Cracked ignition coils

All 4 ignition coils on my 02 are cracked, is that trouble if I don't replace them?

Anyone know where to get a good deal on the OEM Densos? They aren't cheap.

 

You need to replace them or might end up having shorting issues

 

Never seen that, don’t look good though. I’ve seen loose plugs cause melted coils, something to check at least.

 

Ok, the reason I took them out in the first place was cause I washed the engine down yesterday and today it was idling rough, there was a little bit of water in the spark plug wells. Thing is, it only idled rough if it was in gear, not in park or neutral, does that rule out spark plug short?

Should also add I took a 30 min drive first thing in the morning with no issues. Got home, parked for about an hour, then turned the engine on again and thats when the rough idling hit me.

 

cracks like that, its time for new coils. rockauto is usually the cheapest for DENSO coils. dont try Amazon or ebay, they tend to be fakes.


as for the rough idle. the 4cylinders are pretty good for valves getting burnt up.. i'd check valve adjustment before anything/

 

My 06’ Tundra has had cracked coils for 80k now or more. I’m at 275k with stock coils and its still is running strong. Once one fails I’ll be replacing all of them with OEM.

I hooked my buddies Autel up to it and no issues.

 

See i'm inclined to think it has something to do with me washing the engine yesterday... I've never had any idle issues with this truck for the 12 years i've owned it, and immediatley after the only time i've ever washed the engine I've got rough idling. Not a scientific conclusion but seems like more than coincidence.

Sure am hoping its just the moisture in the plug wells.

 

People always say I'm paranoid not wanting to hose the engine down, but every once in awhile you get stories like these and I feel justified.

Once a year or so I'll put the hose on mist setting and let it mist over the engine bay for a minute but that's about it.

 

These cracked coils are the original ones? Or were these replacements that got installed at some point?

 

Just blow the water out of the spark plug tubes and keep driving. If any of those coils are leaking spark you'll get a flashing cel and lack of power

 

Appear to be originals.

 

its not uncommon for the originals that style to crack. on the 4.7 its becoming very common since theyre geting up there in age.

 

The coil is actually in the shaft. So the crack will cause leakage. Especially if waters involved.
The 3.4, the coils up top.

 

Problem solved! The flashing check engine light came on so I thought I was screwed for a second. Been meaning to change my spark plugs out anyway so took the opportunity and swapped em out, boy were they toast. #3 in particular was wet down to the threads (or oily?) either way disgusting, that was probably the one shorting out on me. Learned my lesson to go easy with the hose around the spark plugs. The cracked coils certainly didn't help matters. Will replace those one of these days...

 

I wonder if there's a way to seal the crack with some sort of epoxy. Even then the plastic may be brittle. Maybe you hit the top of the coils with too much water pressure and it caused them to crack from flexing?

 

This used to be common in the VW world. Clean thoroughly with with CRC electrical cleaner first. Some even advise baking in the oven at low temp to make sure they're totally dry. Obviously, any epoxy would have to be adequately dielectric (i.e., non-conductive), so that probably rules out anything metalized like JB weld. I think if a thin enough coat could be applied, perfectly smoothly, then it could buy some extra life. This would be a good time to replace the rubber boots and valve cover seals as well.

Honestly, I think I would pony up for new coil packs and not give it another thought.