Pesky oil leak - need some expertise please

Need some guidance/expertise please.

Just got my 2011 GRiSO back from the shop. I had the roller conversion kit done, throttle bodies balanced, and loaded with a new remap from Beetle.

Bike runs much better than before. Noticeable. No deceleration pops/crackles at any RPM or gear (maybe I heard 1 or 2) on my 40 mile ride back home from the shop.

However, I'm experiencing an oil leak somewhere. When I dropped the bike off to the shop before the work to be done - I noticed my left pant leg was sprayed with oil. It was on the left side frame and surrounding areas. It was very hard to determine where it was coming from at that time. We assumed it was a leaky valve cover gasket, but knew it was getting a fresh gasket in the roller kit. So we figured it would get replaced and sealed up.

On my ride back home from the shop after the work was done, I pulled into my garage and noticed it was spraying oil like before. It was on the left side mostly, a little on the right as well. You could see a droplet on the valve cover, and quite a bit on the frame closest to my leg, none really on the exhaust. Before I purchased this bike a few weeks ago - the previous owner had the base and head gaskets replaced by the MG dealer in his area. Dropped something north of $1,200 doing so. He obviously was experiencing a leak as well. Had them do a dye test, and had all the base and head gaskets replaced.

I just find it very hard to believe that those gaskets would still be leaking. But, at the base of the heads etc, it did look moist/wet in those areas. I just can't tell if that's where it's coming from, or if it's coming from somewhere else and when riding under load the oil is just getting blown backwards over the motor and other places.

Are there any specific areas to look where oil would be coming from? Like a leaking or cracked hose etc? I've noticed two hoses towards the rear of the engine, under the seat and fuel tank that appear to be open ended breather type hoses? They don't connect to anything, but they don't seem to be an exit tube where oil would come out of.

I'm all ears and would appreciate any help. I just want this bike to be leak free and safe for the road. I've not been able to enjoy it since owning it, and it's making me lose faith in these intricate Italian machines. Thanks

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There are numerous places oil can leak from but the fact your rocker cover and upper head are bearing the brunt of it makes me think that unless you have a porous head, which is very rare, the answer may be far simpler.

First thought let’s list some of the common leak points.

Phase sensor gasket.
Oil pressure sensor.
Cooling gallery plugs.
Breather hoses.

Now the thing is, given the location of the oil the only one of those that looks like it might be relevant is the breather hose maybe if it has cracked up by the condensor box but also on the breather box there is a ‘Spare’ spigot on the left hand side that is capped off with a small rubber ‘Condom’. This condom is, in typical Guzzi fashion, made from a material that degrades when in contact with oil! Exactly what you don’t want for something like this! Anyway, over time this condom becomes soft and floppy and eventually will split and when it does you end up with oil from the condensor box blowing back down the left hand side of the bike! The spigot, being just behind the steering head is high enough to deposit oil on the rocker cover and is, apart from the breather hose connection to the condensor box, the only thing that can leak that is high enough to throw oil back onto the rocker cover.

Head and base gaskets are coated steel, the head gasket is laminated the only time I’ve ever seen a head gasket leak was after a rollerisation where the person who did it did not replace one of the oil dowels between head and barrel so it is unlikely to be that and the oil is too high up anyway.

As for the hoses? The one shown in the picture looks like the gutter drain hose which should be plugged onto a nipple just in front of the frame crossmember on the tank. If the oyher one is the same size it is likely the tank vent hose and should likewise be plugged onto an identical nipple on the right hand side of the back of the tank. If it is not connected and your bike still has its charcoal canister connected not having the vent pipe connected may make the bike run a bit roughly at idle.

There is one hose in that general area that is just open to atmosphere. It is the gearbox breather and it just loops up and then points down near the LH inlet manifold.

Pete Roper wrote:

There are numerous places oil can leak from but the fact your rocker cover and upper head are bearing the brunt of it makes me think that unless you have a porous head, which is very rare, the answer may be far simpler.

