Changing spark plugs on 05 turbo... tips anyone?

[baja_burrito]

I was under the car last night and managed to change one of the plugs, but never did get to the others. After getting impatient with it, I left it with one new plug.

From the looks of it, that motor must be lifted a few inches to get the other 3 out, especially considering that the frame is right in my way on the passenger side.

Pointers anyone?

Any help is much appreciated!

(BTW: The n/a model is a whole different ballgame... I've had, and changed the plugs, one of those also.)

[Ti Pit]

I've done all 4 and all of them from above! you need to remove things like the air box and the windshield washer reservoir, battery... but it's really not as bad as it sounds.

[bulwnkl]

My '05 turbo was a pain, but you don't have remove, lift, or lower the engine. I did them all from above, and quite frankly the coil packs are more difficult to remove & replace (WITHOUT breaking them) than the plugs themselves are. It's just tight, and takes some patience (especially on the driver's (left) side).

Remove the battery and windshield washer fluid reservoir for a considerable increase in convenience. I don't recall whether I took the rubber intake hose off or not. I think I just to the airbox top off and pushed it aside.

I've got a post either on here somewhere or at Scoobytruck.com that tells what few tools I used on the plugs themselves. I don't recall anymore what I used, but it didn't actually take much.

[Ti Pit]

Bulwnkl is right, the tuffest part is playing around with the coil packs, they come out easy but are a pain to put back, you really need to remember how you took them out to have an easy time putting them back in.

[BajaSTI04]

This is all GOOD advice! Above is the key to sucsess.

[moonzie]

^ +1

Some advice on tools to acquire before changing your turbo's plugs:

• 3" 3/8 ratchet extension (maybe 2 of these would be better)
• 12" 3/8 ratchet extension
• 3/8 ratchet universal pivot joint
• 3/8" Deepwell socket (don't remember what size..)
• 3/8" drive ratchet.

If you take all those things out, battery, wiper reservoir, air box you can change all 4 hour in 2 hours or less from above. No need to move the motor or work from below. Good luck.

[bulwnkl]

Good tool list moonzie, and good avice from Ti Pit about remembering exactly how the coil packs came out for ease of installation.

I'll bet you that moonzie's list matches what I used almost exactly. The deep-well socket I used was what we used to call a "spark plug wrench." It's a deep-well socket with a rubber insert that holds on to the spark plug insulator to keep it straight and to help you pull the old plugs out. It makes the job MUCH easier than a plain deep-well socket, though a plain one can work, too. Spark plug wrenches come in basically 2 sizes, since spark plugs are nearly all built in 2 sizes. The larger (older, I believe?) size is 13/16, but I've forgotten the smaller size that I think the Subies use. Maybe 5/8"? Can't recall.

Good luck, baja_burrito! You can do it, and it won't actually be as tough as it seems if you're patient.

[BGC]

How long should it take to install the plugs by an experienced Subaru mechanic?

[baja_burrito]

Thanks all for the good advice. This weekend I'll attempt the beast again.

[Baja_Gernaut]

hey what's the mileage on the plugs, changing plugs is not going to make the car faster if the plugs are still good. If you have over 100k on them, it's good to change but when I took out my plugs at 85k, they were still good. the baja turbo uses iridiums so these plugs are good for a long time.

[baja_burrito]

Originally Posted by Baja_Gernaut

hey what's the mileage on the plugs, changing plugs is not going to make the car faster if the plugs are still good. If you have over 100k on them, it's good to change but when I took out my plugs at 85k, they were still good. the baja turbo uses iridiums so these plugs are good for a long time.

Thanks for the advice, but I'm not trying to make the car faster by changing my plugs... It's routine maintenance.

Subaru recommends changing spark plugs every 30k miles... Honestly, I've let this car go to 60k, but I'm starting to feel guilty.

[bulwnkl]

Originally Posted by baja_burrito

Subaru recommends changing spark plugs every 30k miles... Honestly, I've let this car go to 60k, but I'm starting to feel guilty.

As information only: Subaru does not recommend changing the double-iridium plugs on the turbo Baja every 30k miles. It's either 75k or 100k on these, and I can't recall which right now. It'd actually be very slightly better overall to run these fine-wire double iridiums for at least reasonably close to factory recommendation, rather than switching to copper (or single iridium or platinum) and changing all the time.

[baja_burrito]

Originally Posted by bulwnkl

As information only: Subaru does not recommend changing the double-iridium plugs on the turbo Baja every 30k miles. It's either 75k or 100k on these, and I can't recall which right now. It'd actually be very slightly better overall to run these fine-wire double iridiums for at least reasonably close to factory recommendation, rather than switching to copper (or single iridium or platinum) and changing all the time.

Thanks for the advice... However, I'm replacing these plugs with OEM plugs (whatever type of iridium they may be). At 67k miles on this car, it was due for a change. The one plug that has been replaced was most certainly ready for its replacement.

I checked into what you said about the plugs... For the 2005 Baja Turbo, Subaru recommends changing the plugs during your 60k mile service. (This info available on MySubaru, under maintenance schedule). I was thinking that the replacement interval must be the same as the n/a model (which is 30k)... so thanks for making me check!

[BajaSTI04]

^^ yes they are but if you go one step cooler it helps out bunches at the track which = faster

[bulwnkl]

Thanks for making ME look, too. I can't actually find the spark plug replacement interval at my.subaru.com under the Manufacturer Maintenance Schedule, but I do see it @ 60k under the dealer's recommended schedule. The 60mo/60k miles replacement interval is indeed what's specified in my Warranty and Maintenance Booklet, too. Thanks!

Those ILFR6B plugs sure are expensive!

