Other causes for oil burning
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From: You wish
With all the discussion on oil burning, has anyone considered other causes besides ring sealing?
I ask because just recently my car consumed some oil and in the past it really hasn't (now have 10,000 miles).
I tried to think about what I've done in the last 1000 miles to cause this, as I doubt my rings have suddenly lost their seal (I've done 500 mile trips without burning a drop). What came to the forefront is that the last 1000 miles have been spent largely on quick, twisty, high-g roads. This reminded me that I'd heard from several road course junkies about a year ago that they'd had problems with puffs of oil smoke on certain corners, almost certainly due to oil being sucked through the valve cover breather into the intake tract. Usually my driving is 90% straight line (or more), but the last 1000 miles have been on a lot of twisties (maybe 50%). If you're getting puffs of smoke, then you're burning a lot of oil (can't say I've seen any, but I'm not usually looking behind me in a high g turn).
So I removed my intake hose and examined it. Lo and behold, there was quite a bit of oil around the entry hole from the hard line, oil on the inside of the intake tube, oil around the sealing surface between the intake tube and the throttle body and a coat oil on the bottom of the throttle body itself.
Seems to me that despite the engine's tilt to the passenger side, in high g right hand corners some oil may be getting slung into the valve cover breather tube and making it's way into the intake tract. The solution that several folks had talked about was a simple catch can arrangement which won't prevent the oil from moving through the tube, but will prevent it from being burned. An even better solution would be proper baffling in the valve cover itself. I'll take mine off this weekend and see what's already there.
I'm also going to take a 100-200 mile trip this weekend and keep the cornering g's down and see if the oil consumption stops. I'm betting it will.
Comments are welcome. I'm sure this has been discussed before, but probably prior to this particular discussion forum coming into existence.
UL
I ask because just recently my car consumed some oil and in the past it really hasn't (now have 10,000 miles).
I tried to think about what I've done in the last 1000 miles to cause this, as I doubt my rings have suddenly lost their seal (I've done 500 mile trips without burning a drop). What came to the forefront is that the last 1000 miles have been spent largely on quick, twisty, high-g roads. This reminded me that I'd heard from several road course junkies about a year ago that they'd had problems with puffs of oil smoke on certain corners, almost certainly due to oil being sucked through the valve cover breather into the intake tract. Usually my driving is 90% straight line (or more), but the last 1000 miles have been on a lot of twisties (maybe 50%). If you're getting puffs of smoke, then you're burning a lot of oil (can't say I've seen any, but I'm not usually looking behind me in a high g turn).
So I removed my intake hose and examined it. Lo and behold, there was quite a bit of oil around the entry hole from the hard line, oil on the inside of the intake tube, oil around the sealing surface between the intake tube and the throttle body and a coat oil on the bottom of the throttle body itself.
Seems to me that despite the engine's tilt to the passenger side, in high g right hand corners some oil may be getting slung into the valve cover breather tube and making it's way into the intake tract. The solution that several folks had talked about was a simple catch can arrangement which won't prevent the oil from moving through the tube, but will prevent it from being burned. An even better solution would be proper baffling in the valve cover itself. I'll take mine off this weekend and see what's already there.
I'm also going to take a 100-200 mile trip this weekend and keep the cornering g's down and see if the oil consumption stops. I'm betting it will.
Comments are welcome. I'm sure this has been discussed before, but probably prior to this particular discussion forum coming into existence.
UL
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From: Melbourne!
Ult, you are quite correct in your comments. I have noticed it on our S2k track days when following other Stooks through and out of turns. It has also been reported in Aussie magazines during road tests.
However, I will say that I would expect the amount burned in these situations to be marginal - I'd be interested to hear exactly how much you used over your 1,000 mile test period.
However, I will say that I would expect the amount burned in these situations to be marginal - I'd be interested to hear exactly how much you used over your 1,000 mile test period.
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From: WA
The times I have seen the puff of smoke has been high gee right turns after a short straight that where you would use high rpm and then heavy breaking.
My assumption has been the high rpm pumps a lot of oil to the cams that gets pushed forward on heavy breaking so it doesn
My assumption has been the high rpm pumps a lot of oil to the cams that gets pushed forward on heavy breaking so it doesn
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From: You wish
2kturkey,
It was nearly a quart over at least a 1000 mile stretch - maybe more. That seemed like an awful lot to me, but the trail of oil in the intake tube was enough that I could pull away drops on my finger. It was if someone had poured oil through there.
The roads I've been driving on consist of repeated 2nd or 3rd gear blasts followed by hard braking and then cornering. Usually about 15-20 turns per mile with lots of elevation changes.
We'll see if I burn any oil in a straight line :-). If I do it's time to talk to Honda. But I suspect I won't need to and I'll be specing out a catch bottle.
