Author Topic: High oil level when hot (Read 7003 times)

Dirty Steve · « **on:** June 30, 2016, 08:29:24 AM »

Hi all,
Just wanted to check...is it normal to have the oil level way over the FULL line when the engine is hot?
Thanks...

flybox1 · « **Reply #1 on:** June 30, 2016, 08:34:25 AM »

It shouldnt rise much at all
I would suspect an issue with the pump/pump screen. When was the last time you checked it?

Jerry Rxman Griffin aka MuthaF'er · « **Reply #2 on:** June 30, 2016, 09:06:45 AM »

+1.

Perhaps your check valve in the pump is defective allowing the oil to drain out of the tank into the sump after a ride, you check the oil, it 'appears' low so you top it off thus adding un-needed oil which appears prior to draining downward again.

flybox1 · « **Reply #3 on:** June 30, 2016, 09:21:03 AM »

To get the pump out....Drain your oil. Drop the oil pan, and look for three more screws around the pump.
Removing these will release and allow you to drop out the oil pump.
Easy, but a bit messy.
Watch for the 3 o-rings and 3 alignment dowels. Some might come down with the pump, or the might stay in the case.
Just keep an eye out for them.

You'll be able to disassemble the pump and check clearances.
Maybe add in forum member ELAN's pump rebuild kit, and clean the screen.

Garage_guy_chris · « **Reply #4 on:** June 30, 2016, 12:13:13 PM »

I have wondered the same thing. But I have a newly rebuilt engine with an overhauled drain back valve with one of Elan's Super Kits. Mine seems to have the oil level rise about 3/4" to 1" from full cold to full hot. I think its just an expansion thing?!? The other thing i have noticed if the bike is run on the kick stand the oil level goes down about 3/4" to 1" i think this is because the oil can pool on the low side of the crankcase keeping it out of reach for the oil pump to send back to the tank hence the lower level. If i pick it up and ride it or hold it level the oil level increases

Davez134 · « **Reply #5 on:** June 30, 2016, 01:33:48 PM »

Or it could be that the oil inside the tank shifts away from the dipstick when on the side stand at an angle, giving the appearance of a lower level

Dirty Steve · « **Reply #6 on:** June 30, 2016, 09:39:42 PM »

Thanks for the info and diagram, Flybox.
I should have mentioned that I have a Lockhart oil cooler. Don't know if that changes anything.

Dirty Steve · « **Reply #7 on:** June 30, 2016, 09:45:24 PM »

I haven't checked the pump or pump screen yet.

scottly · « **Reply #8 on:** June 30, 2016, 10:03:19 PM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on June 30, 2016, 09:06:45 AM

Perhaps your check valve in the pump is defective allowing the oil to drain out of the tank into the sump after a ride, you check the oil, it 'appears' low so you top it off thus adding un-needed oil which appears prior to draining downward again.

It's normal for the check valves to leak a bit over time, leading to overfilling. In severe cases, enough oil can be added to spill out the breather tube as the scavenge pump moves it from the sump to the tank. (I've never done that, nope, never pumped a quart of oil onto the shop floor, never happened.

)
Steve, before you break out the wrenches, check the oil level after running the bike. If it's still high, pump enough oil out of the tank until it reads full. (I use a differential gear oil hand pump from the auto parts store.)

Dirty Steve · « **Reply #9 on:** July 10, 2016, 05:19:31 PM »

Hi all,
I'm just about ready to pull the oil pump and inspect it, but I'd like to have a more specific idea of what the culprit may be.
Just to reiterate:
After a 2-minute idle, the level is 1/4th inch below the FULL line.
After riding roughly 30 minutes, it's 1 inch over the FULL line.
Stone cold a week later it's 7/8 inch over the FULL line.
Another 2-minute idle and it's back to 1/4th inch below the FULL line.

I'm still trying to get my head around this, but it seems like the check valve (a.k.a leak stopper valve) is working. I mean, the level drops a little bit but that could be due to the oil contracting when it gets cold, no?

Whad'ya think?

PeWe · « **Reply #10 on:** July 11, 2016, 01:47:26 AM »

Probably too much oil. And no other problems.
My bike (CB750 K6) did not keep the oil level in tank when cold. This was from the very beginning when I bought it with 17.500 km.
I remember my worries checking oil level when cold for the first time. Friends told me to check again when warm. Level was then OK.
I bought a newer pump from an F2 that got the rebuild kit that went in last winter. Level stays in tank now. The old pump never did during all years up to 100.000 km
- Drain oil when engine is warm. Easy to suck oil with a big syringe with a hose on until the level is on marked area on the dipstick. I have had +5mm without any problem. I used to have extra when starting the Europe touring where we travelled 2500km from home, then back again. Engine took some oil when running fast all day long, 140-180kmh, sometimes faster. Only problem then was the fuel consumption. 120-140 is better speed but speeds on Autobahn was then either 90kmh in truck lane, next was sometimes double ...

