'll have to take injection system apart to do the heads (if needed) so I'll check that.Edited by dickymint on Wednesday 7th November 12:37
Whilst it's all apart does anyone think a trumpet bases insulator, and shortening of the trumpets would be a good idea?
I have an insulator. Off the top of me head it was around 20 deg difference after a recent run to the manifold/head. Hand held infra red temp thingy. So not sure how accurate it was. Manual mentions shiny surface giving false readings and all that. When I get the car back, be nice to do a few reading for a better idea.
Edited to add, check clearance to the bonnet first.
Edited to add, check clearance to the bonnet first.
Edited by jmorgan on Wednesday 7th November 14:30
Edited by jmorgan on Wednesday 7th November 17:36
If you're fishing around with a magnet, don't waste your time trying to fit the magnet through the plug hole. You need a heavy iron/mild steel wire, the thickest you can find, hold your big strong magnet to the top and the whole thing will be magnetised. I can't think of anything that's particularly likely to have fallen in there from what you've done, so you might want to take the rocker covers off and make sure the valve train is all OK - maybe whatever it is that's bouncing around isn't actually inside the chamber.
GreenV8S said:
If you're fishing around with a magnet, don't waste your time trying to fit the magnet through the plug hole. You need a heavy iron/mild steel wire, the thickest you can find, hold your big strong magnet to the top and the whole thing will be magnetised. I can't think of anything that's particularly likely to have fallen in there from what you've done, so you might want to take the rocker covers off and make sure the valve train is all OK - maybe whatever it is that's bouncing around isn't actually inside the chamber.
The only logical noise from that area would be a loose liner but I'd look at everything else first.A large screw driver held against the ear is very good at tracing engine noises.
rev-erend said:
GreenV8S said:
If you're fishing around with a magnet, don't waste your time trying to fit the magnet through the plug hole. You need a heavy iron/mild steel wire, the thickest you can find, hold your big strong magnet to the top and the whole thing will be magnetised. I can't think of anything that's particularly likely to have fallen in there from what you've done, so you might want to take the rocker covers off and make sure the valve train is all OK - maybe whatever it is that's bouncing around isn't actually inside the chamber.
The only logical noise from that area would be a loose liner but I'd look at everything else first.A large screw driver held against the ear is very good at tracing engine noises.
Boosted.
Guys, thanks for all the replies on this, as ever the PH community comes to the rescue.
My cousin arrived around 7:00PM last night, had a quick listen, and pronounced 'nothing in the bores, sounds like it's coming from the cam area'
He went on to say ' probably a lifter that isn't pumping up right, probably on number 5 cylinder' (he did the large screwdriver trick)
His solution was to get it a bit warmer, by letting it idle around 2K for a couple of minutes. Result:- noise has gone!
His next stage of treatment is to use a Forte flush, and dump the Oil / Filter and re-fill with fresh.
Worth a try I suppose.
I didn't get chance to do this last night, as a quick(yeah right) trip to A&E with SWMBO ensued as a result of her falling whilst taking part in every womans favourite sport; shopping!
PS Adam, I had all the plugs out prior to his arrival, and re-ran the CR test; 170-175 on each of the cyls on the RH bank and 175-180 on each on the left. So I guess that leave me with an airlock, rather than a head gasket issue.
My cousin arrived around 7:00PM last night, had a quick listen, and pronounced 'nothing in the bores, sounds like it's coming from the cam area'

He went on to say ' probably a lifter that isn't pumping up right, probably on number 5 cylinder' (he did the large screwdriver trick)
His solution was to get it a bit warmer, by letting it idle around 2K for a couple of minutes. Result:- noise has gone!
His next stage of treatment is to use a Forte flush, and dump the Oil / Filter and re-fill with fresh.
Worth a try I suppose.
I didn't get chance to do this last night, as a quick(yeah right) trip to A&E with SWMBO ensued as a result of her falling whilst taking part in every womans favourite sport; shopping!
PS Adam, I had all the plugs out prior to his arrival, and re-ran the CR test; 170-175 on each of the cyls on the RH bank and 175-180 on each on the left. So I guess that leave me with an airlock, rather than a head gasket issue.
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