156 engine problems
Discussion
The regular attendees amongst you will have seen Cirvy's post on Monday [url]://www.pistonheads.co.uk/gassing/topic.asp?t=205416&f=99&h=0 re:- my 156 problem.
The latest is that the thread inside the cylinder head is knackered. I have been given two choices......1.) remove the head and re-machine the thread or...............2.) buy a new cyliner head.
The garage is currently putting together a quote for each option, but it looks like my beloved Alfa will be out of action for a at least a week or so.
The real question is....can a re-machined head really be as good.....I am no engineer, neither do I claim to know the full ins and outs of a cars engine, but logic tells me, that once the thread has gone the hole will be bigger....what will stop the plug being unceremoniously ejected again?
Further more has anyone got any advice as to whether a new head will be a better option or whether a re-furbe'd one is just as reliable.
Some pointers on costs may also be useful.....but don't worry I am under no illusions.......I am expecting an arm and a leg job.
Thanks in advance.
Sixpot
The latest is that the thread inside the cylinder head is knackered. I have been given two choices......1.) remove the head and re-machine the thread or...............2.) buy a new cyliner head.
The garage is currently putting together a quote for each option, but it looks like my beloved Alfa will be out of action for a at least a week or so.
The real question is....can a re-machined head really be as good.....I am no engineer, neither do I claim to know the full ins and outs of a cars engine, but logic tells me, that once the thread has gone the hole will be bigger....what will stop the plug being unceremoniously ejected again?
Further more has anyone got any advice as to whether a new head will be a better option or whether a re-furbe'd one is just as reliable.
Some pointers on costs may also be useful.....but don't worry I am under no illusions.......I am expecting an arm and a leg job.
Thanks in advance.
Sixpot
Probably better than the original!
The inserts are called "helicoils" and it used to be common on safety critical or high quality parts to do this as a matter of course when the part was built. These days, it represents a reasonable cost saving not to do so - and aluminium alloys have come on somewhat. I wouldn't be in the least bit bothered (assuming there is enough metal round the hole to physically fit a helicoil)!
The inserts are called "helicoils" and it used to be common on safety critical or high quality parts to do this as a matter of course when the part was built. These days, it represents a reasonable cost saving not to do so - and aluminium alloys have come on somewhat. I wouldn't be in the least bit bothered (assuming there is enough metal round the hole to physically fit a helicoil)!
Many thanks for your responses, they seem to concur with my own research on the topic.
Right here's the damage.....
Parts
1-coil assy £21.94
1- lead £17.73
1-cylinder head gasket set £87.52
10-cylinder head bolts £42.60
8-spark plugs £109.84
1-cam belt £25.23
1-cam belt tensioner £50.60
1-varaitor ( recommended) £100.40
1- cam plastic housing £46.26
4- anti freeze £4.80
1-sundries £1.25
1-cylinder head repair approx £40.00
Labour £260.00
Sub Total £808.17
VAT 17.5%
Total £949.59
The observant ones amongst you may have noticed there is no mention of the balanace drive belt...I have picked this up and am adding this to the list later on.
The ironic thing is...it needed a new variator any way.
Would £40.00 cover the "Helicoil" system?
Anyone any thoughts on the costs and whether any additional work is recommended whilst they are at it.....because I am just made of money (Not)
Thanks in advance
Sixpot
Right here's the damage.....
Parts
1-coil assy £21.94
1- lead £17.73
1-cylinder head gasket set £87.52
10-cylinder head bolts £42.60
8-spark plugs £109.84
1-cam belt £25.23
1-cam belt tensioner £50.60
1-varaitor ( recommended) £100.40
1- cam plastic housing £46.26
4- anti freeze £4.80
1-sundries £1.25
1-cylinder head repair approx £40.00
Labour £260.00
Sub Total £808.17
VAT 17.5%
Total £949.59
The observant ones amongst you may have noticed there is no mention of the balanace drive belt...I have picked this up and am adding this to the list later on.
