carbon in sump

Dec 15, 2012
107
5
austell, GA, USA
I am currently pulling my 1915 engine out of my trike to install larger valve heads. While draining oil I noticed a large amount of non metallic carbon crud under the sump screen. before parking it I had two things happen that I am wondering if they might have been the source of this. This past summer, I did a long trip on the trike mostly at highway speeds. I did not do an oil change on it during the 4800 miles, but did one when I got back. I did not pull the plate at that time, just the plug, but I did not notice any grit in the oil at that time. (There may have been some, just didn't stand out.)
After being home for about a month, I blew a spark plug out, and because I was in a bad area of Atlanta, I just went ahead and limped home on 3.
My first instinct is to assume this carbon is due to combustion gas passing at least one set of piston rings. Engine is a 1915 built in 2005 with about 45000 miles on it. Ran smooth with no loss of power or change in performance until the plug popped out. Could driving home on 3 cylinders have caused this much carbon in the sump?
Unfortunately, I have already pulled it and can't do a compression test right now.
Thanks
 
I am currently pulling my 1915 engine out of my trike to install larger valve heads. While draining oil I noticed a large amount of non metallic carbon crud under the sump screen. before parking it I had two things happen that I am wondering if they might have been the source of this. This past summer, I did a long trip on the trike mostly at highway speeds. I did not do an oil change on it during the 4800 miles, but did one when I got back. I did not pull the plate at that time, just the plug, but I did not notice any grit in the oil at that time. (There may have been some, just didn't stand out.)
After being home for about a month, I blew a spark plug out, and because I was in a bad area of Atlanta, I just went ahead and limped home on 3.
My first instinct is to assume this carbon is due to combustion gas passing at least one set of piston rings. Engine is a 1915 built in 2005 with about 45000 miles on it. Ran smooth with no loss of power or change in performance until the plug popped out. Could driving home on 3 cylinders have caused this much carbon in the sump?
Unfortunately, I have already pulled it and can't do a compression test right now.
Thanks

Don't know if this helps,:Shrug: When I had Beetles, 71 and a 73 every time I changed the oil I would always find crud on the screen... And I had well over 3 hundred thousand miles between both of the engines.. And by coincident I also had a plug blow out, Rode about 60 miles on 3 till I got home and then I Hellcoill it with no ill affects .
 
Can't make carbon without fire. Can't make fire without spark. No plug, no fire, no carbon. 4500 miles on an oil change didn't do it either. Sounds like time for some oversized pistons and rings while you in there doing the heads.
 
Can't make carbon without fire. Can't make fire without spark. No plug, no fire, no carbon. 4500 miles on an oil change didn't do it either. Sounds like time for some oversized pistons and rings while you in there doing the heads.

Yeah. I know it didn't come from the open cylinder, just don't know of limping 20 miles with three helped it along any.*
Bottom end is tight. Heads are new, do you think I'd be better off just picking up a new cylinder/piston/ring set? I'm use to larger engines and was surprised that the cylinder sets didn't cost more.
what surprised me was that I had the sump off several times over the last couple years and nothing.. not the smallest bit of grit. Now there is a lot built up around the screen. I run an external filter and the oil usually came out very clean every 3000.
But I see your point. I don't really want to drop the engine twice in a year as I travel on this one quite a bit.
 
Matman wouldn't bother me a bit if no metal was found . I always drop the plate and clean the screen , anal about that stuff , just the way I am , right or wrong .


I've been inside a lot on engines , including Detroit 60 series, Cats and Cummins and if I don't find metal , do what I'm in there for and be done with it .

If the engine is running good just put the Heli-core in and throw it back together , hard to believe that 1915 didn't have enough power without bigger valves , if that's the reason for change . Hope it all works out for you Rick , if I can help just PM me .ThumbUp
 
Matman wouldn't bother me a bit if no metal was found . I always drop the plate and clean the screen , anal about that stuff , just the way I am , right or wrong .


I've been inside a lot on engines , including Detroit 60 series, Cats and Cummins and if I don't find metal , do what I'm in there for and be done with it .

