Disco 2 Electric Wires Under The Bonnet

Added another job to my list. Just bought a 3m length of 16mm dia Black Corrugated Split Sleeve Tubing (only cost a few dollars and should be easy to put on). The reason I did this is with some of the work I've been doing under the bonnet I've literally just watched the original tubing just literally crumble as I brush against it - obviously the many years of heat and oil fumes exacts a toll on plastics! I just get a little worried seeing all those little wires directly exposed to the same heat and fumes now - might degrade the wire insulation over time and I don't want hard-to-find electrical problems due to damaged wires. Also, it will look nicer/neater!

Gets me thinking though - how long does the ECU last stuck in that hot engine bay? I don't think my laptop would last long stuck in the engine bay! Apart from oil ingress from the injector loom, has anyone ever suffered a problem with their ECU due to heat stress? Seems to be pretty rugged!

It depends on many factors cos there can be differencies from one vehicle to another based mostly on how the owners are acting... elements which can increase engine temps, EGT which means engine bay temperature at the same time are:
- missing engine cover or/and turbo heat shield
- spot lamps, muffs or other restriction in front of the radiator
- big/heavy tyres which are artificially increasing the engine's load hence the tempereature too
- driving much with loaded vehicle eventually roof rack or towing much
...and so on

as long as the ECT is within decent limits all the time the ECU is prepared for that, the cips in it are made to resist up to 120*C but keeping the ECU exposed to high temps without even knowing it as the gauge climbs from the middle only at 120*C can have ill effects on a long run, worst is for all the connectors which are close to the engine, those are suffering more that's why i strongly recommend an additional digital coolant temp gauge or any kind of multi-gauge system which shows the real ECT all the time and dont do anything irrational to artificially increase the ECT eventually tune up the cooling system and you'll be on the safe side

Probably the most important cables to safeguard, and the ones that suffer more than most, is that part of the engine loom that comes across the front of the engine and goes to the water temp sensor, then onto the aircon pump and on to the MAF and then AAP in the airbox. The covering of these tend to break down more than most, and it is not uncommon to get a short where the wires come around behind the aircon pump. Many have replaced the covering on these cables and also replaced the P clips that hold the wire on the front end of the engine with either rubber cushioned P clips or put heatshrink around the P clip to stop it chafing the wires. In extreme cases a new engine loom is required. The other typical cable is that which runs around the top rear of the transfer box, again help by a P clip that chafes it. This could do with covering, but you really need to take the centre console out to get proper access to it.

Hope that helps.

Tony

Hellastony said:

Probably the most important cables to safeguard, and the ones that suffer more than most, is that part of the engine loom that comes across the front of the engine and goes to the water temp sensor, then onto the aircon pump and on to the MAF and then AAP in the airbox. The covering of these tend to break down more than most, and it is not uncommon to get a short where the wires come around behind the aircon pump. Many have replaced the covering on these cables and also replaced the P clips that hold the wire on the front end of the engine with either rubber cushioned P clips or put heatshrink around the P clip to stop it chafing the wires. In extreme cases a new engine loom is required. The other typical cable is that which runs around the top rear of the transfer box, again help by a P clip that chafes it. This could do with covering, but you really need to take the centre console out to get proper access to it.

Hope that helps.

Tony

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Thanks Tony - much appreciated. Will be getting onto it in the next few days - will have to hope the wires around the transfer box are okay then unless taking the centre console out isn't that big a deal?

You can get to the cable from underneath, but can't really see what you are doing. Its not hard or difficult to remove the centre console, no, just a bit fiddly, (be careful with the plastic bits), and you have to disconnect the handbrake too, so make sure the wheels are chocked, but once removed you can at least see the cable and do with it what you want reasonably easily.

Tony

Hellastony said:

You can get to the cable from underneath, but can't really see what you are doing. Its not hard or difficult to remove the centre console, no, just a bit fiddly, (be careful with the plastic bits), and you have to disconnect the handbrake too, so make sure the wheels are chocked, but once removed you can at least see the cable and do with it what you want reasonably easily.

Tony

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Might put it on the list then to have a look - certainly need to sort out the loom that goes around the front of the rocker cover first - it's in a bad state. Wrapped some wires with black electrician's tape before I purchased the conduit. Maybe the electrician's tape wasn't a great idea?

Electrician's tape is better than nothing, but not easy to remove after it has been heated, and where you are....!!!!!!!

Hellastony said:

Electrician's tape is better than nothing, but not easy to remove after it has been heated, and where you are....!!!!!!!

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Yeah, best insulation is a blanket of air so the conduit is the way to go - electrician's tape will reduce chaffing but, as you said - hard to remove! Get's hot here in the summer in Melbourne, but not as hot (and on a consistent basis) as arid areas (70% of Australia) - southern coastal fringe is fairly temperate.