djmuyssson

First - Thank You to everyone who has taken the time and effort to help others on this forum, I've had my LS for a couple years now and this forum has been one of the best sources out there. It really is greatly appreciated!

Second, sorry for the long post but the goal is to help provide relevant details and some Q&A I've asked myself about the issue.

Some basic info: 2007 LS460, RWD, 92K miles, std suspension. Everything works, standard fluids replaced as called for.

Concern - Lately it seems like there is more exhaust coming from the pipes over the past several months than what I recall in the past. It evaporates pretty quickly, is not grey or black, but isn't bright white either, just lots of exhaust smoke when sitting at lights waiting for green.

Lots = I can look in the side view mirrors and see exhaust reaching over the cars beside me. Sometimes if I'm looking forward, I can see it flick its way along the side of my car almost to the front before it evaporates. If I accelerate hard there's an exhaust trail behind me for a little bit.

I should note that it's been getting colder up here in Ottawa and I know the cold effects visible exhaust, but when looking at other cars, relatively speaking they just don't seem to produce the same volume as me (even trucks with a similar sized - or larger - engine produce less).

Observations:
- It doesn't happen at cold startup and high idle.
- It starts to happen when the engine has warmed up a bit and is now down into the 600-800rpm range.
- When I come to a stop, it doesn't happen instantly, it takes ~3-4 seconds then 'ramps up' in volume as I watch behind me through the side mirrors.
- When I pull away gently from the stop, I don't really see anything trailing behind me.
- When pulling away moderatly from a stop, I can see the small 'plume' where I was and a bit of a trail through the intersection, and then it's gone and clear.
- If I accelerate hard from a stop, I look like a rocket ship with a HUGE stream behind me, which stops when I stop accelerating (so I don't zip into illegal speed issues...)
- Even after driving for 30 minutes on the highway (so engine = cat + muffler all hot), I'll come to a stoplight and will start to see exhaust plume up after a few seconds.

Questions I've asked myself:

Is it Oil?
- No burning oil smell that I can tell, no real smell at all in fact.
- Oil is still clear after 3000 miles (last change)
- Oil level is unchanged from last change.

Is it coolant?
- No gunk on dipstick, last oil change had no film or separation of fluids in the oil pan
- No sweet smell from exhaust
- Coolant level not dropping since I added a bit over a year (and 16,000 miles) ago

Is it extra fuel?
- I don't think so, most of my driving is in-city so it's never great.
- It hasn't changed since I bought the car.
- Oil doesn't smell of gas

Am I just crazy?
- Most signs point to yes
- My wife agree's with the signs.

The three really odd things that make me think something is up are:
1 - It doesn't happen when it's cold (?)
2 - There's a 3-4 second 'lag' time before it 'ramps up' when sitting at a stoplight - Doesn't happen at stop signs (??)
3 - It continues to happen even after a long drive where things should be nice and hot in the exhaust system (?!?!)

Wrap up

If anyone knows what it is or a suggestion I could look into, I'm all ears.

Also, I've been thinking of taking it into a trusted shop to get them to take a look at it (I'm not a mechanic). I wouldn't mind knowing if there's something I should ask for first & work my way through (i.e. compression test? fluid checks? etc?)

Thanks for reading everyone! Have a great Christmas and Happy New Year!.

jdanielca

i think i have the same general observations, funny I used to live in Ottawa, Laurier Ave W. I have not paid much attention to when it happens though I notice it is more than anyone else's car, however...not every car is a V8 so... apples and oranges.. gotta remember that. I do notice it is doing more than when I first got the car a year or so ago.

I am not burning coolant, I know that much, because coolant level is remaining constant. Gas is hard to say...my mpg in the city is HORRIBLE, because this city where i live in is like no other US or Canadian city... the roads are traffic and yesterday traffic was so bad it took me an hour plus to cover 2km or so. So having said that my high way is like 20 something mpg in the city is is like 8-10mpg.

What are you doing in the city ? I lived in ottawa a long time ago from 05 to 09, traffic was really non existent back then, dont know about now haha

djmuyssson

Public transpo ridership has been declining since 2011, and with the new light-rail introduction downtown (which was/is a disaster), the volume of cars on the road are at all-time highs. In short, traffic is much worse than even two years ago.

In terms of fuel economy:
All City: 13 MPG (US), 18 L/100km
All Highway: 28 MPG (US), 8.4 L/100km
Total over ownership: 17.6 MPG (US), 13.3 L/100km

I did pull off 10 MPG / 23.8 L/100km once, so I know it's possible with heavy shoes / really bad traffic.

