I did my research on this Seafoam stuff, both here and on other sites, and decided that I'm gonna give it a shot. I plan to do the TB and some in the tank - I have 3 oil leaks as it is, so definitely not putting any in the crank.

I changed my plugs about 2 months ago, but I have had misfires on 1, 2, and 3 (not bad enough to throw a code, dealership watched it on their cpu). I ordered a new coil pack/rail and will install it shortly.

- Should I change the plugs again or will the Seafoam clean them well enough?
- Seafoam first and then immediately do coil pack/rail?
- Do the coil first and then seafoam?
- Does it even matter?

 

I would do the plugs and or coil pack after seafoam. The key is to do one change at a time and see if that improves or changes how the engine will run. I wouldn't mix new parts and seafoam right away either, gotta give it time to see what helps. I personally have had bad experiences with seafoam and will never touch it again. A couple weeks after doing seafoam in my 01, an engine that never had any trouble suddenly blew a head gasket and because of that it is no longer my daily driver. It now sits in my back yard with an engine that needs to be rebuilt. While I can't sit here and say that seafoam is the only cause I'm certain that it played some part in the blow head gasket and will never use it on an vehicle again.

 

I personally have had great experience with seafoam!!! As far as your misfire do you have a cap/rotor or individual coil packs? I'm not familiar with your year model. My '90 had 1 coil, a distributor cap and rotor, and spark plug wires. I would do the seafoam and clean the contact points inside the distributor cap and on the rotor and see what happens. at least by doing this you'll have minimul money invested. also, after doing all this, if its still missing then with the engine running start pulling the plug wires off the plug one at a time. if it runs worse then put the wire back and move on to the next wire. if you pull a wire off a plug and the idle doesn't get worse then that's your problem plug, wire, or contact inside the distributor cap.

 

Well, has anybody else done seafoam in a 00/01? Maybe it's a bad idea with the weak 0331 casting that's in these things.


Distributorless ignition for 00/01. Coil rail looks like this:

 

If you run seafoam through it, like others mentioned run it through before you change out the parts. What kind of plugs did you use? I found that with the '00-'01 XJs with the coil pack ignition its best to use what it says on the driverside firewall. Just plain ole' champion cooper plugs. I tried running the special platnum ones and had a slight missfire. I never believed the whole plug debate until I experienced it for myself.

 

i've run seafoam in all my vehicles and had good luck. lucas fuel treatment is awesome too! is it consistently missing on those 3 cylinders? it may be clogged injectors, bad injector o-rings, or the spark plug boots are failing.

 

I know I used Champions, but now I can't remember if it was the copper ones or not. Might have been the platinum. I guess that answers my question: change the plugs when I do the coil pack. Now to decide if I want to do the Seafoam...

 

Any info on the Lucas oil stabilizer?
Is it a fad/advertising ploy, or will it help with engine longevity/oil pressure/cold starts?

I have used the Marvel Mystery Oil, pulled plugs, injected the oil into the cylinders with a rubber hose (connected to a 50 CC syringe) (for turkey injecting) and unstuck a cylinder/seized engine before.

 

I would run 1/3 of the seafoam through the intake and put the rest in the gas before you replace the plugs.

x2 Marvel Mystery Oil is a good product and has worked great for many years. I would run some of this in the gas tank after running the seafoam through. I've heard bad things about lucas oil stabilizer because of how thick it is. I've personally heard it make valve ticks louder, and when run in a cold environment will take the oil longer to reach he valvetrain. Marvel Mystery however seems to quiet valvetrain noises down nicely and cleans well.

 

Also,
I just added a can of Seafoam to the gas in my 98.
I've heard so many people do it repeatedly, I figured what the heck.
My rig was running fine in the first place... I'll see if it increases throttle response, power, or gas mileage. I added the 12 gallons of gas so it wouldn't be overconcentrated.
Hopefully this'll get the gunk out and make the engine perform better for another 250-300,ooo miles...
Also, other that the one guy who had the head gasket go, I haven't heard too many bad reports.

 

Really?
You added Marvel to the gas tank?

I never thought about it.
Does it say that on the can?

Has anyone else done this?

 

Its safe for both gas and diesel engines. Says on the can how much to add to your fuel. I believe the ratio is 4oz to every 10 gallons of fuel. I've used it in farm machinery as well. I had this old Farmall tractor that never idled right, it would sometimes even stall. I took the whole carb apart and cleaned it. Put it back together and still had the same issue. I put half a bottle of marvel in the gas tank which holds about 8 gallons. Within an hour of running it the problem went away. 6 tanks of gas later and its still running great! It also seems to start a little quicker.

 

Thx - man

 

I've used lucas oil stabilizer in most of my vehicles with no problems, I've also seen Marvel mystery oil free up a siezed engine. my 94 4.0 has developed a slight knock this winter and I think I'm gonna try marvel my next oil change. both products are good in my book. never tried seafoam, I like the lucas fuel treatment.

 

how do you disconnect the wire harness from the coil pack?? cannot get it to disconnect --thanks mike