The ironic thing is...it needed a new variator any way.
Would £40.00 cover the "Helicoil" system?
Anyone any thoughts on the costs and whether any additional work is recommended whilst they are at it.....because I am just made of money (Not)
Thanks in advance
Sixpot
Helicoils are pretty cheap to do once you have got the kit, so £40 from an engineering shop ready equipped sounds fair. I've just had one done in a pedal pushrod and it's quick job.
The rest of it all sounds there or there abouts. You could try EB Spares or Shop4Parts just to get a check price on the spares if you wanted - at least then you know there is no excessive mark up being put on the parts.
e.g. www.shop4parts.co.uk price for 8 OEM NGK plugs is £54.96 +VAT & P&P and Variators £76.00 + +
The rest of it all sounds there or there abouts. You could try EB Spares or Shop4Parts just to get a check price on the spares if you wanted - at least then you know there is no excessive mark up being put on the parts.
e.g. www.shop4parts.co.uk price for 8 OEM NGK plugs is £54.96 +VAT & P&P and Variators £76.00 + +
The part are generally slightly more than I would expect to pay for genuine parts at retail. eg. Variator is £80.40 and plugs are £10.5 each.
NGK plugs from a factor should be nearer £6.50 each.
A gasket set is ok at about £80, and stretch bolts £35-£40.
It is mostly good though, and it does seem a fair price- they have to make money, I suppose.
However, I notice that no timing belt guide pulley is listed (£15+vat approximately).
The labour is very low for the work involved, so all in all, I wouldn't grumble.
>> Edited by Alfa Mad on Friday 9th September 01:58
NGK plugs from a factor should be nearer £6.50 each.
A gasket set is ok at about £80, and stretch bolts £35-£40.
It is mostly good though, and it does seem a fair price- they have to make money, I suppose.
However, I notice that no timing belt guide pulley is listed (£15+vat approximately).
The labour is very low for the work involved, so all in all, I wouldn't grumble.
>> Edited by Alfa Mad on Friday 9th September 01:58
Well there's no going back now....I've given the go ahead to the garage, so we'll see what it's like......It had better be like new to drive when it's finished or I want my money back 
Last seen the head was being packed away in it's very own little cardboard box and was awaiting collection.
>> Edited by sixpot on Friday 9th September 08:54
Last seen the head was being packed away in it's very own little cardboard box and was awaiting collection.
>> Edited by sixpot on Friday 9th September 08:54
In an ideal world, all threads in aluminium would have thread inserts. So you're improving the head by getting the thread heli-coiled. It's a no-risk option, and shouldn't be expensive, as other posters have said.
A couple of points though - if one thread has gone, the others may be on their way out too. Threads are usually stripped by over-enthusiastic tightening and a rock-ape mechanic may have done the same on all 4. So get all of them done at once. It should cost twice as much as one, not 4 times. The cost of removing the head far outweighs any cost saving by doing them one at a time.
Secondly, the plug relies on its steel thread to conduct heat away from the electrode direct into the aluminium head. By putting in an insert (which is usually stainless steel) the plug is more insulated and runs hotter. Therefore you may need to get a grade colder plug than standard if you're driving hard. Maybe worth asking Alfa or (more profitably perhaps) a spark plug manufacturer.
A couple of points though - if one thread has gone, the others may be on their way out too. Threads are usually stripped by over-enthusiastic tightening and a rock-ape mechanic may have done the same on all 4. So get all of them done at once. It should cost twice as much as one, not 4 times. The cost of removing the head far outweighs any cost saving by doing them one at a time.
Secondly, the plug relies on its steel thread to conduct heat away from the electrode direct into the aluminium head. By putting in an insert (which is usually stainless steel) the plug is more insulated and runs hotter. Therefore you may need to get a grade colder plug than standard if you're driving hard. Maybe worth asking Alfa or (more profitably perhaps) a spark plug manufacturer.
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