Detroit Help, we are stumped

[Liquid Asset]

To start, we have rebuilt both engines, and at first, everything ran fine. we had no problems for the first 25 hours. We went to the keys in July, and everything went fine on the way down, and then the engines ran great for the first 2 1/2 weeks while we were there. One day on the way in from fishing I noticed my temp starting to climb. I pulled it down and went through all the processes, adn could not find any reason that we were having trouble other than there had to be a loss of coolant. We limped back to key West on one engine and waited for the engine to cool. At this point, we realized there was not any coolant in the engine. I called my mechanic back home and he proceeded to come down to Key West the next day.

The initial thought was that there was a crack in the head and it was dumping the water into Cyl #2 on the port bank. We decided that there was not anything we could do in Key West and we came home on one engine.

Today, the mechanic put the bore scope in #2 and pressurised the water system without running the engine and found no water coming into the cylindars, so there is not a leak in the mid section. The problem we are having is where is the water escaping from the coolant pasages to the oil sump. It is getting in there, because when you pressureise the system, it will dump 6 gallons of coolant into the sump imedietly.

We are sure that there is nto a cracked liner, and it is not coming from a liner o-ring. Do yall know of anywhere else it can come from? could there be an internal crack on head that is allowing coolant to go into the oil passage? Could the waterpump seals be bad and dumping it out of the back into the gear drive area on the front of the engine?

My mechanic ran out of time tonight, but he was stumped at first thought and suggested I ask some guru's to see if anyone had any brilliang ideas. The water is going in there, but it is not going where we thought it was.

the good news is that I shut down the engine in time and we did not do any damage to the fresh engine. The bore scope shoed nice pretty liners (we lubricated the cylindars when the mechanic got there to protect them from damage from water).

Hopefully you all can help. Thanks in advance and sorry for the book.

[sammidog]

Ask your question on www.boatdiesel.com. From what I'm told you will have an answer there. You have to pay to join but in your case it will be worth it.

[Genesis]

Bad seal ring on the head (these engines don't use a conventional "head gasket".

But.... how much coolant is ending up in the pan? If its basically all of it, I bet you DO have a problem with a liner O-ring, as the head seals obviously get uncovered as the level drops...

[captddis]

I'm with Karl, Were the liner inserts replaced? And were the heights checked? They seal the coolant on the top, and the sealing area in the block have to be clean and smooth. The Compression seals under the head only seal compression.
That said, I vote the liner o rings. There are thin aluminum seals under the big water plugs in the block under the blower. But it does not sound like that.
If you got it hot the o rings might be toast anyway.
If you can't get it to leak cold, put hot water in and try it.

[Liquid Asset]

It leaks cold & hot. I never got the temp over 190. I was fortunetly watching it, so It never got hot before I shut it down. The problem that we are having is, it was running just fine, then all of a sudden, coolant went into the oil and the engine got hot. We put more than 25 hours on the boat before this happened.

It does not appear that there is water leaking anywhere in the mid section of the motor around the seal rings for the liners. They are new, but you would see water (especially since there is so much) leaking down with the airbox covers removed. We do not see water leaking down anywhere, it appears it must be an internal leak where it can not be seen visully.

[Brian Degulis]

What engines do you have?

[Liquid Asset]

8V92TI's @650hp

[Roscoe]

Were the engines rebuilt in the ER or are they remanufactured?

[DCMY #92]

Pat - My rebuild experience is on 6V53s rather than 92s, but they should stack up the same. I agree with you that if the liner O-ring seals were leaking you will see the water in the airbox. I can tell you from personal experience that if you had a substantial leak at a liner O-ring you would experience a drop in power, lots of steam that smells like antifreeze out the exhause and the liner with the leak will probably be cracked.

I suspect one of the several square O-rings that seal the coolng passages between the bottom surface of the head and the fire deck (top of the block) were dislodged from their recess in the fire deck when the head was set on. This is not uncommon if the mechanic did not use guide pins when installing the head. Any coolant that leaks through one of these O-rings goes directly to the sump along with the oil from the valve rocker arms. If it is one of these O-rings it won't matter if the engine is hot or cold.

To find out for sure you will have to remove the heads. When you do be sure to use guide pins in place of two of the head bolts to avoid disturbing the seals in question. If one is pinced or out of place it should be obvious.

If you have room in the bilge to drop the oil pan you might be able to tell which bank has the probelm by pressurizing the cooling system cold and avoid pulling both heads.

I'm also in Palmetto - send me an eail and I will give you my phone number if you want talk about it.

