Alternate Title: Plug Wires Roasting on an Exhaust Manifold

Real Title: Plug Wire Routing with Hooker 2149 Headers

I was cruising on the Freeway at about 80 miles per hour, and the car kind of hick-uped. I was on flat, so I didn't really notice a difference in power or anything. I came to a hill and I noticed I had to push the pedal almost all the way down to maintain speed. Hmmm, I thought. I got back on a flat stretch and I decided to try some acceleration and downshifted into 3rd, and the car made a LOT of go-noise, but didn't accelerate.

I decided at this point that the fuel pump was about to kaput, so I was going to pull over at the next off-ramp. There was a decent size hill, probably 3% between me and it. The car severely lost power at this point and I at about 75% throttle, I slowed to about 55 mph before getting to the off-ramp. I pulled over and popped the hood. It was at this point that I found that I had slammed the old thermostat gasket in the locking mechanism. :cuss After fanagalling the release a bit and I got the hood open.

The first thing I heard with the hood open, was a LOUD, popping. CRAP! I thought for sure it was a spun bearing, but it didn't quite sound right, and I was making 55 psi oil pressure at idle when I parked. So I shut the car off real quick, as soon as I heard that.

I also found that I have air in the cooling system, because the coolant was boiling in the water pump...:( It still stays really cool, but I have a very stout cooling system. I still need to bleed that soon.

So I'm looking around, and the boiling coolant makes me think I blew a head gasket, I checked the oil, but its still perfectly clean Mobil 1. So I'm looking around the engine, and I finally noticed, after about a minute of searching and the engine being off, the cast iron air pump fitting on the right exhaust manifold is GLOWING red. :eek:

That led me to find the #2 and #4 spark plug wires burned straight through the insulation and on the #2 plug wire, you can actually see the lead. :eek: So I let the car sit for about ten minutes, and then put on my awesome pair of Sheep Skin Gloves and pulled the plug wires off of the spark plugs and laid them out, they were indeed shot. I wrapped them real good with electrical tape and drove home, about 60 miles. I didn't have any problems and the car was restored back to full power.

What I think happened, was my routing, up over the air pump fittings, between the head, worked pretty good for the last 6,000 miles. But the constant heating up/cooling of the plug wire made the insulation brittle, and finally burned through. I think this allowed 54,000 volts to be directed into the steel header. I'm sure this helped it to heat up pretty quick and that killed the other wire that was resting on it.

From here is where the real problem began. A stock Corvette should have enough power to not care if it has two dead cylinders...mine didn't care when I had the first one. I think the problem is that 2 and 4 fire almost completely opposite each other. Since they were now connected, they were firing each other, regardless of time or compression or whichever. Unfortunately my O2 sensor is on the other side, so neither I, nor the computer, had any clue anything was wrong with EGT(Exhaust Gas Temp). I have to wonder how hot that poor cylinder head got. The header got so hot that it melted the hose to the airpump, you can see that in the picture. Thats what the loud popping was. I put my hand over it with the glove on, and the popping went away.

I haven't driven the car since parking it, I'm going to pull the spark plugs first and retorque the head before I touch it. I looked at the oil through the fill and it wasn't boiling or anything, but my oil system flows a heck of a lot of oil.

So anyways, the moral of the story, routing your plug wires through the air-pump fitting on Hooker 2149 Headers, is not a good idea. :D

:seeya

 

Hmm, doesn't sound like a lot of fun. I'm running Hooker 2151 headers and luckily have not had this problem yet. Several of my wires run VERY close to the headers but so far so good.

If you replace the plug wires you might try some of the MSD 8.5's apparently they take the heat very well. :cheers:

 

I have a set of MSD 8.5's sitting in a box. I got them from forum member GCrouse for a great price, they wouldn't fit on his heads. I was running AC Delco 8 mm's, they were just over two years old, so I didn't change them when I got the new wires.

I shouldn't have had a problem, except I had both wires resting on the air-tube. I thought it'd be ok. I was doing a lot of uphill driving, I was coming from Phoenix, at 1,300 feet, and the problem manifested itself at about 8,200 feet, so I'm sure the uphill driving heated up the headers pretty well. Probably equivilent to 50 consecutive 1/4 mile runs.

My other plug wires, which are pretty close to the headers, all feel fine. I was getting ready to change the plugs right now, and I realized I left the spark plugs in Phoenix, about 255 miles away. :( I'm quite a ways from the nearest auto parts store, I'm going to see if my sister can pick me some up today.

 

The same thing happened to me, except it with the TPIS long tubes. My brother-in-law ran the wires from the opti over the headers (using the Made For You clips), as opposed to coming from underneath. I totally fried one of the wires clear thru.

I ended up replacing the wires with MSD 8.5's and they now come up from underneath the headers. Car is running like a champ again. :)

Mike

 

msd is the way to go for spark plug wires. Also be careful running those lines near headers or exhaust manifolds

 

MSD superconductors are the wires to have, also try using fire wrap on cyl6 that one is very very close, also 90deg boots on all 8 work the best. the standard small block chevy HEI set should do the job. this time make SURE those wires aren't touching anything. use wire seperators and even zip ties if you have to.

 

Same thing happend to me. Almost shipped the car back to MTI for more engine work. A friend of mine sprayed water on each header pipe when they were hot to determine if all cylinders were firing. One was not showing any steam. Last test was the wire. It was burned bad. We made up a longer Taylor Wire and rerouted it.

 

there normal wires like spiro pros scare me, if you get any oil on them they leak & cross fire with the wire they are laying on. trust me i learned this the hard way. they aren't real bad by any means but i'd push at anyone to spend the $20 more on super conductors.

 

This is true. Hell, I smoked a GTP on 7 cylinders once! :lol:

Go with MSD Superconductor 8.5mm wires, they work for me!