Overheat

[Julio A.]

I was stuck in severe traffic yesterday under the mid day summer sun for at least and hour and a half. Gosh, that was unbelievably uncomfortable in so many different aspects.

I thing I noticed is that the oils temp lights were turning on at 1500 RPM. When I finally reached my destination, it suddenly rained. So i'm pretty sure temperatures went down. When I started it up again, I took a alternate and non-congested route and the oil temp light went back to normal for the duration of my trip back.

I'm curious, so when the oil pressure light comes on at above idle speeds, does that mean I'm over normal operating temps?

[tvrla]

Julio - I'm thinking you've confused the oil pressure light with the charging indicator. The oil pressure light should never come on when the engine is running! But if it was the charge light, I wouldn't worry about that at all.

It's a bad idea to idle, or go slow, for long periods in hot weather as the cylinder heads and valves get very hot and don't cool. Wear can be accelerated under those conditions. At the minimum, your oil should be changed as the high temps have probably scorched it.

[Bob_Roller]

I agree, change the oil .

If it was your low oil pressure light that was coming on, not a good thing .

I think the switch comes on at 3 psi or there abouts, you don't want to run an engine with that low of a pressure .

If you ever get into that situation again, I'd park the bike after 10-15 minutes, you are not helping your engine by getting it that hot .

I've got a temp indicating dipstick, from a cold start on an 80 F day, 20 minutes at idle speed will get the oil temp to around 275F .

It goes up quicker, if you have the engine at operating temp already .

[Matt Chapter]

It's a bad idea to idle, or go slow, for long periods in hot weather as the cylinder heads and valves get very hot and don't cool.

So, since I'm in central Texas, I'm gonna print this out, put it on my boss's desk, and tell him I'll be back in late October.  No more rush hour for me!

Seriously though, when dealing with egg frying pavement temperatures and helmet to swimming pool converting traffic, what's a guy to do?  Is the R65 really being killed in those conditions, or should I just step up the oil changes a little, maybe go with a thicker grade of oil than 20w50?  My commute, at the worst, is 45 minutes to an hour, with about half in parking lot mode.  I distinctly remember doing this in 110 F a couple times last summer.

I have recently found some new routes to try with less traffic, so perhaps that'll be enough to keep me moving. Or maybe it's time to add something water cooled to the stable.

[EGRG]

In dead slow lines like at the international Bridge I just turn the bike off if your lucky the you may be going down hill and just put her in neutral. In Mexico i carefully drive on by between lanes or on the drivers side. I don't idle engine long. I keep the revs a little higher if I must. A good synthetic oil helps maintain viscosity at higher temps than normal fossil oil.

[Barry]

Overheating is not a problem I'm likely to have too often in our wonderful British climate which after the summer temperatures we had last week is now back to Winter again.

In a traffic jam there's no safety valve in an air cooled engine, no coolant to boil and  blow off forcing you to shut down. The engine just gets hotter. If I lived in a hot climate I would use the highest  quality oil (not necessarily the thickest) and fit a sump thermometer. As I understand it 250 Deg F is fine but higher temperatures begin to be a concern. By 300 Deg F it's time or perhaps past time to do something as the sump temperature is only an average and in some parts of the engine the oil will be hotter. Given which stopping is perhaps not the best thing to do as once the oil stops flowing  there's bound to be a temperature overshoot for a brief time in the hottest parts of the engine.  

So even though 300 Deg F might still be OK I would anticipate the overshoot and shut down at some lower temperature say 280 Deg F at most.

[Semper Gumby]

I've got a cooler on mine for summer ops.  I've never seen the oil pressure light on when the bike is running.  Might you want to look at the pressure relief valve next to the timing chain?

[nhmaf]

IF the oil pressure light comes on while the engine is running - it means bad news - pull over and shut the engine off ASAP!   As others suggested, perhaps you mistook the GEN light for the oil pressure light.  Excessive idling in town without RPMs getting up to 3000 or so will result in a continual discharge of the battery, which may be more of the situation that you were getting in to.   Anytime that I am sitting still in traffic for more than a minute or so, especially if the temps are getting near 100, I shut the engine off.   You do need to be wary of doing this alot, too, as frequent starting without intervals of running at decent speed to recharge will also result in a depleted battery.   For the most part, I try to avoid traffic congestion whenever I can, regardless of the vehicle.  Different routes, if possible, or changing my start time (either earlier or later) to try to avoid peak periods.   OF course, if I lived in Los Angeles, that would probably mean I would never leave the house.

[Julio A.]

I'm positive that it was the oil temp light that was going off. Anyway, I had a short ride today and it never turned on again while I was running.

Changed the oil for safety's sake.

[Barry]

The oil pressure switch is set at approx. 5 PSI so it really is time to shut down if it comes on even at idle. Normal hot oil pressure is something in the region of 20-30 PSI at idle rising to at least 60 PSI and usually higher by 3000-4000 RPM. So if you had 5 PSI at 1500 RPM the oil must have been seriously hot and thin. Wise move to change it.

There's an old rule of thumb that says the minimum safe oil pressure in an engine should be 10 PSI per 1000RPM. It's time to do something when pressures fall below this guideline. Even engines with a few hundred thousand miles should reach these figures or it's time for an overhaul or at least thicker oil in the short term.

[nhmaf]

Yes - get it out of your mind that it is an oil "temp" light - it is NOT!   It is oil PRESSURE, and when that light goes on, it means the pressure is dangerously close to "0" - very expensive engine damage will soon follow if it stays on with the engine running.


[Edit - another possibility is that your pressure switch could be failing (or wire connection to it).  These things do occasionally fail in other ways besides the usual "leaking" failure mode - and it can be the devil to determine that it is the pressure switch and not an imminent lubrication disaster when one is on the side of the road...   Good that you changed your oil, but I'd also carefully check the electrical connections to that switch as well - possibly if things were REALLY hot, something expanded and may not have been making good electrical contact!