Dysard Member 12 Member For: 18y 10m 27d Posted 26/11/10 10:15 PM Share Posted 26/11/10 10:15 PM Hi All,My car is running badly above 4000rpm, missing like hell. In the pictures attached I've placed what I suspect is a good coil and a bad coil(white residue?). Can you guys confirm? Only changed all the coils about 5000kms ago, which is why I want to check...Cheers Link to comment Share on other sites More sharing options...
Adam Here since the start... Lifetime Members 10,282 Member For: 21y 8m 2d Gender: Male Location: Victoria Posted 26/11/10 10:33 PM Share Posted 26/11/10 10:33 PM You can't tell they're dead just by a visual inspection.You need to get them tested. Link to comment Share on other sites More sharing options...
Dysard Member 12 Member For: 18y 10m 27d Posted 26/11/10 11:04 PM Author Share Posted 26/11/10 11:04 PM I have some spare coils, so I'll swap with one of them. Just wanted to check on others who have had arcing and if the white residue in that particular spot is what they've also encountered? It is really high up on he coil... I would have expected it to arc out down the bottom. Link to comment Share on other sites More sharing options...
spoolxr6 Member 312 Member For: 14y 1m 13d Posted 26/11/10 11:15 PM Share Posted 26/11/10 11:15 PM I don't think that the residue is an indication that it's acring. Have you exhuasted other options, plugs, valve springs, cat? Where they genuine coils? Link to comment Share on other sites More sharing options...
Dysard Member 12 Member For: 18y 10m 27d Posted 27/11/10 12:16 AM Author Share Posted 27/11/10 12:16 AM I swapped the white residue one out with a spare coil and the problem cleared up. Just out of curiosity, if the residue isn't due to arcing, what else could it be? Just wondering if I have another problem perhaps brewing. The residue is only on that cylinder (#5). Link to comment Share on other sites More sharing options...
bjc Donating Members 2,823 Member For: 21y 3m 24d Gender: Male Location: Townsville Posted 27/11/10 05:24 AM Share Posted 27/11/10 05:24 AM I'd say its coolant leaking in as mine has the same problem (same cylinder) but I do not have any misfiring at this stage! I gapped my plugs 2weeks ago (14th) in prep for my tune with Dave (blueboost) from CPV and found this problem but mine had run all the way to the plug which had started to rust. Damp residue at the top was green and dry residue is white, exactly like leakages around the thermostat or lines to the turbo.All my coils have cracked housings aswell (80,000km's) and still firing strong at this stage as the dyno didn't show any problems with 320-330rwkw. Did have a couple of 360rwkw runs but no actuator or turbo mods meant boost was wacky and still no misfiring or pinging.When I told Dave he said there is nothing in the area for coolant to leak out of and hadn't seen the problem so was a bit dumbfounded!This had happened with my BA supercharged xr8 on one of the back cylinders and it was flooded (yes full of coolant). The V8 was missfiring all the time and that was the problem. cleaned the jacket out, replaced it with a new plug and cleaned the coil well with thinners or similar and sprayed it with lanolin then used some tablets in the coolant system to temporarily stop the leak and it was all good.If anyone wants some proof with my xr6t and the leakage also I'll take some photos but give my back a week to recover before I do so.In the interim Dysard I'd by some of those tabs I was talking about that seal the cooling system when it touches air (cant remember the name) and see how you go as water just doesn't climb into plug hole 5 and my car has same problem so coincidence, I think not! Link to comment Share on other sites More sharing options...
supercharged88 Member 153 Member For: 16y 5m 2d Gender: Male Location: Far Nth QLD. Posted 27/11/10 07:18 PM Share Posted 27/11/10 07:18 PM The white residue is fairly common around the coil.This is normally caused by water after the engine has been washed or driven in very wet conditions.The water gets trapped around the boot and after sitting for awhile begins to react with alloy cylinder head,corroding the alluminium. Link to comment Share on other sites More sharing options...
spoolxr6 Member 312 Member For: 14y 1m 13d Posted 27/11/10 09:09 PM Share Posted 27/11/10 09:09 PM There is no coolant passages remotely near the coils or the top of the cylinder head so don't go putting any sealer in the system for nothing as it clogs up everything. Link to comment Share on other sites More sharing options...
bjc Donating Members 2,823 Member For: 21y 3m 24d Gender: Male Location: Townsville Posted 28/11/10 12:24 AM Share Posted 28/11/10 12:24 AM Cylinder 5 only though is wierd and that's what makes me think it's coolant not to mention as I wrote Damp residue at the top was green and dry residue is white, exactly like leakages around the thermostat or lines to the turbo. This was confirmed by a mate who was with me when I was doing this (he watched of course).I dont wash my engine bay and do majority of my own servicing and tell my mechanic when he does do anything "no engine bay cleaning" plus I know it was coolant in the 8 and its identical in the 6 just no where near as much.Either way I'll check in a few weeks as I'm running some decent boost now! Link to comment Share on other sites More sharing options...
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