Jerry Rxman Griffin aka MuthaF'er · « **Reply #11 on:** July 11, 2016, 08:33:51 AM »

Yeah, too much oil. Just remove some. If it shows slightly below full don't sweat it until you get a quart low.

70CB750 · « **Reply #12 on:** July 11, 2016, 09:22:22 AM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on July 11, 2016, 08:33:51 AM

Yeah, too much oil. Just remove some. If it shows slightly below full don't sweat it until you get a quart low.

Exactly.

The K0 takes 3 quarts to be full, unlike later models, no need to go crazy if the oil level is within an inch/inch and half from full.

Dirty Steve · « **Reply #13 on:** July 11, 2016, 10:54:55 AM »

I don't believe I have too much oil because after a 2-minute idle it's 1/4th inch below the full line. It only spikes after a ride (and goes back down to normal after cool down and a 2-minute idle check).
My question is why does it spike so high when it's hot. It goes from 1/4th inch below the full line to 1 inch above the full line.
Thanks...

PeWe · « **Reply #14 on:** July 11, 2016, 11:55:52 AM »

2 minute idle is not enough for reach oil level completely.
My bike had always oil level at the last cm on dip stick or even lower. It took at least 10 minutes driving to show full oil level. Then add oil if needed. Maybe others have same experiences?

Ventilation from valve cover OK, not obstructed by its hose with a bad bend? I have never had a problem with it but it might affect the oil level on dipstick....

Dirty Steve · « **Reply #15 on:** July 11, 2016, 12:59:44 PM »

Well, my understanding is that when checking the oil, you're not waiting until the engine warms up before you check it. You're simply making sure the oil circulates throughout the system, so you can get an accurate reading.
Am I wrong about that?
I'll look into the ventilation in the valve cover.
Thanks for your input!

01Thomas · « **Reply #16 on:** July 11, 2016, 01:14:40 PM »

Trust me on this: it is definitely not an oil expansion thing. Yes, the oil will expand a bit but not enough to raise the oil level 1/8-inch - not to mention a full inch or more.

regards
Thomas

Quote from: Garage_guy_chris on June 30, 2016, 12:13:13 PM

I have wondered the same thing. But I have a newly rebuilt engine with an overhauled drain back valve with one of Elan's Super Kits. Mine seems to have the oil level rise about 3/4" to 1" from full cold to full hot. I think its just an expansion thing?!? The other thing i have noticed if the bike is run on the kick stand the oil level goes down about 3/4" to 1" i think this is because the oil can pool on the low side of the crankcase keeping it out of reach for the oil pump to send back to the tank hence the lower level. If i pick it up and ride it or hold it level the oil level increases

Dirty Steve · « **Reply #17 on:** July 11, 2016, 05:07:21 PM »

Quote from: PeWe on July 11, 2016, 11:55:52 AM

2 minute idle is not enough for reach oil level completely.
My bike had always oil level at the last cm on dip stick or even lower. It took at least 10 minutes driving to show full oil level. Then add oil if needed. Maybe others have same experiences?

So you're saying when your bike was cold, there would barely be any oil showing on the dipstick at all, then you'd run it 10 minutes and it would be at the full line?

markreimer · « **Reply #18 on:** April 14, 2017, 12:26:30 PM »

Quote from: Dirty Steve on July 11, 2016, 10:54:55 AM

I don't believe I have too much oil because after a 2-minute idle it's 1/4th inch below the full line. It only spikes after a ride (and goes back down to normal after cool down and a 2-minute idle check).
My question is why does it spike so high when it's hot. It goes from 1/4th inch below the full line to 1 inch above the full line.
Thanks...

Did you ever determine what caused this?

I have just rebuild my oil pump with Elan's kit and am having the IDENTICAL thing happen. I just changed my oil/filter and measured 3L into the bike. It was a hair under the full mark after running it for a few minutes. 10km ride later, it'd 3/4" above the full line. I let it idle for a few minutes and it's back to just under full. I'm wondering if there might be something funny with Elan's kit? I did notice the springs were a hair longer than stock for what it's worth. Did you rebuild your pump, or was this happening with everything stock?

PeWe · « **Reply #19 on:** April 14, 2017, 02:10:28 PM »

I'm sure the oil level you can see when hot is the real max level. If it is above, there is too much oil in.
Oil will flow back in engine due to the oil pump is not keeping the oil in tank. No problem at all. My first oil pump worked as that for almost 100.000km until I replaced it with another with less than half use that keep oil in tank.

I made recently 2 close oil changes. Around 2.6 liter was needed. All oil will not come out during a nornal oil change. Different when tearing engine apart and fill it with oil from dry.

martin99 · « **Reply #20 on:** April 14, 2017, 02:52:13 PM »

Quote from: PeWe on April 14, 2017, 02:10:28 PM

I'm sure the oil level you can see when hot is the real max level. If it is above, there is too much oil in.
Oil will flow back in engine due to the oil pump is not keeping the oil in tank. No problem at all. My first oil pump worked as that for almost 100.000km until I replaced it with another with less than half use that keep oil in tank.

