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Comments
-Brian
Cheers Pat.
would it cause a throttle problem like I attempted to describe though? it revs OK, just stumbles at tip-in.
-Colin
Ken
I am still inclined to think valve timing,though it does not seem to be off by much,obviously this being my first sube I don,t have a lot of experience with the boxer engine it is alot simpler to time an I4 engine, although timing is timing.
In this case Colin I would love to be proved wrong although everything points to timing,given how you went about aligning the marks makes me believe that you ended up one tooth out and thats what is giving you the stumble as opposed to an all out misfire.
Cheers Pat.
10-15 degrees is alot in advance terms, isn't it? does it pre-detonate at all with some load & throttle?
when revving, does it stumble and then gradually increase revs, or does it stumble and then catch up to where it should be revving at?
-Brian (probably thinks he knows more than he actually does)
So, you could sync the two pulleys that do settle at TDC, and then rotate them with the belt until they are in phase with the stubborn pulley (wherever it wants to sit). If the pully doesn't want to go to the mountain, bring the mountain to the pulley!
Craig
I played with my Miata's timing recently. Stock setup is 10 degrees before TDC. I advanced the timing to 14 degrees, because Mazda was very conservative, and you gain a little low end torque that way.
Some owners go as far as 18 degrees, but then premium fuel is needed. So a change of 8 degrees requires the use of premium fuel.
-juice
I agree with Pat's diagnosis and will set the timing again, using Craig's suggestion if necessary. (Good idea Craig! Should have been standing there in my garage at the time, lol.)
Feel a little better today and am back at work but didn't do anything last night with the car due to the flu.
-Colin
Bottom line, you should be able to turn the crank pulley and verify that everything lines up at TDC with the belt on. If that's the case, I would dismiss valve timing as an issue.
Brian, Juice: I think we are beginning to confuse spark timing and cam timing here. Colin's issue pertains to synching the cams and the crank for proer intake/exhaust valve timing, which is entirely different from when you tell the plugs to fire. With bad spark timing, you lose performance and get into issues like pre-detonation. With bad valve timing, the engine probably won't run at all, and you could cause major damage if the piston and valves collide (older Hondas are famous for this).
Craig
Could the belt have slipped, so all the marks are off? Sounds like some of them lined up, though.
-juice
that was the thinking on the white-out marks, that even though the LH cam wouldn't stay at TDC it was in the right place. (still don't know why, I seem to recall it did last year when I last had the belt off.)
anyway, several rotations of the engine still didn't result in the two cams lining up at their TDC marks. I think I should work to that goal and get the crankshaft at TDC on piston #1 and then I'm in business.
-Colin
Thanks for the explanation Craig (and pardon my rambling postings Colin). That makes sense. If the cam timing was off, the engine wouldn't sound normal, would it? At least it wouldn't be running smoothly like it should?
So, what else could cause a initial stumble like Colin's?
-Brian
I'm so thankful to have this community of real people (as opposed to sales & service folk) to get some opinions from! The Questions:
1. Gas grade. 90% of my driving will be stop & go & freeway driving (Bay Area Cal). I usually gas up at Costco but now that I have a vehicle I actually care about I'm wondering about the rumours that Costco gas is poor quality so I question putting their regular in the Subie. I was thinking mixing 1/2 - 1/2 reg & super each fill up. The dealer said mid grade was fine but use premium in the mountains.
2. Alignment. Re: the rumour that new subie's often come with poor alignment. It feels ok to me, but what do I know? (not much) Is it worth having the alignment checked?
3. Tire Pressure. I'll check it today (when I find my guage, which is in one of the piles of stuff taken from my old van & not sorted yet)
I'm sure this has all been discussed to death before, but I don't have the leisure to check all 3,700 messages here - a nice little search program would sure be a blessing!
Thanks all - hope to see you in the mountains before too long!
Jillian
If it ain't broke, don't fix the alignment. It is tricky to get right with AWD, but if it's not pulling to one side I say leave it be.
