I'm trying to decide between a rebuild of a 2QM-15 or a repower...I have the skills to rebuild the 2Qm, but I am wondering if it is worth it with a 26 year old engine. Has anyone done this, and did you have trouble getting parts such as rings, gaskets, etc? What about the transmission and parts for it? Any info or opinions appreciated.
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Rebuild or not.
Excellent question. First, are you satisfied with the power of the 2QM? My own 1979 2QM20 is too small for my H37C for example. Second, is cost an issue? I also have the experience to do the work myself. And I am sure the parts are available. I know a repower would be a minimum of $6000. if I did the work myself. I do not know the cost of the parts but could guess less than $2000. Another $1000. probably to have the yard lift and move the engine plus new mounts, etc. Bottom line for me: if the engine is running, wait until it breaks. Then if big enough, rebuild.
Excellent question. First, are you satisfied with the power of the 2QM? My own 1979 2QM20 is too small for my H37C for example. Second, is cost an issue? I also have the experience to do the work myself. And I am sure the parts are available. I know a repower would be a minimum of $6000. if I did the work myself. I do not know the cost of the parts but could guess less than $2000. Another $1000. probably to have the yard lift and move the engine plus new mounts, etc. Bottom line for me: if the engine is running, wait until it breaks. Then if big enough, rebuild.
I just had the top end of a 1977 yanmar rebuilt
All of the parts were readily available from Mack Boring. I had to wait a bit for the new exhaust elbow.
All of the parts were readily available from Mack Boring. I had to wait a bit for the new exhaust elbow.
I think the difference is similiar
to rebuilding a vehicle engine or replacing it with a totally different engine, (Chev into Ford or whatever). Rebuilding is likely always cheaper if you can pull, dismantle, re-assemble & re-install. From what I have seen parts are still available for the 2QM (I have the same engine by the way) If you replace, since the 2QM15 is no longer produced you have to go with a new engine. A new Yanmar "may" have a similiar foot print & systems (tranny, electrical fuel etc.) it is essentially a totally different engine. As Ed stated a re-power with a new engine & tranny is going to run minimum $6K plus your labour. If you are in the re-building frame of mind, the real question is why? Are you having issues with the existing 2QM? If so are you 100% sure that rebuilding is necessary? If the reason for replacing for more power, ability to run a bigger alternator, fresh water cooling etc. then that is more of a philosophical decision rather than one of necessity. It would seem that because you are thinking of rebuilding that these factors are not the major motivator. Having said all of that, if/when I run into this situation, I would be hard pressed to make the same decision. In the end I would likely re-power to gain the advantages of a new & larger engine: more power for cruising, accessories & emergencies potentially better reliability (the 2QM is very reliable & respected for its durability) better availability of parts (moot if the above is true) I can still get all of the regular maintenance items for the 2QM. Have I totally muddies the waters?
to rebuilding a vehicle engine or replacing it with a totally different engine, (Chev into Ford or whatever). Rebuilding is likely always cheaper if you can pull, dismantle, re-assemble & re-install. From what I have seen parts are still available for the 2QM (I have the same engine by the way) If you replace, since the 2QM15 is no longer produced you have to go with a new engine. A new Yanmar "may" have a similiar foot print & systems (tranny, electrical fuel etc.) it is essentially a totally different engine. As Ed stated a re-power with a new engine & tranny is going to run minimum $6K plus your labour. If you are in the re-building frame of mind, the real question is why? Are you having issues with the existing 2QM? If so are you 100% sure that rebuilding is necessary? If the reason for replacing for more power, ability to run a bigger alternator, fresh water cooling etc. then that is more of a philosophical decision rather than one of necessity. It would seem that because you are thinking of rebuilding that these factors are not the major motivator. Having said all of that, if/when I run into this situation, I would be hard pressed to make the same decision. In the end I would likely re-power to gain the advantages of a new & larger engine: more power for cruising, accessories & emergencies potentially better reliability (the 2QM is very reliable & respected for its durability) better availability of parts (moot if the above is true) I can still get all of the regular maintenance items for the 2QM. Have I totally muddies the waters?
I think our marine diesels are like farm tractors.
As long as the company is in buisness, we can get any part.
As long as the company is in buisness, we can get any part.
Not sure if a rebuild is necessary, but......
The reason I am thinking about the rebuild, is twofold: first, I am a stickler for reliability...I've sailed into my dock once because of clogged filters, and that was all I want to practice that skill, even though it went fine. Second, I put the boat in the yard the other day to redo the stuffing box and wax the topsides, and I noticed oil that appears to have run out from the back of the valve cover, and the dipstick was dislodged...signs of pressure in the crankcase...I haven't had time to check if the breather tube is clogged, which might be the problem, but I've never had any problems before, and don't want them to start now. There is no water in the oil, overheating problems, or unusual smoke, just the oil on the engine where there has been none before. Really, I was trying to find out if anyone has actually rebuilt a QM series recently and if they had parts acquisition problems...I appreciate the thoughts and advice...But I am still worried that I will get the engine torn apart and won't be able to find something like a new oil pressure relief spring or a rear main seal or a clutch...things like that. I also am leaning toward the new engine repower, as a few more horsepower would be nice, but if I can rebuild for $2000, I probably would do that.
