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12ht idle

Posted: Thu Nov 04, 2010 7:02 pm
by cjman1966
i recently put a full rebuilt 12ht into my sixty.it has 3000 klms on it now,but my problem is when the motors cold it idles and runs perfect,but once its at operating temperature it starts to miss at idle.valve clearences were re adjusted at 1000klms....any ideas???? maybe check valve clearences again??someone told me nothing to do with fuel because if it was it would be there all the time?? true or false?? otherwise once going the motor hauls ass!!!! cheers clint...

Re: 12ht idle

Posted: Mon Nov 08, 2010 5:49 pm
by 62series
sorry bud not to do with ur question but i need to rebuild mine as wondering what it cost you to do?

Re: 12ht idle

Posted: Mon Nov 08, 2010 6:22 pm
by BadMav
Yes I would double check your valve clearances.
Is it using water?
Is there water in the oil?
Are there bubbles coming up in the radiator?
Check your water trap and filters to rule them out as well.

Re: 12ht idle

Posted: Mon Nov 08, 2010 7:16 pm
by cjman1966
ok it does not use water and it has new radiator and water pump.... i replaced everything mew on the motor,bar the injector pump.by the way i was told that the pump would play up all the time.not just when it gets to opereating temperature. as for the enquiry about the price,well i work in automotive spares so i got out of it very cheap..as u know to buy these motors second hand can cost u up to $4000

Re: 12ht idle

Posted: Mon Nov 08, 2010 8:44 pm
by koffeeblack
BadMav wrote:Yes I would double check your valve clearances.
Is it using water?
Is there water in the oil?
Are there bubbles coming up in the radiator?
Check your water trap and filters to rule them out as well.
Sorry to hijack this a little, but say there is water in the oil, could it be valve clearance? As I know someone with the same issue! After replacing headgasket, it idles funny and has water in the oil.

Re: 12ht idle

Posted: Mon Nov 08, 2010 9:15 pm
by BadMav
koffeeblack wrote:
Sorry to hijack this a little, but say there is water in the oil, could it be valve clearance? As I know someone with the same issue! After replacing headgasket, it idles funny and has water in the oil.


No, unrelated (unfortunately for your friend). Water in the oil could indicate a cracked head or blown head gasket, same for bubbles in the radiator. Insufficient valve clearance will cause rough running by not letting the valves close all the way when everything heats up and expands.

Re: 12ht idle

Posted: Tue Nov 09, 2010 7:56 pm
by matts_gemmy
check your little vacum diaphrams on the side of ur injector pump arnt u/s sounds like your cold starts a bit dicky. i disconnected all of mine not required in my opinion and plus in gets rid of all them ugly looking grey lines running around everywhere :)

Re: 12ht idle

Posted: Wed Nov 17, 2010 10:31 pm
by koffeeblack
BadMav wrote:
koffeeblack wrote:
Sorry to hijack this a little, but say there is water in the oil, could it be valve clearance? As I know someone with the same issue! After replacing headgasket, it idles funny and has water in the oil.


No, unrelated (unfortunately for your friend). Water in the oil could indicate a cracked head or blown head gasket, same for bubbles in the radiator. Insufficient valve clearance will cause rough running by not letting the valves close all the way when everything heats up and expands.
Thanks mate....for nothing :( haha jk...

Damn dunno if i should buy his rig.....

Re: 12ht idle

Posted: Wed Nov 17, 2010 10:41 pm
by BadMav
koffeeblack wrote:
BadMav wrote:
koffeeblack wrote:
Sorry to hijack this a little, but say there is water in the oil, could it be valve clearance? As I know someone with the same issue! After replacing headgasket, it idles funny and has water in the oil.


No, unrelated (unfortunately for your friend). Water in the oil could indicate a cracked head or blown head gasket, same for bubbles in the radiator. Insufficient valve clearance will cause rough running by not letting the valves close all the way when everything heats up and expands.
Thanks mate....for nothing :( haha jk...

Damn dunno if i should buy his rig.....
Give him a hand to lift the head off and find out what happened. Even if it is totalled, at the very least, you'll have seen how they go together anyway.