7M-GE Valve Guides

[Chassis 33]

The missus Supra is burning out at an alarming rate, due to failed valve stem seals, what I'm trying to figure out is whether to do the rope trick so I don't have to change the head gasket (it was done 18months ago by the previous owner, but they didn't replace the seals) or if there is a high likely hood that the valve guides are worn at 140k, whether to strip the head off and do a full rebuild.

Any suggestions?

Regards
Iain

[M3 Mitch]

No first hand experience with Supras, but I'd be inclined to try the "rope trick" or use compressed air to hold the valves while changing the seals. If you do the rope, you may be able to measure side-play with a dial indicator, if you use compressed air I think the valves will be held tightly enough that you can't move them.

You could try to visually inspect the seals, probably they are hard to see with the springs in place, but you could give it a try.

Had the head off a 3S-FE in a Camry 87 awhile back, the valve guides seemed to be fine, didn't measure them but the valves felt snug enough in them.