I made recently 2 close oil changes. Around 2.6 liter was needed. All oil will not come out during a nornal oil change. Different when tearing engine apart and fill it with oil from dry.

+1
I only check the oil level after at least a ten mile ride, when you can be sure it's up to full operating temperature and is fully circulated. If I leave it for say a week or so afterwards and check when cold the level could have dropped a good inch lower. Checking when not properly hot is the most common reason why owners overfill their bikes.

markreimer · « **Reply #21 on:** April 14, 2017, 04:12:14 PM »

I'm sure that's usually the case, but it is not for me. My oil level changes while riding. Idle - goes down. High rpm - goes up. Different situation than the common accidental overfill. Read the earlier description a bit close, he describes how the oil level changes throughout a ride. Overfilling would mean the level would always be high, and only drop while parked if you had a leaky stopper valve, or if it was blown out the overflow tube.

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seanbarney41 · « **Reply #22 on:** April 14, 2017, 04:34:20 PM »

I love a good mystery as much as the next guy, but...you are over-thinking this. If you have adequate oil pressure, your good. If your oil level exceeds the top line on dipstick but does not overflow, you are good. If your oil level does not fall below the bottom line on the dipstick, your good. Enjoy the ride.

markreimer · « **Reply #23 on:** April 14, 2017, 04:39:18 PM »

Quote from: seanbarney41 on April 14, 2017, 04:34:20 PM

I love a good mystery as much as the next guy, but...you are over-thinking this. If you have adequate oil pressure, your good. If your oil level exceeds the top line on dipstick but does not overflow, you are good. If your oil level does not fall below the bottom line on the dipstick, your good. Enjoy the ride.

That's exactly the issue.... at its worst it's risen so high it's blown out my overflow and onto my tire. And at startup, drops right down to the empty mark

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Dirty Steve · « **Reply #24 on:** April 14, 2017, 09:27:42 PM »

I'm not going to be able to answer this to anyone's satisfaction, but I started checking the oil level when hot (after roughly a ten-mile ride), rather than a two-minute idle like before, and now judge that as being the real oil level (per the advice of several people on this forum). When I first did this, of course, the oil level showed well over the FULL line, so I drained it down even with the mark. I continued to check the oil level when hot (at FULL mark), when stone cold (1/4th inch below FULL mark), and after a two-minute idle (dropped down halfway between the two marks or lower-can't remember). After doing this numerous times and seeing that the levels were consistent at each of these intervals, and that the oil pressure was good, I decided I was no longer getting gas in my crankcase, and that the oil pump was working fine, and that the high readings I was getting were due to me not knowing when to check the level.
I have to reiterate, though, that I was originally getting gas in my crankcase, and that my overflow tubes never worked (I made sure they were clear). And it's still a mystery to me why that happened, except for something someone mentioned earlier, which is that when you've got excess fuel in the bowl, it seems more likely that the vacuum from the engine will suck it through the carbs rather than allow it to drain out the overflows. I would love to see a more thorough debate on this issue, if anyone's game. And I've got some other half-baked ideas I'd love to get some feedback on, so I don't spread anymore misinformation than I already have.
Thanks!
Steve.

markreimer · « **Reply #25 on:** April 14, 2017, 09:39:33 PM »

Thanks Steve. I appreciate the feedback. I may have to do the same. My 750 always had a steady oil level, whether hot, cold, just starting or after a long ride. After rebuilding the pump, top end and swapping my bottom end (had a cracked case) I've got this weird fluctuating oil level like you and apparently quite a few others. I guess as long as the tank isn't dry, or doesn't overflow, oil pressure is good, the engine should be happy.

PeWe · « **Reply #26 on:** April 15, 2017, 12:15:34 AM »

One more thing...When I used 10W-40, the oil level could get a little bit lower after sitting a while with the newer pump. 20W-50 kept the level better.
When idling in periods of a minute or 2 with a few minutes to next start during ignition adjustments, oil level was lower despite a really warm engine. Level OK to top mark after a 20 minute ride and checked direct.

Gasoline in oil will smell, very easy to detect. I have not had it in my bike, only old cars with bad automatic choke and/or extensive city driving. Oil level sank after a longer trip around 400km and really warm engine.

markreimer · « **Reply #27 on:** April 15, 2017, 08:59:07 AM »

Thanks PeWe. If anything, I've learned that prior to my engine and pump rebuild, I must have had an unusually stable oil system in my 750. Never fluctuated at all! It's sounding like that isn't the golden rule. I'm going to spend the day riding instead of staring into my oil tank today.

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Author Topic: High oil level when hot (Read 7003 times)