After changing spark plugs I get lower gas milege

Hi, This is my first post:

I did not know that Saab has so crappie spark plugs. My previous car was a Chevy Cavalier 96 from 0 miles now has a 100K. When I changed the first set of spark plugs at 60K, even though the manual said every 100K, on the Chevy they were like new. When I got my Saab 9-3 '99 with 36K mile I thought it has the same king of plugs, without consulting the manual (who reads the manual anyway). So with that in mind, day before yesterday my Saab started to cough in the lower rpm, with every shift. I said myself: maybe is the muffler that I replaced last week, maybe not. I checked the spark plugs and I could not believe: they were toasted, the hook that comes around was almost gone completely on all four. So, because I could not find Bosh I went with the original NKG crap....Needless to say the Check Engine light came ON, so I had to disconnect the battery for 15 minutes to reset it. Anyway getting to the point: now, after changing the spark plugs everything seems to be OK, but my gas mileage went from a 25.5 mpg (at least) to a 24 mpg (at most).....!?!!??? What can it be wrong???

Reply to
gogoasa
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Did you gap the plugs to the specified gap?

I've had great luck with NGK and lousy luck with Bosch Platinums, seems many turbo engines just refuse to run well with them.

Reply to
James Sweet

"gogoasa" skrev i en meddelelse news:BtCOc.57663$ snipped-for-privacy@twister.rdc-> When I got my Saab 9-3 '99 with 36K mile I thought it has the same king of

NEVER EVER run a DI-Saab on Bosch plugs. You can fry your DI-module i a very short time. Only use the correct NGK-type plugs and as mentioned, gapped right.

NGK BCPR-6ES11 if it's a turbo. And gapped at 1,0 mm.

Cheers!

Reply to
Henrik B.

"Johannes H Andersen" skrev i en meddelelse news: snipped-for-privacy@nsuvuooiaiosizefitterwiuoveswernuaz.com...

I believe that Saab-dealers are doing a very poor job, adresse this issue. They should expect a lot of Saab owners eventually changing the plugs by themselves, therefore it should be pointed out, everytime the sell a new Saab.

Besides that, the factory should apply a big bright sticker under the hood, stating: "ONLY USE NGK PLUGS". And a writing on the very first pages of the usersmanual as well.

Hmmm, maybe I should send a mail to my contact at the factory and suggest this all. It's in their interest as well. :o)

Cheers!

Reply to
Henrik B.

Agreed, but how to spread the message? NGK spark plugs look like 100 years old while BOSCH plugs look much fancier. Even worse, the Haynes manual lists Champion spark plugs for the car.

Reply to
Johannes H Andersen

Or, in the USA, 1.0mm :-)

Champion pays Haynes for the advertisement (also the color chart in rear of those books with spark plug wear pictures).

Reply to
- Bob -

"- Bob -" wrote in message news: snipped-for-privacy@4ax.com...

Actually there are a lot of others plugs that are listed for this car (check the internet), in my case only I could not find anything else than Champion at the auto parts stores (I was looking for something more expensive than

1.25$). And then I was going to the dealer to ask them to read my engine codes anyway (of course they are full right now, but I can try next week), so I just picked up 4 plugs NGK.

Here is what I got in response at the same post on SaabCentral:

Welcome aboard and let me be the first to throw out a warning that you will no doubt hear 80 times in the course of this thread. Saabs are picky about their plugs! Since The Trionic engine management system was designed around NGK plugs and their particular characteristics, most people opt to stay with them. Most are convinced tiny variations between NGK and different brands of plugs make a big difference to the ECU. I'm not convinced...and that's why everybody loves me. You are driving a turbocharged car now...they are in general a tad more hard on spark plugs. Perhaps the reason your plugs seemed okay in your cavalier after 100k miles was because they may have been platinum. Platinum plugs last longer as they have a higher melting point than the nickel ones, but at the expensive of a bit more electrical resistence. The high heat in a turbocharged car will wear plugs faster, so the stock NGK plugs (nickel) go pretty quickly. Many of us here (notably myself) obsess about the plugs (thanks SPATL!) and rotate them out frequently. I bet I haven't had a set of plugs yet I've kept in more than 10,000 miles. Additionally, the gap on these plugs erodes relatively quickly. Pull those plugs out and make sure they were gapped correctly to begin with. Go with something between .035 and .040 inches for the gap. Anything more and you'll get a bit of a high boost misfire. You'll find Saab-friendly spark plugs are hard to find because of the fact that Saabs require resistor core spark plugs. Since Saab uses a direct ignition system utilizing a coil over plug system integrated into a cassette, there are no plug wires to suppress radio/electrical interference. Therefore, the the plugs themself use a resitor core to suppress spark energy and prevent it from bleeding back up toward the ECU. You MUST use these resistor plugs or ECU go BOOM BOOM. FYI, if you HAVE to use Bosch, Bosch makes the Super plug with a resistor core. Just check out the side of the box to make sure it says resistor core.

bkrell

Reply to
gogoasa

Let's see how you do, "someone", with your first post.

