This is mainly a question for the Subie techs around here or anybody particularly familiar with the 3.0. So, I just had all three cats on my 09 Legacy 3.0R replaced under warranty at Morrie's Minnetonka. (They took good care of me, BTW. Good experience. Thanks, guys.) The odd thing is, these failed at 24k. One was actually breaking apart. I am reading up on what may have caused this and have found lots of different possibilities. If anybody has ideas on what to check, please share them! The question I have for the moment, however: I just changed the oil in the 3.0. (I've had the car less than a month and I don't know what crappy oil was put in there, so I changed it for peace of mind and put some Rotella T-6 in.) When I was changing it, I noticed a noticeable fuel odor both from the oil and especially on the oil cap. I thought this may be a product of the testing Morrie's needed to do after installing the new cats so didn't think much of it. Oil was warm when changing. I did not see a rainbow sheen of fuel in the drain pan. Anyway, I've put maybe 100-150 miles on this oil now. After a 40 mile drive home last night, I decided to sniff the oil cap when I got home. I smelled fuel again. Am I correct in thinking after a longish drive, it should have burned off? Do the 3.0 motors have fuel dilution issues? A few people on BITOG seem to think so. I've never noticed a fuel odor like this on any other car I've had. I've got a Blackstone kit on the way to check the oil in the motor after a month or two. Any thoughts would be appreciated. Thanks much.
What kind of mileage are you getting?? Is it compareable to what other people get and the window sticker?? Usually when you smell gas in the oil is when the cylinders are getting washed down with too much fuel. By time that happens, you are going to be getting some crappy mileage. If you are washing down the cylinders, I would start to quickly figure out what is going on. I would be checking fuel pressure to make sure the regulator is working properly. Once you start getting fuel in the oil, the oil will thin out to the point where a new motor will be needed. Russ
Hey, Russ. Mileage is actually pretty good. I'm averaging (according to the mileage readout) at or above highway rating.
And, yes, I know I should take that reading with a grain of salt. I need to burn through a tank or two and average them manually.
I haven't seen any problems with over fueling, nor have I even seen a 3.0L engine fail due to something other than neglect. It is possible that you have a faulty front A/F sensor in one or both banks causing a tad bit of a rich condition. If it was as bad as you're making it sound, and getting raw fuel into the crankcase, then it should be mis-firing from the rich condition, or the ECM would set a CEL for a system too rich code. I have seen a few A/F sensor failures, and maybe even one or two rear 02 Sensor's go. If the post cat sensor is showing a lean condition, that bank may be slightly adding fuel which could be an issue causing catalyst failure at a premature rate.
Thanks for the reply. I have not heard any misfires or detonation. (doesn't mean it's not happening) No further CEL after the cats were replaced. As far as neglect goes, maintenance records on the carfax from the previous owner show approx. ever 3000 the vehicle was 'serviced' at the dealer. I ASSUME these are oil changes, but I have no way of knowing for certain. I haven't had it long enough to neglect it, personally. All I know is the cats were bad at 24k and I smell fuel when I smell the oil cap after driving. What do you think? Is the smell of fuel in the oil, even after a fresh oil change, enough to have it diagnosed under warranty?
It would be nice to see an oil sample from it. I know you said you have a Blackstone kit on the way, and it would be nice to see what they say. I have never heard of any 6 cylinder having a washout issue, and you shouldn't be able to smell raw fuel in the oil, really at any time, unless maybe just after a complete cold start. If you have a scan tool that shows live data, it would be interesting to see what the STFT, and LTFT is on both banks, and what the rear 02 Sensor reading is. That would at least give a starting point to a cause for a fuel smell in your engine oil. I guess I have never run Rotella T6 before, so it's not just the oil that has a different smell to it, is it?
I'm don't know what oil was in it before, but it smelled like fuel when I changed it. I don't think it's the T-6. I ordered the Blackstone kit just after changing the oil and had planned on taking a sample after 1000 miles or so. But, after smelling gas in the oil after a fresh fill and 40 mile drive, it concerns me a bit. It was certainly not a cold start. I don't have a scan tool, unfortunately. What do you think about the warranty question? Is the suspicious odor of fuel enough for a diagnosis?
I have never had anybody with this concern, and I don't know if we have any kits available to us to check for contaminents or other fluids in the oil. Well minus the cheap "headgasket failure" checker, which cannot be trusted IMHO.
Well, the old oil went into a well-contaminated drain pan, so I can't take a sample of that. I have to rely on the new fill for analysis. The thing is, the car seems to run fine. Engine sounds smooth, (minus the cam chain whine) plenty of power, pulls strongly and smoothly, no stuttering, no audible misfiring, no detonation that I can hear. All I have to go by are bad catalytic converters and oil that smells like fuel. If the oil smells like gas, then it would make sense that fluids are exchanging in the combustion chamber both ways, right? If it burns an excessive amount of oil, that could help explain the bad cats. I haven't had the car long enough to watch the oil level, though. I have not noticed any exhaust oddities upon startup or while running. I watched for smoke and sniffed the exhaust (!) after changing the oil and saw nothing. I'd LIKE to figure this out before anything else goes wrong, though...