If the engine is running good just put the Heli-core in and throw it back together , hard to believe that 1915 didn't have enough power without bigger valves , if that's the reason for change . Hope it all works out for you Rick , if I can help just PM me .ThumbUp

Reason for the new heads is that someone already helicoiled this one and it cracked and spit out the helicoil. The Crack is between a valve and the spark plug so I went with some higher quality heads. (Cb)*
 
I'll pull heads off tonight. I guess I'm just torn between did the engine start blowing past a piston recently, or is this just carbon built up that I missed because my last couple oil changes I just drained the plug and not the sump screen.*
 
One thing about it my friend YOU have to live with your decision if I was that concerned I'd do what I thought was best .

A couple great engine guys on here that could help you I'm sure ,,,,,,one that comes to mind is loner and always willing to share knowledge . A PM may save you a lot of grief and a little money ,,,who's not up for that . GOOD LUCK :)
 
Thanks for the suggestion Rick. I sent Loner a PM. I have no problem working on it but sometimes I find myself going further than what was needed. If I don't hold back I'll have a new engine over a popped plug and some carbon
 
That is just sludge, I find it all the time on my VW engines. The sump plate is the lowest point on the engine so it collects there. It's nothing I have ever worried about.
 
I've seen sludge in car and motorcycle engines quite a bit, I was just concerned because I had seen none for 35000 or so miles, then suddenly a pile of large crunchy chunks.
 
I thought about that and about the oil quality. I usually get Castrol, *and it is possible I may have put some cheap stuff in there at one time. . On one of my trips I lost my oil cap for I don't know how long, then used a rag zip tied over the filler neck. Could have been a few different things. No idea.
I have an external filter. I will check it next.

- - - Updated - - -

It has actually been more like 10k since sump plate was pulled
 
I've been using hp 1 pram filters. I put a fresh one on before and changed it after the trip.so no more than 4 to 5k at the most on filters. I use to drop the sump plate every time I changed oil but haven't the last couple changes. I guess I need to go back to cleaning the screen every time I change oil.
 
One thing about it my friend YOU have to live with your decision if I was that concerned I'd do what I thought was best .

A couple great engine guys on here that could help you I'm sure ,,,,,,one that comes to mind is loner and always willing to share knowledge . A PM may save you a lot of grief and a little money ,,,who's not up for that . GOOD LUCK :)
Thanks for suggesting Loner. Got a message back with some good suggestions. Going to plan to do at least a rering when I replace heads. I pulled the heads and cylinders today. Pistons look good, cylinders are pretty good with just a very light ridge of carbon at the top, rings have too large a gap.
I also realized when I got it out that my crankcase breather has been blowing oil.
 
Am I searching correctly? I'm finding rings about 100 bucks and whole cylinder piston ring sets are about 200 to 250. Makes me want to just bite the bullet and put on new top end .*

- - - Updated - - -

Updated information: I don't have a odometer on this so my mileage is a list in a maintenance journal that comes from my gps tracker. I was only counting the second page which is what I've done over the past 3 years. Since 2005 the engine has a total of 96000 miles. Guess that increases the chance of these rings/cylinders being worn.
 
Reason for the new heads is that someone already helicoiled this one and it cracked and spit out the helicoil. The Crack is between a valve and the spark plug so I went with some higher quality heads. (Cb)*

Just an informed? guess here but..... you've been leaking hot combustion gasses via the crack in the head from the spark plug area into the valve area---- this hot combustion gas has heated the oil and cooked it to coke (think hot turbocharger and stopping the engine without a cool down) What you're seeing on the plate is the chunks that the screen "filtered" out. Swap out the heads as you've been leaking a while ---- at least long enough that the erosion finally weakened the spark plug threads enough that they couldn't hole the plug in any more!

Can't speak for the 1915 engine but if you drove a 1600 or 1700 cc over 50,000 miles without doing a valve job many rebuilt or bought new/used engines at about 65,000 miles when the valve head dropped into the cylinder and did MUCH damage!
 
ThumbUpThumbUpThumbUp,,,,Makes perfect sense ,,,,ThumbUpThumbUpThumbUp . A lot of good tough little motors short lived from lack of oil changes and valve adjustments at the right time .
 
Am I searching correctly? I'm finding rings about 100 bucks and whole cylinder piston ring sets are about 200 to 250. Makes me want to just bite the bullet and put on new top end .*

- - - Updated - - -

Updated information: I don't have a odometer on this so my mileage is a list in a maintenance journal that comes from my gps tracker. I was only counting the second page which is what I've done over the past 3 years. Since 2005 the engine has a total of 96000 miles. Guess that increases the chance of these rings/cylinders being worn.

