The V8 Owners Forum -

Hi Peeps,

We have news, A broken valve spring!!!
The very last rocker has about 2-3mm of movement on it and on closer inspection the valve spring is broken. It's the rear most valve (exhaust?).

Now the big question is it replaceable without removing the head?

I'd download a piccy but not sure how?

There are ways - like feeding some rope in via the plug hole then turning the engine carefully by hand to compress it and hold the valve in place - but given how easy it is whip a head off, I'd not bother.

A tried and tested process.

O Disconnect the battery so the starter cannot function.

O Remove all spark plugs.

O Feed a long piece of soft rope down one plughole (don’t lose the free end of rope).

O Bring that piston to Top Dead Centre of the combustion stroke by hand.

O Bear down on the spring and collet with an appropriate lever:



Google for "valve spring lever"



O Pop out the collets

O Fit new seals and or springs as requ.

O Re-assemble.

O Remove rope.

O Repeat as many times as requ.

Avoids the possibility of a broken head bolt, but can't inspect for piston or valve damage.

Well done for sussing that out!

Really it would be good to replace all the springs also if you are running any sort of high lift cam you need to be careful with your spring selection to avoid coil bound issues.

DaveEFI wrote:There are ways - like feeding some rope in via the plug hole then turning the engine carefully by hand to compress it and hold the valve in place - but given how easy it is whip a head off, I'd not bother.

Thanks all just to let you know I managed to replace the broken spring in situ. I used the rope and made my own tool using a old flat bicycle spanner and welding (first time welder!) some side rails to give it some strength the a lot of grinding and smoothing off. I then removed the rocker finger and used the rocker shaft with a section of cardboard from a pringles tub to go between the tool and the rocker shaft (no metal to metal contact) and happy me 5mins later spring swapped!
I would have taken the head off but for the sake I have to remove the engine to get the heads off as the engine is so far back in the bulkhead.

I've taken note re the high lift cam and the getting the right valve springs, I will drive it carefully (as always) and investigate where this valve spring come from, they have a dark green paint marking on them. Any clues?

Thanks again everybody for your help and advise, off to the cooling section now, radiator blocked!

LDV8 wrote:made my own tool using a old flat bicycle spanner and welding (first time welder!) some side rails to give it some strength the a lot of grinding and smoothing off. I then removed the rocker finger and used the rocker shaft with a section of cardboard from a pringles tub to go between the tool and the rocker shaft (no metal to metal contact) and happy me 5mins later spring swapped!

I feel a patent application pending!

Actually, I'm quite enthusiastic about your success because I never done it myself, and never spoke to anyone who done it either, but the soft rope trick has been part of "Valve Stem Oil Seal Replacement Mythology" for a long time, and now you proved it works. Is that a worlds first, I wonder?

LDV8 wrote: I would have taken the head off but for the sake I have to remove the engine to get the heads off as the engine is so far back in the bulkhead.

Nah, I changed the head gaskets on mine without removing the engine. It's quite fiddly I'll grant you!, but it is possible.

Chris.