Coil pack weather strip

Joined
2 October 2003
Messages
3,767
Location
NOTL, Ontario. Canada
Guys,

I'm writing this thread as an information or solution to help with a mis-firing problem I recently had with my NSX. What was found and the solution that was derived.


Background:
Model year-1997 with 33k
Stock with the exception of a GTLW exhaust
Complete tune-up @ 25k in 2011- includes - spark plugs, air filter, fuel filter, valve adjusted, new coil packs etc. (All courtesy of Acura 15 years emission warranty)

I always wash the car by hand, using little water as possible and always take it for a short drive to burn off any excess water. The car is stored in a heated garage during the Winter and always under covers. I never drive the car in the Rain.
The Car drove and worked flawless from 2011 to Spring 2014. After a very long Cold Winter, started the car in April 2014, no problems, I took it for a short drive and it drove flawless. On my second long drive (bit warmer), when under load, the car would start to misfire and when I let off the gas it would return to normal.

Last weekend at the NSXCC Spring Tune-up event, Super Tech (Rob Magro) confirmed that the car is misfiring under load. Today, we decided to try and isolate the problem and resolved the issue.
First thoughts, were.... that the Gas in the car may have gone bad, even after putting Stabile in a full tank of 91 Octane gas during the Winter storage months. New was gas added, and the problem remained.
Note:No codes were registered, No check engine light came on.

- Checked the front coil packs, all clean no moisture, gasket in the Coil packs is installed and looks to be in good shape(soft).
- Check and replace the mis-fire detection module...same issue
- Checked the rear bank coil pack cover gasket, all looks good
- Pulled cylinder number 3 coil pack (rear) and discover moisture, all other coil packs looks clean.
- Replaced Coil pack and Spark plug...problem solved.

My solution to try and stop water from getting into the Coil pack and causing problem.I installed a piece of automotive weather striping under the air intake, between the trunk and glass hatch. The weather strip is installed on the lip under the air intake above the rear bank coil packs. My hope is that by installing this wether strip, water would not drop onto the VC and get into the coil packs, when you are washing the car. I hope this information would be helpful to others.

See pictures below:
First picture- lip above the coil pack
Third picture is where the weather stripping was installed
Last picture is the spark plug that was removed

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I keep a cut opened trash bag in a zip-loc in the trunk and before every wash I drape it over the top of the engine being sure to cover the rear bank completely and haven't had a problem yet.
Let it dry while wiping off the car and doing the windows and then reinstall the trash bag in the zip-loc and good for the next time.
Cheap and effective.

Cheers
nigel
 
I keep a cut opened trash bag in a zip-loc in the trunk and before every wash I drape it over the top of the engine being sure to cover the rear bank completely and haven't had a problem yet.
Let it dry while wiping off the car and doing the windows and then reinstall the trash bag in the zip-loc and good for the next time.
Cheap and effective.
I'm going to ask a stupid question .. I presume this isn't just a problem with car washes...what about rain? I'm struggling to understand why Honda would have knowingly put a vent right over a location where you wouldn't want moisture, without also designing something to deal with drainage. Doesn't sound right. Also strange that I've never had this problem even though I've daily driven mine for 13 years .. driven probably 100s if not 1000s of miles in rain .. and also occasionally run my car thru car washes. What am I missing?
 
Ian,
Agreed, that there is a design flaw that Honda over looked. If you look closely at the section under the intake grill it is flat, with no provision for the water to drain, therefore it would take the path of lease resistance, and can flow into the engine bay or to the ridge around the trunk.
In my case I don't event drive my car in the Rain...so this indeed was a Big surprise for me. I will be testing my solution today, as I plan to wash the car. I'm planning to place some paper towels over the coil pack area and see if they get wet.

