Oil in Coil Pack Connector

Hello,

I am running a 1998 Tacoma SR5 4WD 2.7L L4 engine, with ignition coil on the side of the head(sorry bad explanation not very good at that; image attached).

I was experiencing a struggling start-up and rough idle misfire for a number of weeks, a few months back, never being able to exactly pinpoint the issue. I changed the spark plugs, charred wires repaired, TBS in good condition, plug wires in good condition, etc. I did however, when changing the spark plugs find some oil on the ignition coil pack connector for #2 and #3. I thought not much of it and cleaned it with some shop rags and called it good. after replacing all the plugs, it started again no problem.

Problem solved... right?

That's what I thought until it started misfiring again a few weeks back and last night it completely sat down on me for the first time since having it; so I decided to do some poking about again.

I looked around checking and checking when I noticed that the same pack connection had oil on it again. I have checked for leaks all around the wires and whatnot, but found nothing even closely resembling a leak. I am wondering if anyone had any advice or has experienced anything like this before.

 

Change the spark plug tube seal along with the valve cover

 

You are talking the wire harness connector not the spark plug boot?

look for a oil leak on the front of the engine being blown back.

 

-Ok so I'll take the spark plug tube seal and valve cover into consideration.

-It is the harness connector into the ignition pack itself that I am referring to.

What stumps me it that their is no oil on any other area near where the connector is located. The only part with oil buildup is the connector itself. This makes me perplexed as if it were oil blow back wouldn't more be covered? Regardless, I'm going to try to clean it again and add UV dye to my oil to see is I can id any microscopic leaks or a trail leading to the connector.

 

I will give you that it is indeed strange .

Just had this thought makes perfect sense !!! No other visible oil source!!!

Coils them selves leaking oil? old school coils were filled with oil I never cut any of the new ones apart.

I had coils leak oil back in my muscle car days then fail completely in a few hours of engine running

 

oh really, that’s really interesting. I didn’t know that about old coil packs.

Was there a solution to them cracking that you found or was it just an inevitable thing?

 

one of those things it happens.

manufacturing flaw fails after time

thermal cycling things just break down.

If you take the time and do some searching no doubt information on coils leaking oil could be found.

 

Well I just went out and changed the coil.

and…….

It’s still sputtering and stalling…yay!

Frustrated but not defeated just yet; I’m gonna look into the fuel injectors and spark plugs again to see if the injectors are stuck open as engine smells heavily rich and the spark plugs could have gotten fouled up by the misfires.

Thanks for all your help so far everyone!

 

I had an oil leak at the seal just behind where the coil packs are mounted. This is the seal for the hole where the earlier models had a distributor mounted. I didn't even know it was there until I started taking the coil pack mount off. I was getting oil in that area and on the side of the engine for a very long time.

Here's the post where I talk about it: https://www.tacomaworld.com/threads/3rz-oil-leak.637272/#post-21978362

 

LC engineering sells an expanding plug to fit that hole.....


2RZ/3RZ Distributor Block Off (lceperformance.com)