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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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 Posted: Sun Feb 08, 2009 7:30 pm Post subject: "knocking" sound in new engine? |
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After months of work on the engine, we installed it again and finally could start it for the first time. HAppy as we were, all went well with no leaks and the engine seemed to run very smoothly. Valves were properly set, as well as the 123 Ignition.
Specs:
an original 602 engine block, a race ground cam shaft from Kent Cams, 9.0:1 pistons and barrels and original cilinder heads. Original flywheel with new flywheel bolts, brand new clutch.
We let the engine run approx. 2000-2500 rpm for about 20 minutes and it never gave any strange sounds and did not hold in. We dropped it to stationary and it purred like a kitten. Then we turned it off and started again a few times (started immediately every time).
And now, the engine makes a knocking or rambling sound which requency increases with the revs.
I've checked the valve clearances again and re-set them with a barely warm engine. After this, the sound had not gotten less, i would even say it got louder.
I made some video's and i would very much appreciate if you guys could tell me what you think this is!
Video 1: Engine first start (mind that the exhaust is a leaky)
http://www.youtube.com/watch?v=Wv7nUfLmy6k
Video 2: Running in at 2000-2500 rpm and going stationary
http://www.youtube.com/watch?v=NaU7wKVMG8I
Video 3: Starting engine and knocking sound in the engine at stationary
http://www.youtube.com/watch?v=Tq7tw-eJxfY
Thanks!
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yellowpickup
Dropped
Joined: 27 Aug 2008
Posts: 273
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| Posted: Sun Feb 08, 2009 7:44 pm Post subject: |
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| i had some knocking that increase with revs ect.. one of my spark plugs were wrong |
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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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| Posted: Sun Feb 08, 2009 7:50 pm Post subject: |
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| yellowpickup wrote: | | i had some knocking that increase with revs ect.. one of my spark plugs were wrong |
I really hope it will be as simple as that! Thanks anyway, i will check it tuesday when i am back in the barn.
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dyanut
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Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire
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| Posted: Sun Feb 08, 2009 8:35 pm Post subject: |
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Dennis,
I'm not sure how a spark plug could be the problem, since the engine ran OK earlier...
Was the oil pressure light going off, to indicate adequate pressure, during that last run?
Anyway, I'd advise not firing it up again until you've tried turning the engine using the starting handle and listening for any unusual noise(s).
Removing both plugs will make that easier.
The closest I've heard to that sort of noise from an engine is when one of the cylinder head studs has broken, or when one of those 'peg' bolts which holds the lower end of the rocker shafts has worked loose.
Those special(ly awkward) bolts can be replaced with Allen bolts, btw, then it's easy to tighten or remove them.
( Thread size M8 x 1.25, cannot recall the length at the moment.)
Both of these possible faults are easy to check, by removing the rocker covers and easy to fix if one of them is the cause. ( Fingers crossed...)
Ken |
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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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| Posted: Mon Feb 09, 2009 1:03 am Post subject: |
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| dyanut wrote: | Dennis,
I'm not sure how a spark plug could be the problem, since the engine ran OK earlier...
Was the oil pressure light going off, to indicate adequate pressure, during that last run?
Anyway, I'd advise not firing it up again until you've tried turning the engine using the starting handle and listening for any unusual noise(s).
Removing both plugs will make that easier.
The closest I've heard to that sort of noise from an engine is when one of the cylinder head studs has broken, or when one of those 'peg' bolts which holds the lower end of the rocker shafts has worked loose.
Those special(ly awkward) bolts can be replaced with Allen bolts, btw, then it's easy to tighten or remove them.
( Thread size M8 x 1.25, cannot recall the length at the moment.)
Both of these possible faults are easy to check, by removing the rocker covers and easy to fix if one of them is the cause. ( Fingers crossed...)
Ken |
Hi Ken,
Oil pressure light had not (yet) been hooked up.... yes, i forgot and no i did not check if the pressure was ok. I will definately do this.
I've listened carefully while turning the engine slowly and at a certain point, there is a soft *clack* to be heard. as if you dropped a marble from 1mm on a wooden table.
Loose weird peg bolts, i can imagine, could definately cause this sound now that i think of it. Since the engine had time to warm up and the bolt had time to work itself loose, this could be a very easy but unnoticable cause of this sound.
Cilinder head studs are those 3 long shafts that mount the cilinder head on, right?
On our Dutch 2cv forum i got some replies saying that it could be cam follower(s) being stuck or having too little space. For the record, i used freshly ground followers but one of them was not going in any of the holes, so i used a previously used one from that block. As i wasn't able to notice ANY wear on it. Perhaps this is a good lead.
Other possible causes:
- Spark plugs or cables that connect them
- very off 123 electronic ignition
- piston hitting the cilinder head
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JuanNavarro
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Joined: 16 Feb 2008
Posts: 171
Location: Madrid (Spain)
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| Posted: Mon Feb 09, 2009 10:02 am Post subject: |
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First check for a communicated spark plug, a plug that doesnt make spark, but have electric continuity allowing one cilinder to work but not the other.
I have a similar problem yesterday (I hope is the same easy problem), yust when going out of the MOT (technical inspection)
Power leak, sound like those microcars (allowed to drive w/o licence) and engine bouncing, reduced idle speed (near stall) and the problem ocurs suddenly, after a time running al idle in a very cold morning without "scarf"
The problem was a spark plug full of carbon/oil particles between electrodes, a slight cleaning an the problem is solved, you better replace by new ones to properly check.
I hope thats your problem. Good luck. |
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björn
Lowered
Joined: 19 Jun 2007
Posts: 1695
Location: hillywood(hilversum)/holland
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| Posted: Mon Feb 09, 2009 11:46 pm Post subject: |
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ground controle whe found the problem
deez will tell you more
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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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| Posted: Tue Feb 10, 2009 12:34 am Post subject: Solved! |
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It was the flywheel that had come loose. the new flywheel bolts seemed to have gotten loose. We tightened them again with great care and the sound had gone. Tomorrow i will finish putting all things together and make the first official test drive!!!  Thanks for your support on this!
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ami8i
Snailer
Joined: 29 Oct 2007
Posts: 80
Location: Austria (Graz)
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| Posted: Fri Feb 20, 2009 10:10 pm Post subject: |
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Hello Dennis,
IIRC the flywheel screws require 'threath glue' and torque is limited, please check Citroens workshop manual.
»Horst
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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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| Posted: Sat Feb 21, 2009 8:01 pm Post subject: |
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I did not use thread glue (i do have it, expensive Loctite) but we did use the exact force stated in the Haynes book to tighten the bolts. Until now, 160km driven, it has not come loose :)
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JoZeF
Grave Digger
Joined: 25 May 2007
Posts: 1734
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| Posted: Mon Feb 23, 2009 4:54 pm Post subject: |
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what did the cam cost you ? did you supply an original one ?
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Deuche Fester
Dropped
Joined: 17 Apr 2008
Posts: 102
Location: Hilversum, The Netherlands
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| Posted: Tue Feb 24, 2009 12:05 am Post subject: |
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I sent them my original cam and they ground it to a fast road profile for £48.00 GBP plus shipping and vat.
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