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Posted: Sun Dec 18, 2011 6:36 am |
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Joined: Nov 13, 2011 Posts: 24
Trade Rating: 0
Location: UK
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Couple of months ago my head gasket went, i replaced this and after a short drive it "went again" as diagnosed by mr RAC man and a compression test.
I hadnt replaced the headbolts or had the head skimmed !!!
So I have re done the head, changed bolts, belts, tensioner, skimmed head new gaskets, follwed the letter of the law on tightening the head bolts etc....
Started the car today, and its still miss firing on idle, but seems to run ok at high revs.
Does anyone have any suggestions?
Does anyone know of a mobile diagnostic service (midlands area)? as im begining to think i may have/ have damaged something on the electrical/ injection systems..
Any help is appreciated as I am on the verge of beating the car with a large stick!!!
Thanks
Dave
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Posted: Sun Dec 18, 2011 6:49 am |
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Joined: Feb 07, 2010 Posts: 3085
Trade Rating: +12
Location: Essex
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How long has it been left with water in the bores?
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Posted: Sun Dec 18, 2011 6:51 am |
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Joined: Feb 07, 2010 Posts: 898
Trade Rating: +5
Location: Melton Mowbray Leicestershire
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Are your injectors okay? I know last year when my headgasket went i put the miss fire down to the head gasket failing, rebuilt it to find that it was a dodgey injector causing the miss fire. Although having said that its gone again now 2000 miles later. Im hoping that its just a bad gasket but if that seems fine then it leads to a problem with the liners.
Did you have the head pressure tested before getting it skimmed?
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Posted: Sun Dec 18, 2011 7:01 am |
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Joined: Sep 21, 2011 Posts: 317
Trade Rating: 0
Location: UK
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It could be loads of things, not necesarily related to the new head gasket. Best to get its diagnostic codes read, misfires should show something up. If no error codes are logged, then you're back to compression testing, checking valve timing, etc. Its possible if the first time you contaminated something, that the valves aren't seating properly, or the bore is scored, etc etc but I'd have thought it not too likely.
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Posted: Sun Dec 18, 2011 8:14 am |
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Joined: Jun 10, 2011 Posts: 156
Trade Rating: +2
Location: Tamworth, Staffordshire
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Make sure you've tightened the inlet manifold back on properly, my housemates had come loose and hers started misfiring/crap idle, would run alright if you held the gas down, the engine light never appear on that. Also check your coilpack, mine went just after the head gasket got changed (coincidence but it's worth checking) and mine wouldn't idle properly (along with misfire), i wouldn't have noticed it but the eml started flashing, pulled over and it was only having issues on idle.
If your EML is flashing then you should get the codes read, just beware that some of the codes on there are probably years old.
As for a mobile diagnostic guy, there's one round birmingham i used when the snow killed off my car a few years ago. Can't remember the details but they were in the yellow pages.
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| Now a 2010 Renault Megane Coupe owner | |
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Posted: Sun Dec 18, 2011 1:55 pm |
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Joined: Nov 13, 2011 Posts: 24
Trade Rating: 0
Location: UK
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Thanks to all, anymore info would be helpful also.
Next step ill check the compression, also may tighten inlet manifold, but im reconing on an injector fault, any ideas if i can isolate injectors one at a time? If one has gone then if i disconnect one at a time then each start will be worst until i find the injector with the fault, hands up who thinks this would work?
I have just remembered there is a guy in Rugby who can do diagnostic checks.
Other suggestions, wasnt left long with water in bores, bores didnt loook scored, timing is bang on (can lock both crank and am with bolts through holes), didnt get head compression checked, tend to rule this out as it improves as revs are raised.
Thanks again to all who responded.
Dave
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Posted: Sun Dec 18, 2011 2:22 pm |
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Joined: Feb 07, 2010 Posts: 898
Trade Rating: +5
Location: Melton Mowbray Leicestershire
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The easy way i found to find out on which cylinder the miss fire is to remove the exhaust manifold heat shield, then put a few drops off water on each branch of the manifold. Then start the car up and watch to see on which branch of the manifold the water doesnt evaporate as quickly as the others.
That will show you on which cylinder the miss fire is pressent, if you think it is a injector then you can check by swapping the injector from the cylinder is miss firing on and swap with one from a good cylinder. If the missfire follows the injector then it could be a problem with that injector.
The engine should be cold when trying the above test.
Also when you have a dodgey injector it doesnt always record a fault code on the ecu as i found.
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