Well, I went down to pull my plugs and survey them. I pulled the driver side ones, having not pulled them since I got the truck. Just caked with carbon. Literally used a screwdriver or my finger to just scrape it off, then wiped them clean with a cloth. I am beginning to think they are the wrong plugs. Well, I didn't feel like screwing around and going to the store to get new plugs to stick in, so I put the old ones in all nice and clean. While working on the passenger side plugs, something catches my eye. A crack in my exhaust manifold:

100_1695-1.jpg?t=1237767406

I think "Well, s#!t. One more thing to add to the list." It looks pretty straightforward to change, although this may be the beginning of my problems.

I took your guys advice. As tempting as it is, I quit driving it. There was something troubling though. I had previously pulled the plugs on the passenger side, and found the number 8 plug to be wet. I did the same thing today. I am afraid that there is oil getting past the rings on that cylinder, with the way it mis-fires under load until I am at about half or full throttle, and doesn't mis-fire at all on the freeway, unless I bog it down while changing freeways. Get it back up to speed, and it cruises perfectly. I can hear the misfire, but it also sounds strange, almost like there is no compression on that side. I don't know. I haven't done a compression test yet, so we'll see. I hope it's not the rings.

 

All Rovers come from the factory with a cracked exhaust manifold, weld it shut.

Rings on these things almost never go bad.
Throw some cheap plugs in to her and see what happens.

 

I agree with Spike, Throw in the stock champions and see how she does. They are still good plugs.

I have changed both of my manifolds now, and the PO had done them as well...

 

Those arent cracks, those are overpressure release ports - in case anyone ever sticks a tater in your exhaust.

If you look a little aft of the one the light is highlighting you'll see the other one, since I said those.

 

It's a weak point, I just bought a pair (2) mos. ago on ebay $30. only needed pass. side was very easy to change


old school methodology says if it smokes winding out under load, it's the rings. (have a friend follow you, as you may not see it while driving)

If it smokes a puff after sitting it's the valve guides and/or seals.

Good tip on the cheap champion plugs, too.

luck,greg

 

You know what, I never thought of that. It doesn't smoke at all, only when I ran the (I almost called it seabreeze) Seafoam through it. Not when it's sitting, not when I'm driving, nothing. SO...maybe it's not the rings. It is running super rich though, I do know that for sure. Those plugs were just caked. I mean, I was litterally chipping the carbon off of them, and little black flakes were coming off. Maybe the plugs are cold? I'm gonna check the NGK website.

 

I did some rooting around, and found that the plugs that are currently in my rover (NGK BP6ES) are not the correct plugs. They are one number off from the plugs that are supposed to be in the '01 Range Rover 4.6 (BP5ES). So I have the wrong plugs. Could be the reason they look like this:


100_1568-1.jpg?t=1237865886


And I'm willing to bet cash money that they are gapped wrong too. I kept putting it off, but I am going to put some standard Champions in there first thing tomorrow. We'll see just how she wants to run then. I bet that clears some of the misfire issues!

 

You can bet that your heads are all carboned up too. You need to run Seafoam or RXP rhrough your gas tank after you change the plugs.

Those plugs don't look that old. It looks like one of the plugs in the first picture has oil on the crush washer. Did you notice that?

 

Yeah, that plug was out of the #8 cylinder, one I have been having problems out of. Last night, I found a chart that explained the NGK spark plugs. The BP6ES plugs ARE too cold, not to mention gapped at .32 when they need to be .44 . I'm not saying this could be the root of all my problems, but I have read a few times on these forums that a plug that is in the incorrect heat range can cause the truck to run like crap. Plus, I been looking at pictures of plugs that are too cold, and they look just as badly fouled as mine. I mean, the carbon is literally caked everything. And I already ran about a can and a half through the intake. Just about killed everybody for half a block with the fumes.

 

Yea, your #8 plug is carbon fouling.
More & more I've read that the recommended heat range cheap champions are the ticket.

I think it's personel choice. but the right heat range UNDER NORMAL CONDITIONS & gap when necessary is a must.
One range up or down isn't going to hurt usually.

If all your plugs were the same & misgapped, why is #8 the only one carbon fouled? Injector?

I consider that soft carbon fouling, you could probably blow it out on the highway - but the incorrect gap can booger up performance.



luck,greg