Do you idle the car a lot or make a lot of short trips? Guessing not. Reason I ask is because I've had a couple oil samples come back with excess fuel in the sample. Both samples were from winter fills where the majority of my driving included a few minutes of cold idle followed by short commutes to work (under 5 miles) and a couple minutes of cooldown. Oil also had a faint gas smell to it. Changing winter driving habits (read: taking the looooong way home) eventually cleared up the smell and yielded healthier sample results. If you don't want the new fill to go to complete waste, you can always warm the car up, drain about a quart, fill the sample kit, and then top it off.
You're guess is correct. I commute from Hudson to St. Paul. Plenty of time for the engine to warm up. I drove a total of about 70 miles yesterday, none of which were short trips. I had the same thought about taking a sample. I may take one right away and another after 1000 miles or so.
Another thing you can do is check your plugs. IF you are getting too much fuel, your plugs will be black, you will lose the nice tan that you would normally have. Was the oil that smelled like gas (before the current oil), did you do that change or was that the oil that was in the car when you picked it up?? This will all be speculation based off of some of the ideas and some past experiences, so bear with me a bit. If it is a fuel issue, your mileage will suck. I had a chev truck that had a wash down issue (pressure regulator). I couldn't get better than 8mpg. The oil was thin and I was putting in plugs every 3-500 miles. Once I fixed the regulator and things "kinda" went back to normal, but it took 2-3 oil changes before it didn't constantly smell of fuel. It had hard starts, random miss fires and was just a general mess to drive. So pending a fueling issue (which would show up on a scan tool with fuel trims out of whack), and the oil was from the previous owner, Sheen might be onto something. The previous owner might have been making lots of short trips, idling, etc. If the car wasn't getting up to temp and letting the fuel system lean out, that could be where the extra fuel is coming from. And a plug check will kinda clue you in on if it is a current thing, or something from the previous owner. Russ
I do need to pull a couple plugs and have a look, you're right. I haven't gotten around to that yet. The oil I drained came with the car when I bought it less than a month ago. Supposedly, the dealership I bought the car from changed it when they put it on the lot, so it shouldn't have been that old. That oil smelled like gas when I drained it, the new oil smells like gas under the filler cap. So, the old oil probably had some relatively short test drives on it, and the testing that Morrie's needed to do when replacing and testing the old/new cats (Morrie's burned about 1/4 tank in testing). I'm guessing it has may have done a lot of idling while running those tests. Maybe some fuel was introduced into the oil then. Morrie's said the exhaust makeup checked out fine after the new cats were installed, and I have no reason to doubt that. I believe they had a scanner of some kind running during the test after replacing the cats, so I'd hope any abnormal things would show up then. As we know, when draining oil, you never get all of it out. It also doesn't take much gas to produce an odor, especially when warm. Maybe it's just leftover and hasn't all burned out yet. Like your truck needing several oil changes before the smell went away. MAYBE I'm just being paranoid. Wouldn't be the first time. 3 bad cats at 24k just makes me want to find out WHY they went bad. Like I said, the car is performing well. I just have bad cats and fuel-smelling oil to go on. As I said, mileage seems good. I'll need more data to verify that. Too small a sampling so far. I'll check the plugs hopefully this weekend. Guys, thanks for the input. I appreciate it and welcome any further thoughts.
Be careful with your coil connectors. The little tabs get brittle in the crammed engine bay, and if you are rough, they break off.
Thanks for the tip. I'll be gentle. I can see that the drivers side rear is going to be a real trick to get out of there with so little clearance. Any tips on accessing that one specifically?
Do all of them from the bottom, on a not so warm engine. Other than that, get yourself some decent u-joint sockets, and go to it.
Well, after a 40 minute drive home last night at about 10:30, I checked the cap again. Smelled of fuel, and saw just a bit of white grease/foam in the cap. It was out in the cold last night, and as we know the white foam is an oil emulsion caused by moisture in the oil not burning off. I would hope 40 minutes of running would get the car hot enough to cook moisture out of the oil caused by a cold start. Maybe a PCV issue? I've noticed no drop in coolant in the short time I've owned it.
No, the caps on the H6's always collect that. It's where the moisture ends up, as the "flow" of fresh hot splash oil from the chain isn't likely to reach the cap as there is a baffle in the timing cover.
Ok. Thanks for putting that fear to rest. I will make sure to check the PCV valve. I've seen the foam before in cold weather and short trips in other cars, so I'm not TOO concerned there. Thanks.
If you have any doubt about the valve, replace it. We have them in stock here, and I will get you one if need be.
Well, the PCV was a bit sticky. Put one aside for me please! I'll stop by Monday or Tuesday. Interestingly, there was a whiteish sealant around the top of the threads. Does the factory have a habit of using that?
Yes, Im pretty sure it's just pipe sealant. Some 4-cylinders have it too, but I always see it on the 6-cylinders.
