Cummins QSM11's..........
- Thread starter WarrenG
- Start date
trit21
Active Member
Warren, best place to ask these types of questions is www.boatdiesel.com. Tony Athens, owner of SBMAR.com, is the person that can answer any question you have about the QSM11, or any Cummins products, from many many years of experience with commercial and recreational use. IMO.
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
The QSM has been a good engine in Sea Ray applications. There aren't any systemic problems to watch for. However, we have had 3 boats with crankshaft seal leaks and 2 of them ended with broken crankshafts in their 4th year due to excessive forward to rear crankshaft movement. Unfortunately, Cummins wouldn't help either owner with the repair cost which was expensive. Be sure you get an engine survey done by a Cummins technician and look for an oil leak on the front of the engine before writing the big check.
cod
Active Member
I have them in my boat and I am very happy with them. Very little smoke at start up. Hardly any black soot develops on the boat hull. Always start right up and run great. But with all things marine there are always issues. These are the things that I have upgraded or repaired based on reading issues with other QSM owners.
1. Early models (I think 2003 and earlier) had problems with the air filter screening being sucked into the Turbo and destroying it. Although mine are 2005's, I decided to change it with new Air filter mfg. by Walker Engineering just to be on the safe side.
2. The bracket that holds the heat exchanger will fail and crack if it hasn't done so already. I had new custom steel brackets made. Easy fix. Tony Athens @ Boatdiesel.com sells them already made up if you don't want to go thru the trouble of making a template.
3. This is probably the biggest issue. The exhaust manifold is a "dry" system. There have been many reports of the exhaust manifold gasket failing, I would guess from the extreme heat. May never happen but the possiblity is there. I had it happen to one of my engines at about 1,100 hours. Doesn't prevent you from using the boat(Tony Athens suggested to live with it, but keep engine clean). Down side is the soot that develops on your nice white engine. I decided to take care of it last month. Fairly big job being that it requires the removal of the heat exchanger, aftercooler and turbo.
1. Early models (I think 2003 and earlier) had problems with the air filter screening being sucked into the Turbo and destroying it. Although mine are 2005's, I decided to change it with new Air filter mfg. by Walker Engineering just to be on the safe side.
2. The bracket that holds the heat exchanger will fail and crack if it hasn't done so already. I had new custom steel brackets made. Easy fix. Tony Athens @ Boatdiesel.com sells them already made up if you don't want to go thru the trouble of making a template.
3. This is probably the biggest issue. The exhaust manifold is a "dry" system. There have been many reports of the exhaust manifold gasket failing, I would guess from the extreme heat. May never happen but the possiblity is there. I had it happen to one of my engines at about 1,100 hours. Doesn't prevent you from using the boat(Tony Athens suggested to live with it, but keep engine clean). Down side is the soot that develops on your nice white engine. I decided to take care of it last month. Fairly big job being that it requires the removal of the heat exchanger, aftercooler and turbo.
Morgan Jane
Active Member
If the QSM's are like the QSC's, the leaks are not really crank shaft seal leaks and are fairly simple to fix. The leak is most likely between the metal carrier plate that holds the crankshaft seal and and the metal timing cover. The contact between the carrier plate and the timing cover is just metal to metal. In order to make a seal, Cummins uses a permatex type sealer. Once the permatex stops sticking, an oil leak will occur. Just seems like there should be a gasket. Just isn't though. Regardless, the whole thing can per repaired in less than an hour with a 1/2 inch breaker bar, a 1/2 inch 15mm socket, 1/4 rachet and a 10mm 1/4 inch socket. You take the balancer off, pry the old plate off, clean it up, apply new permatex and put it back togther. The real trick is keeping the engine from rotating. very, very simple once I talked to a Cummins mechanic. Please PM me and I can go over the details if anyone is interested. Probably a $400 service call that you can fix yourself in less than an hour.
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I've posted a bunch of stuff on here about my life over the past 8 years with QSM-11's. The only "catastrophic" issue with these engines is the cheap Racor air filter that was put on the engines. It's this brown imitation Air Sep filter that fails and the metal screen gets sucked into the engine destroying the turbo and who knows what else as it goes through the pistons and out the exhaust. Make sure the air filter is removed and look at the turbo blades for any pitting, chipping or other damage.
