[tango1111]

I have some Bosch Platinum-4 spark plugs i 've purchased when we had our Buick Century ,paid around $60 for them , never got to install them.I am wondering i could use on my 2005 Caravan 3.3L.
I read somewhere online that the gap is the same for all the platinum 4 plugs,what is the difference then between all the different numbers for different makes/models as long as the size/thread are correct? any help would be appreciated.

 

[Jeepman]

I have some Bosch Platinum-4 spark plugs i 've purchased when we had our Buick Century ,paid around $60 for them , never got to install them.I am wondering i could use on my 2005 Caravan 3.3L.
I read somewhere online that the gap is the same for all the platinum 4 plugs,what is the difference then between all the different numbers for different makes/models as long as the size/thread are correct? any help would be appreciated.

Bosch part # 4481 may work. What's your part #. Best to check with a Bosch distributor as to what plugs work for your vehicle. There are differences and those differences make a difference in workability/performance.
I would stick with the OE Champions which seem to do the job very well.

 

[andyg]

Even if the size is correct, plugs can differ between tapered seats or washers or their heat range and actual reach into the chamber.

Another thing, the +4 plugs are terrible for Chrysler ignition systems. The best plugs to use are the standard double platinum plugs that the system was designed for.

 

[Vision67]

The engine control system is optimized and designed for the OEM spark plugs. If you use anything else, you risk sub-optimal performance. I had to learn that the hard way.

 

[sideburns2009]

Another for bad experiences with Bosch +4's in a Chrysler, not to mention other cars. They're hype. They don't create one huge spark with those 4 electrodes. A spark can only arc to one electrode at a time, and it arcs to a different one every time, therefore creating the same size spark as any other spark plug, not one huge spark amongst all 4 electrodes like the box shows. Go with OEM.

Source: Hooked up to a coil and battery back. Compared a Bosch +4 to a Champion Platinum in a dark room at the shop.

 

[IrishBrewer]

Here's another vote against the Bosch plugs.

I thought I would be doing a good thing replacing the plain old OEM style plugs with some long life plugs, especially since the rear three are no joy to get to. I was thinking this would be the last time I have to touch them. No such luck. After replacing all with the Bosch plugs, the engine ran like crap. I got some new OEM style plugs and replaced them all and threw the Bosch plugs away. I then adopted a policy for all my vehicles to only use OEM type plugs that the engine was designed for. I'm all for new and improved parts when appropriate but it never seems to work with spark plugs.

 

[Sunvanse]

$4.29 at Advance Auto for OEM Champions.

 

[kmr16442]

A friend brought me her car, Hyundai Santa Fe, to replace plugs. She got the Bosch plugs recommended by the auto parts store. After taking intake plenum off and various other pieces the Bosch plugs went in and then I started the car up. It ran like crap and wanted to stall at every light. After another 1 1/2 to remove plenum and stuff, NGK oem plugs were installed and car ran like new.

 

[tango1111]

Thanks for all the replies!The plugs i have are Platinum+4 # 4459 (18-3758-0),i will try to sell them on e-bay or Craig's list .Definitely a waste of $17 a pair.I will get the Champion OEM ones and replace them.
I was working on cleaning the EGR valve on the weekend and i thought i would just remove and clean the 3 front plugs.Bad idea.They are put on so tight that I couldn't even move them 1/10 of a turn.I can use some kind of a lever arm to take them out but I am worried now that whoever did the last job on the plugs just overtightened them and i might crack or break the plugs.Any ideas how to make the task easier/safer?

 

[Jeepman]

Thanks for all the replies!The plugs i have are Platinum+4 # 4459 (18-3758-0),i will try to sell them on e-bay or Craig's list .Definitely a waste of $17 a pair.I will get the Champion OEM ones and replace them.
I was working on cleaning the EGR valve on the weekend and i thought i would just remove and clean the 3 front plugs.Bad idea.They are put on so tight that I couldn't even move them 1/10 of a turn.I can use some kind of a lever arm to take them out but I am worried now that whoever did the last job on the plugs just overtightened them and i might crack or break the plugs.Any ideas how to make the task easier/safer?

How long have they been in there?
Plugs, now days, have an anti-seize coating on them from the factory, so yours should be okay as long as they havn't been removed before and are now missing the antiseize coating.
The ones on the front will likely have lots of rust on them, the backs will have a little. Best to make sure the socket is well down on the plug to start. The rust will make this more difficult.
Use a long handled wrench to break them loose.

 

[andyg]

Another thing that helps is having the engine warm when loosening them. It will help with the fronts, but the backs will just be hard as the engien will be long cool by the time you get to them.

The good thing about plugs is that even if you break the insulator off, the metal threaded part will be intact and should come out.

 

[tango1111]

Jeepman, not sure how long they ve been there as the van was pre-owned but had only 60k on ,so i am assuming probably still the original ones.

 

[Sunvanse]

Only 60K? You are replacing them 40K too soon. I replaced mine at 102,500 last week. I was afraid the fronts would not budge, they were so rusted you could not make out the hexagon shape. To my relief they did unscrew fairly easy, and internally they still looked good although the gap was approaching 0.70". The rears unscrewed too easily in my opinion, but was happy I was able to reach them from above with only the top of the air cleaner removed. As others have reported, I notice no improvement on how the engine accelerates or drives but the idle seems smoother.

 

[n8ech]

AndyG:

I had always thought/been told that one should remove plugs from aluminum heads when they are cold or at least cool. Has that information changed with the newer technology?

My understanding was that when warm the aluminum was more prone to cross threading/stripping.

Don

 

[andyg]

I'm no metallurgist, but in my experience heat helps all bolts or plugs. Aluminum expands more than steel during heating so I would expect the aluminum threads in the head to expand more than the steel plug making removal easier.

 

[Jeepman]

Haynes Manual says to let the engine cool down completely when removing spark plugs. Here's what Ford says. http://www.autopartscentres.com/links/SparkPlugRemoval.pdf

 

[sideburns2009]

Haynes Manual says to let the engine cool down completely when removing spark plugs. Here's what Ford says. http://www.autopartscentres.com/links/SparkPlugRemoval.pdf

I've always been taught, especially with aluminum heads, to let the engine cool all the way down too. I would think, but maybe I'm wrong, that the expanding aluminum would make the spark plug holes smaller as the aluminum expands out, and harder to get the plugs out.