First thought let’s list some of the common leak points.

Phase sensor gasket.
Oil pressure sensor.
Cooling gallery plugs.
Breather hoses.

Now the thing is, given the location of the oil the only one of those that looks like it might be relevant is the breather hose maybe if it has cracked up by the condensor box but also on the breather box there is a ‘Spare’ spigot on the left hand side that is capped off with a small rubber ‘Condom’. This condom is, in typical Guzzi fashion, made from a material that degrades when in contact with oil! Exactly what you don’t want for something like this! Anyway, over time this condom becomes soft and floppy and eventually will split and when it does you end up with oil from the condensor box blowing back down the left hand side of the bike! The spigot, being just behind the steering head is high enough to deposit oil on the rocker cover and is, apart from the breather hose connection to the condensor box, the only thing that can leak that is high enough to throw oil back onto the rocker cover.

Head and base gaskets are coated steel, the head gasket is laminated the only time I’ve ever seen a head gasket leak was after a rollerisation where the person who did it did not replace one of the oil dowels between head and barrel so it is unlikely to be that and the oil is too high up anyway.

As for the hoses? The one shown in the picture looks like the gutter drain hose which should be plugged onto a nipple just in front of the frame crossmember on the tank. If the oyher one is the same size it is likely the tank vent hose and should likewise be plugged onto an identical nipple on the right hand side of the back of the tank. If it is not connected and your bike still has its charcoal canister connected not having the vent pipe connected may make the bike run a bit roughly at idle.

There is one hose in that general area that is just open to atmosphere. It is the gearbox breather and it just loops up and then points down near the LH inlet manifold.

Hey Pete,

So I had a few days to really dig into this GRiSO.

A few things that I was able to button up and get sorted out. I'll list them here and explain what is still going on.

Oil was definitely over filled. Not good. Probably more than likely the culprit of all my problems but I'll dig further. It was a out .5 L over. So the shop went by the book. I now have it to a level where it's just over the low line indicator on the dip stick.

There were quite a few open ended hoses. One was a fuel tank over flow hose which was easy. The other was the drain port hose on the rubber battery tray box, easy.

The two that were more critical....one being the clear hose on the back left (sitting on the bike). This connects to the air box on the rear, it was disconnected. I connected it, but need to get a worm gear clamp or the like to make sure it stays.

The other was on the right side, the larger diameter hose that connects from the front of the bike in front of the fuel tank (oil bypass box?). It was connected there at the front, but disconnected at the rear air filter box. It was for some reason just routed at a 90 deg angle towards the cylinder head half way of the fuel tank. This one was a little oily on the end and had a white type of gunk at the end. I cleaned it the best I could, followed the contour of the tank and hugged it as close as possible, then hooked it to the rear air box port.

Upon doing all this clean up, I pulled the battery, and opened up the air box. Yep, a pool of oil at the bottom. Ugh. Cleaned all this up and was very methodical in doing so. Buttoned her all back up. Oil leakage areas cleaned up, all hoses connected.

So this is all AFTER I got the bike back just last week. I had the B roller kit installed, throttle bodies balanced, and I loaded the Beetle map. On my ride home the bike felt great, but it's when I got home in the garage is when I noticed the spray of oil on the sides etc. That's what prompted me to clean and do all the steps above.

Ok, but now that everything is hooked up....the first time I started the bike back up it was running pretty rough. I figured the computer was relearning and adjust air/fuel? It would idle at 1200ish rpm, then dip, then catch itself, stumble, etc. Wasn't like before when I rode it home. I disconnected the main fuse for 5 seconds and reconnected. Ran better, but still fluctuating idle and kind of 'confused'. Spoke to beetle and tried rewriting the map and resetting the TPS...still about the same.

