2000 Legacy Head Gasket Sympton

[chilli]

Last night my 2000 Legacy GT with the SOHC 2.5 litre phase II engine began to run very rough and had no power.

The check engine light then came on and stayed on until I made it home.

I plugged in my code reader and it revealed a misfire at the number 4 cylinder,at which point I removed the number 4 sparkplug wire and found the boot to be covered in what looked to be engine oil.

Once the engine cooled I removed the sparkplug and there was no evidence of fouling.

Is this a sign of an external head gasket leak that I have heard so much about or could it be something else ?

I plan on changing spark plugs and wires and see if that helps. Any other suggestions ?

The car has 62000 miles on it and has had no other problems .... love the car.

[Cougar]

Hopefully the misfire was just due to the oil on the plug. If cleaning up the plug and wire doesn't help you may want to try new plugs. I would recommend NGK's if you do change them.

 

You can also have a block check done to see if exhaust gases are getting into the coolant. It is a inexpensive test to do and you will know if it really is a problem or not. If this happens again and you can pull over to a safe area, you could try looking for spark jumping to ground from a bad spot in the ignition.

 

There are other things that could cause this problem like the MAF sensor or TPS but hopefully you won't have to go there.

[soobynooby]

I've got a similar problem with a 2000 OBW (2.5 SOHC). The check engine light is on. The codes are O2 sensor and cylinder 4 misfire. It idles rough, but runs smoothly when you give it some gas. A compression test shows that the #4 cylinder is low. It's in the shop, but they won't get around to it till next week. I'll keep you posted. My engine has no signs of an external leak.

[brus brother]

I have the same oil in the spark plug hole and have been told that there are O-rings that need to be replaced. Too bad this discovery appears 2K miles past 60K warranty!

My 2000GT was running like crap until I replaced the spark plugs. SOA does recommend the wires at 60K as well but I just did the plugs. Remarkable difference. You can get the NGK plugs from 1stsubaruparts.com (aka Liberty Subaru in N.J.) for $2.09US a piece. Get you order together and save on shipping by combining items. You might have some more local discounters in Canada.

BTW I understand there are some 55,000,000 US voters looking for safe haven in Canada.

[gorka]

about sparkplugs for this type of car personal recomendation --------- NGK with "V' shape. i using this type for my 3rd subaru never ever any problem of this kind

[friendly_jacek]

Since the thread was revived, what was the outcome of these cars with oily spark plugs?

I'm curious because i have 00, too.

[richierich]

The spark plug wires go through the valve cover. There are spark plug grommets that are suppose to keep the oil off of the plug wires and the plugs. The grommets get hard and they start to seep oil onto the wires.

 

The Valve covers need to come off and replace the spark plug grommets, and should replace the valve cover gaskets as well as the valve cover grommets, and new spark plug wire (cheap from the dealership than aftermarket, btw) and spark plugs if it is time.

[friendly_jacek]

Thanks!

Totally makes sense. When I read the post the first time, i thought it was internal plug fouling.

[brus brother]

Richierich,

You seem to be spot on with the diagnosis and remedy. My grommets were replaced under warranty. Are the grommets an updated version or do you see this as an ongoing but otherwise routine maintenance issue?

The spark plug wires go through the valve cover. There are spark plug grommets that are suppose to keep the oil off of the plug wires and the plugs. The grommets get hard and they start to seep oil onto the wires.

 

The Valve covers need to come off and replace the spark plug grommets, and should replace the valve cover gaskets as well as the valve cover grommets, and new spark plug wire (cheap from the dealership than aftermarket, btw) and spark plugs if it is time.

[Dusza Beben]

Hi all, I'm glad I found this site! I have a '00 Outback Limited that I've put 265,000 miles on and I experienced this problem as well. After several sets of spark plugs and wires (thinking that was the problem) I decided I'd had enough and on closer inspection noticed the oil inside the boot. I thoroughly cleaned out the plug boots and installed new plugs. Before putting the boots back on I coated the inside of the open end of the boot with dielectric grease. (Dow-4 is what I use) and I haven't had a problem since! The dielectric grease, also called vapor proofing compound, is essentially pure silicone in paste form and it seems to do an excellent job of conditioning the boots and sealing out oil. Not too long winded I hope for my first post

 

DB

[richierich]

I do not believe they are updated. I have seen no signs of change in part #. Usually I see it about 80-100k miles, or 5 years old. After we replace the spark plug grommet, etc I have seen no comebacks, but they don't have more than 40k miles on any of the ones we have done, so I guess time will tell. The grommets just seem to get hard and brittle.

 

Dusza Beben, you just seem to be masking the problem. You have an external oil leak, even if you can not see it unless you pull off the plug wires. Someday it might get bad enough to fill up the spark plug well with oil. I recommend you fix the cause of the problem, not just the symptoms. Though the grease on the spark plug wires are not a bad idea against future problems.