Engine hesitation

[slbert]

Hey Ya'll,
New to the form....it looks great.
Anyway, have a 2002 Outback, 2.5l, 115,000 miles (bought used at 90K). Love the way it drives, handles etc. It started to hesitate under load....acceleration, going up hills, but fine on the flat. A code has been thrown at me, but my reader is at a friends place. It felt like the front O2 sensor, or fuel filter (replaced both, car is slightly better) Could be some bad gas (my wife has been filling up at a discount place for a while....good gas seems to have helped, as has an injection cleaner) Anyway, started to look at the plugs. Pulled off the one by the battery, and oil leaked out....does this mean that plug seal is gone? If I am replacing it, should I do the HG on that side at the same time (as it seems there is history of problems with that) Would the oil leak cause a code to be thrown?
Many thanx for any input.
Steve

[porcupine73]

Hello slbert and and to the board! The best place to start would be getting the code(s) read.

Quote: started to look at the plugs. Pulled off the one by the battery, and oil leaked out....does this mean that plug seal is gone?
That generally means the spark plug tube seal is leaking. They're underneath the valve cover and tend to compress with age, allowing some oil to leak into the spark plug tubes. To replace them, the valve covers have to come off, which means you also need valve cover gaskets and valve cover bolt hole washers.


Quote: Would the oil leak cause a code to be thrown?
Sometimes if it is enough oil leaking in there it can cause cylinder misfire codes. Did your CEL flash at all? For misfire it usually flashes for a while then goes on solid.

Knock sensor would be another thing to look at that could cause symptoms you describe.

Spark plugs should be NGK. Spark plug wires should be OEM wires from a Subaru dealer. Soobs sometimes misfire on anything else. For oem parts, you can get them for much less than a typical dealer walkin by buying from Subaru dealers who sell parts online. There are dozens, i.e. www.subarupartsforyou.com www.subarugenuineparts.com www.subaru-parts-dealer.com www.subaruparts.com etc

(re: spark plug tube seals) Quote: I do the HG on that side at the same time (as it seems there is history of problems with that)The engine doesn't have to come out or the heads come off to do the spark plug tube seals; just the valve cover. To do HG's typically the engine would be pulled, though people sometimes do them without pulling the engine.

The bigger question would be...If you have not had the timing belt replaced yet, it is overdue. This is an interference engine so if the timing belt breaks it will likely bend valves and possibly ding pistons.

When doing the timing belt, there are a number of things that are smart to replace at the same time, such as water pump and gasket, front crank seal, reseal oil pump&replace discharge o-ring, replace geared/toothed idler near water pump and check other idlers, replace front cam seals. Also valve clearance is due for inspection&adjustment.

So, if the timing belt hasn't been done, and you wanted to do the whole deal in one shot, you might opt to have the HG's replaced while all that work is done. Much of that work is easier to do with the engine out. And if it's a manual trans you can check the clutch at that time too.

Subaru OEM parts in general are pretty good quality, so I would stick with OEM as much as possible. The OEM HG issue was fixed ~03 so new stock OEM HG's would be the way to go there too. Replacing HG's requires a few key steps to be successful, such as milling the heads, ensuring proper surface finish, proper cleaning, proper head bolt tightening sequence and torque, etc.

[slbert]

Hi Again,
Thanx for the fast reply.
Yes I need to do the timing belt....didn't think of the other things to go along with it. The engine light does blink at me when the car is doing it's hesitation thing, but returns to just "on" when it is running smoothly.
I am reasonably handy with cars, but have the issues of time (being employed in other then being a mechanic), and the need of the car being out of commission for as short a period as possible.
I might get stuck taking it to a Subaru dealer 'cause they have the parts on hand and hopefully be able to do it expediently. If I can escape without doing the HG, I'd prefer that.
Later,
Steve

[porcupine73]

Sounds like misfire then, typically right when misfire is detected the CEL flashes for a while then stays on solid. There's some other codes that flash too.

If you work it out with the dealer ahead of time then they can be sure to have all the parts in stock that are needed. Everything on the list other than the HG's can be done pretty easily without pulling the engine.

If you're looking to save some $$, since you're in Toronto, I'd look for an indy shop Nile Jenkins site, or e-mail him and he'll know who's good in that area. Then you could probably order all your OEM parts from a US dealer who ships to Canada via usps (to save on shipping/brokerage costs) and just have the indy shop install them.

[slbert]

Thank-you again.
I have decided to do this myself....we'll live without the vehicle for a few days. Is there a good resource you recommend....ie chiltons, or Haynes?. I figure I'll do the plug seals first, to get the thing back drivable (probably getting the parts from the dealer, seals, gaskets, etc, as you listed) then get the timing belt and bits, on-line (or ebay).
Another newbie question....the oil filter tube runs in the valve cover.....do I need to drain the oil first, or is it low enough i don't need to worry about it?
Later,
Steve

[porcupine73]

No need to drain the oil to do the valve cover gaskets. A very small amount will drip out but not much.

There are good free articles on www.endwrench.com about how to do the timing belt and lots of other tasks:

T-Belt Time: All About Subaru OHC Timing Belts

Step-by-Step: Timing Belt Inspection and Replacement (this is for a 2.5L dohc; the sohc you have is easier).

There are some tricks to getting around some of the special service tools they list, i.e. if you have a manual trans put 'er in fifth and set the parking brake when loosening the crank pulley bolt.

The main tips are align all timing marks per the procedure before removing the old belt. This way no piston is near tdc, so you won't risk bumping the valves into the pistons as long as you don't turn the crank too far with the belt removed.

The timing belt must be aligned dead on, one tooth off and it will start but run poorly and lack power. Two teeth off and it won't start.

A big benefit of an OEM timing belt is the timing marks on the belt are dead on. Aftermarket belts sometimes the marks aren't in the right spots.

Subaru Valve Train Service

I would do the timing belt, water pump, tensioners, etc, first, then put it back together but leave the LH timing cover off. Then make sure the engine starts and runs correctly. Then let engine cool completely, then remove the valve covers to do the spark plug hole seals, and check&adjust the valve lash at that time.

[slbert]

Hey,
Got my reader. Only P0301 and 304. So misfiring on 2 cylinders. I'll look at the plugs and start to do the necessary things tomorrow morning. It might have been some very bad gas, as my wife had been consistently filling up at the same "cheap" gas bar.
Later,
Steve

[slbert]

Hey Porqupine,
Changed my valve covers, tube seals, wires and plugs today. Plugs 1 & 4 were both pretty bad. Looks like the previous owner had Champion plugs put in. It now drives like the beast I remember when we first got it.
Many thanx for your input.
Now I'll shop for a timing belt and all those things you mentioned and do it on my own.
Later,
Steve