Strike one - opening with an overgeneralization based on limited facts.

OK, and?

Strike 2. Not reading, and then badmouthing, the information you yourself ignored. Not looking good, "someone".

What kind of muffler did you put on it? This could be significant if you're actually, you know, looking for a solution, rather than just here to make noise.

See, here is where there are two lights getting brighter, not sure which is the case. Could be "troll", could be "clueless". Let's read on and see if we can determine, shall we?

I'm going with "troll pretending to be clueless" on this one. No subtlety.

IF you actually have a Saab and have done all this, and have the attitude that it's Saab's crappy fault and NGK crappy this and whatever else, it's clear that you're...let's put this gently...not Saab's target market, and would be happier elsewhere. However, seems to me you're just gathering the topics most likely to elecit heated discussion in this group, all in one message, which smells pretty troll-ish to me.

If you're actually serious and can't imagine why I'm giving you a hard time, think about your communication approach. "Hi, I've got a (year/model) Saab, my plugs wore out at x,000 miles and with the new ones my milage has gone down by an insignificant, meaningless amount. Am I doing anything wrong here"?

Reply to
Dave Hinz

Er, yeah, it's in the _owners manual_, y'see.

Our newly-arrived(?) participant(?) doesn't bother with such things, so this one couldn't be helped either way.

Reply to
Dave Hinz

[...]

My reply to the SaabCentral reply:

It is not worth while experimenting with other plugs since the DI system is designed around the NGK plugs. The NGK plugs are normally changed at 24k miles interval. They last well because of the automatic cleaning system.

Reply to the thread:

Another important issue is the torque required for the spark plugs. Naturally, the plugs should sit air tight in their holes, but some care should be exercised because of the aluminum head and the small diameter holes. It is easy to overdo it and damage the threads.

Reply to
Johannes H Andersen

Just go with the cheap NGK's. Replace every 10K. No problems. Spark plugs are not that complicated and do not have to be expensive to do the job. The only reason Platinum plugs are expensive is that platinum costs more than gold, so a little bit on the electrode and/or tip adds a lot to the cost. NGK's should cost you $1.50-$3.00 depending on where you buy them (all copper).

If you want expensive plugs, try my Nissan. $11 - 16 each, depending on where you get them. Lots of platinum. Of course, they last 60K miles so if you figure it out over 60K, it all comes out about the same.

Reply to
- Bob -

(year/model)

Dud, I was actually trying to introduce my problem better. I think there were tons of posts about "bad gas milleadge". So, yeah I expected to find somebody that will say: o, dud, it happened the same to me last year and this is what I did, or this is what is still doing....

Generic CENTER muffler, this is sometime called SILENCER. I bought it from the internet, Starla for 87$ The normal muffler is still the original. Also the exhaust smells horibbly..

I did actually hate it my SAAB before... When I went 1.5 years ago to the action to get my new car, I was looking for Nissan, Honda, or Passat. (only V6). But the price, and the fact that is a manual and has some 185bhp, convinced me to give it a try. Yeah I got my 1999 9-3 for 11K with 36K miles. The whole last year I wasn't happy with my decision, I try to make my wife take it, so I can get a different car, but abaut 4-5 months ago I discovered SaabCentral and this. Also I have donne some work at my wife Toyota abd then at my Saab. Needless to say the Saab qualyty and design build for the customer is evident. So I started to love it.... Ohhh, by the way: I drove every car outhere...

Reply to
gogoasa

Going from 25 to 24 MPG is insignificant. A warm day could change it that much, or tires, or an aftermarket muffler, or any of a dozen thihgs. 4% isn't all that significant.

So you figured badmouthing things you don't understand, and the documentation provided with the car, was a good way to do that? Odd.

Any unusual color smoke coming out the exhaust? Or, is it just paint from the muffler and normal new-muffler stink? You _did_ peel the labels off of it before installing it, of course?

Reply to
Dave Hinz

"gogoasa" skrev i en meddelelse news:x28Pc.64583$ snipped-for-privacy@twister.rdc-kc.rr.com...

Crappy muffler.

If the exhaust smells that bad, you either have:

  1. Bad fuel quality or...
  2. Bad Catalytic converter or...
  3. Something generally wrong with the Trionic (enginemanagement).

Cheers!

Reply to
Henrik B.

Ok, finally something contructive... Yes, I pilled the stikers from the muffler. Now I have filled up the gas tank with the new Mobile V power fuel (93+ octane - the highest available in US) + a can of injector cleaner. I have also reset the trip odo and the SID. Now the SID says 15.5 MPG which it never ever in the worst nightamers would show, however when I got home (after 10 miles) showed 20.1 mpg, also never seen before that low...But I will post the final average after this tank (15 galons) and we will see if the SID lies or I am realy screwed....

Reply to
gogoasa

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