Voyage III

Engine Problems - Repower or Overhaul?

Under Construction

During the latter part of our 2006 east coast trip, the engine became progessively harder to start in the mornings, particularly as the air and water temperatures dropped. We were also seeing more white smoke than usual (probably unburned fuel) and occasionally a fuel slick from the exhaust. Originally we suspected fuel issues and we were collecting a lot of gunk in the Dahl filter, but the real problem was probably low compression. At about 3800 hours, the Volvo 2003T had performed well over 20,000 miles of cruising (including about 600 hours on this trip), and it appeared to be time to take some steps.

The Volvo requires some special tools and adapters to remove the injectors and check compression, so I hired a local diesel shop to do a compression and leak-down check. The technician hooked up his gauge and we noted about 250 psi, which sounded low to me, but not that low. When I asked him what it should be, he said he was really not sure (for this I was paying $90 /hour !!), but thought it should be closer to 350 psi. (In fact, the Volvo shop manual specifies 290-350). He did not have the tools he needed for the leakdown, but told me it didn't matter where the problem was - it wasn't worth rebuilding anyway. Conventional wisdom is that an overhaul would cost more than a new engine. As long as the injectors were out, I asked him to bring them into the shop and get them checked, and find out for me what their shop would charge for a rebuild versus a new Volvo, and he took them along.

After a day or two of no feedback, I called and talked to the service manager who told me they were really not interested in "getting involved in a small engine rebuild" and he would have to get back to me in a week or two on a new engine quote. On the injectors, he said they would cost about $450 each to test and adjust. I thanked him for his advice, asked him to prepare my bill and that I would be in shortly to rescue my injectors. After spending thousands of dollars on parts from this place over the years, to say I was less than impressed with the service department would be an understatement. I won't mention their name here, but they are the only Volvo-Penta dealer in the West Palm area. Later on, I heard from a dealer in Fort Lauderdale that they used to be good but the new service manager has destroyed their reputation.

At this point, I had my injectors back so I took them to a local injector shop where they tested them for free and told me they were "better than 80%" and not likely the source of my starting problem. If I did want them rebuilt, it would be about $80 per injector. Passing on that for now, I decided I needed to do a leak-down test to determine if the problem was valves or rings before proceeding with any decisions. The following describes the tests I performed, data gathered (both on new engines and rebuild options), and the thought processes leading up to the decision to perform a top overhaul myself.

Leak-down test

A leak-down test consists of blowing 100 psi air into each cylinder (at top dead center) and noting the leakage amount while trying to determine where the leakage is going. For example, if the problem is worn piston rings, an airflow into the crankcase and out the breather tube or dipstick pipe would be evident. Leaking valves would be indicated by airflow into the intake or exahaust manifolds.

A typical leak-down tester consists of a 1 mm oriface ("damper valve" in diagram) with a pressure gage on the downstream side. With input air set to 100 psi, the output gage will read leakdown percentage - i.e. 85 psi would approximate 15% leakdown.

In my case, 2 of the 3 cylinders indicated 10% (at the edge of acceptability) and one (nearest exhaust elbow) read about 70%. There did not appear to be much coming out of the crankcase, but a definite hissing could be heard around the exhaust manifold, and the muffler was clearly bubbling. From this I concluded that most of the problem was associated with the exhaust valves - particularly on cylinder #3 (although the muffler would bubble with all three cylinders).

Performing the leakdown test was time consuming, mostly because of the difficulty in getting the piston exactly at TDC. If it was off by just a hair, the pressurized air would force the piston down or start the engine spinning. Consequently I spent a lot of time rotating the engine by hand. This doesn't take much force with the injectors out, as the only resistance is the force of the valve springs. Part of my routine to get the engine to start during our trip on a cold day was to rotate the engine by hand in hopes of coating the cylinder walls with oil and improving the startup compression. Most of the "diesel books" say rotating a 43 hp engine by hand should be difficult - since mine was not too much harder than doing it with the injectors out it was a good indication that compression was the issue. (Later, after the overhaul, it was MUCH harder to turn the engine by hand).