[Baja_Gernaut]

you're right, 8 dollars a pop is crazy. When I replaced my plugs on toyota landcruiser, it used iridiums as well. Almost a hundred dollars in plugs. Fortunately the baja is only 4.

[kev m]

Originally Posted by Baja_Gernaut

you're right, 8 dollars a pop is crazy. When I replaced my plugs on toyota landcruiser, it used iridiums as well. Almost a hundred dollars in plugs. Fortunately the baja is only 4.

If it makes you feel any better, my new(er) Moto Guzzi (air-cooled, pushrod V-twin) uses 4 plugs, two outer and two inner - the two INNER plugs are $43 A PIECE from a dealer.

Best I've been able to find is an almost identical heat range plug from another supplier for $11 a piece.

[Baja_Gernaut]

43 dollars, sh^&5 I would use those plugs until it melts to the head. That's crazy

[baja_burrito]

Alright, plugs are done! They were a royal pain in the a**, but they're done. Going from the top is definitely easier. Removed the washer fluid reservoir and airbox to get to them.

Since no one has ever done an actual write up, I'll be the first. When I get home, I'll post some pics and another tool list.

[moonzie]

lol. I think I replaced my plugs around 120k miles. The old plugs looked just fine, no excessive wear at all. No difference in performance or fuel economy. Went with the OEM temp Iridium.

[bulwnkl]

I changed my plugs last night (second time I've done them on the Baja; I'm at ~110k miles now), so I thought I'd report that I'm a big loser. I missed moonzie's estimate of 2 hours or less by probably an hour. OTOH, I had my little boys helping me, which they love to do, and we were having a good time visiting as I went along. The tool list above is still all I needed.

I went with Pulstar plugs this time. When I took out the factory plugs before, I had put plain-jane NGK copper plugs in. They look good, and only slightly worn. I can see that the mixture is mostly right on target, though it does appear to be rich sometimes. I think that makes sense given how rich the turbo engines run under boost. I'm curious to see whether these plugs show me ANYTHING different or better than those copper NGKs. I run oil analysis roughly annually, and that should show me some things even if I can't see it in mpg.

OBTW, the Pulstar plugs' insulators are a little fatter than standard plugs', so a spark plug wrench grips them TIGHTLY, and it's nearly impossible to get that plug wrench off once it's all down in the head and snug. That probably added 30 minutes to my total time last night all by itself. Beware!

[kev m]

Ya know Bulwnkl, most tuners today would say you can't tell crap about how a motor is running from plugs (some extremes not-with-standing) largely because of the plethora of different fuel additives and formulations.

That said, even so, without performing a plug chop you REALLY can't tell anything, since you're seeing only what is left from the richest or leanest the motor ran the entire time those plugs were in.

[bulwnkl]

Hmm... interesting. I do have the dremel right handy...

When you talk about tuners, are you talking about them making tuning decisions based on a dyno pull or three on clean plugs? I've looked at some of the explanations and pictorials of that. What I'm doing when I look at plugs is to see whether I have a chronic pinging issue that I can't hear, whether I have an injector that's badly out of whack (UOAs will catch that far sooner than plugs, but plugs will tell me which one if it's anything other than all of them), whether I have an oil consumption problem anywhere, etc. Are you talking about something else, or these kinds of things?

I know what you mean about additives. It was always immediately apparent when I got a fuel supplier that put MMT in the fuel way back when, based on the deposits. I can also see the difference between a couple of additives I've used relatively long-term at different times over the years.

[kev m]

Tuning decisions (analysis of running conditions) based on plug reads as oppossed to an exhaust sniffer.

A lot of the explanations and pictorials on the subject are simply out-dated.

Again, without performing a plug chop (putting a BRAND new set of plugs in, operating at a given rpm/condition, cutting the fuel/spark and coasting to a stop/allowing her to spin down on the dyno) and pulling the plugs for an immediate read) then it is unlikely you will get any real meaningful read from a plug.

SURE if carbon fouled you KNOW you're running pig rich SOMEWHERE.

If oil wet you know you have a mechanical problem.

But even pale white/gray doesn't NECESSARILY mean you're dangerously lean.

As for pinging, doesn't the turbo utilize a knock sensor?

[bulwnkl]

I think we're talking about watching for different things. I would agree with the superiority of the short run & chop method for specific tuning help. Honestly, though, I probably wouldn't use that method on this engine, since it's such a pain to change plugs.

I'm not playing with ECU programming at this point, so taking a couple hours to change plugs after a super-short dyno run (I don't even know where the nearest 4-wheel chassis dyno is? 250 miles away maybe?) seems kinda silly to me. The ECU and O2 sensor are going to keep the average mixture at lambda during most of my driving now that we've gotten rid of our 'big' trailer (unless we have to re-po it here shortly). Since that can only watch average, though, reading plugs is a very simple and useful way for me to identify an issue in an individual cylinder. As I had mentioned before, UOAs will do that, too, and do it faster for me than reading plugs after 30,000 miles. Looking at plugs will help identify which cylinder(s) are the culprit(s), though.

That's where I see that the carbon deposits, oiling, and the sometimes complex subtleties of color and deposits come into play. I agree that white/gray doesn't _necessarily_ mean dangerously lean conditions. As a component of the overall maintenance/watch strategy, though, I have found looking at plugs to be quite useful.

Yes, the truck has a knock sensor. And, I've never, EVER heard this truck ping (unlike nearly every non-turbo vehicle I've owned or driven in the last ~15-20 years, which all seem to ping on purpose). That doesn't mean it isn't, though.

If you know of more up-to-date explanations or pictorials on the topic, I'd be interested to read them.