[Boss Lady]

There are three cooling zones on the liner, from the top of the liner it is water cooled with coolant contained between two o-rings recessed into the block, the second zone is air cooled by the inlet air passing through the ports, the third zone is below the ports and is cooled by water circulating through the engine block in direct contact with the liner. If you have an o-ring leak it should show up in the air galley. If it is not an o-ring, then you have a cracked block, since coolant will be leaking below the air ports in the liner and will drain directly into the pan. The most common failure is the o-rings. These can be damaged during installation, damaged by over heating, or damaged from using the wrong kind of lubricant during assembly, Detroit specifies hydrogenated vegetable shortning (Crisco) as the preferred lubricant for this purpose, LOL (I did not make this up!). Petrolium based lubricants will damage the seal. Detroit also warns against using methoxy proponal based anti-freeze, since it will damage the water seals also.

Hope this helps. Good luck

[DCMY #92]

Having thought about this some more - a more likely possiblity than either a cracked block/head or pinched coolant seal is a loose or cracked injector tube. The copper injector tube passes through the water jacket in the head. If this was a full overhaul the tubes may have been replaced when the heads were reworked. If a tube cracked or leaked at the upper end where it is rolled into the head the coolant would drain directly to the crankcase. It is likely that the engine might run OK for a while before a cracked or improperly rolled tube let go. It might also leak big-time when it does let go. If this is the culprit you should be able to tell by removing the valve covers and looking for water gushing up from around an injector.

Maybe the 92 series is different, but the 53 series has no coolant between the double O-rings on the liner and no water jacket below the airbox as described in the previous post. Unless the block were cracked through the fire deck I don't see how coolant can get into the crankcase without passing through the air box. Maybe the block or a head is cracked, but it seems unusual that would occur without first overheating.

Be careful of using Crisco to lubricate the liner O-rings. The overhaul manual does say to use Crisco or antifreeze. Apparently since the manual was written in the '40s the formula of Crisco may have changed. There are cases (including both of my engines) where the Crisco became acidic at engine operating temperatures and corroded the liner undermining the O-ring seals. This was not electrolysis. The corrosion occured in the empty space between the two seals on all liners and the wet portion of each liner above the seals was in perfect condition. It took a few years after the overhaul for the liner seals to fail. During the repeat overhaul to correct this I used the same antifreeze I run in the engines. So far (about 6 years), no leaks. Now that I have posted this information they will probably blow the next time I run the boat.

[Boss Lady]

The Detroit 92 series engines have wet liners (meaning that the coolant is in direct contact with the liner itself in the hot zone) unlike your 53 series which have dry liners and the engine relies on thermal conductance to the block to keep the liners from melting.

The 92 series design provides much more efficient cooling, which allows higher HP output over the older designs. This design does have an achilles heal. If you lose the coolant, the liners superheat and roast the o-rings. This can occur with engines showing near normal operating temperatures. This is why several people on this forum have stressed repeatedly that 185 F is the danger zone for the 92 series. Geniusis recomends extra sensors be added to give early warning of coolant loss so you can shut down and find the problem before you roast an engine.

My Detriot manual for the 92 series is dated August 1976. Hydrogenated cooking grease is an organic material, the manual does recommend using permanent antifreeze as an alternative to the Crisco.

[SKYCHENEY]

It is my understanding that 53's have wet liners similar to that of the 92's. The 71's are the dry liner engines.

[Boss Lady]

My bad, I only have experience with the 71 and 92 series. The 71s do have dry liners, I made the mistake of assuming that the 53 was dry as well.

[Liquid Asset]

Yall pray, because I found out some information today that on the 92 series detroits, there was a casting set run of water pumps that did not have a weep hole. When the water pump went, it dumped allt he water into the oil sump (stupid Idea). This casting has been corrected, and is not longer made, but rebuild water pumps can come in this style. 2 years ago, when we purchased the boat, the water pump was replced by the mechanic in Panama city before we brought the boat home. what we just discovered is that the water pump has no weep hole. My mechaic is on his way over to pull the pump, and hopefully this will be it.

Based on the volume of water, it is not a issue in the cylinders. If it is not the water pump, It has got to be a head gasket that gave way because it was defective. My mechanic did use the guide studs when installing the heads because I was here when he did them.

After all the lookiing around and talking to people, I am betting on the water pump, but we shall see.

[DCMY #92]

I'm not looking to argue or be right - just provide accurate information.

My 53 series DDA service manual (copyright early '80s) recommends either Crisco or antifreeze to lubricate the liner O-rings at overhaul. It states no preference for one over the other.