I've heard some people report they bought cars with 40psi pumped in the tires. That's to avoid flat spotting while they sit in the dealer's lot, but they are supposed to air them down during the PDI (pre-delivery inspection). If not, go ahead, 30-33psi is good depending on how soft or sporty you want your ride to be.
Congrats! I'm a little jealous, and I'm trying to talk the wife into a Bean, too.
-juice
Brian: I didn't think we needed disclaimers here, otherwise I'd have to tag ALL my posts with them!!
Jillian: If the H6 calls for premium, why not just use that all the time? Though you won't really hurt the engine, you will lose a little power. I'm just going to stick with premium in my Bean.
My Bean drives nice, and seems to be aligned correctly. I can't say the same for my first Outback, which was misaligned from the get-go. If your Bean seems OK, the alignment is probably fine. It's pretty obvious when it's bad.
Definitely check the tire pressure. My first Subaru was delivered with 35 psi in the tires, and the new Bean was set to 32 psi all around. I usually stick to the recommended 30F/29R inflation, or slightly higher, being careful to maintain that 1 psi difference front to back.
Craig
It was a peice of cake with the engine out of the car, but I imagine a real hassle if it wasn't.
Basically you have to get the cam gears and the crank gear turned so that the marks on the frontside of them are pointing directly up, then you have to find the marks on the new timing belt, find the mark that is in-between teeth instead of on them, then put that one on the driver's side cam mark and run the rest of it through the rest of the path - hopefully with marks all aligning. If they don't align, something is wrong.
Keep in mind that to get it off in the first place you have to remove the fans off the radiator (allow better clearance), the crank pulley and all belts, the front timing cover (lots of 10mm bolts along the edges), and then you need to pin the timing belt tensioner in it's most closed position (you can push it by hand to get it there), then remove the small cover over the timing belt where it runs on the crank gear.
Also note that the vertical position in the driver's side cam gear is when valves are open - so you need to muscle it up into position with an open-end wrench, and then prop it so that it is marked upwards - should be exactly when the valves are 100% open, so it should hold itself there without much problem.
With proper tools, I could probably do it in about an hour to hour and a half - but only because I've done it before.
Also note that this is for a MY00, though I believe it's the same for all SOHC engines, I would consult a manual for sure before undertaking this yourself.
talked to my dad about it and he remembers muscling the LH cam sprocket into position! he was busy with other things this weekend and stayed nice and clean while we toiled away.
-Colin
Greg
Greg
-Colin
I use only premium and lately, have been tanking up with BJ's Wholesale Club fuel. Like Costco, I doubt these "clubs" would try to use less than a fair grade of gas. The negative publicity would certainly damage their reputations. With premium and just over 11k miles, I average between 21-23 mpg in mixed driving, mainly of the city variety.
Congrats on the purchase and best of luck with the LL Bean!
Don
Well anybody who does a head job on a Subie in situ without removing the engine also has to be respected, my hat is off to you my friend, I would have pulled the motor.
Craig you beat me to it with explanation of the difference between valve and ignition timing.
For Brian and juice what causes detoanation or the more common term pinging, is to much advance in the ignition timing causes the mixture to light off when the piston is on the way up instead of in the combustion chamber, you can imagine the explosion is trying to force the piston back down.
You have an irristable force meeting an immovable object that is why detonation can wreck pistons and bearings.
Valve timing on the other hand is timing the intake and exhaust valves opening and closing in sequence.as well obviously the valve and ignition timing are interdependant.
Cheers Pat.
Pat: I'm familiar with ignition timing, as I've played with it a bit on my Miata, but had to eat a little humble pie when it came to valve timing.
Installing a K&N filter element is as easy as replacing the paper air filter. I have photos but PhotoPoint is down, sorry. It's easier if you take part of the intake apart, but that's just a couple of nuts and bolts, an electrical connected to the MAS to unplug, and a vacuum hose underneath to disconnect. It's easier than it sounds, put it that way.
-juice
btw, the head torquing procedure just for fun-- committed it to memory.
