SSwolf

Can anyone tell me if this is true. Chevy dealer is telling me the coils can not be tested, and they either are working correctly or not working at all. Can't a coil be putting out less than optimal power? Thanks in advance.

thunderstruck507

iTrader: (18)

These coils put out enough I doubt it would cause anything noticeable if one lightened up a bit.

Plugs, plug wires, coil harnesses would all be suspect before the coil IMO. What makes you think you have a bad coil?

SSwolf

I have new plugs and wires. This engine was a transplant and the idiots that pulled it pressure washed the hell out of it. Now one by one I have been replacing electric components and sensors. I am eliminating problems one by one to solve a couple of problems. When I went to ask how to check out the coils, the dealership said it works perfect or not at all and there was no way to check their out put. According to them there is no way to have them work intermittently or work any way but perfect.
If there is a way to check them I could eliminate them as part of my problem.

thunderstruck507

iTrader: (18)

Most parts stores sell a spark check tool...basically you plug it up like a spark plug and it has a window where you can see the spark jump a gap. I would set it up and see how far the spark can jump and find out what it should be either by research or try someone else's coil known to be good and see how far it jumps.

This might not be the best way, it's just an idea I had. May be best to pull the fuel pump relay first though so you're not still squirting fuel into the engine during this process.

SSwolf

Thanks for the help and idea, I appreciate it.

gametech

iTrader: (1)

It IS possible for coils to give an intermittent problem, but this normally involves extreme heat or vibration. While theoretically possible, testing for such failure would likely be beyond the scope of most dealerships. In their view, it would be more cost effective to replace than to check.

99RTA

iTrader: (-1)

Well just keep going to the dealer for advice and you'll be walking in no time! OF COURSE THE COILS CAN BE TESTED! Go find any garage that has a modern snap on scanner with a scope..........geez what the hell is wrong with our world? No knowledgeable people in it any more!

Try this if you think water was forced into things the easiest thing for high pressure water to enter is the connectors. You may want to unplug everything and try a hair dryer to dry everything.

shoemike

iTrader: (25)

If you have EFILive you can log {GM.STATE14}
this will show individual coil status (ok or fail)
There are also PIDs for each coil {GM.IGNCOILx}
These will show individual coil control circuit (short to GND/12V or open)