Pick you poison - I used Crisco on the first overhaul (seals failed) and antifreeze on the second overhaul (so far so good) based on advice from the guys as Florida Detroit Diesel.

[captddis]

Always used a light swipe of engine oil on the o rings. None of them have ever failed.

[yachtsmanbill]

Just to throw a wrench in the works, Ive always used Loctite anaerobic sealant. Alignment studs are always the key to success too. ws

[Genesis]

Sealant is not necessary on an O-ring. In fact, its counter-productive since an O-ring actually seals better under pressure, and a sealant can interfere with the physics of it.

[Boatsb]

I'm not looking to argue or be right - just provide accurate information.

My 53 series DDA service manual (copyright early '80s) recommends either Crisco or antifreeze to lubricate the liner O-rings at overhaul. It states no preference for one over the other.

Pick you poison - I used Crisco on the first overhaul (seals failed) and antifreeze on the second overhaul (so far so good) based on advice from the guys as Florida Detroit Diesel.


Which 53 series have you rebuilt twice? I have 8v53's and they should run forever. I have never heard of someone rebuilding them twice in a short time.

[DCMY #92]

I have 6V53s in a 1965 41DCMY. I bought the boat 25 years ago. The boat was oringally had gas engines and was repowered with the 6V53s prior to my purchase. I don't know how old the engines are or how many hours they had on them, but the serial numbers don't have enough digits to be listed in DDC's data base. I overhauled the engines the first time several years after I bought the boat due to them being hard to start. They did not need overhaul due to wear (hone marks were still visible in the liners) but due to corrosion in the combustion chambers and valve stems from sitting around the compression was low. The heads were "hemis" instead of flat and the valve stems were necked down about 50% above the stellite heads. I also changed all the rod and main bearings during this overhaul.

It was obvious that the engines had at least one previous ovehaul since there was only one liner O-ring installed rather than two. The connecting rod cap studs had also been upgraded to the current larger diameter.

I installed new (not rebuilt) heads on both engines when I did my first in-frame overhaul. After the liner seals failed a few years later all of the liners had to be replaced due to the OD corrision. I again installed new cylinder kits even though the pistons were not damaged. This may have been overkill but since the liners and rings had to be changed - why not also change the pistons. In the big scheme of things cylider kits for DDCs are pretty cheap.

I agree that you would be hard pressed to acutally wear out a 53 series by running it.

[DeeRow]

Yall pray, because I found out some information today that on the 92 series detroits, there was a casting set run of water pumps that did not have a weep hole. When the water pump went, it dumped allt he water into the oil sump (stupid Idea).
...
After all the lookiing around and talking to people, I am betting on the water pump, but we shall see.

So Pat, was it the water pump?

I assume that it was something "minor" 'cause your starting other threads about headliners and paint.

[Liquid Asset]

Nope, It was a head seal ring. It blew out and we dont know why, but the mechanic said it was most likely his fault. It is fixed, and we are off again. Fortunetly we did nto do any other damage after he inspected it.

Once we change the oil tomorrow, we will run the boat and be back to normal.

[DeeRow]

Glad to hear that your mechanic stood behind his work.

Mark

[Boss Lady]

Pat, how long do you think you ran that engine on the water/oil mix? I would definitely drain what water I could off the old oil and have an analysis done to see if you have any bearing material, same goes for cutting open the oil filter. To be on the safe side.

Chris

[Liquid Asset]

Chris,
Unfortunetly because we imedietly changed the oil adn removed the water from the cooling system, the old oil is gone. When this happened in Key West, we wanted to preserve everything and when my mechanic got there we drained the oil and put new in and lubricated everything with it by running it for a minute without water. This was to keep anythign from rusting that should not have had water on it

My mechanic said not to worry about it. He has carefully inspected everything and said that this is not his first experience wtih this much water in the pan and it did not get so high as to reach the bearings. He did 20+years in the Navy as a detroit mechanic. I did not run the engine long at all, and I stoped it before it overheated. He will stand behind anything anyway. He has become a personal friend and does a lot of work for us, to the point that he is the one and only paid person that gets on our boat.

[Boss Lady]

Good, a friend will get you further down the road than a dollar will.

My concern is what happens when coolant gets mixed with the oil and is pumped through the bearings. and cam lobes. Sometimes you get lucky. I usually don't have that kind of luck. You first oil analysis will tell the story.

Hope all goes well. BTW how is the weather down there? We have a drought going and the fish bite has been terrible here.