So here is my thought, and questions. Since the throttle bodies were balanced BEFORE all the hoses were connected, I'm assumed they now need rebalanced. This could be causing the poor and inconsistent idle? By now having the oil bypass hose connected to the air box, is that creating a different type of vacuum situation to where the throttle body balance adjustment is now out of whack? I understand by having the front and rear air box connections unhooked, it was sucking in unfiltered air. Not good. Fortunately, I don't think it was like this for long at all.

I'm open to your thoughts. I'm really hoping that if I rebalance the throttle bodies, it will clear things up. I'll be getting that done tomorrow. Any insight is greatly appreciated. Thanks

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First thing you need to do is remove the throttlebodies and clean them thoroughly, they won’t function properly if they are dirty and oil clogged.

Once they are reinstalled you need to make sure that all the hoses, vent, breather and drain, are connected correctly and the two airbox drains, (Both the one at the back on the left and the one that exits the bottom of the box in the centre, are not only connected but plugged as well.

Sadly, even after that I suspect that you will still have stumbling problems at idle because I am afraid that the damage to your throttlebodies has already been done. The ‘Chuffing’ and resultant sudden drop in idle speed is due to excess air passing the butterflies due to choke, plate and spindle wear in the TB’s themselves as a result of having run without effective air filtration for who knows how long. The reason why it has suddenly manifested itself is that after remapping you have cleared the trims and the ecu has returned to baseline settings and, being an open loop map, will not re-trim. Even if you were to revert ro a closed loop map though it won’t re-trim in a manner that will combat the spitting. This is not a result of the remapping per-se and it would have occurred anyway as soon as you disconnected the battery or pulled the main fuse as either of these actions will clear the trims.

So what can be done about it? Well, sadly, not a lot. BUT it may be able to substantially improve the issue.

As stated the starting point has to be clean throttlebodies and properly connected hoses. From there the TB’s should be balanced in the usual manner. Then, running the open loop map you can try just increasing the CO trim basically until the ‘Chuffing’ subsides. The more wear in the TB’s the higher the CO trim will need to be and it can be disturbingly high! Like +20 or more! It all depends on how much wear there is and how much inaccuracy there is in the air metering.

The only real fix is new throttlebodies and they, sadly, are no longer available, (Although the factory claim they are but I know people who have been waiting close to two years for them to appear! It’s just not happening.)

As I’ve said before and bang on endlessly about, this is the reason it is so important to make sure you use a proper paper element air filter, make sure the entire vent/breather/drain system is connected properly and the bike is correctly tuned. In this case I’m sure that the problem can be minimised but sadly it can’t be fixed.

Pete Roper wrote:

First thing you need to do is remove the throttlebodies and clean them thoroughly, they won’t function properly if they are dirty and oil clogged.

Once they are reinstalled you need to make sure that all the hoses, vent, breather and drain, are connected correctly and the two airbox drains, (Both the one at the back on the left and the one that exits the bottom of the box in the centre, are not only connected but plugged as well.

Sadly, even after that I suspect that you will still have stumbling problems at idle because I am afraid that the damage to your throttlebodies has already been done. The ‘Chuffing’ and resultant sudden drop in idle speed is due to excess air passing the butterflies due to choke, plate and spindle wear in the TB’s themselves as a result of having run without effective air filtration for who knows how long. The reason why it has suddenly manifested itself is that after remapping you have cleared the trims and the ecu has returned to baseline settings and, being an open loop map, will not re-trim. Even if you were to revert ro a closed loop map though it won’t re-trim in a manner that will combat the spitting. This is not a result of the remapping per-se and it would have occurred anyway as soon as you disconnected the battery or pulled the main fuse as either of these actions will clear the trims.

So what can be done about it? Well, sadly, not a lot. BUT it may be able to substantially improve the issue.

As stated the starting point has to be clean throttlebodies and properly connected hoses. From there the TB’s should be balanced in the usual manner. Then, running the open loop map you can try just increasing the CO trim basically until the ‘Chuffing’ subsides. The more wear in the TB’s the higher the CO trim will need to be and it can be disturbingly high! Like +20 or more! It all depends on how much wear there is and how much inaccuracy there is in the air metering.

