Hi All

Awhile back I had posted two messages one asking what spark plugs everbody was using and the 2nd was concerning my check engine light on.

Well I went to the dealer the other day and he found lots of misfires. They said that I can only run Volvo OEM plugs. I had used bosch and it had caused the misfires. I found it hard to believe but my check engine light hasn't come on since.
He said the Bosch plugs ran hotter. They must be different because I do notice a small drop in power since switching back to the Volvo plugs.
I had used aftermarket wires, cap and rotor but that doesn't seem to make any difference.

Just wondering if anybody else has run into the same problem.

Tks
John


PS The guy at the service desk had a good tip though (maybe you all know this) I said that my steering had some stiff spots. I was afraid I would have to replace my rack. The guy there said to spray a good quality penetrating oil on the knuckle(he had the proper name for it, kinda looks like a u-joint) under the dash. Well it worked perfect, my steering doesn't have any tight spots at all.

 

The Bosch work good sometimes.

Do you remember if they were the FR7DP plugs?

If not try them.

Volvo plugs are better but we use the Bosch platinums all day long and have very Few problems with them.

 

Yes they were FR7DP, it is strange I am the only person having problems with them. The funny thing is with the Bosch plugs there is a slight but noticable increase in power but every say two hours of driving there would be a split second that the car would misfire. Maybe it was doing it more often but too slight to pick up by ear but every once in a while it would almost be like a backfire through the carb. I know it is fuel injected but that is the only way I can describe it.
I have had the Volvo plugs in now for about a week including a weekend away trip and it hasn't backfired once as well the check engine light hasn't come on.
It's too bad because I am trying squeeze more power from the car without spending too much money.

John

 

Bosch is the manufacturer of Volvo plugs. Perhaps your gap was incorrect? I have use Bosch Platinums for 20 plus years. No problems.

r.

 

Good point, I still have the Bosch plugs so I will check.
Do you know what the proper gap is for a 98 C70 2.5 turbo?

John

 

I drive a 2.3 high pressure...............I do not know your gap. For the record, I gap my Bosch single electrode plugs a tad wider than what the spec calls for. I find with a good spark they do not foul as quickly. I would go 5 thousands wider. I use them also in a 1965 Healy which has a Lucas ignition (read: poor spark) and they are teriffic!
Additionally I use them in a BMW Hartge H-3, a Mazda MX-5, and a Mazda Proto V.
R.

 

The service advisor at the dealership I use also told me to use only the OEM plugs for the same reason we see right here on this forum, inconsistency. Some people have perfect results, some skipping and knocking. With my luck I'm going OEM, seems basically a sure thing.

 

Well of course your service advisor wants you to use Volvo plugs..............That's what he sells and makes a profit on. Ask him who manufacturers volvo plugs...............would you believe it is Bosch?? BMW sells synthetic oil for their autos under their own label Would you believe that Casterol makes it? Volvo makes autos...........not spark plugs. Think long and hard about your decision and perhaps TECH wants to make a comment. He worked for a Volvo dealership for years and is now independent.............he uses Bosch. Now, with that said, I use the dealer for my transmission fluid changes and for coolant changes. I am not against a dealer but replacing plugs with Bosch single electrode platinum simply makes good sense.

R.

 

As far as the service advisor goes, I know this guy and he is always straight up with me and never puts on the hard sell for the dealership. And I HATE buying parts from the dealer, cha-CHING. As far as Volvo making cars and Bosch making plugs, your exactly right. It would not be unheard of for a OEM to have a product made for them with different specs. and properties to perform better in their specific application, (ie the tranny fluid) leaving their (Bosch's) closest stock plug slightly different. Believe me, I'm not trying to argue this point to death but rather trying to make sense of the inconsistent results people are getting with something that should be so simple.
P.S. I did ask who makes the plugs. The advisor wasn't sure so he called the parts dept. They said Volvo- either their stupid or smart asses.

 

Nope. Bosch makes them. A tip for you Skipper: I am not sure what year c70 you have but if it has an Asin/Warner transmission, be advised that you should look to Volvo for the correct auto trans fluid. You could have a costly repair on your hands if you deviate from the Volvo fluid in the Asin/Warner. I have the dealer change my fluid simply because he uses the correct fluid and disposes of quite a few quarts of old fluid. Ditto for the rad coolant. It simply is too dificult to collect the drained coolant and is, to me, cost effective to have the dealer change it.

r.

 

Thanks for the tip Reg, I didn't know that but I will certainly take your advice.

John

 

John, query the search engine on this site for the Asin/warner transmission. They were used in the (I believe) late 90s and 2001 and 2002 70 series. There is a lot of info re: this transmission and I "play it safe" by going to the dealer for the fluid flush maintenance.

Reg

 

I always gap the plugs to .30

 

Reg

I did the search, boy that has been a heated discussion! I havn't changed my transmission fluid yet but tomorrow I will call the dealer and see what they have to say.
It will soon be snowing here and my car will be put away but in the spring I will certainly have the fluid changed.



Tks Tech

That is what I gapped the Bosch plugs at but I am going to check them again to make sure I didn't make a mistake.


John

 

If memory serves me right (I am in Pennsylvania this week and so do not have my "book") but I believe .30 is the factory setting and so I gap at .35...........always 5 over the factory setting.

R.

 

plugs at dealer are made for your engine

plugs at autozone are for a lot of different engines

even though they both fit the same hole

would you put kmart hub caps on just cause they fit? or the volvo wheels even though volvo did not make them?

 

Well, I can't let that one go. An automobile is manufactured so as to make a profit. Don't be myopic and think that Volvo is going to use the best (read: more costly) parts on their autos when a part that "works well" will do a fine job. Volvo does not have OZ make their wheels............if they did the cost of the vehicle would skyrocket! The same is true for plugs. Bosch is a world renown manufacturer of sparking plugs and while they can sell you an expensive part....................they make less costly parts for the auto manufacturers. Think of the differences in plug wires. I can obtain a set of 'after-market' wires that will outlast the factory wires and have less resistance to boot! Same holds true for the ignitions system.
The manufacture's recalls are great examples of cutting corners.
Always remember: A fool and his money are soon parted.

R.

 

I guess it went over your head.

 

Every time I see this spark plug thread it goes on and on. You have to admit that something must be different with the OEM Volvo vs. stock Bosch plugs. There wouldn't be so much debate if the plugs were a 1 for 1 swap. I don't say this because I think Volvo is so wonderful and would only put the best on their cars. Obviously the specs. are different in some small way. All of these people who think enough of their cars to do their own maintenance can't be incorrectly gapping their plugs or missing damaged plug wires. Maybe the stock Bosch plugs require a slight deviation in gap from stock spec. and they run fine. At this point, who knows? We're not talking about big money here, the difference in cost of the stock Bosch plug doesn't mean anything if I have to buy the Volvo ones anyway and do the job again.