An epoxy resin could be suitable. Thermoplastic polyamides are the usual choice for these applications.

"i can hold it but it gets hot but not hot enough not to be able to grab it firmly" sounds like it might be 50°C/120°F? West System 105 room temperature set two-component epoxy seems to have a dry heat deflection temperature of 120°F and with glass that should go up a bit...

i would say 50-60C but there is no load on it other than self weight. i will give it a go. might be better (easier)to find a suitable to find a 3D printer with suitable "ink"

it starts to soften on a hot day when the engine gets heat soaked and does change shape a bit. i dont see it lasting long term

You may be better off with a resin like this, see link. You may get a little better performance out of West System epoxy by post curing your part in an oven. Gougeon brothers have a data sheet on doing just that. If you are in the UK., talk to Wessex Plastics.
B.E.

You are judged not by what you know, but by what you can do.

• http://www.acpsales.com/pds/EHT%20LAM.pdf

It does sound as if it's on its way out. Note that any humidity or actual water will markedly worsen the degradation (any condensation after use?). To get hot/wet performance up, as berkshire says, elevated temperature cure is probably needed. Master Bond have a lot of high temperature epoxies (usually with exaggeratedly high service temperatures claimed; this stuff http://www.masterbond.com/tds/ep17ht-lo claims 650°F service for a Tg of 225°C with a 300°F cure—believe that if you will, but the 225°C Tg is possible and a use temp of about that should also be possible if it doesn't get wet much). While you might not need to go to a 300°F cure some sort of elevated temp will give much improvement with the right resin.

NB: I think that E-Z Lam 'Flexural Modulus' should be 'flexural strength.' I'm willing to bet that 400°F use temp goes with the 350°F post cure. Even the 150°F post cure might be adequate, although it does sound a bit low. For lower post-cures you're probably looking at a dry service temp of about the same as the post-cure. As post-cure increases the service temp will probably lag. Any moisture will knock about 20 to 50°F off.

technirez have a few different epoxy resins that can be easily post cured upto about 130C i will use one of them as i have found a local supplier