[Carsucharda]

As the title suggested, searching oil, oil leak, oil consumption, or oil burn, all end up with threads discussing oil type dino vs syn, rear main seal leaks, and FD failure. Its a lot to wade through.


ANYWAYS, I have a 99 lt. 157000 miles give or take. had it 1.5 years bought used with 153000. when i first bought it i drove around for a couple weeks with a few long trips in there and i noticed after a while a sputter and decreased gas mileage. After some helpful advice i pulled the plugs and found cyl 1 plug heavily oil fouled (read: oil had started to form carbon chunks that built up and shorted out the plug) and the others all lightly fouled with oil. I was at work after hours and all the places to buy plugs had closed so i cleaned them and stuck them back in. Viola! bike runs good gas mileage is up (hit a peak of 50mpg one time while babying it) Fast forward. I am riding to work this morning and i feel a sputter not big but enough to remind me of last year. I snuck out of work to buy plugs and came back put them in. runs great again. the old plugs are all fouled again #1 still the worst offender. SO, am i doomed to putting new plugs in once a year? Does this thing have a pcv valve? Is my engine not long for the world? is it time for me to buy an adaptor for my leak down tester? Is buying new plugs each year cheaper than finding/ rebuilding an engine?

Secondly, while changing the plugs i came across a noticable amount of oil hanging off my exhaust manifold. I followed it back to two possible places which were also oil soaked. there was some slight oil film on the timing cover area. there was also a noticable amount of oil in the area where the oil pressure sending unit and coolant temp sending unit are. So what "good german seals" should i be looking to replace?

I know for a fact that this bike was well maintained (the sellers shop had records) and was previously owned by someone who frequented this site and made many of the mods and upgrades already listed on this site. He was also at a CCR event in 2002 as i have a sticker on the front and back of the bike attesting to that. I think its still a good bike It just needs some love

Whew... that was long winded. So, thoughts suggestions advice?

PS. I dont want to add another oil thread (really!) so lets not discuss what kind of oil Im using or you are using.

 

[casualemt]

I am sure that you will get some LT wrencher chiming in soon, but my 2 cents is get an adapter for your compression gauge and check your compression first, then do a leak down test, put some oil in the cylinders and check compression again, if it comes up, then probably rings, a usual source of oil in the cylinders, but I know on vertical motors you can also get oil leaking around the valve seals into the cylinders, so it would be a top end job. Anyway you look at it the most logical next step to me would be the compression test...The other thing you might think about is to strip the tupperware and completely clean the motor, with gunk and a high pressure hose or spray nozzle, then ride the bike some and check for oil leak sources. As another thought, given that you are only replacing plugs once a year because of fouling, you might consider using a different oil. I used to manage a marine repair facility, and there are a couple of big refinerys nearby, we had some oil guys come and give an afternoon seminar to our mechanics on different applications for different types of oil. Without getting too deep, as oil threads can do, their take on older engines/diesel engines that had a tendancy to leak oil,(Detroit diesels a huge leaker) they said that the single weight (30W) oils had a much larger molecule than the multi weight oils, therefore required a bigger hole to leak from, end result being less oil leakage with single weight oil...

 

[patrick2000]

"After some helpful advice i pulled the plugs and found cyl 1 plug heavily oil fouled (read: oil had started to form carbon chunks that built up and shorted out the plug) and the others all lightly fouled with oil."

Getting the motor up in the RPM will most likely eliminate these issues. The BRICK needs to spin to stay healthy (IMO).

 

[pauleknight]

:corn:

 

[kellenbenz]

Just a thought ...but at that mileage a set of plug wires may be in order.

Ron

 

[MMutch6923]

Beemer Boneyard has an engine from a 03 with 7k miles on it. I would consider buying it. I don't know how much a new engine or how much a rebuild would cost since I am new here but I would think it is quite a lot. With as many miles as you have on your bike, I would not go with just a top end rebuild. I had a similar problem with my HD years ago. Did the compression test and again after spraying oil in the cylinder and determined it was the rings. Top end rebuild was enough since the bike was not high milage and I sold it shortly after anyway. Yeah, I know, flog me for making the comparison with a HD. If you are handy enough to do the work yourself, I would consider keeping an eye out for other parts as well such as a low milege tranny and final drive. I tend to lean toward the overkill though but I have had good luck with used parts on project vehicles over the years.

 

[rowie]

I just searched for the word "oil" and found this thread! but I agree - and the same is true on other motorcycle boards..... Can't help but good luck with sorting it out.

 

[jzeiler]

OK Here goes my shot. If you don't venture above 4,000 rpm very that could be the cause of your oil fouling. But if you rev her up from time to time then we need to look furthur.

Mods done to the bike. Is the brown wire cut? Is the air box temp sensor disconnected? Either one was a popular way to eliminte high temp stumble but if both are done that can lead to detonation.

Down the road with long term detonation you will end up with fractured piston ring lands and oil consumption will drastically increase. Easy fix just replace the pistons and rings. No honing of cylinders is required as they don't wear only the rings do.

I do recommend a cylinder pressure check be conducted as that will tell you the condition of the the pistons.