That is high mileage, while you have it out you might as well rebuild the entire engine. While your doing that you might as well go for a rebuild that will give you more HP, put on dual carbs. Sure, it will cost a lot but at least you'll have peace of mind knowing you have a good, reliable engine.:pepper:
 
ThumbUpThumbUpThumbUp,,,,Makes perfect sense ,,,,ThumbUpThumbUpThumbUp . A lot of good tough little motors short lived from lack of oil changes and valve adjustments at the right time .

Well.... in my defense....:cxtv: the oil never went over 3000 or so between changes. Except on long trips.. just didn't drop the sump plate.

I did pull the jugs and checked the rings and they have about 3x the gap they should. I was thinking about just new rings but for the price, a whole new set of pistons jugs and rings seems like a good idea. Doing route 66 next spring and want the engine running dependably as it will be a little over 6k miles total. .*
 
NO NO Matman don't misunderstand my blanket statement , my point was people I've talked to that have owned VWs not knowing the importance of regular valve adjustments . It takes me about 45 minutes to adjust valves twice a riding season , maybe overkill but piece of mind for me .

This may be a practice of yours also , don't know , but do know some have no clue , so I certainly didn't mean it the wrong way .:):D
 
Mahle vs. AA? Not being critical, but if you need to ask, then no - use the less expensive. Like you say, you don't want this to become a money pit and you aren't looking to build a super high dollar/performance engine.
 
Mahle vs. AA? Not being critical, but if you need to ask, then no - use the less expensive. Like you say, you don't want this to become a money pit and you aren't looking to build a super high dollar/performance engine.

Just found out AA us making mahle sets now. Lol. No I am not building a 300hp monster just want reliability. Bottom end seems good. I ordered a set of AA 94mm and have the cb heads ready. Light match port and polish. Realized when I got under the trike my hydraulic clutch had been weeping so I'll replace seals in that too. I'm off this week so I'm hoping to get it back on the road before next weekend.
Thanks for the advice everyone.*

- - - Updated - - -

The original heads and cylinders were both chinese. Not bad mileage....*
 
Just found out AA us making mahle sets now. Lol. No I am not building a 300hp monster just want reliability. Bottom end seems good. I ordered a set of AA 94mm and have the cb heads ready. Light match port and polish. Realized when I got under the trike my hydraulic clutch had been weeping so I'll replace seals in that too. I'm off this week so I'm hoping to get it back on the road before next weekend.
Thanks for the advice everyone.*

- - - Updated - - -

The original heads and cylinders were both chinese. Not bad mileage....*


Hey Matman, where did you get your heads and cylinder kits man? I think I have a cracked head on #1 and 2 so figured I would replace both heads. While I am in that far I'm planning on either rering or replace pistons and cylinders.
LOL, probably going to split the case as well and put in an Engle 110 or equivalent cam and straight cut timing gears. Probably going to end up doing rod, cam, and main bearings as well.
 


Actually I have found that Car Craft has better prices for the same products. Granted, they are a little tough to navigate at first but once ya figure their system out it isn't bad.
http://carcraftstore.com/

They have some dang good prices. $199.99 for the 40 x 35.5 valve heads with dual Scat springs and chrome molly retainers and keepers.

Much like everyone though, the Mahle Piston/cylinder kits are up there in price. Jeez, I remember getting a standard 85.5 set of Mahle Pistons and cylinders for about $85!!!

Of course back then a person could get a counter weighted 69mm crank for under a hundred brand new. :xzqxz:
How times have changed.
 
Actually I have found that Car Craft has better prices for the same products. Granted, they are a little tough to navigate at first but once ya figure their system out it isn't bad.
http://carcraftstore.com/

They have some dang good prices. $199.99 for the 40 x 35.5 valve heads with dual Scat springs and chrome molly retainers and keepers.

Much like everyone though, the Mahle Piston/cylinder kits are up there in price. Jeez, I remember getting a standard 85.5 set of Mahle Pistons and cylinders for about $85!!!

Of course back then a person could get a counter weighted 69mm crank for under a hundred brand new. :xzqxz:
How times have changed.

Ya times have changed but the VW aircooled lives on in many forms.
 

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