Dielectric grease applied to both ends of ignition wires

[dukbludvl]

So, I'm a moron. It's been years since I've changed plugs and wires. This week, I installed new Delco platinum plugs and new Delco wires on my 2003 GMC Yukon 5.3L 2wd with Delphi coils, about 150k on the motor. Everything went well with getting the old plugs out and new plugs in. Then, I went ahead and installed the new ignition wires and mindlessly glopped a bunch of dielectric grease on BOTH ends of the ignition wires before putting them on, thinking it would help with conduction and not act as an insulator.

I should have known right away that I effed that up because I figured I'd fire up the engine and she'd be smooth and happy. But, it was actually a little hard to start then it wanted to stall. I drove it around some -- ran in to work and back to the house, so maybe 30 miles round trip, with a couple stops in the middle. It idled rough, but otherwise ran fine most of the time -- no ticks, knocks, bangs, and seemingly no misfires, but maybe I missed some misfires? It did stall on me a few times when I started it and tried to put it in reverse to get out of a parking space.

Anyway -- need your advice. How do I undo this mix-up? My plan is this:

A. Remove these wires with all the grease in them and put on a totally new set of wires with only a thin coating of grease applied with a Q-tip to the boot only -- and not to the conductive metal/wire ends inside the boot.

B. Wipe the grease off the plug terminals that the boots were installed over as best I can with a paper towel.

C. Take a Q-tip and try to wipe the grease off the inside of the coil boots/connectors, and wipe the outsides of the coils with paper towels to try to get all the grease off as best I can.

My questions are these:

1. Any other suggestions about how to get the grease off the plugs so it won't interfere with the conductivity of the plugs? Is wiping it off sufficient, or should I replace my new plugs with another set of new plugs?

2. Have I permanently damaged the Delphi coils by essentially cramming grease up them from pushing the wires on? Do I need to replace my coils?

3. Anything else you all recommend?

Thanks in advance for your help on this. I just want to get my Yukon back running right again. The stalls and rough idle had me freaked out for a bit.

Jon

 

[mb1500]

If you’re making good contact I would think that the grease would be irrelevant. Go ahead and clean up what you can as far as the grease goes and see what happens.

 

[OR VietVet]

A glob is never needed, just a very thin film and I really don't see the grease causing a problem. Pull the wires and clean up the plug tips and and use the Q-tip to clean the excess grease at the wires and again, very very thin film is all that is needed. I would think that you should have set a misfire code and recheck that plug to make sure you did not crack it during install.

 

[wjburken]

I like to put a little on an old plug and push the old plug into the plug wire just to get a nice thin coating prior to putting it in the new plug. Just like the old brylcreem commercial-A little dab will do ya!

 

[Fless]

If your electrical connections are good, the dielectric grease gets displaced by the contact. It displaces air that corrodes contacts. So I'd be looking for a contact problem, maybe a wire that's not snapped on all the way or is broken.

If it bothers you, remove as much of it as possible but a little isn't going to hurt the electrical connection.

 

[OR VietVet]

Dielectric grease, or tune up grease, is a silicone-based grease that repels moisture and protects electrical connections against corrosion. It is also used to keep dirt, water, and other elements out of electrical connections. It has many uses, including automotive tune-ups, home electrical work, and recreational vehicle wiring. Dielectric grease does not dissolve in most liquids, so it is good for marine and outdoor applications. You can use this grease to lubricate the rubber parts of electrical connectors, spark plug wires, and to protect electrical connections on your boat or recreational vehicle from corrosion. Since dielectric grease is a silicone grease, it should not be used on silicone-based rubbers or plastics, as it will break them down over time. The grease does not conduct electricity, so it shouldn’t be applied directly to the mating surfaces (pins and sockets) of an electrical connection.

How to Use Dielectric Grease
To use dielectric grease during an automotive tune-up on a gasoline or diesel engine, apply a bit of the grease to the end of the rubber boot on a spark plug wire and spread it around so it is just covering the inside of the lip. This will prevent high voltage electricity from traveling inside the boot and “leaking” out into the engine block. Additionally, the dielectric grease will make it easier to slide the boot over the ceramic insulator on the spark plug and ensure that there is a water-tight seal around the plug that will protect the connection from water and dirt.

You can also apply dielectric grease to the gaskets on multi-pin connectors that are typical in the electrical systems of boats and recreational vehicles. Simply take a small dab of the grease and smear it around the gasket on both sides (if possible) before inserting the gasket around the connection.

Dielectric grease can also be applied to the metal parts of virtually any electrical connection that will be exposed to the elements to serve as a sealant that protects the connection from contamination and corrosion. This should be done very carefully, as the grease will cut off the flow of electricity through the connection if some of it is left between the mating surfaces. As always, we recommend working with your local auto mechanic when doing any maintenance on your vehicle.

