Passenger side cylinders not firing. Ideas?

[T.J.]

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92697

 

and

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93547

 

Still need to go get them.

 

Thanks, T.J.

[T.J.]

When testing it is best to leave all the plugs in except the one you are working on, unless you want to see if there is a leak between the cylinders. We aren't concerned about that though. By cranking the engine a few seconds you should top out the gauge for a reading. I think you should see somewhere around 165-185 lbs normally but I'm just guessing. All cylinders should be within 10 lbs of each other if things are good.

 

So, should I at least disconnect the plug wires so the engine doesn't start?

[nipper]

So, should I at least disconnect the plug wires so the engine doesn't start?

 

hehehehe starting a bad bad thing

 

Also be alert for OWOWOWOW as the engine cranks

 

(sparks from the cables)

 

 

nipper

[Cougar]

Thanks for catching that about the ignition guys. I wasn't thinking about that. Perhaps the best thing to do is disconnect the wiring to the coil packs. This way there is no danger of allowing the high voltage to buildup more than it should since the plugs will be disconnected.

[nipper]

Thanks for catching that about the ignition guys. I wasn't thinking about that. Perhaps the best thing to do is disconnect the wiring to the coil packs. This way there is no danger of allowing the high voltage to buildup more than it should since the plugs will be disconnected.

 

Just remove the plug wires.

 

I would also like to see a compression test with all the plugs out. i havent ruled anything out yet.

 

nipper

[OB99W]

You might want to electrically disconnect the fuel injectors as well. Gas can wash oil off the cylinder walls, making compression testing inaccurate.

[frag]

Manual underhood starters are cheap (and can be home made easily) and are the best way of making a compression check without having any spark or fuel problem.

[Cougar]

Very good point Frag.

[T.J.]

Big news! I think...

 

Here are the results from the Vacuum guage:

 

50cmHg (or about 20in.Hg) steady vacuum on drivers side manifold measured from the brake cyl. hose. This is in the green zone on the guage, indicating "normal motor".

 

35-40cmHg (or about 13-16in.Hg) oscillating vacuum on the passenger side of the intake manifold measured from the fuel pressure regulator hose (smaller diameter). This is in the small red zone on the guage indicating "late ignition timing".

 

 

Now for the compression guage (in psi) w/ plugs in:

Cyl #1= 91

2= 180

3= 89

4= 200

 

W/ all plugs removed:

Cyl #1= 80

2= 179

3= 89

4= 198

 

Both guages are pretty vague so all numbers are approximate.

 

So the passenger side seems to have less vacuum and the needle oscillates w/ the rpm of the engine instead of being steady. I'm not sure if this is indicative of the problem or merely a result of the lack of compression and or combustion.

 

The passenger side cylinders are indeed significantly down on compression. It is also a little odd that the #1 cylinder dropped about 10psi w/ all of the plugs removed while the other cylinders appeared to lose a couple psi or less.

 

I performed all of the tests multiple times and the numbers were consistant. I can't speak to the accuracy of this guage but the results were repeatable.

 

So maybe the loose timing belt theory has legs? Anything jump out at you guys?

 

Thanks, T.J.

 

OT: wOOt for getting advice from NY and AK. The internet rocks.

[2X2KOB]

My gut feeling (aside from the burrito) is cam timing. Or a horribly failed head gasket, which is very unlikely as they don't generally fail in that mode.

 

Can you check the cam sprocket alignment marks?

[T.J.]

Are those under the timing belt cover? It looks like I would need to remove the radiator to check those in which case I will get to see if the timing belt tensioner is loose.

 

I don't have a garage or means of removing the engine. If it comes to that I will likely take it to a mechanic.

 

T.J.

[2X2KOB]

No, you can do a full timing belt change without removing the radiator. You should be able to verify cam timing by the marks without draining the cooling system.

[T.J.]

Edit: Ignore. I just put 2and2 together.

 

Thanks, T.J.

[2X2KOB]

Edit: Splain.

 

K,thx,bye.

[nipper]

Big news! I think...

 

Here are the results from the Vacuum guage:

 

50cmHg (or about 20in.Hg) steady vacuum on drivers side manifold measured from the brake cyl. hose. This is in the green zone on the guage, indicating "normal motor".

 

35-40cmHg (or about 13-16in.Hg) oscillating vacuum on the passenger side of the intake manifold measured from the fuel pressure regulator hose (smaller diameter). This is in the small red zone on the guage indicating "late ignition timing".

 

 

Now for the compression guage (in psi) w/ plugs in:

Cyl #1= 91

2= 180

3= 89

4= 200

 

W/ all plugs removed:

Cyl #1= 80

2= 179

3= 89

4= 198

 

Both guages are pretty vague so all numbers are approximate.

 

So the passenger side seems to have less vacuum and the needle oscillates w/ the rpm of the engine instead of being steady. I'm not sure if this is indicative of the problem or merely a result of the lack of compression and or combustion.

 

The passenger side cylinders are indeed significantly down on compression. It is also a little odd that the #1 cylinder dropped about 10psi w/ all of the plugs removed while the other cylinders appeared to lose a couple psi or less.

