Thread stipped in cylinder head 300tdi

[jberesford1]

Hi all

whilst fitting a new rocker i managed to strip the thread out of the block with one of the stud bolts. I have managed to remove the stud but have no idea where to progress from here.

Anyone used the helicoil systems or can suggest another method?

thanks
Jon

 

[Gazbo]

Anyone used the helicoil systems or can suggest another method?

A common problem, Helicoils or Recoils are good, bit awkward for access to do the hole right at the back against the firewall, but it's a normal type repair process on these engines.

 

[jberesford1]

Hi Gazbo

How easy are they to fit yourself?

 

[Marmaduke]

Personally I'd remove all the pushrods and plug the holes to stop any swarf going deeper into the engine, never used heli coils though so I can't advise you there

 

[wammers]

Pretty simple, but then again i have done dozens of them.

 

[Dippypud]

Easy to do, take your time, you can watch on-line vids to see if your happy to have a go at it ...

I've taught our son to do it, so it all to play for ....

 

[jberesford1]

Thanks guys. Will order and give it a go. May be in touch again pending failure

Pretty simple, but then again i have done dozens of them.

 

[R1nut]

They are very simple to do, just take your time once the hole is in and tapped its on the home straight!!!!!

 

[Kwakerman]

Main thing with Helicoil (and similar) is to ensure you are truly square to the surface when you drill the thread out and tap the new one. If you get it at an angle you will end up stressing the replacement bolt or the pedestal wont sit flush on the head.

 

[Flossie]

You've stripped the alloy head or the iron block?
Suspect you've done the head?
Easy peesy, done mine a few years ago with the engine in situ and my leg in plaster.
The kit has the correct drill bit, tap and insert.

 

[Gazbo]

How easy are they to fit yourself?

Sorry for the late reply, timezones, workshop, just back to the forum. Already lots of good replies.
As said by those before, an easy job, I usually would not use the drill particularly in the alloy head, because of the shavings, that as said will get all down the pushrod tunnel bores, if the thread is pulled right out of the holes the Helicoil tap will start straight into the hole that's left, put some grease on the tap to hold the shavings, for alloy you should use the 1.5 x diameter length coils, this will give the stud the best hold in the coil and head (8mm dia thread X1.25 pitch X 1.5 long coil gives 12 mm of engagement in the alloy)
By load testing each thread, (I'm assuming maybe only one or two have stripped), you can work out if they all need doing or you will get away with doing just a few.
Any holes that still have the threads in will require use of the drill which can be really "grabby" when drilling a threaded hole in alloy and bring the problem of swarf getting in the engine, it will take a bit care, and also as said , the tap needs to be kept square to the longitudinal surface of the head, all sounds complex but not really so.