Spark Plug Tube Removal And Re Fit Is It Possible?

[Barrie Tyrer]

I have a 1998 Rav 4 one of the spark plugs blew out, this was repaired badly by a garage using a heli coil, this has now failed and come out.

I am planning to try and fit an insert, can anyone advise if it is possible to remove (and then refit) the spark plug tube to give better access.

Thanks in anticipation

[IanXT4]

I am not sure what you mean by "spark plug tube"

From what I understand fitting an insert with the head in place is a skilled job and requires practice.

A while ago I came across a system called Time-serts, these inserts looks better than traditional helicoils.

I would find a good engineering shop that has a kit (or something similar) and can do the job.

http://www.timesert..../install.html#A

[crofter]

I am not sure what you mean by "spark plug tube"

From what I understand fitting an insert with the head in place is a skilled job and requires practice.

A while ago I came across a system called Time-serts, these inserts looks better than traditional helicoils.

I would find a good engineering shop that has a kit (or something similar) and can do the job.

http://www.timesert..../install.html#A

Looks interesting,Ian,and could see what you mean Vs coil type inserts although I have used the coils in the past without any probs,but not on deep seated plug threads.

To me drilling down into a deep recess with a handheld drill would seem to leave you open to incorrect alignment.

Also when you counter bore surely there does not seem to be any stop on that and it is impossible to see how you have gone.

I know that you are not endorsing that system,just throwing it in as a possible solution and they are just MY thoughts on it.

Most definitely go along with you re consulting a good engineering place that reconditions engines.

Barrie, my comments after your first posting still stand re repairing in situ as although you are correct that grease on a tap causes swarf to stick to it it can also cause that same swarf to stick to the threads you have cut when you withdraw the tap.

If you are contemplating trying to fit a coil of the same size,I would suspect that the spark plug and coil would have been jumping up and down before the parting and enlarging the hole. Perhaps also damaging the seat.

As I have said I have never fitted a coil to a deeply recessed hole(no sniggering at the back there!!!)and would like to learn from anyone that has done it

I wish you all the luck possible with this and hope you reach a satisfactory solution

Del

[Barrie Tyrer]

Thank you for the comments and suggestions, in my research I have discovered Time serts and they do a range specifically for fixing failed heli coils called big-serts.

I was really hoping someone knew if it was possible to remove and refit the spark plug tubes if it was, I think it would be possible to do a repair without taking the head off.

At present I do not have the time to take the head off and the car is not worth the cost of a garage repair

[anchorman]

I don't know for sure but I would just have a fiddle. It surely won't have been cast with them on so I guess they will be pressed in.

What about warming the head gently on a radiator then spraying some of that freezing fluid you can get for plumbing down the inside near the bottom then grip them with a rubber strap wrinch/bottle opener...............

...........just have a look - you haven't got a lot to lose.

Can you get the thread inserts in from the cylinder side instead?