Question about Spark Plugs in a 93 5S-FE

[JoeDB]

Has anyone installed Bosch Platinum +4 plugs in their 4 cyl engine and had any problem with them?
My 93 Camry engine started running rough like one of the spark plugs was misfiring. Those plugs had about 50,000 miles on them and I was planning on changing them out anyway. I went to the auto parts store and bought some new plugs. There were several manufactures to choose from for my engine so I decided to buy the Bosch Platinum +4. Bosch is a good name brand, more expensive and good quality, right. After I put the new plugs in it still wasn't running right. When I first cranked it up it sounded and felt like it was hitting on 2 or 3 cylinders, after about 5 seconds it would smooth out and idle fine but when I would accelerate it would hesitate and sound and feel like it was hitting on 2 or 3 cylinders again.
Not having any diagnostic equiptment on hand I decided to drive it to the repair shop. Good thing the shop was only a couple of miles away because it died on me and I had to let it sit for a few minutes before I could make it the rest of the way. When I got to the repair shop I could smell that I had toasted something under the hood.
The manager of the repair shop called me later and told me that the Bosch Platnum +4 plugs are to hot of a plug for this engine and they had to replace the plugs, plug wires, distributor cap and rotor.
I went back to the parts store and told them what the manager of the repair shop told me and they said that Bosch recomends these plugs for that vehicle. So, I am wondering who is right?

[Brian R.]

Buy the recommended plugs (NGK or DENSO) for that engine. Don't use Bosch since I've heard of alot of people having trouble with them and other brands.

[JoeDB]

Thanks for responding.
The manager of the parts store filled out a claim form to send to Bosch for the repair cost on my vehicle. We will have to wait and see what happens.
I wanted to let the members of this forum know about this problem. I learned the hard way $353.83.

[xfeejayx]

There are plenty of spark plug discussions on this forums, and the general consensus is exactly what Brian said. Stick with standard NGK platinum plugs, They're everything you need and nothing you don't, and they last 'forever.' You can't go wrong. +2 and +4 can only hurt.

edit
$2.82 a pop from sparkplugs.com

hope you can get your $$ back for the damage

[JennyDee]

I agree to stay with the OEM suggest plugs (NGK or DENSO) as I have expernienced the same issue with the Bosh 4 point plugs. My experience has been has also been to purchase the plug wire set, cap and rotor from Toyota and not go with aftermarket parts. My feeling is that there is a resistance value between these components that relates to the igniter resistance. I was having some plug failure ( cylinder) closest to the distributor, where I noticed the wire moving up and down when running. Turns out that the porcelain seemed to have seperated inside the plug and that let the top of the plug move. It happened twice and I now think that it was related to a bad wire set, as I have changed out the plugs and wire set with OEM parts and the problem is gone. JD

[GSS123]

JoeDB, please post back on the results of your repair claim. Myself I try to stay with OEM recommended replacement parts for just about all repairs. Often you pay more but this forum is loaded with posts showing minor to major problems with some after market replacement parts. I have a good working relationship with the local Toyota dealer parts manager so that may explain my bias.

[jdmccright]

Most spark plugs are rated to work in a specific "heat range" though there are no specifics on what that range is for each vehicle. Plugs that run too hot for a particular engine, such as plugs with platinum (Pt) tips that are billed as OEM replacements for regular copper core plugs, tend to cause predetonation under load and also just don't last because of the extra heat.

Now, there are Pt plugs that do work and there are even some cases where they may help, but mostly for modified engines that are designed to accommodate these higher heat range plugs. A good search in this forum for spark plug recommendations is a good way to find out the good, the bad, and the ugly for your engine.

Quite frankly, I've got normal Bosch Pt (I think) plugs, not the stupid +2 or +4 electrode jobbers, in my '92 Cam 5SFE and they've been running for well over 100k miles (hafta check my service logs it's been that long!)...would I buy them again? Maybe. I haven't seen any degradation nor improvement in performance, but that's not to say I'd get the same longevity from a standard set for 1/2 the price.

I'll check my logs and see if I wrote down what I put in and when...got my curiosity up now...and edit this post.

[jdmccright]

Just changed the plugs in mine tonight. I did have Bosch Pt (stamped FR7DPX). But were at 80k miles, not 100k like I thought. The car was running a little rough and wouldn't idle high when cold, but wasn't missing. Acceleration was getting sluggish and mpgs dropping some (from 25 to 22 mpg). I forgot how long it had been since I changed them...oops.

I installed new Autolite Pt plugs (AP3923) since the store didn't have the recommended NGK Pt ones.