The only real fix is new throttlebodies and they, sadly, are no longer available, (Although the factory claim they are but I know people who have been waiting close to two years for them to appear! It’s just not happening.)

As I’ve said before and bang on endlessly about, this is the reason it is so important to make sure you use a proper paper element air filter, make sure the entire vent/breather/drain system is connected properly and the bike is correctly tuned. In this case I’m sure that the problem can be minimised but sadly it can’t be fixed.

Kind of as I suspected, unfortunately. Ugh.

However, to be fair, I don't honestly believe these hoses were disconnected long at all. If I've read the log of work done on this bike, and the probable shop that left the hoses disconnected in the fashion I noticed...I'm 'hoping' it was honestly less than 100 miles.

When I picked the bike up last week from the roller kit install and throttle body balance, it ran awesome on my ride home from their shop. I had loaded the Beetle map there, then rode it home. It was an immediate improvement over the factory map when we started it up.

Now, I am wishful in thinking, and could very well be accurate in my assumptions....that these hoses were truly unhooked for VERY little time. It was in 2 shops' hands within the last 100 miles. And both shops unfortunately had overfilled the oil to the 3.5 L that the book states. It's unfortunate that the shop that did the roller kit didn't notice these hoses not being connected. Overlook..could have been the shop that worked on it before I got it that left them unhooked. That's my hope - and that was less than 100 miles ago.

The fact that the bike ran well when I rode it TO the shop (even on the factory map and flat tappets) AND coming home from the shop after the work done is just kind of giving me hope here.

I'm really hoping the throttle bodies just need a good cleaning and rebalancing.

If they were truly clogged and worn out, wouldn't the bike have ran poorly before and after the work and remap? That's where I'm kind of trying to play devil's advocate.

The only thing I've done since getting the bike home has been hooking up the hoses I mentioned. I'm betting whatever oil residue that was on that oil bypass line is playing funny with the throttle bodies since it's now hooked up. Again, wishful, but also seems logical. Obviously that hose being hooked up is creating more vacuum at that air box and it's maybe sucking in whatever residial oil was left in that line or box? No?

Just talked to the shop owner. We are going to take the throttle bodies off tomorrow and put them in an ultrasonic cleaner just for good measure.

I wouldn’t do that! The TPS is very difficult to remove without destroying it and it wouldn’t take kindly to being submerged in an ultrasonic cleaner!

Also make sure that the hoses to the charcoal canister are connected or remove them and plug the manifold ports where the little barbs are that the individual hoses connect with 5mm screws. If the hose is disconnected from the charcoal canister it is another leak point for air that will upset the mixture.

Pete Roper wrote:

I wouldn’t do that! The TPS is very difficult to remove without destroying it and it wouldn’t take kindly to being submerged in an ultrasonic cleaner!

Also make sure that the hoses to the charcoal canister are connected or remove them and plug the manifold ports where the little barbs are that the individual hoses connect with 5mm screws. If the hose is disconnected from the charcoal canister it is another leak point for air that will upset the mixture.

Man, I don't know what the heck to do at this point.

He offered to pick the bike up tomorrow and trailer it back to his shop. We talked about this in great detail over the phone. He offered to take the throttle bodies off and clean them in the ultra sonic cleaner to make sure they were as clean as possible. He would not be touching the TPS he said, or submerging it.

If that is not recommended, what do you suggest we do? This is getting more complicated than I feel like it needs to be. It's also making me not want to mess with another European bike. LOL

Just make sure the TPS doesn’t get submerged. Also make sure that he knows how to balance the TB’s and how it is absolutely vital that the throttle stop screws not be touched!

Get him to watch my Throttlebody do’s and don’ts video if he is the least unsure.