Bram
 
Ian,
Agreed, that there is a design flaw that Honda over looked. If you look closely at the section under the intake grill it is flat, with no provision for the water to drain, therefore it would take the path of lease resistance, and can flow into the engine bay or to the ridge around the trunk.
In my case I don't event drive my car in the Rain...so this indeed was a Big surprise for me. I will be testing my solution today, as I plan to wash the car. I'm planning to place some paper towels over the coil pack area and see if they get wet.

Bram

Let us know ASAP. If it works I'm headed to get this done today.
 
As for my car, it doesn't get wet unless it's getting a bath.
If it's gonna rain, it stays in. If it's not out, it's in a cocoon just in case.
Silly, but it took me a long time to get and pay for the car I always wanted and there'll never be another one for me so I treat it acordingly.

Cheers
nigel
 
Tested with my hose, and it worked just great...few spots of water on the paper towels...nothing over the engine or coil pack area.
I plan on installing another weather strip along the lip over the front bank to help protect these coils as well.

Bram
 
I'm struggling to understand why I appear to be different from everyone else. I've had my car for 15 years during which time I've put about 110k miles on it and I've driven it many many times in torrential rains for hours at a time. I've also had it through a car wash many times although I typically just hand wash it. Yet, I've never had any coil plug issues that I know of .. so why am I different? Is it the fact that it has been daily driven (4-6 days a week) and any moisture dries out? The coil packs have only been out once and that was 8 years ago at 162k miles at the major service interval. The mechanic at the time (Mark Basch) didn't mention any issues with the coil packs although he did have trouble getting some of the spark plugs out (I can't remember if they were on the front or rear bank) so I'm starting to wonder if that was a sign of some corrosion in the spark plug hole. He had been the one who had done the previous major service at the 88k mile mark (just before I bought it) so I had confidance that they had originally been installed correctly. Has anyone with coil pack rusting had issues with getting the spark plugs themselves out?
 
A little over a year ago I had the car apart to do my timing belt. The car is a 1991 with original plugs and coils. 50,000 miles. No moisture evidence found at all. This was the second timing belt change so everything was apart at least once before.

BTW I hit the engine with high pressure washer cold water once a month in the summer.
I think our dry climate here allows this area to completely dry out.


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When I first got my NSX, I took it to one of those hand wash places for a quick scrub thinking I'd rewash it properly later as I just wanted the dirt off. They have jets that spray the undercarriage and somehow it shot water directly at the rear coils, corroding them. The car was sputtering and hesitating pretty badly. It was recommended I let the coil packs dry and reinstall. Did that and didn't work. Then I was advised to replace all 6, which I did. It improved but the car never felt the same.

Now I wash the car myself by hand, with a towel over the engine.
 
I have been dealing with this problem for a couple years now. my thread name is "CEL on in my 91"

I had corrosion in my coil packs and some water in the spark plug wells. I replaced the rear coil packs twice, along with a bunch of other things I tried. I've come to the realization that the coils and plugs need to be changed at the same time. if the coil has corrosion then so does the tip of the spark plug. when I changed the coil it certainly helped until the corrosion took over the coil also. which is why I thought I had this problem solved.

so this is my newest plan of attack for this issue. i ordered 6 new OEM NGK plugs, 3 aftermarket coils(they are cheap and work fine for this test, if you want a oem unit you can buy it afterwards if this fixes your issue), and my new trick is going to be using dielectric grease on the plug tip and coil and around the spark plug well seal on the coil pack itself. this should allow no moisture to effect the spark ever again! if my problem comes back it should have nothing to do with the rear coils or plugs after this.
 
also looking for pics of reference for this.

just today, i had to have 2 of the rear coil packs replaced (one was completely done and another was half-way dying) along with corroded spark plugs. car is back to running strong and smooth after the replacements and cleaning out the holes and burning off the excess junk, but would love to see what this additional fix looks like. i do have a new coil cover gasket on its way but want to add any additional preventative measures i can if possible!
 
Use some Honda bond on the gaskets and let it dry to get them to stay in place. It's a snug fit and even with the line up holes in the cover, when you push the cover on the gasket always seems to work it's way out in places I have found.
 
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