[mlaird]

I'm in the market to buy a used 6, and took a look at one at a dealer. It's an '05 with the V6, and when I took it for a test drive, it exhibited two problems. First, there was a bit of a vibration and a rumble at highway speeds which was definitely from the wheels and not the engine (the sound didn't change when I put in the clutch and let the engine idle). Second, the car produced small puffs or clouds of smoke from underneath the right side of the engine compartment after I parked it at the dealer and let it idle with the hood open. The smoke sort of puffed out from the right wheel well area, then went away, then a minute later another small cloud puffed out from under the engine.

The dealership says that their mechanic checked these problems out and found that there is a bent rim that was causing the vibration and rumbling, and that they'll fix that. That sounds plausible, and shouldn't be hard to test if I go back for another test drive. For the smoke, they say that the oil filter is right over the exhaust, and when they changed the oil, it was done sloppily and leaked onto the exhaust, making the smoke. They claim they've cleaned that up and that it shouldn't be a problem.

Does this explanation sound reasonable? Is a messy oil change capable of dripping oil onto the exhaust? The smoke puffs did seem to come out at periodic intervals like there was a slow leak from somewhere that was dripping onto the exhaust. I only drove the car for maybe 10-15 minutes, so it seems like a one-time spill would have either burned off completely in that time, or would have made a continuous cloud of smoke. What I saw seemed to indicate a leak that was continuing to drip onto the exhaust.

Thanks for any advice...

 

[aztrojans12]

It definitely could just be some oil burning off, since when you remove the oil filter some oil will drip down onto the exhaust. The oil should burn off relatively quick. Since you are going to test drive the car again and check if the vibration is gone since they fixed the rim, just pop the hood again and see if smoke is coming out while at idle. If the problem still exists, then don't buy the car until they fix the issue.

 

[mlaird]

It definitely could just be some oil burning off, since when you remove the oil filter some oil will drip down onto the exhaust. The oil should burn off relatively quick. Since you are going to test drive the car again and check if the vibration is gone since they fixed the rim, just pop the hood again and see if smoke is coming out while at idle. If the problem still exists, then don't buy the car until they fix the issue.

Thanks for the opinion. I still question whether it was just a sloppy oil change or whether the fellow forgot to tighten the oil filter all the way. It seemed like something must have been leaking while the engine was idling and I was watching, rather than just burning off something spilled previously. In either case, it's good to know that the oil change could very well have been at fault. Leaking from somewhere else would be much more problematic!

I'm going to look through these forums more, but are there any issues in particular that I should look out for on an '05 V6 with 80K miles on it?

 

[Uh-Oh]

Personally I would walk away..

Either they honestly didnt know about the bent rim or they did know but wanted to get off cheaply (alloys are expensive).
Either one is bad because they either havent inspected the car or they are being dishonest. Also indicates either abuse or poor previous maintenance.

Same with the smoke.. could be that they are being honest about the oil or it could be something else.. you don't know.
A well run car sales location would have made sure neither of those would have happened while a customer was taking the car out...

If you still want it see if they willing to giving you a warranty (like 30-90 day or something) if they wont then walk away.

I'm going to look through these forums more, but are there any issues in particular that I should look out for on an '05 V6 with 80K miles on it?

Checkout the stuff on pre-cat failures (leads to engine failure).

Also the clutches go on the I4 I dont know about the v6.

 

[aztrojans12]

Your 2 biggest issues, in my opinion, are the PCV valve and pre-cats. If you look through the forum you will see plenty of info. about these. Basically, if your PCV valve stops functioning properly ($8 part, 10 minutes to replace), it will act like a straw and suck the oil right out of your engine at a fast pace. If you don't catch that you are low on oil, you will likely spin a bearing and ruin your engine. I wouldn't be too worried about the PCV valve because it is cheap and easy to replace, in fact I would recommend replacing the valve and hose every 25-30,000 miles to be safe (including when you first buy the car). The issue that worries most people, including me, are the pre-cats. The general consensus is that if you have multiple misfires and dump fuel into the pre-cats, the fuel will burn hot and break apart the precat "honeycomb". Once this ceramic honeycomb breaks apart, the pieces are sucked back into the engine which wreaks havoc and ruins the engine. If I was you, with the car at 80k miles, I would replace the spark plugs AND ignition coils once you buy it (unless, of course, this was recently done). This will cost you around $300 if you are mechanically inclined enough to do the job yourself. By the way, if you do this, replace your PCV valve and hose at the same time, since it is easy to access once you remove the intake manifold to access the back 3 spark plugs.

 

[Egierda]

Walk away.


These motors have three main sources of oil leakage:
1) Oil pan gasket
2) Front crank seal
3) Rear main seal


If the dealership hasn't fixed it yet before trying to sell it then I wouldn't want to do business with them.

 

[Sacramento6]

That being said, it could have easily been a poorly tightened oil filter. If they drip down the filter housing, it'll drip right onto the exhaust. Certainly not an "end of the world" kind of thing.

 

[Egierda]

Those are both legit claims but just make sure that none of those other areas are showing signs of leakage. Why, you ask? Because the rear main seal alone is a 10+ hour job to replace, lol.