The net from the test was that compression was indeed low (I verified the 250 psi or so using an automotive compression tester and my leak down jig), and the bulk of the problem was the valves. A top overhaul then would probably help a lot. What I did not have a good feel for though was how close I was to needing more than that. Is 3800 hours a lot for this engine? When would a full overhaul (cylinders, bearings, etc.) be needed, and what else was likely to fail soon? How much would the top overhaul cost and how would it compare to a new engine? Since we do a lot of cruising in remote areas, a reliable engine is needed and I did not want to do a partial fix only to have more problems soon. The next step was clearly to do some research.

New Engine research

There are a lot of sources of information on the internet, and I started with searching out info on the Volvo 2003T, trying to see what experience others had with rebuilds or replacements. The engine hasn't been built by Volvo for over 10 years, but there are a few of them out there, particularly on Valiants and some European built boats. I found a lot of maintenance hints here and there, particulary at boatdiesel.com (good site although it costs $25 to access the archives). The Valiant owners group on Yahoo was also helpful, but I was really not able to find any definitive data on longevity or rebuild success.

At the Miami boat show, I spoke to a Volvo factory guy who thought a rebuild was certainly feasible - he thought the "advice" from the service guy was crap. He did say though that at 3800 hours we should start thinking about the accessories - turbocharger, starter, alternator, plumbing, injection pumps, etc. and if I plan to overhaul, he would recommend a full overhaul - including the cylinders and accessories. It would still be much cheaper than a new engine in his opinion and the 2003T basic engine should last a long time.

The Valiant 40 version of the 2003T develops 43 HP at 3200 RPM and includes the Volvo MS2V V-drive. It is perfectly adequate under most conditions, but into a 4-5 foot head sea with 20-25 knots of wind it is underpowered, making it difficult to exceed 2-3 knots. The 48 hours we spent motorsailing into the trades from Luperon to Boqueron into those conditions had me wishing for a much bigger engine. Consequently, I began looking in the 50 HP range for new engine choices.

The Valiant 42 now ships from the factory with the Westerbeke 44B, with an option for the 55A. They were very helpful, quoting me a good price for either engine from them, and sending me a drawing of the bed configuration in the 42 for comparison. Another choice recommended by some folks on the Valiant newsgroup was the Beta (either 43 or 50 HP). The nearest equivalent Volvo is the DL55 (55 HP). The Yanmar choices would be the 3JH4 (40 HP) or 4JH4 (55 HP).

All the engine replacements were considerably larger than the 2003T (with its 3 cylinders, the non-turbo version only develops half the horsepower). Most were 4 cylinder and would extend farther into the engine room. The major issue with a new engine though was the V-drive. The Volvo MS2V has a 20 degree down angle, whereas the only available V-drive today is the Hurth ZF-15MIV, with a 15 degree down angle. The shallower angle means the other end of the engine will sit closer to the hull, and that combined with the longer blocks will make for a challenging installation.

The current engine beds are capped with aluminum angle brackets and sit on glassed rails that extend about 10 inches up from the hull, leaving plenty of room for access to the shaft seal and clearance by the oil pan. The Valiant drawings for placement of the Westerbeke 44B (with the Hurth V-drive) have rails that extend only 3 inches above the hull. The factory thought I may need a longer shaft to accomodate it, but they couldn't be sure without more accurate measurements.

Cranking up my CAD software and laying out the dimension drawings of all the engines I had brochures for, I calculated clearances and bed modifications assuming the same shaft placement. The result was not encouraging as to free space but it did look like both the Westerbekes (44 and 55) would fit, as would the Yanmars and the smaller Beta (with the special shallow oil pan). All of the choices would extend into the space where our water and bilge pump components reside, necessitating finding a new space for them, and a lot of other changes would be needed, including a larger space for the instrument panels, new exhaust hoses and muffler (and possibly through-hull flange), new charging system components, etc. The engine beds will have to be cut way down and reglassed to accomodate the appropriate mountings of the new engines. Also, since the cabin woodwork neatly surrounds the engine space (see picture) much of the bulkheads and cabinets would have to be removed to facillitate removal, rework and installation of a new engine.

