Helicoil

Now then, it can't just be the one thing, my clutch is still in the queue to be fixed, so whilst I was waiting for parts, I thought it's about time I set the tappets, having never done them since I put the engine in about 2 years ago!

So I set about the simple task of removing the rocker cover and the no one bolt brought the pedestal bolt out with it I replaced the rocker seals when I got the engine, so I know that I torqued the rocker bolts as they only need a little nip up and I was wary with this being an ali head and my last one being cast. I've never touched the pedestal bolts and the that came out is a little stripped.

When I tightened it back in, it felt like it was going to about 10nm (by touch), so I took it back out, cleaned it up, put some threadlock on it and stuck it back in.

If that does not hold it, will a helicoil be ok? I assume the bolt just goes into the head and does not go through to the block?

I am seriously falling out of love with the Landy at the moment

Oh and to top it off, my garage is such a tip I could not find my feeler gauge so after all that, I never even set the tappets lol.

Don't know if this applies to metric threads, but affects imperial sizes when inserting threads into blind holes. Most over the counter thread kits come with taper taps only, so in a blind hole the thread insert can be too tight near the bottom of the thread. Bolt then reaches correct torque before the bolt head clamps the item down = problem. You might need to use a bottom tap before putting the insert in to prevent this problem. This is complicated by the fact that (with imperial thread sizes) the oversize "normal" tap needed for the insert is a different TPI to that needed for the bolt.
In other words, whatever thread you use in a blind hole, make sure you prepare for the insert with a bottom tap with the same TPI as the bolt.
Hope that helps.

I had that exact same prob only yesterday in a blind hole on a cummins lump dare not drill the remains of the snapped stud out as did not want to drill into the inlet manifold, thats when I noticed the tap was only a No2! bit of bodging and some stud lock fixed that!

I had a disco that had the same issue, helicoil fixed that, it doesnt need to be drilled deep, i brought a helicoil set that came with the coils, tool to insert them, drill bit and tap, i think off eBay..


I only drilled it deep enough for the helicoil to go in as thats the only threads that your bolt will use to hold it down.


never had an issue since and the engine still lives but with another owner.

I had this happen on my 300tdi.

The helicoil is only about 8-10mm so you can get away with using the normal tap as you don't need to bottom it out.

I then covered the helicoil in locktite and wound it in quickly I then very quickly followed it in with a new stud and lots of locktite.

I was going to drill it out and go a size up and use a custom stud so there was no helicoil etc. but I opted for simplicity - been in there for about 4 years now.

When I did it I removed the rocker shaft, laid in lots of sheeting and tissue round the head and taped it all down, then exposed only the hole I needed to fix, did it in situ. Cleaned out the hole then removed all the sheeting etc so there was no aluminium swarf left lying about - at least it is ali so it's soft swarf!

I seem to remember I then tipped some diesel around the head to wash it all out in case there was any metal dirt anywhere and then changed the oil.

Sorted out all my major jobs now, so it's back to this one. It's defo a problem. Tried a run today and the bolt ended up coming out so I got a nice coating of oil around the head.

I just wanted to check something about the 200 TDI. I need to remove the rocker. The rocker bolts aren't head bolts from what I can see - it looks like there about about 5 of them? This is different to the NA which is why I'm checking before I destroy anything. They are only M8 bolts but seem to be very tight, so I hope none of them strip - I feel like I'm opening a can of worms here...

sp00k said:

Sorted out all my major jobs now, so it's back to this one. It's defo a problem. Tried a run today and the bolt ended up coming out so I got a nice coating of oil around the head.

I just wanted to check something about the 200 TDI. I need to remove the rocker. The rocker bolts aren't head bolts from what I can see - it looks like there about about 5 of them? This is different to the NA which is why I'm checking before I destroy anything. They are only M8 bolts but seem to be very tight, so I hope none of them strip - I feel like I'm opening a can of worms here...

Click to expand...

from what I remember the head bolts are not the rocker bolts but it has been years since I did mine, the head bolts are much bigger and 4 or five of them are visible externally from the injector side.

Seems to have done the job!

200 tdi head bolts are all 19mm heads.