1) torque all bolts (6) in alphabetic order to 22ft-lb (A is center top, B is center bottom, C is front top, D is rear bottom, E is front bottom, F is rear top.)
2) torque all bolts in alphabetic order to 51ft-lb
3) loosen all bolts 180 degrees in order
4) loosen all bolts additional 180 degrees in order
5) tighten A and B in order to 22lb-ft
6) tighten C-F in order to 11lb-ft
7) tighten all bolts in order 80-90 degrees
8) tighten all bolts in order an additional 80-90 degrees, but no more than 180 deg total
I believe the idea here by specifying a number of degrees to turn that they know not only torque but also thread depth. But I'm not a mechanical engineer-- maybe they just liked being difficult. ;-)
-Colin
9) do the hokey-pokey and turn yourself around
Man, talk about jumping through hoops!
-juice
actually, it kind of makes sense - it makes sure the head is on straight and even. (doesn't it?)
hopefully your dad will be able to coax that pesky cam into place!
-Brian
BTW. speaking of dementia, in my mispent youth it was not the first time a couple of mates and myself hauled an engineout in a snowbank, using ropes and idiot manpower no hoist.
We would probably haul it out after work on a Friday dismantle it on my poor mothers living room floor, Saturday the block and crankshaft to machine shop for a rebore and regrind.
While waiting for that dismantle the head and lap the valves using handpower and grinding paste, Sunday put the whole lot back together and drive it to work on Monday.
Cheers Pat.
That article verifies that the right side cam lobes are "relaxed", and the left side under pressure, when things are lined up correctly.
They gave part numbers for tools to hold things in place, before things come apart, because the left side will rotate all by itself.
Regards,
Frank
since this car is SOHC, I need only to lever the LH cam gear into a TDC position.
-Colin
http://www.motor.com/MAGAZINE/Articles/112001_08.html
Well, he died, may he rest in peace.
Unfortunately, however, they're having a devil of a time keeping him in the casket!
(hint: sing the song!)
Cheers!
Paul
Ross
-Colin
-Colin
but I still tripped the MIL right after starting up. still have the near-normal idle, and still have the stumble when you tip into the throttle off idle.
however I think I know what it is. look at this pic, taken after 15-20 minutes of engine running and over 10 minutes of moderate to hard driving. (yes the car runs quite well for that sort of stuff.)
So besides the fact I can't hold my camera completely still to get a good low-light pic, what do you see?
No water temperature. The engine is most definitely not cold, and the heat works fine because I tried. I'm fully aware of the dangers of driving with the car this way-- the fans are going full tilt all the time and it wouldn't surprise me if the thermostat is full open as well.
So where is the coolant temp sensor on a SOHC EJ25? I bet it's unplugged, and I bet it's on the intake manifold in an inconvenient place. Could be on/near the radiator too, pulled that to make work a little easier.
-Colin
http://www.imagestation.com/album/?id=4292183933
sorry about the duplicate pic, and they are mostly in reverse order, lol. I put some time into the captions though! hope you enjoy.
-Colin
All that said his opinion is to be careful where you get your super unleaded and premium and that just because the sign says Exxon, Texaco, etc doesn't mean the owner is honest about the grade of gas he is selling.
Remember that all the advertised brand name detergents are additives to the gas after refining and not a quality of gas.
the ECU probably is going crazy trying to figure out the engine temp. but, it's idling at the normal warm idle, so that part is working (or at least it appears to this novice). doesn't it take engine temp into consideration for fuel mixture?
Is that a bit of carbon in them heads?
-Brian (thanks for bear-ing with my ramblings)
For normally aspirated engines, you could get headers, a bigger cat, a cat-back exhaust, an intake kit, low restriction air filters, or an underdrive pulley. But the gains are minor.
Colin: how did you port the heads? What tool did you use? I'm just curious, I don't think I'd ever go that far into my engine.