A local Yanmar / Westerbeke dealer was helpful in thinking through the options, and the opportunity to see and touch them at the Miami boat show was invaluable. We were able to talk to Volvo, Westerbeke (who gave us a good understanding of the differences between the 44 and 55 particulars and the fact that Valiant is selling the "old" version of the 55), Yanmar (no help at all as the people manning the booth had no technical knowledge whatsoever), Beta (who tried to convince me that their 40 was a better choice as it was a "real" 40 HP whereas the Volvo was not ?), and Hurth who helped us understand how the V-drive bolts on to the various engine choices.

After quite a bit of analysis, it looks like the base cost of any of the engine choices would be in the $10-12K range (plus shipping), and we would need another couple of K$ in parts (exhaust systems, mounts, possible shaft mods, controls, instruments, etc.). Assuming I did the work myself, it would take about a month or so of work, several weeks of that hauled out.

The old engine, would be of no value to anyone (even overhauled), judging from the lack of a secondary market for them, and would likely be junked.

Overhaul Estimate

The Volvo 2000 series engines have a deep oil pan that mates to the block at the level of the crankshaft, supporting the main bearings. Consequently, any operation that requires access to the crankshaft (such as removing pistons for ring replacement), would require removing the engine from the boat. Although it has been rumored that removal is possible without tearing up all the woodwork, the width of the aft cabin door is such that it would not go easily, and without the removal of accessories (and perhaps the head) - see picture. Given the amount of woodwork, yard time, crane rental, etc. to accomplish this, my inclination was to go the new engine route if this was necessary, although the additional work of repowering (beds, exhaust system, instruments, fuel system, etc) would justify at least a deeper analysis.

A "full" overhaul would replace the pistons and rings, probably oversized (.25 mm) after boring and honing the cylinders, replace the main and "big end" bearings, and oil seals. The top end would get new valves and stem seals (and possibly valve seats and guides). The injectors would get overhauled, the injection pumps checked, the heat exchanger and oil cooler examined, and the turbocharger rebuilt. (I've rebuilt the alternator, starter, lift pump and both water pumps recently and they would not need attention). The transmission could also need some attention.

Volvo parts costs were obtained on the web at marinepartsexpress.com (an excellent source for Volvo parts - full selection and quick turnaround for orders). For the head, a rebuilt head w/trade-in could be had for about $800, or I could do the work for less than $500 in parts and a couple hundred more for some special tools (needed if the guides and seats needed replacement). Pistons, rings, bearings, and seals would be another $1800, and the turbo rebuild kit is $150. Doing the work in my garage would take me a couple of weeks (say 100 hours), plus another week to remove it from the boat and replace it afterwards along with the woodwork. (So 150 hours for me versus maybe 75 hours for a professional).

Bottom line then, is about $2800 in parts plus 75 * $90/hr = $6750 labor = $9.5K (for a professional) or $2800 and 3 weeks (for me).

I'm beginning to see why the conventional wisdom is that a new engine is a better deal.

Decisions

An objective analysis of the current state of the engine would look like this:

• Low compression (250-260 psi vs. specified 290-350)
• Hard starting when cold
• Small amounts of white smoke when running
• Occasional fuel sheen on water from exhuast
• More than 10% leakdown in several cylinders
• Leaking oil seals in bell housing - accounts for half quart of oil in 50 hours
• Injectors at "80% performance"
• Some corrosion in salt water plumbing
• Voltage regulator becoming flaky
• Deteriorating rubber on some fuel lines
• Injector pumps, transmission, turbo have never been serviced in 3800 hours

The leakdown test gave me a pretty good feeling that the issue was leaky valves, not piston ring blowby. If that were the case, performing a top overhaul would fix the immediate problem, and perhaps delay the overhaul/repower decision for quite a while. Since a top would not require removing the engine from the boat, it would be a relatively quick procedure, and cost me perhaps $500 or so in parts. At least one other Valiant owner I know took this route and has had good performance for quite a while since.

On the other hand, it would not restore new engine reliability and there would likely be some other problems down the road. Nevertheless, if a top overhaul were to fix the starting problem, I would be no worse off than I was before the last trip. Failure of accessories to come (eg. turbo, transmission, etc.) could be handled without removing the engine from the boat, and (hopefully) degradation of the rings / pistons would be slow in coming and give plenty of warning.