Thanks for the reply, good to know I'm not the only one noticing this odd behaviour.

Moisture

It is just condensation inside the exhaust system. It doesn't happen when cold because the exhaust system isn't warm enough for the evaporation to happen.

If you've smelled the exhaust, both when cold and warm, and you don't smell anything out of the ordinary, nothing to worry about.

jdanielca

well good to know my numbers are not too far off from yours,

Moisture

28MPG on the highway for a car like this is excellent. But there is way too much of a discrepancy between 28 on the highway and 13 in the city. That city MPG is awful!

djmuyssson

Both numbers are my best/worst with 100% of the type of driving stated. That said, I usually average 16 MPG most of the time I fill up. I'm in the city and only a 5-10 minute drive from almost everything (work, stores, friends, activities, etc) so a lot of my trips are short and full of traffic lights.

Once rolling the LS is fantastic on the highway, but the constant stop and go really kills it (it's not exactly a light car...). I'd also note it's the RWD model, not AWD so the parasitic loss might play a factor as well. Genuinely did pull off a 28 MPG (US) average on a long haul over two days that was all highway, was shocked when I ran the numbers.

Makes me wonder what the hybrid assist would do to my in-city numbers on a LS600h =)

Moisture

How do you figure that RWD causes more parasitic loss than AWD? it's the other way around.

The driving pattern you mention is the worst for your engine. In that case you want to change the oil quite often and take her out on the highway for a 30+ minute drive minimum once a week to let excess fuel and moisture evaporate from the oil supply.

djmuyssson

Sorry, I wasn't very clear with that comment was I! I was trying to say that being able to pull off 28 MPG highway might be due in part to it being RWD and not AWD. As you mention, AWD would make the numbers worse.

And yes, very good advice on oil changes/stretching its legs regularly. I've been changing oil every 3000 miles, and (trying) to head out of town every couple weeks.

Moisture

3000 miles oil changes is a good call according to your driving habits. You want to limit the amount of fuel dilution inside your crankcase as best as you can, because it is inevitable with such a driving pattern.

jdanielca

yeah i think I am going to change my oil soon, I am reaching 3000 miles or so since june or july.... the traffic is really bad ihere so....i think i am going to follow that 3000 miles...

Moisture

what sort of oil/weight you using?

jdanielca

factory 0w20 toyota. but the car is supposed to be able to take 5W20 so I was thinking of switching to https://products.liqui-moly.com/oils...n-5w-20-1.html

Moisture

This engine is OK for use with up to 20W50... in fact, most engines are good for up to 10w50. Manufacturers would need to design impossibly thin engine clearances for something like a 5w20 to be the upper limit of what would be too "thick" inside an engine.

My recommendation is to stick to 5w40 oil. I use this year-round, but will sometimes go for 5w50 or 10w40/50 in the summer. Not any thicker than that unless the manufacturer specifies its ok (in other markets) and i am trying to deal with some sort of oil consumption or a worn engine.

Liqui-moly is fine stuff, but you can get better for the same price or even less. I would recommend you take a look at Motul oil, absolutely excellent stuff.

Looks like LM has introduced some new "molygen" stuff. It's probably good too, but I would make sure not to use thinner than 5w40.

https://www.motul.com/us/en-US/produ...00-x-cess-5w40 - this is what I am using now. it is excellent.

Here are two more worth mentioning:

http://renewablelube.com/store/index...&product_id=96 if you are able to source this where you live, this is the best oil you can possibly use.

https://www.redlineoil.com/5w40-motor-oil

these are the top oils in my opinion.

jdanielca

well I can understand going thicker if theres oil consumption although some may argue otherwise, but I have 0 oil consumption at the moment anyways. The previous guy who owned the car was doing 5W30. I might go as far as that maximum. I have 0 appetite for risk haha what you are suggesting is a bit too much for my appetite. You are located in Ontario canada and you use that thick of a oil?

Another thing about my car is the engine was totally taken apart a few months ago, i am not gonna get into why and what etc too much to type.. and put together again, i posted about it here in forums. essentially only thing not changed were piston rings... coz the idiots who were doing it under recall did not consult me anyways So far not much oil consumption. I am holding steadish at 1/2way point between low and full. I am at about 2000+ miles or something, I will check later today what the oil level is and post back. So since i got the car last year, I had changed it to 0W20 Toyota.. then the car went into lexus for 3 months... they changed it to Lexus branded 0w20.... and i have had it about 6 months since they redid the engine and i am thinking about maybe 5W30 to see how the mpg is with that,