-juice
Wow.... I have done heads on Fords, Datsuns & Toyotas. All had simple sequence and torque specs (lb-ft), with no 'song & dance' attached. I got lost somewhere in the jig - so what do you think the final value is? The initial compression and release crushed down the gasket some, so I wonder what it ends up being. The sad part is that probably no aftermarket shop would have the patience to do it right, compromising the job if this is indeed critical to final gasket seal.
Just a comment on the discussion of valve vs. ignition timing. I believe most conventional distributor type ignitions are camshaft driven - either direct engagement or by offset gear. But 'distributorless' systems may use a crankshaft position sensor to time ignition. Thus, depending on the type, a jumped or mis-positioned timing belt/chain can affect both valve and ignition, or just valve timing. That can make diagnosis by feel and ear more difficult, requiring pulling the cover and actual inspection.
I once had an engine rebuild (in my younger days) that drove me crazy for weeks. Usually the negative battery terminal is tied to the block, and a secondary wire comes off the block or head and connects to the body. We accidentally left off the head-to-body wire. Without it, the return path for body mounted electricals is thru CV/universal joints and other poor conductors. Had all sorts of problems related to drivability and accessories, especially when the draw was high. The alternator was not getting proper feedback from the externally mounted regulator, and was running wild. Higher than normal voltage replaced adequate current. Finally figured it out when I measured between block and body and got a voltage (should have been 0v - common ground)! It is always the dumb things that kill an otherwise well done job......
Steve
juice, used a right angle grinder (air version-- electric ones aren't nearly as good IMO) and two different cutting / grinding tips. my dad actually did it last year when I install the cobb tuning cams and the heads were off the first time. anyway, where you see the grinding in the center of the port there was a lot of casting flash. built a plastic model? well you know how some parts have little extra pieces of plastic on the edges? same type of thing, this cylinder head started out life as two cast halves.
steve, funny you should ask about the final torque valve. my friend and I were curious so even though we weren't stopping based on torque, we set the torque wrench to find out when it would break over. turns out, the center two head bolts are installed with somewhere around 60-65ft/lb and the outer ones around 50.
good job on clarifying ignition on distributorless engines-- I didn't do such a good job the other day and didn't elaborate. but you are correct, since the cam angle sensor (CAS) is in the LH head and I had it 180 degrees out of phase, the intake timing was also 180 degrees out of phase. strange that the engine ran well, must be thanks to the even firing sequence of the boxer four. obviously no matter what the reason that was a serious mistake that needed to be corrected.
-Colin
-juice
The problem would almost always go away after stopping the car for a while (usually overnight) but has returned every few weeks. I switched to premium gas from a different station, still does it. I took the car to the dealer and they couldn't reproduce the problem. The Check engine light has never come on, so they didn't know where to start. They checked for loose wires/hoses and ended up changing the Champion spark plugs which they said were "fouled out". Two days later, the problem returned.
Any theories on what might be causing this? I'm taking it back in and I'd love to hear if this problem has happened to anyone else. It seems to be happening more frequently in the last 2-3 weeks.
-Al
I'm thinking ECU, not plugs. Ask if the service manager will take a ride with you so you can show him the problem. Of course it's interemittent so Murphy's Law means it won't happen then.
-juice
The problem would almost always go away after stopping the car for a while (usually overnight) but has returned every few weeks. I switched to premium gas from a different station, still does it. I took the car to the dealer and they couldn't reproduce the problem. The Check engine light has never come on, so they didn't know where to start. They checked for loose wires/hoses and ended up changing the Champion spark plugs which they said were "fouled out". Two days later, the problem returned.
Any theories on what might be causing this? I'm taking it back in and I'd love to hear if this problem has happened to anyone else. It seems to be happening more frequently in the last 2-3 weeks.
-Al
fouled plugs means the mix is too rich at idle. major things that can cause that would trigger the malfunction indicator light though... but still, I would first check the first oxygen sensor and check that the catalysts are not clogged.
-Colin
Sounds like you're almost there in getting your vehicle back to normal. I echo Steve's comments about having admiration for your technical expertise! I've learned a lot from just reading your posts here at Edmunds.
Good luck!
Ken
-juice