Inlet Vacuum Problem

[alan.barker]

if you drill out and put a helicoil it will be better than new and stronger
Alan

[AHM]

Can you get tapered helicoils?

[alan.barker]

why do you need a tapered helicoil. The taped hole is not tapered, it's what screws into it that is tapered.
Or have i missed something
Alan

[Craven]

Sorry Alan

[prezoom]

I always start with left handed bits. Many times they will walk the broken part out. If those fail, the best thread removal tool I have found is from the tool distributor MAC. It is not tapered, but uses a specific drill bits and splined shafts, which are driven into the drilled hole. The kit comes with a collar that slips over the splined shaft and the wrench is used on that collar. Have never broken one. Like Rohan, I use heat and a can of freeze on the offending part before attempting removal, along with a little Kroil or AFT/Acetone mix.

Eastwood used to offer packages of three different sized left handed drill bits. Not sure if the still do. I get mine from MSC here is the US. They come in packages of ten, but if you get a few friends together and split the packs and costs, they are very reasonable. Plus, package up different sizes as they make great Christmas gifts for your mechanical minded friends.

[Elanman99]

Can you get tapered helicoils?

I doubt they exist but in any event helicoils are not relevant when you are trying to create a hermetically sealed joint. Gas or liquid will quite happily find its way along the helical gap.

The only reason I mention it is that at some time in its past history the cylinder head on my car has been fitted with a helicoil in the heater water valve tapping!

I had to make numerous attempts to create a leaktight seal but the only technically correct solution I could come up with is a known as a bodge.

To add insult to injury, the temperature sensor tapping is also helicoiled. Now that IS a parallel thread and as its a 'face' seal should be no problem. In my case the helicoil has been drilled/installed out of square so it needs a seriously wedge shaped copper washer (and hermetite, and tape, and luck!)

Ian

[William2]

My main priority is to do it without removing the head. Do you guys agree that using a heat gun is a good method for heating the area, apart from burning off the lovely grey paintwork!!

[Elanman99]

If the heat gun you have in mind is the type used for paint removing or shrinking sleeving then its jet of hot air will not be concentrated like a blowtorch flame. The heat will be carried away by the aluminium casting and in effect you will trying to heat the whole head.

Drilling out in stages done very carefully would be my preferred method after I had taken off the radiator to facilitate access.

Ian

[512BB]

William,

You have already said that you have rounded the hex, so there is no point in heating anything, and it will have to be drilled out.

I have looked at your picture carefully. The plug is flush, or even a little recessed in the hole. If it were a little raised to the head metal, you could have cut a slot in the plug with a dremel or hacksaw, and then heated around the plug with a fine blow torch to HOT, and then it would most likely have come out with an appropriate screwdriver.

But as the plug is flush, the above does not apply, and it will only come out by careful drilling and then folding the remains in on itself and or chasing round. As I said before, make sure your drills are sharp, or new, and don't forget the rags. If I was nearer, I would come and do it for you !

Sometimes, those plugs go in to a central point, so you will know where the centre is for drilling. If that is the case, start with a 3mm drill. If the base of the plug is flat with no centre point, start with a drill that is a good fit in the hole, prob about 4mm, as that will be the centre. Make sure you go in horizontal, or parallel to the plug.

Now get on with it, and keep us posted.

Leslie

[el-saturn]

...................you can also leave it where it is. you only need to provide for a new position 20? backwards or 1 inch above the current position (while head in situ). it'll work, but it's not as nice as getting the plug out - and some of u won't like this BUT we had to FIX a bunch of issues even in pouring rain: donington e.f. cheers sandy

[tonyr27]

I've had reasonable success in removing damaged allen headed bolts by gently tapping in a Torx head tool and heat application. Worth trying before drilling & tapping.

TonyR

[types26/36]

I've had reasonable success in removing damaged allen headed bolts by gently tapping in a Torx head toolg.TonyR

+1 .........done it on rounded off allen CV bolts (but without the heat)

[William2]

Gents, very pleased. I followed the advice for the drilling method. Started with a 4mm drill and then went up in drill sizes by 0.5mm to 8mm having first sharpened each drill in my wizard machine I got from Lidl!! Then I carefully removed the remaining piece of screw by tapping it with a small screwdriver blade and hey presto. Luckily the drill chuck just cleared the side of the head. Fortunately the thread is undamaged and the vacuum fitting screws in fine. I can breath a sigh of relief!!

[billwill]

well done.