The reason I am thinking about the rebuild, is twofold: first, I am a stickler for reliability...I've sailed into my dock once because of clogged filters, and that was all I want to practice that skill, even though it went fine. Second, I put the boat in the yard the other day to redo the stuffing box and wax the topsides, and I noticed oil that appears to have run out from the back of the valve cover, and the dipstick was dislodged...signs of pressure in the crankcase...I haven't had time to check if the breather tube is clogged, which might be the problem, but I've never had any problems before, and don't want them to start now. There is no water in the oil, overheating problems, or unusual smoke, just the oil on the engine where there has been none before. Really, I was trying to find out if anyone has actually rebuilt a QM series recently and if they had parts acquisition problems...I appreciate the thoughts and advice...But I am still worried that I will get the engine torn apart and won't be able to find something like a new oil pressure relief spring or a rear main seal or a clutch...things like that. I also am leaning toward the new engine repower, as a few more horsepower would be nice, but if I can rebuild for $2000, I probably would do that.
Call a dealer?
I guess you could call a dealer Jim. Ask the question, "if I rebuild my 2QM are there any parts NOT available?" Up here I would call Ike Torresen - Related Link. Down there I think your dealer is in Houston maybe.
I guess you could call a dealer Jim. Ask the question, "if I rebuild my 2QM are there any parts NOT available?" Up here I would call Ike Torresen - Related Link. Down there I think your dealer is in Houston maybe.
rebuild if you can
I completely rebuilt mine 3 yrs ago. not that big a project if your a half decent mech and can read. where to start? first; all parts are available for this engine except for one. (the exhaust manifold). this hasn't been avail for years and its unlikely you'll find another one in decent shape. there' usually cloged with rust and crud build up in the water pasages. I cleared mine by pokin around in it and boiling it in radiator cleaner full strength. after several boils and a lot of pokin i finally got it cleared. (i then converted my engine to fresh water cooling)I HIGHLY RECOMMEND THIS!!!!!!!! cost about $600. Sen-dure manuf. in Fla. oil leak on the valve cover gasket is a common occurence. with the passage of time the "O" ring or gasket, whichever you have, some had gaskets others had "O"ring, drys out and hardens. I have had to replace mine about every 3 to 4 yrs. I seriously doubt that you have enough blow by to push the dip stick out and still have enough compression to start. that much blow by and there would be almost silch for compression. If you decide on rebuild, completely tear down, replacing sleeves,pistons,ring etc. usually replacement of rods isn't nesc. also pressed in cam bearing are usually with in specs. mine were after about 20+ yrs. on the issue of piston etc. buy the complete kit. it comes with piston,rings,"O" rings for sleeves and sleeves.cost about $180/cly. if memory serves me parts are about $600-$700. thats for pistons,rings,sleeves,rod bearings,main bearings,all seals and gaskets. if you need head work take it to a good auto machine shop and they can completely rebuild for a couple of hundred. carefully check head for rust and corrosion. mine rusted thru at one of the intake valve ports. a new one from yanmar is $1000. i was lucky enough to find a used one from an engine in Maine that had been converted to fresh water cooling early in its life. a good investment, if you don't already have it, is a shop manual. when taking engine apart take "special" note of how many shims are under the high pressure injector pump.save them. they pertain to the injector timing. don't change them in any way, unless you want to go thru all kinds of crap to get the timing right again. the beauty of this motor is the replacability of the sleeves. the bad and ugly is that yanmar did'nt offer it in anything other than raw water cooling. this killed a lot of these motors long before their time. If you repower with a new engine its a lot of work to get everything modified to mount etc. and cost of a new yanmar 2GM series is about $6500-$7000 plus you still have to put it in the boat along with mod to make mounts etc fit. I would repower only as a last resort. On the clogged filter situation. Don't know what boat you have. but you may have alge and lots of crud in the tank. I had to remove mine when I bought it in 91 and completely clean it out at home. initially I was replacing filters about once a month. 1979 "O Day 30" GOOD LUCK Capn jim sv Que Pasa
I completely rebuilt mine 3 yrs ago. not that big a project if your a half decent mech and can read. where to start? first; all parts are available for this engine except for one. (the exhaust manifold). this hasn't been avail for years and its unlikely you'll find another one in decent shape. there' usually cloged with rust and crud build up in the water pasages. I cleared mine by pokin around in it and boiling it in radiator cleaner full strength. after several boils and a lot of pokin i finally got it cleared. (i then converted my engine to fresh water cooling)I HIGHLY RECOMMEND THIS!!!!!!!! cost about $600. Sen-dure manuf. in Fla. oil leak on the valve cover gasket is a common occurence. with the passage of time the "O" ring or gasket, whichever you have, some had gaskets others had "O"ring, drys out and hardens. I have had to replace mine about every 3 to 4 yrs. I seriously doubt