UL
It was nearly a quart over at least a 1000 mile stretch - maybe more. That seemed like an awful lot to me, but the trail of oil in the intake tube was enough that I could pull away drops on my finger. It was if someone had poured oil through there.
The roads I've been driving on consist of repeated 2nd or 3rd gear blasts followed by hard braking and then cornering. Usually about 15-20 turns per mile with lots of elevation changes.
We'll see if I burn any oil in a straight line :-). If I do it's time to talk to Honda. But I suspect I won't need to and I'll be specing out a catch bottle.
UL
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From: You wish
Well, its been sunny today in SoCal, so I went out and put some more miles on the car. I'm now at 125 miles since I topped up the oil. No hard right hand corners, and I was trying to avoid revving the car too much.
The results? My oil level hasn't moved a millimeter. If I burned nearly a quart over 1000 miles, I think I'd see some movement in 1/8th that distance. Also, I haven't noticed the oil smell coming from under the hood that I did recently. And no oil in the intake tube. Seems that the valve cover breather vent can be a major source of consumption if you do a lot of spirited driving in the twisties. I'll keep a skeptical eye on the oil for a few hundred more miles (supposed to rain again this weekend :-( ), but I think its time to do the catch tank solution. Near 1g cornering just can't tolerate a simple vent cover :-)
UL
The results? My oil level hasn't moved a millimeter. If I burned nearly a quart over 1000 miles, I think I'd see some movement in 1/8th that distance. Also, I haven't noticed the oil smell coming from under the hood that I did recently. And no oil in the intake tube. Seems that the valve cover breather vent can be a major source of consumption if you do a lot of spirited driving in the twisties. I'll keep a skeptical eye on the oil for a few hundred more miles (supposed to rain again this weekend :-( ), but I think its time to do the catch tank solution. Near 1g cornering just can't tolerate a simple vent cover :-)
UL
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From: You wish
Yeah, you're right. Just had to put the top down and drive. I live down in the South Bay, right on the beach between Redondo and Palos Verdes. I did the whole loop around PV yesterday and then up the beach to Playa del Rey and back.
Sucks that job opportunities may take me away from here.
UL
Sucks that job opportunities may take me away from here.
UL
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An update on my oil consumption issue: having added a full quart at 1,000 miles, I called my dealer and asked what the normal oil consumption should be. The service manager did not know, but suggested I bring in the S2000 as soon as possible for a compression check. I asked if he knew about others having similar situation or if he knew about any engine failures with warranty replacements. He said no.
By the time I could find an opening in my schedule to take the car in, the clock said 1,200 miles and was now down another 1/2 quart. After a day in the service center the Manager said he called the Honda Tech line which confirmed usage of 1 quart per 1,000 miles to be usual for a new S2000. He asked me to keep a detailed log of any subsequent oil usage and to let him know by phone whenever I need to add a quart.
The look inside the engine was deemed "normal' - compression within specs on all four cylinders.
So, I feel better having logged an official service request into the Honda system. My dealer was straightforward in working with me and I am going to get past this apprehension about engine health and get on with enjoying driving. After all, this is what warranties are for.
I'm putting this in perspective for myself - this is an exotic, unique engine and I cannot treat it like the transportation appliances that most cars are. I have an older sports car sharing the garage, and its owner maintenance requires a daily oil check, along with a daily look at the radiator level, brake fluid container, and tire pressures. It also requires an engine oil change of all 12 quarts, change of transmission oil and differential oil every 2,000 miles.
I'm sure some of you will disagree with this perspective, but this is how I'm coming to terms with this. I would be glad to hear from anyone for discussion.
By the time I could find an opening in my schedule to take the car in, the clock said 1,200 miles and was now down another 1/2 quart. After a day in the service center the Manager said he called the Honda Tech line which confirmed usage of 1 quart per 1,000 miles to be usual for a new S2000. He asked me to keep a detailed log of any subsequent oil usage and to let him know by phone whenever I need to add a quart.
The look inside the engine was deemed "normal' - compression within specs on all four cylinders.
So, I feel better having logged an official service request into the Honda system. My dealer was straightforward in working with me and I am going to get past this apprehension about engine health and get on with enjoying driving. After all, this is what warranties are for.
I'm putting this in perspective for myself - this is an exotic, unique engine and I cannot treat it like the transportation appliances that most cars are. I have an older sports car sharing the garage, and its owner maintenance requires a daily oil check, along with a daily look at the radiator level, brake fluid container, and tire pressures. It also requires an engine oil change of all 12 quarts, change of transmission oil and differential oil every 2,000 miles.
I'm sure some of you will disagree with this perspective, but this is how I'm coming to terms with this. I would be glad to hear from anyone for discussion.