HELP!! burnt out coils 99 Legacy

[ajfsgrl08]

I recently put a coil on my 99 subaru legacy. It was only on there for 3 months befor it burnt out on me! :twisted: I'm wondering if its because i bought it at a regular parts store and not the dealer if that made a difference? :?:

I dont really know why it would but i guess its possible. This is the second coil i put on it in the last 6 months :!: Have any of you had this problem? I'm hopeing its not electrical. My b/f thinks that it is getting to hot cause its so close to manifold. I dont really know i'm just wondering if any of you have any idea's. :neutral:

[Huffer]

Topic moved to Electrical systems.

Sounds like you have a bad part - take it back and get them to replace it under warranty.

[ajfsgrl08]

I have done that already 2 time's!! That's why im getting frustrated with it. So i don't know why 2 completely different coil's would go bad in like 3 months time. Other than that i would think it was just a bad part.

[Huffer]

Bad manufacturer then... have you tried an OEM part?

[decke48]

what manufacturer? if you can measure the voltage of the center wire in the plug going to the coil pack shouldnt be over 12~volt

[ajfsgrl08]

The car is a '99. It has the 4 wire plug on the coil.

Does anyone have the proper resistance for the 4 wire plug coil.
Primary resistance and secondary resistance.
Is it the same as the 3 wire coil. The Haynes manual doesn't even mention the 4 wire coil.

The current coil has been on the car for only 2 weeks and the car is running like crap again. With no codes. The first week and a half the car was getting about 30-32 mph highway, now it is down to 19 mpg. :shock: :mad:

How can I test the voltage input to the coil since it is a 4 wire plug? Which wire/wires do I test?

If I made the mounting brackets and baught the coils could I wire up coil on plug?

I'm getting VERY sick and tired of changing the damned coil.

Is the coil simply overheating and burning out?
The intake is hot enough after driving for more than 15 min that I can't keep my hand on it for more than a second or so. Would a set of thermal spacers help keep the intake cool enough so that the coil wouldn't get so hot? How much cooler does the Intake run with spacers vs. without?

I am running NGK wires with NGK copper plugs.

[Huffer]

Is the coil you have on there a factory Subaru part or an aftermarket manufacturer item?

[ajfsgrl08]

It is a Diamond coil. It has Subaru written on it. I baught it from Advance auto.

[Huffer]

If you bought it from Advance, it's not a factory supplied item. Only coils purchased from a dealer are factory items. Advance may supply factory replacement parts but you couldn't buy a factory oil filter from them. See what I'm saying?

[ajfsgrl08]

Yes.

There has to be some reason why they keep burning out though.

[ajfsgrl08]

I baught a coil from subaru today.

The #'s on the coil are almost the same.

The one from advance:

SUBARU
DEDiamond
FH0362
7X04

The one from Subaru:

SUBARU
DEDiamond
FH0362
8522

The guy at Subaru looked up the specs for testing the incomming voltage, and he said that as long as it is over 10v then input voltage is ok.

Round 3 underway.
Lets see if this one lasts longer than 2 weeks! :shock:

[ajfsgrl08]

I also got the specs for testing the 4 wire plug coil.

I don't have the haynes book right handy to compare the #'s, but here are the #'s from Subaru.

Primary resistance:
Between terminals 1 & 2 0.73 Ohms +/- 10%
Between terminals 2 & 4 0.73 Ohms +/- 10%

The termnals are numbered 4321 when looking at the coil from the pass side fender of the car. #3 terminal is a ground.

Secondary resistance:
Between terminals #1 & #2 12.8K Ohms +/- 15%
Between terminals #3 & #4 12.8K Ohms +/- 15%

Insulation between primary terminal and case: 10M Ohms or more.

[Huffer]

So did you test the new coil from Subaru vs. the Advance Auto one?