Really, there has never been an easier bike to tune than a W5AM Guzzi. It’s just that if people don’t understand how the system works or why cleanliness is so very important they open themselves up to a world of pain. That isn’t the bike’s fault.

Well, first things first. The shop owner came over this morning with intentions of trailoring the GRiSO to his shop. We discussed the intricacies of cleaning the throttle bodies and the TPS. He fully understood and isn't foreight to Italian bikes.

I had a chance to show him and go over the bike mentioning the hoses that I discovered being disconnected. We both agreed the game plan was to delicately clean the throttle bodies and give it another shake down.

Right before we were to load it up I asked if he wanted to hear it run so I could have him witness the fluctuating and erratic idle. I fired the bike up, and as my luck would go, the motor idled at 1500ish RPM for a short second (like it always did) and jumped right down to 1200 RPM where it should be. It never once dipped down low like it was doing over the weekend when I had the battery disconnected, hoses all hooked up, etc.

I stood there in somewhat disbelief, but also relief! We let it run for a good couple minutes and I took it for a test spin. Ran through the gears nicely and like it should (and what I would expect). Got back to the driveway and we decided to pull the plugs just for good measure. Sitting on the bike, left side was good, more white than I would have imagined, but good. The right side was pretty black, interesting. We cleaned it off with a wire brush and put them back in.

Took it for another good spin and it rode just as well as the first time. Pulled the plugs and they were more of a mocha brown. I'll monitor again after putting some more miles on it.

We did discover that the front fork seals were/are leaking.....and this was 'most likely' the oil leak I thought I was having. They are leaking worse than I had thought, which makes sense, as I'm riding the oil is spraying backwards. Doh! I'll address that.

But this brings me back to the fluctuating/erratic idle I was having over the weekend. It seems to have 'cleared itself up'. I don't know why or what - but it's idling perfectly now. My elementary logic is telling me that after the battery was disconnected, the fuel trims were reset and I threw the Beetle map at it as well. The ECU was just conflicted and confused and trying to relearn itself. Makes sense to me, but I'm by no means a wizard when it comes to that.

I did ask Beetle if the map he provides makes any difference for altitudes. I live and ride at about 8,400 FT above sea level in the mountains here. I'm wondering if he can tweak the map to justify or take advantage of tuning for that further. I'll wait to see what he says.

There is no ‘Learning’ done with Mark’s map. It’s an open loop map.

When removing the plugs how do you remove the plug caps?

"When removing the lugs how do you remove the plug caps?"

What do you mean? We pulled the spark plug boots off and removed the plugs?

If it doesn't relearn anything, ok, that makes sense.

I'm fairly convinced that whatever crud that was initially in the idle stepper circuit was cleared out, now that the hoses are hooked up. It just points that way in my opinion. It's running literally perfectly fine now other than the things mentioned in my last post.

OK, that may be a contributor to the poor running. You should never pull the plug caps off from above, it almost always damages them, either breaking the resistor in the cap and/or tearing the rubber of the cap. This allows the spark to arc to earth at the rocker cover making the ride very jerky as one or both cylinders cut in and out. You can check if this is happening by removing the plug cap covers and watching and listening for the spark to snap to earth. If you do it at night or in a darkened garage it is more easily visible.

The safe way to remove the caps is with a long, thin screwdriver inserted through the cooling tunnel above the exhaust manifold in the head. You can poke around and feel the rubber of the plug cap and hook the tip of the screwdriver underneath it and lever it off the plug. Once unclipped from the plug electrode it can be withdrawn from above with ease.

Got it! That's a very nice trick and I appreciate you sharing that. I just figured there was no other way to remove the spark plug boot other than pulling up on it. Great to know moving forward.

I'm going to put some more miles on the bike and see how everything settles and shakes out. I'm just happy that the rough idle has subsided, at least for now and hopefully forever!

Get the fork seals fixed first or you’ll oil your brakes.