Damage from potential overheating of 98 R1100RT

[dequanimous]

I left my 98 R1100RT running for about about 10 minutes in the garage with the Throttlemeister revving about 1500 RPM (it never leaves the garage in winter). I came back in 10 minutes and the RPM gauge showed 4000 RPM and she was HOT. I shut it off immediately. The oil temp gauge was on the last bar before the red and it looks like the plastic above the head got bubbled. The bike runs fine but I would appreciate some guidance on these questions:

 

1. How the heck did the RPM ramp to 4000 RPM?

2. Did I do any damage to the engine?

3. Can the bubbling be repaired?

 

I know next to nothing about wrenching this bike other than how to ride it, which is why I bought it in the first place. Would appreciate advice. Thanks, Dave

[Rinkydink]

1. Did you have the fast idle lever on also?

 

2. Change the oil and filter. Your oil will probably smell burned.

 

3. If there is not too much body panel warpage you can probably have it painted. According to how bad it is I wouldn't worry about it.

 

4. I bet you never let it happen again so just ride it and if your hall sensor doesn't crap out you caught it in time.

[GordonB]

The RPM's went up to 4000 probably 'cause you locked in the idle speed while the engine was cold? And as it warmed up went the RPM's

[smiller]

The engine speed probably increased as the engine warmed up, which would be normal. I think you can be confident that you did no damage to the engine. The fairing can be repaired/repainted by any body shop that is familiar with plastic body part repair.

 

BTW you do not need to run the bike periodically during winter storage (if that's what you were doing.) Just store it in fall and leave it alone until spring (other than maybe charging the battery once in a while.)

[FlyingJoe]

Most likely the engine is fine, the most important element to do is change the oil as was mentioned. If you are really concerened get an oil analysis done after riding it for another 40 hours or so and do a compression check

[Eckhard Grohe]

Some people have also found that the oil sight glass started to leak after an event like this.

[dequanimous]

No I started the bike with the choke on, then shut it off and set the Throttlemeister at 1500 RPM.

 

What is the "hall" sensor? Obviously, I am technically challenged.

[dequanimous]

I had no idea that the idle speed increased as the engine warms up. Like I said, I just ride and change the oil.

 

This whole episode made me physically sick because my bike is pristine and I want to keep her that way.

[dequanimous]

I was told by the BMW tech to occasionally start the engine during the winter and let it warm up. Wish that I'd known it wasn't necessary.

[dequanimous]

Thanks for the comments. I know you tech savvy guys are thinking "what an idiot" and you are right!

[DavidEBSmith]

A couple of points:

 

- Starting the bike during the winter isn't necessary, but it isn't bad. If nothing else, starting it occasionally might chase away the little critters that like to nest in places like exhaust pipes and fuse boxes. If you do want to warm it up during the winter, you need to do it carefully. Starting it and letting it run and walking away isn't good, as you've found out. The other end of the process is that if you do start it just to warm it up, you have to make sure it gets really warmed up, all the way to operating temperature (but not beyond). This allows any condensation in the oil and the exhaust system to burn off, and not collect in little acidic puddles to eat through whatever metal they're sitting in. If you must start the bike during the winter, start it with the fast idle (choke) lever, let it fast idle for 30 seconds to a minute (or until it will idle without stalling), then shut off the fast idle. Let it sit at idle until you get four or five bars on the oil temperature gauge. Don't go wandering off - sweep the garage floor or straighten up your lawn tools while letting the bike warm up. (Did I mention that you should have the garage door open and not be in a closed space?) When the oil temperature gets to four or five bars, shut the bike off.

 

- Get a Battery Tender and leave the bike plugged into it all winter. Don't use a trickle charger, use a Battery Tender, an Optimate, or similar "smart charger". These will keep the battery topped up (which helps protect it from freezing) without overcharging and boiling off water.

 

- The Hall sensor is a solid-state replacement for the points on old distributor-equipped vehicles. It's located under the black cover on the front of the motor. It's an electronic device that tells the Motronic brain where the motor is in its rotation cycle so that the Motronic knows when to fire the spark and inject the fuel. The wiring to the Hall sensor (and less often the sensor itself) is susceptible to damage from heat, either from an overheating incident or from cumulative damage over the years. The classic symptoms are (1) the bike will start and run cold, but stops running when it warms up, and then starts again when it cools off, or (2) the bike won't run after riding in the rain, but runs again after it dries out. If your bike is running, you probably haven't damaged it, yet.

 

- It's bad for most any vehicle to start it in cold weather, walk away and ignore it for 10 or 15 minutes. Some current vehicles are computer controlled to the point that they'll automatically reduce the idle as they warm up, but most vehicles have some sort of mechanical choke or fast idle or other device that won't release until it's manually released or until you blip the throttle. The other day, my wife went out to the garage and started the Exploder to let it warm up, which I noticed a few minutes later when I heard the engine revving way too high. The difference is that the Exploder has a cooling system with a radiator and a water pump and a fan that cools the motor at 0 mph. The RT doesn't. It has an oil cooler that depends on airflow over the cooler to cool the motor, and you don't have any airflow at 0 mph. That's why the police bikes (that regularly sit idling on the side of the road) have cooling fans built in, and why BMW tells you to start your bike and ride off, and why the bike gets really hot running at fast idle with no airflow.

[BucksTherapy]

I had no idea that the idle speed increased as the engine warms up. Like I said, I just ride and change the oil.

 

This whole episode made me physically sick because my bike is pristine and I want to keep her that way.

 

If you are heating your bike up while it is stationary you can significantly alleviate concerns of overheating by placing a fan in front of the bike. This is how most folks deal with the heat when they need to work on the bike while it is running, eg throttle body sync.

 

This method has worked great for me.

[Rinkydink]

I see that you have a "mere" 5 posts so let me be the person to tell you, you are not an idiot. There are plenty of BMW owners (many told their stories here) who've experienced just what you have. The more you read on this board, the smarter you will become and hopefully the fewer mistakes you make. The knowledge found on this site is amazing. Keep us posted on what you find and good luck.

[MotoBoy]

Well, you might not get smarter, but you'll become more informed. There are some folks on this board who really know a LOT about these bikes and their quirks. Over the past several years, there have been quite a few folks who have written in about having done just what he did, and as I recall, no one ever indicated any lasting mechanical difficulties.

[dequanimous]

I appreciate all the comments and advice and have learned a great deal from this forum after being a member for only a couple of days. You guys really know a lot about your Beemers and I am clueless. I did have a semi legit excuse for leaving the bike running - You can't trust a 6 year old and a 1 year old by themselves for more than about 60 seconds!

[ChrisM]

I don't believe in starting the engine unless you're going to let it get up to normal operating temperature (by riding it). Short running times just add to the moisture and acids in the oil, cylinders, exhaust, etc.

 

However, it might not hurt to pull the plugs and turn over the engine with the idle and throttle closed, just to circulate the oil, without any start up. Put it in neutral and let the clutch out so that the transmission splashes some oil around too.

 

On the other hand, the ideal is always to find one of those occasional good days and ride.