 

I performed all of the tests multiple times and the numbers were consistant. I can't speak to the accuracy of this guage but the results were repeatable.

 

So maybe the loose timing belt theory has legs? Anything jump out at you guys?

 

Thanks, T.J.

 

OT: wOOt for getting advice from NY and AK. The internet rocks.

 

The 10psi drop is telling you that you have a HG issue. That the HG is leaking into the other cylinder.

 

No one has mentioned a wet compression test, but i think that would only confirm the fact that the head has to come off.

 

On the vacume gauge, not only is the reading important, what the needle is doing is also important.

 

http://www.international-auto.com/index.cfm?fa=ad&aid=47

 

nipper

[Cougar]

Sorry to hear about leak. It isn't real bad but it should be fixed.

[nipper]

The 10psi drop is telling you that you have a HG issue. That the HG is leaking into the other cylinder.

 

No one has mentioned a wet compression test, but i think that would only confirm the fact that the head has to come off.

 

On the vacume gauge, not only is the reading important, what the needle is doing is also important.

 

http://www.international-auto.com/index.cfm?fa=ad&aid=47

 

nipper

 

This is my PS:

(sorry just got back in from the movies) Still check the timing. Also 200 is awfully high. You may have the beginings of an HG issue, you may have a jumped timing belt. Check the timing first before doing anything else.

 

nipper

[T.J.]

Thanks again for the help guys. I will look into checking the timing myself and go from there.

 

T.J.

[BoostedBalls]

I'm thinking timing belt. Maybe you lost a seal and the belt got oily, that happened to my 93 legacy once.

I usually leave the covers off after doing a belt replacement, helps a lot in troubleshooting later on.

[T.J.]

I'm thinking timing belt. Maybe you lost a seal and the belt got oily, that happened to my 93 legacy once.

I usually leave the covers off after doing a belt replacement, helps a lot in troubleshooting later on.

 

Yeah. By the sound of it, it would be nice if it were the timing. I was just looking up how to tell if the timing is off. Will it be obvious when I can see the belt? Are there marks on the crank sprocket and cam sprockets?

 

Really? Leaving the cover off wouldn't make it suseptable to debris?

 

Thanks, T.J.

[nipper]

Leaving the covers off are only a problem if your going to drive in snow.

 

You just need to line the marks and you can tell if they are off or not.

 

Which leads to the question how old is the belt and tensioner/idler ?

 

nipper

[T.J.]

I drive in snow. It's one of the main reasons we drive Subarus.

 

Again, I bought the car used but as far as I know everything has about 50,000 miles on it.

 

Thanks, T.J.

[T.J.]

SUCCESS!

 

First off, a big thanks to everyone who read this thread in an attempt to help me out, whether or not you were able to contribute. It was very much appreciated.

 

An the cookie goes to (drum roll).....

 

Cougar for suggesting on page 2 (in his first post!) that the cam timing may be off on one side of the engine. Nice call!

 

Story:

I finally got around to removing the timing belt cover last weekend and the first thing I noticed was a little piece of plastic that fell out as I removed it. It looked like it had been chewed up a bit. The next thing to jump out at me was the large hole in the timing belt that was almost half the width of the belt.

 

Next I checked the timing and sure enough, the passenger side was off by 3 or 4 teeth. Great, problem found! At this point I decided I was going to take it in to richierich to have him fix it right and make sure there were no other associated problems. He is a member of this board, professional mechanic, and an all-around good guy. Two of my friends have had work done at his shop per my recommendation. However, I called him back because it occured to me that if my 1/2 timing belt snapped as I limped the car 20 or so miles to his shop it would probably ruin the engine. He not only confermed that it would be better for me to do it where it sat, but he even gave me some helpful tips on the procedure before letting me off of the phone. Thanks again Richie!

 

Replacing the belt was very straight forward and went smoothly. As I was reassembling the cover I noticed a small piece of threaded aluminum embedded in the side of it! It turned out to be a part of one of the bolt holes for one of the upper timing belt cover bolts. Soooooo I have concluded that...

 

Cliff notes: Previous owners got metal debris inside timing belt cover which eventually got into the teeth of the timing belt causeing it to skip on the passenger side cam gear. Said debris then burst through the timing belt and lodged itself in the timing belt cover. Mystery solved.

 

I now have about 180 psi. of compression on all cylinders and the car is totally reassembled. I had to wait untill today to pick up the timing belt guide that was conspicuously missing the first time I removed the cover.

 

I now have an idea of what to look formard to when I replace the t-belt on my Impreza, I have more tools than I did before and the Forester is once again purring like the lumpy Subaru it is.:burnout::burnout:

 

Thanks again everyone, T.J.

 

Here is a picture of the damaged belt and the debris that did it:

[OB99W]

SUCCESS![...]

:clap: for both T.J. and Cougar!

[T.J.]

Indeed.

 

I saved a couple hundred bucks on the installation alone, plus whatever it would have cost to get the problem diagnosed in the first place. $$$$

 

T.J.