 

[dshealey]

OK Here goes my shot. If you don't venture above 4,000 rpm very that could be the cause of your oil fouling. But if you rev her up from time to time then we need to look furthur.

Mods done to the bike. Is the brown wire cut? Is the air box temp sensor disconnected? Either one was a popular way to eliminte high temp stumble but if both are done that can lead to detonation.

There is no brown wire on a '99. The same thing is accomplished by removing the yellow "Cat Code" plug (looks like a relay) under the top box. However, unless the Motronic is the correct one, unlikely on a '99 unless it had been replaced under the technical service advisory by a previous owner, removing the plug does not work, and the only remaining fix is to unplug the air box temp sensor (right behing the left side radiator top, near the fill cap).

Down the road with long term detonation you will end up with fractured piston ring lands and oil consumption will drastically increase. Easy fix just replace the pistons and rings. No honing of cylinders is required as they don't wear only the rings do.

Yep, I did that.

I do recommend a cylinder pressure check be conducted as that will tell you the condition of the the pistons.

 

[MMutch6923]

Down the road with long term detonation you will end up with fractured piston ring lands and oil consumption will drastically increase. Easy fix just replace the pistons and rings. No honing of cylinders is required as they don't wear only the rings do.

Sorry to disagree here but yes, cylinders do wear. Cylinders should always be re-honed before replacing rings and pistons. The cross-hatch pattern necessary for oil retention should be refreshed even if you do still see original cross hatching remaining.

 

[Dick]

Sorry to disagree here but yes, cylinders do wear. Cylinders should always be re-honed before replacing rings and pistons. The cross-hatch pattern necessary for oil retention should be refreshed even if you do still see original cross hatching remaining.

First time ever that I've heard of re-honing a brick engine with the Nik-o-sil (sp?) cylinder lining. Least on this site! I couild be wrong - btdt!

 

[saddleman]

Sorry to disagree here but yes, cylinders do wear. Cylinders should always be re-honed before replacing rings and pistons. The cross-hatch pattern necessary for oil retention should be refreshed even if you do still see original cross hatching remaining.

The only time I have ever had to hone Nikasil cylinders (like the LT's have) is when I need to make a clearance change. The honing machine I use cost $50,000 & you must use diamond stones. Most electroplated Nikasil cylinder walls can only be resized a max of .001 & even then It's risky. The bores I resize are sleeved unlike the LT that are electroplated so I know the exact thickness.

 

[jzeiler]

Sorry to disagree here but yes, cylinders do wear. Cylinders should always be re-honed before replacing rings and pistons. The cross-hatch pattern necessary for oil retention should be refreshed even if you do still see original cross hatching remaining.

Here is a shot of cylinder walls at 100K+ miles. No wear! This coating is extremely hard and applied after the initial honing at the factory.

Of course there is no saving it if you have a ring break and score the cylinder wall as it is base aluminum under the coating.

 

[MMutch6923]

in regards to honing nikasil lined cylinders I will copy and paste a couple items. First something from Ted Porter:

"Nikasil cylinders are also honed but with an Aluminum Oxide hone in 240
grit. BMW DOES recommend honing Nikasil just like any other cylinder when
replacing rings.

The Aluminum Oxide hone is less aggressive and is recommended for Nikasil.
The more aggressive Silicon Carbide is not recommended because it can damage
Nikasil if it encounters a nick or other surface imperfection by catching an
edge and lifting the Nikasil."

Ted Porter is a factory trained mechanic with a long record at well known and well regarded dealerships on both coasts. Now his training and experience are available at his independent shop in Scotts Valley, California. With his extensive history working on BMWs from 1955 to present, you can entrust your beemer to The Beemer Shop.

Honing is essential, the roughness aid the ring to bed in and develop a flat profile with the cylinder wall. If you do not hone, this important part of the running in process will not happen and as soon as you start hammering the bike after the initial run in period the rings will heat up too much and this causes them to develop a dish shape making even less contact with the cylinder wall. The end result is a smoky engine with higher than normal oil consumption.
Honing the Nikasil cylinder can be a problem, as to much aggressive honing will eventually strip of the nikasil coating of the Aluminium.
- For you that don't know; in 1980 BMW started making the cylinders completely from aluminium and coating it with a very thin but very tough nikasil coating. This gave the cylinder walls incredibly long life at the expense of the piston rings. Rings are less expensive to replace so this is a welcome change and it does increase engine life overall -.
Honing should be done by an engineer that does nikasil cylinders in general and understand the danger.
Normally a honing tool is used that look similar to a bottle brush as this type of honing device place very little pressure on the walls but still enough to leave the hone marks in the tough nikasil cylinder wall.
The purpose of honing is 1st; to aid the shaping of the rings during run in period and 2nd; oil get trapped in the grooves providing adequate lubrication to the piston rings. This is why nicasil engines last longer because the grooves does not get worn away providing less lubrication with age.
Even though the grooves is still in place after many miles, the walls are too smooth to bed the rings in properly, so it is for this reason that a light hone must be done.