The decision was therefore made to perform a top overhaul, spending a couple of weeks on it, and then if the problem persists (or other problems present themselves), a new engine (Westerbeke 44B) would be ordered and plans would be made to remove the Volvo, rebuild the engine beds and install a new exhaust system.

Overhaul

It was my guess (turned out to be right) that the valve seats could be lapped, and the valve guides would be re-usable, therefore I ordered new valves and stem seals only (along with a head gasket and some odds and ends of o-rings, etc.), and started removing the head. The steps were:

1. Drain the antifreeze and seawater coolant
2. Remove the coolant plumbing and heat exchanger
3. Remove the fuel pipes
4. Remove the valve cover and valve bridge
5. Remove the push rods, labeling them for re-assembly
6. Remove the thermostat housing and thermostat (and the attached refrigeration compressor)
7. Remove the secondary fuel filter and its plumbing
8. Remove the head bolts in reverse order of installation
9. Loosen the head by rotating the crankshaft to build compression in the cylinders
10. When the head is loose, remove the injectors
11. Lift the head off the engine - I used wood shims to slide it out of the engine space without scratching the mating surface
12. Discard the old head gasket

With the head safely back in the garage, carbon and remnants of the gasket were removed with a variety of scrapers - a razor blade worked well, and rust and scale were removed where found. The coolant pipe was knocked out of the head and replaced with new rubber gaskets. Using a valve bow (about $30 at Pep Boys), the 6 valves were removed and the cavities and seats were cleaned with solvent and rags. After the stem seals were removed, the valve guide play was measured with a dial gauge and shown to be in-spec, and the springs were examined for nicks and measured to be in-spec as well.

The valve seats had plenty of material, but several (particularly the exhaust valve nearest the elbow) had deep pits in the surface. Using the old valves and grinding compound, the seats were ground flat and smooth using a suction cup, then the new valves were lightly lapped in their target positions to form a good seal, then all was solvent cleaned.

The new stem seals were installed, followed by the valves themselves, springs, washers and keepers, using the valve bow.

In order to test the seal, a shop vac was stuck in the each manifold, while a smokey candle was held near each valve to see if there was any air flow (there was not).

Finally, some engine paint was used to touch up scratches and rust areas on the external part of the head, and the head was returned to the boat.

In the boat, the new head gasket was laid on the engine block and held in place with two small pieces of masking tape (the shop manual says to use studs for positioning, but there was not enough room in the engine space to get the head over the studs). With the head lowered into place, a few bolts were started into their holes and then the tape was removed. Following the shop manual, the head bolts were torqued in order, first to about 15 ft-lbs, then to the final 51 ft-lbs.

At this point, the valve push rods and valve bridge were installed (with a new oil o-ring), and the valve lash was set. Using the leak-down tester, the results were much better, with each cylinder having less than 10% leakage. Also, when the injectors were replaced, it was very much harder to turn over the engine by hand - indicating considerably more compression than before.

Note in the picture the shiny copper injector sleeves. It was very important to get these very clean to prevent blowby around the injectors. I've had trouble in the past when there was any carbon remaining at the bottom of the sleeve - since the injector is held in place with a clamp, a small amount of grit on the sealing surface will cause leakage of exhaust gases into the engine compartment. If this happens you will be able to feel the "breeze" and smell the gases. The only way I've found to get a good seal is to scrub the bottom of the sleeve with a circular wire brush from a dremel tool on the end of a long shaft. The sleeve should be bright and shiny when you are done, and no pits or scratches should be evident in the sleeve.

After assembling the rest of the parts (heat exchanger, fuel lines and filter, valve cover, etc), the system was filled with antifreeze mixture and the fuel system was bled all the way to the injectors while turning the engine by hand, then the engine was started. After about 10 revolutions, it came to life with some initial white smoke, then settled down and ran smoothly.

When all was said and done, the total expenses for the top overhaul were for the valves, stem seals, head gasket and some miscellaneous o-rings, seals, etc. and totaled $340 plus shipping from marinepartsexpress.com

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