Over the years, a couple have noted chafing/stress in the main engine harness at the rear of the valve cover. When I put new hoses back there on the 93 years ago, I had quite a struggle with that harness getting it back in place, and recovered the crumbling heat insulation with some fresh stuff.
Today, I was looking at how this spot fares on the 97, and noted it's routed differently. Looks much less stressful than the 93's though it's a simple change. The 93s is both pulled tight by a metal heater pipe, and needlessly soaked with heat from that pipe, where the 97's harness doesn't wrap around it - no contact, and no stretching stress.
Here's the way I'd describe it. The harness (nearly an inch thick bundle of wires) comes up from the rear of the valve cover and goes into a black plastic cover right at the top of the firewall pretty much straight up. On the 93, the harness detours toward the right side of the vehicle, around the lower metal rear heater pipe (at the elbow), then back and up to that plastic cover. As a result, the 93 harness is pulled very tight here and as mentioned gets a lot of heater line heat - thus the heat insulation is deteriorated badly.
So, how about other's harnesses?? It's easiest to see with your chin above the air cleaner using a flashlight. If it's not touching the heater pipe yours has the better routing.
DougM
Today, I was looking at how this spot fares on the 97, and noted it's routed differently. Looks much less stressful than the 93's though it's a simple change. The 93s is both pulled tight by a metal heater pipe, and needlessly soaked with heat from that pipe, where the 97's harness doesn't wrap around it - no contact, and no stretching stress.
Here's the way I'd describe it. The harness (nearly an inch thick bundle of wires) comes up from the rear of the valve cover and goes into a black plastic cover right at the top of the firewall pretty much straight up. On the 93, the harness detours toward the right side of the vehicle, around the lower metal rear heater pipe (at the elbow), then back and up to that plastic cover. As a result, the 93 harness is pulled very tight here and as mentioned gets a lot of heater line heat - thus the heat insulation is deteriorated badly.
So, how about other's harnesses?? It's easiest to see with your chin above the air cleaner using a flashlight. If it's not touching the heater pipe yours has the better routing.
DougM