*end of copying and pasting

I do not know who the person was that I quoted in the last part I pasted from the BMW tech section of the Horizons Unlimited site. For all I know, he could be a lunatic on that board. It was well worded and is something I agree with. But for all you know, I could be a lunatic as well.

Mark

 

[saddleman]

in regards to honing nikasil lined cylinders I will copy and paste a couple items. First something from Ted Porter:

"Nikasil cylinders are also honed but with an Aluminum Oxide hone in 240
grit. BMW DOES recommend honing Nikasil just like any other cylinder when
replacing rings.

The Aluminum Oxide hone is less aggressive and is recommended for Nikasil.
The more aggressive Silicon Carbide is not recommended because it can damage
Nikasil if it encounters a nick or other surface imperfection by catching an
edge and lifting the Nikasil."

Ted Porter is a factory trained mechanic with a long record at well known and well regarded dealerships on both coasts. Now his training and experience are available at his independent shop in Scotts Valley, California. With his extensive history working on BMWs from 1955 to present, you can entrust your beemer to The Beemer Shop.

Honing is essential, the roughness aid the ring to bed in and develop a flat profile with the cylinder wall. If you do not hone, this important part of the running in process will not happen and as soon as you start hammering the bike after the initial run in period the rings will heat up too much and this causes them to develop a dish shape making even less contact with the cylinder wall. The end result is a smoky engine with higher than normal oil consumption.
Honing the Nikasil cylinder can be a problem, as to much aggressive honing will eventually strip of the nikasil coating of the Aluminium.
- For you that don't know; in 1980 BMW started making the cylinders completely from aluminium and coating it with a very thin but very tough nikasil coating. This gave the cylinder walls incredibly long life at the expense of the piston rings. Rings are less expensive to replace so this is a welcome change and it does increase engine life overall -.
Honing should be done by an engineer that does nikasil cylinders in general and understand the danger.
Normally a honing tool is used that look similar to a bottle brush as this type of honing device place very little pressure on the walls but still enough to leave the hone marks in the tough nikasil cylinder wall.
The purpose of honing is 1st; to aid the shaping of the rings during run in period and 2nd; oil get trapped in the grooves providing adequate lubrication to the piston rings. This is why nicasil engines last longer because the grooves does not get worn away providing less lubrication with age.
Even though the grooves is still in place after many miles, the walls are too smooth to bed the rings in properly, so it is for this reason that a light hone must be done.

*end of copying and pasting

I do not know who the person was that I quoted in the last part I pasted from the BMW tech section of the Horizons Unlimited site. For all I know, he could be a lunatic on that board. It was well worded and is something I agree with. But for all you know, I could be a lunatic as well.

Mark

So how would the average do-it yourself mechanic perform the hone job in his garage at home with the engine still in the bike for a simple re-ring job. Don't forget the Ra finish needs to stay constant.

 

[MMutch6923]

So how would the average do-it yourself mechanic perform the hone job in his garage at home with the engine still in the bike for a simple re-ring job. Don't forget the Ra finish needs to stay constant.

It would not be for the average home mechanic with the engine still in the bike. I am no mechanic, just a relatively okay wrencher at home. Hey, for all I know, it may not be an absolute necessity. After 150k miles I - myself and I could well be in the minority here - would consider it a necessity. I do not mean to step on any toes here at all. When the time comes for me to work on my own LT, I will be somewhat clueless. Working on the HD I had was prolly more like working on a lawnmower in comparison and with that, I had varying degrees of success. It was plagued with problems and could well be due to the guy working on it.

Mark

 

[Carsucharda]

Ok. If there were no scoring on a cylinder, at least not enough to catch my fingernail on, i could in theory take off the head and the lower end and slide the pistons out and re ring them (honing discussion aside) without taking the engine out of the bike. In this process i would also, i assume be able to get to the seal or o ring or whatever is leaking down on my oil pressure gauge and coolant temp gauge. ok so now all i need is to want to tear down my bike instead of topping off the oil. I knew i shouldnt have ridden it. Now i dont want to stop. thanks everyone for your.02

 

[Carsucharda]

oh and i put around a lot so ill bring up the rpms this summer.

 

[jzeiler]

Ok. If there were no scoring on a cylinder, at least not enough to catch my fingernail on, i could in theory take off the head and the lower end and slide the pistons out and re ring them (honing discussion aside) without taking the engine out of the bike. In this process i would also, i assume be able to get to the seal or o ring or whatever is leaking down on my oil pressure gauge and coolant temp gauge. ok so now all i need is to want to tear down my bike instead of topping off the oil. I knew i shouldnt have ridden it. Now i dont want to stop. thanks everyone for your.02

FWIW I don't think your issue is just worn rings unless you have also been running a K & N filter dry. Most likely is the fractured piston ring lands so you would be replacing both pistons and rings. I know of one owner that did just that with the engine still in the bike with no issues at 100K or so. On the other hand Don Aurthur had 306 K on his when he totaled it out on the way to the Iron Butt rally several years ago. He never opened up the engine.

The oil/water pump is readily accessible for repair and replacement without tearing anything else down.