The front oil seal is a problem as well. Mine wasn't a crank seal but the front gear cover. There are no timing belts per se on these motors as they are all gear driven (very industrial monster motors). The original gasket material that Cummins put on the front gear cover absorbed oil and then would expand and ooze out the seams until it failed. If you see black ooze coming out the front gear cover, then you have the original goop and it needs to be replaced. Cummins came out with a new material that is an orange color goop and it does not absorb oil and will last. I'm an engineer... now I may not be the smartest guy in the room but who in the world would put a material that is not compatible with oil as a seal for oil? Sounds like the dude used to work for Cat... designed aftercoolers... Oh yeah.. it's not a real easy task replacing this seal as the front cover is attached to the front engine mounts so the engine has to be lifted off the mounts to replace the seal. I do a lot of work on my engines but I'm not lifting an engine off the mounts... A few years ago, enough screaming would get Cummins to pay. Not sure about now... This should have been a recall IMO.
The other "common" issues that always seem to happen are:
My 2 cents.
The front oil seal is a problem as well. Mine wasn't a crank seal but the front gear cover. There are no timing belts per se on these motors as they are all gear driven (very industrial monster motors). The original gasket material that Cummins put on the front gear cover absorbed oil and then would expand and ooze out the seams until it failed. If you see black ooze coming out the front gear cover, then you have the original goop and it needs to be replaced. Cummins came out with a new material that is an orange color goop and it does not absorb oil and will last. I'm an engineer... now I may not be the smartest guy in the room but who in the world would put a material that is not compatible with oil as a seal for oil? Sounds like the dude used to work for Cat... designed aftercoolers... Oh yeah.. it's not a real easy task replacing this seal as the front cover is attached to the front engine mounts so the engine has to be lifted off the mounts to replace the seal. I do a lot of work on my engines but I'm not lifting an engine off the mounts... A few years ago, enough screaming would get Cummins to pay. Not sure about now... This should have been a recall IMO.
The other "common" issues that always seem to happen are:
- Exhaust manifold leak (you can live with this... very annoying though)
- Cracking of the beer can quality coolant reservoir mount (this needs to be fixed and happens to all of them. I think Cummins has now designed 3 different brackets.. I designed and fabricated my own out of 1/4" plate steel... they work great now)
- Transmission cooler bracket replacement (Cummins will pay for this... This HAS to be done as the stupid thing will leak and the leak is right buy the air intake causing saltwater to go into the engine. Look for any rust by this heat exchanger and the hydraulic fittings.. if there is, get the oil sampled and make sure no saltwater has been going in the engine)
My 2 cents.
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- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
Gary,
You are obviously obsessed with trying to get a rise out of Cat owners...........well, here ya' go.
The Cummins guy who selected the timing cover gasket material that absorbs oil was just drinking the Cummins Kool-Aid. He selected the cheapest possible approach to a design challenge. He never worked for Caterpillar.....he was recently transferred to selecting gaskets from designing brackets and accessory mounts on the QSM-11 line.
For the original poster, just ignore the brand digs........the QSM-11 is a big tough engine that delivers loads of torque and that has minimal potential for future problems.
You are obviously obsessed with trying to get a rise out of Cat owners...........well, here ya' go.
The Cummins guy who selected the timing cover gasket material that absorbs oil was just drinking the Cummins Kool-Aid. He selected the cheapest possible approach to a design challenge. He never worked for Caterpillar.....he was recently transferred to selecting gaskets from designing brackets and accessory mounts on the QSM-11 line.
For the original poster, just ignore the brand digs........the QSM-11 is a big tough engine that delivers loads of torque and that has minimal potential for future problems.
osd9
New Member
Cummins are cute....
Isn't this the spot where Dom posts his finger-flippin' CAT picture?
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
probably.............
osd9
New Member
Knowing that you're tormented by the 'mental' picture is sufficient.