 

[Sacramento6]

^^Yeah, don't get me wrong. I'm just saying that it wouldn't surprise me if it indeed was a loose oil filter dripping on the exhaust. Should it be a gasket or main seal, walk away.

 

[21drfrank]

Walk away. Simply put, there are too many good used cars out there to chose from, and I certainly wouldn't purchase any used car that had even a hint of a problem on the test drive. I mean, the dealer is trying to put his or her best foot forward, and the car is blowing blue smoke? I don't give a hoot what the problem was, spilled oil or not, the car is blowing smoke! I just bought a used Dodge Caliber for my daughter--we test drove a number of used cars--and every one was in new-car condition for the test drive. The transmission(s) may fall out by Christmas, but there was no hint of a problem on the test drive. Forget the car--the dealer is the one blowing smoke...

 

[cmorty72]

I'd honestly just walk away.
Simple stuff like this should never have been overlooked by any reputable stealership (bent rim for instance).

As for the spilt oil on the "Y" of the exhaust producing small puffs or clouds of smoke... :huh:
All I can say is that it must of been one helluva spill.
I've changed my oil on my 6 many a time, and had an occasional spill from my used oil filter when removing it.... but never enough to cause what you experienced.

Just out of curiousity, what kind of stealership was it?

 

[mlaird]

Either they honestly didnt know about the bent rim or they did know but wanted to get off cheaply (alloys are expensive).
Either one is bad because they either havent inspected the car or they are being dishonest. Also indicates either abuse or poor previous maintenance.

The vibration was very minor; I was being very careful to notice anything wrong.

Same with the smoke.. could be that they are being honest about the oil or it could be something else.. you don't know.
A well run car sales location would have made sure neither of those would have happened while a customer was taking the car out...

I tend to agree, but if the fellow is telling the truth, then their mechanic had just changed the oil and then they put it out on the lot for sale. So I can see how it could have happened.

If you still want it see if they willing to giving you a warranty (like 30-90 day or something) if they wont then walk away.

They do offer a 30-day, 1000-mile warranty.

Checkout the stuff on pre-cat failures (leads to engine failure).

I am going to read up on that. I am surprised that a cat failure could do anything more than cause power loss until it is replaced.

Also the clutches go on the I4 I dont know about the v6.

I'm not too concerned about that; I don't ride the clutch at all, so I get really good life out of my clutches, historically speaking.

 

[mlaird]

^^Yeah, don't get me wrong. I'm just saying that it wouldn't surprise me if it indeed was a loose oil filter dripping on the exhaust. Should it be a gasket or main seal, walk away.

I agree -- if there is something major going wrong like a main seal, then I'd walk away. A simple mistake during an oil change is a different matter.

Is there any way to see the leaks you guys are referring to, preferably without having to put the car on a lift? Valve cover gaskets I'd expect to be easy to inspect, but the main seal is probably pretty well hidden.

If I go back to that dealer I certainly will be looking and sniffing around for any sort of smoke, and will be very suspicious if I see more. Anything more would contradict their explanation.

 

[mlaird]

Walk away. Simply put, there are too many good used cars out there to chose from, and I certainly wouldn't purchase any used car that had even a hint of a problem on the test drive.

My dilemma is that I want a car that seats 5 tall people, handles well, has a manual transmission, and I'd prefer a hatchback. If I go for a car like a Mazda 3, Ford Focus, Subaru Impreza, etc., then my tall kids will be cramped in the back seat. That's not the end of the world, but I'd prefer more room for them, as the 6 provides. If I go for some other mid-sized sedan, like an Altima or Camry, I'll be giving up handling big-time, plus most of them don't offer a manual transmission. Plus, none of those cars offer a hatch.

Finding a 6 hatch with manual transmission looks like the perfect match for me, but there aren't very many cars like that available. Fortunately, I'm not in a rush, but I also don't want this to drag on forever...

 

[aztrojans12]

The clutches have been known to go out early, however I have over 100,000 miles on my car and still have the original clutch, so I don't know if I have gotten lucky, or I just don't race my car and beat the clutch up. "I am going to read up on that. I am surprised that a cat failure could do anything more than cause power loss until it is replaced." For most normal cats this is the case. The problem for the Mazda 6 V6 is not the regular, larger cat, the problem is the "pre-cats". There are (2) of them, and they are located very close to the engine. The problem is, if the ceramic honeycomb breaks, the backpressure is enough to suck that debris right into the engine. If this occured with the larger, regular cat, it would not be an issue because it isn't near the engine and the backpressure won't suck everything back in. However, the pre-cats will, and it will ruin your engine if it occurs. Unfortunately, there is little to no warning that this is about to happen. It definitely has me worried, but I have over 100,000 miles on my car and take very good care of it, including replacing ALL of the plugs AND coils as a maintenance item, since misfires are the likely culprit of destroying the pre-cat.

 

[e4w]

dont forget about O2 sensors, i replaced both upstream sensors this weekend jic!

i think our V6 do have weak front main seals, i noticed a wet spot on the front my oil pan recently.