that you have enough blow by to push the dip stick out and still have enough compression to start. that much blow by and there would be almost silch for compression. If you decide on rebuild, completely tear down, replacing sleeves,pistons,ring etc. usually replacement of rods isn't nesc. also pressed in cam bearing are usually with in specs. mine were after about 20+ yrs. on the issue of piston etc. buy the complete kit. it comes with piston,rings,"O" rings for sleeves and sleeves.cost about $180/cly. if memory serves me parts are about $600-$700. thats for pistons,rings,sleeves,rod bearings,main bearings,all seals and gaskets. if you need head work take it to a good auto machine shop and they can completely rebuild for a couple of hundred. carefully check head for rust and corrosion. mine rusted thru at one of the intake valve ports. a new one from yanmar is $1000. i was lucky enough to find a used one from an engine in Maine that had been converted to fresh water cooling early in its life. a good investment, if you don't already have it, is a shop manual. when taking engine apart take "special" note of how many shims are under the high pressure injector pump.save them. they pertain to the injector timing. don't change them in any way, unless you want to go thru all kinds of crap to get the timing right again. the beauty of this motor is the replacability of the sleeves. the bad and ugly is that yanmar did'nt offer it in anything other than raw water cooling. this killed a lot of these motors long before their time. If you repower with a new engine its a lot of work to get everything modified to mount etc. and cost of a new yanmar 2GM series is about $6500-$7000 plus you still have to put it in the boat along with mod to make mounts etc fit. I would repower only as a last resort. On the clogged filter situation. Don't know what boat you have. but you may have alge and lots of crud in the tank. I had to remove mine when I bought it in 91 and completely clean it out at home. initially I was replacing filters about once a month. 1979 "O Day 30" GOOD LUCK Capn jim sv Que Pasa
Capn Jim
Do you have any details from your fresh water cooling conversion on your 2QM? Sendure is not very responsive to calls.
Do you have any details from your fresh water cooling conversion on your 2QM? Sendure is not very responsive to calls.
Contact Mack Boring
If you need a part for a Yanmar they are "it" . They are the Yanmar "kings" in the US, if they don't have it or can't get it then I'd start worrying. Here is the link http://www.mackboring.com/ I had a 2QM-15 that was running solidly after 20 years. I sold my old boat -- but its probably still running. Other than a bit hard to start when cold (probably slightly burnt valves - and needing a valve job) that engine was a real reliable work horse and never failed me once she got started.
If you need a part for a Yanmar they are "it" . They are the Yanmar "kings" in the US, if they don't have it or can't get it then I'd start worrying. Here is the link http://www.mackboring.com/ I had a 2QM-15 that was running solidly after 20 years. I sold my old boat -- but its probably still running. Other than a bit hard to start when cold (probably slightly burnt valves - and needing a valve job) that engine was a real reliable work horse and never failed me once she got started.
thanks, Capn Jim, Ed, Fred and everyone else
really appreciate all the response...that is what makes this board special....capn Jim, what sort of exhaust elbow is not available, the U shaped one or the more common angular shaped one? I think my problem is probably just the o-ring (or lack of one) in the o ring groove in the valve cover....seems that somewhere along the line someone used "blue goo" for a gasket, and I guess it finally gave up....so I'll replace it with the proper o ring or an upgraded version of the gasket maker sealant. Thanks for all your help...I probably will rebuild when it gets to be that time..
really appreciate all the response...that is what makes this board special....capn Jim, what sort of exhaust elbow is not available, the U shaped one or the more common angular shaped one? I think my problem is probably just the o-ring (or lack of one) in the o ring groove in the valve cover....seems that somewhere along the line someone used "blue goo" for a gasket, and I guess it finally gave up....so I'll replace it with the proper o ring or an upgraded version of the gasket maker sealant. Thanks for all your help...I probably will rebuild when it gets to be that time..
Part thats not available on 2QM
Its not the exhaust riser "U" shaped fitting,which is bolted on the rear of the manifold, that part is available. the exhaust manifold is the part that has the thermostat mounted on the top of it. the manifold is bolted to the side of the head. that's the part that is no longer available. if your cover has the groove in it then it takes an "O" ring. I would'nt bother with the sealant. I've done it before and its really just a stop gap measure until you can get the proper gasket or whatever.
Its not the exhaust riser "U" shaped fitting,which is bolted on the rear of the manifold, that part is available. the exhaust manifold is the part that has the thermostat mounted on the top of it. the manifold is bolted to the side of the head. that's the part that is no longer available. if your cover has the groove in it then it takes an "O" ring. I would'nt bother with the sealant. I've done it before and its really just a stop gap measure until you can get the proper gasket or whatever.
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