 

[Fless]

Eric O shows how he does it (the link starts at the wire install):

EDIT: put a scan tool on it and check for misfires.

 

[FrankU]

I have used Dielectric grease many times over the years on lots of vehicles and never had any kind of problem.

I'd ohm out the spark plug wires while rolling or shaking them between your fingers.

Check spark plug gap. Or even look at the secondary voltage under the hood at night to look for arching.

Good luck

 

[Big Mama]

Yeah, sounds like at least one connection is amiss more than the grease causing problems.

 

[Fless]

I wanted to ask if you gapped the plugs, and at what gap? The platinum and iridium tipped plugs can be damaged if not gapped properly, although most times they're pre-gapped and don't need to be changed.

Any other work done at the same time? All electrical connectors reinstalled?

 

[mikeseay]

So, I'm a moron. It's been years since I've changed plugs and wires. This week, I installed new Delco platinum plugs and new Delco wires on my 2003 GMC Yukon 5.3L 2wd with Delphi coils, about 150k on the motor. Everything went well with getting the old plugs out and new plugs in. Then, I went ahead and installed the new ignition wires and mindlessly glopped a bunch of dielectric grease on BOTH ends of the ignition wires before putting them on, thinking it would help with conduction and not act as an insulator.

I should have known right away that I effed that up because I figured I'd fire up the engine and she'd be smooth and happy. But, it was actually a little hard to start then it wanted to stall. I drove it around some -- ran in to work and back to the house, so maybe 30 miles round trip, with a couple stops in the middle. It idled rough, but otherwise ran fine most of the time -- no ticks, knocks, bangs, and seemingly no misfires, but maybe I missed some misfires? It did stall on me a few times when I started it and tried to put it in reverse to get out of a parking space.

Anyway -- need your advice. How do I undo this mix-up? My plan is this:

A. Remove these wires with all the grease in them and put on a totally new set of wires with only a thin coating of grease applied with a Q-tip to the boot only -- and not to the conductive metal/wire ends inside the boot.

B. Wipe the grease off the plug terminals that the boots were installed over as best I can with a paper towel.

C. Take a Q-tip and try to wipe the grease off the inside of the coil boots/connectors, and wipe the outsides of the coils with paper towels to try to get all the grease off as best I can.

My questions are these:

1. Any other suggestions about how to get the grease off the plugs so it won't interfere with the conductivity of the plugs? Is wiping it off sufficient, or should I replace my new plugs with another set of new plugs?

2. Have I permanently damaged the Delphi coils by essentially cramming grease up them from pushing the wires on? Do I need to replace my coils?

3. Anything else you all recommend?

Thanks in advance for your help on this. I just want to get my Yukon back running right again. The stalls and rough idle had me freaked out for a bit.

Jon

Clean the contact points and wires with brake cleaner, let it dry and reassemble with a light coat on D grease on the boots only.

 

[mbp1979]

Make sure you do have a cracked plug also that could be causing your issues. It happens brand new in the box.

 

[corvette744]

I just replaced my plug wires and plugs and also put a good amount on the boots both ends.I also do not see how this would cause a misfire with out setting off your check engine light.i would assume its not the grease and find out what happen-im leaning towards a cracked plug.Especially the passenger rear one.Also make sure you didnt get anything in the MAF sensor.So you didnt have this issue before the wire and plug change??

 

[MrBlack247]

I grease both ends.

 

[sealandsky]

So, I'm a moron. It's been years since I've changed plugs and wires. This week, I installed new Delco platinum plugs and new Delco wires on my 2003 GMC Yukon 5.3L 2wd with Delphi coils, about 150k on the motor. Everything went well with getting the old plugs out and new plugs in. Then, I went ahead and installed the new ignition wires and mindlessly glopped a bunch of dielectric grease on BOTH ends of the ignition wires before putting them on, thinking it would help with conduction and not act as an insulator.

I should have known right away that I effed that up because I figured I'd fire up the engine and she'd be smooth and happy. But, it was actually a little hard to start then it wanted to stall. I drove it around some -- ran in to work and back to the house, so maybe 30 miles round trip, with a couple stops in the middle. It idled rough, but otherwise ran fine most of the time -- no ticks, knocks, bangs, and seemingly no misfires, but maybe I missed some misfires? It did stall on me a few times when I started it and tried to put it in reverse to get out of a parking space.

Anyway -- need your advice. How do I undo this mix-up? My plan is this:

A. Remove these wires with all the grease in them and put on a totally new set of wires with only a thin coating of grease applied with a Q-tip to the boot only -- and not to the conductive metal/wire ends inside the boot.

B. Wipe the grease off the plug terminals that the boots were installed over as best I can with a paper towel.

C. Take a Q-tip and try to wipe the grease off the inside of the coil boots/connectors, and wipe the outsides of the coils with paper towels to try to get all the grease off as best I can.

My questions are these:

1. Any other suggestions about how to get the grease off the plugs so it won't interfere with the conductivity of the plugs? Is wiping it off sufficient, or should I replace my new plugs with another set of new plugs?

2. Have I permanently damaged the Delphi coils by essentially cramming grease up them from pushing the wires on? Do I need to replace my coils?

3. Anything else you all recommend?

Thanks in advance for your help on this. I just want to get my Yukon back running right again. The stalls and rough idle had me freaked out for a bit.

Jon

Just spray the boots and contacts out with CRC's LPS degreaser. Q tips won't get everything.

 

[dukbludvl]

I didn't check the gaps with a tool, but I eyeballed them and they all looked the same coming out of the box. I'm starting to think I don't really have any issues with the plugs/wires, and that maybe this is more of an air/fuel mixture or air delivery issue. I drove it about 30 miles tonight with a few stops/starts and had no issues with idle or stalling. In fact, I think maybe the idle is better now than it was before the plug/wire change. It's steady at 650, whereas before it was usually around 500 but a little bouncy and sometimes dipped below 500. I just got this Yukon a month ago from the only other owner who got it new in 2003 and had it for 17 years. He installed a K&N cold air intake years ago, and the K&N filter is quite dirty. So, there's that, plus I think maybe my rough idle and stalling could have been due to a sticking throttle body. My old 2000 Yukon did that for the first time in 2002 and it freaked me out. That 2000 Yukon had drive by cable, so I just moved the butterfly plate in the TB and cleaned all around it good and it was good fro the next 100k miles or more. This 2003 is drive by wire, so I think I need to find a buddy to get on the accelerator pedal to open up the butterfly plate while I clean around it -- is that right? My plan is also to reinstall the stock air filter box and get rid of the cold air intake. I'll clean up the TB when I do that hopefully this weekend.

Now, for a perhaps related issue -- or maybe it's a totally separate issue. I had a CEL code on last week before I did the plugs/wires, and I had it read and it came back as P0420, Catalyst System Efficiency Below Threshold (Bank 1). The CEL stayed on for a day, then went off for a day -- did that most of last week. Now, after the plugs/wires change, the CEL has been on steady, so I just had it read again at AutoZone tonight. It's showing the following:


P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0101 Mass or Volume Air Flow Circuit Range/Performance
P0102 Mass or Volume Air Flow Circuit Low Input
P0101 Mass or Volume Air Flow Circuit Range/Performance

Not sure why the same P0101 code is on there twice. Anyway, the AutoZone print out say "ASE certified Master Technicians have seen this issue on your type of vehicle and the most like solution is: Repair Engine Control Module (ECM) Wiring.

Anybody have any insights into what might be going on with this?

 

[Fless]

The duplicate code is likely a history code, with the current code. Are you sure that the MAF connector is seated properly? And that the air intake tube is sealed tightly at all connections?

I'd clean the MAF with MAF cleaner. Also the throttle body with TB cleaner. Then redocument the codes to see if they're the same, and clear them.

My $0.02.

 

[corvette744]

Im guessing bad converter bank 1 or bad o2 sensor after the cat.

 

[Rocket Man]

Sounds like you have a different problem other than the plug wires but FYI I use dielectric on both ends but I use a a-tip and use it sparingly. It’s meant to go directly on the contacts also, it conducts electricity. If you blobbed it on like you said, it might be physically interfering with pushing the boots onto the plugs due to it having no place to go when you push them on. The boots are so tight that if they’re filled with enough dielectric you’re not going to be able to push them all the way on. You should feel a click when the wires seat on the plugs. If not, remove as much of it as you can with q-tips and try re-seating the wires, making sure you feel each one click on. Same at the coil side.

 

[dukbludvl]

Thanks to everyone for your feedback. I did some more work on the Yukon this weekend, including replacing the K&N cold air intake that the previous owner installed with the stock air filter box, as well as a newer (few months old) MAF sensor off my old Yukon. In doing this I noticed that the intake connection at the front of the throttle body was way loose. I should've checked that sooner. Anyway, while I had the intake tube off I also cleaned the TB. It wasn't all that dirty, but I cleaned it up good anyway, just around the butterfly plate and where I could reach at the front. I didn't remove the TB so didn't clean very far behind the butterfly.

I also happened to disconnect the battery for about 30 minutes to install a newer one off my old Yukon.

Put it all back together and fired it up and the rough idle is gone. So are all the CEL codes -- the code for the Bank 1 cat problem is gone, as well as the mass air flow codes. I've driven nearly 300 miles since I did this work and no more CEL codes.

I think all cylinders are firing just fine. Likely no issues with the plugs/wires, but I'm going to remove the wires and clean up the extra grease just in case. They all seem to be seated properly anyway -- I heard the usual click when I put them all on.

Do you all think the loose intake tube could have been causing all of these codes, including even the Bank 1 cat P0420 one?