We have one of the largest collections of Detroit Diesel 149 Series parts in stock, even hard-to-find parts. Plus, all of our items ship fast, and can be delivered to you in as little as two business days. You can shop with confidence knowing our easy to use website allows you to make the right choice the first time. All of our items are covered by our satisfaction guarantee. Shop with us today and you will see Diesel Pro is the best choice for Detroit Diesel parts. If you have any questions, call us at 305-545-5588 (hablamos español). To get started, simply select your engine. You can also read on below for more series 149 specs and information.

Detroit 149 Service Manual

The Detroit 149 service manual is in stock. This is an invaluable tool, whether you are an expert mechanic, or engine owner. If you do not already have one, you can view the manual here if you are interested in additional specs or information not listed here.

How to Locate the Serial Number:

It may be necessary to locate your serial number when ordering some Detroit Sereis 149 parts. To do so, follow the directions below: To properly identify your engine, locate the two numbers on your engine, one will be the model number and one will be the serial number. The model number will be an eight digit code, starting with a 9.

For 8 cylinder engines: the serial number and model are stamped on the rocker cover rail at the left, rear corner of the block, as viewed from the flywheel end. For 12 and 16 cylinder engines: the serial number and model can be found on the rocker cover rail on the right front cover of the block, again viewed from the flywheel end. Another important feature that can be seen in your serial number is whether it is Left-hand rotation engine, or a Right-hand rotation engine. One way to tell is by using the serial number. If the 5th digit is a 3 then it is a Left-hand rotation. If it is 7, then it is a Right-hand rotation engine.

Parts for the Raw Water Pump on a Detroit

If you need a raw water pump, or any parts related to this system, check out our corresponding pages by selecting your engine below and clicking on the Sea Water Pump button. The series 149 engine uses two positive displacement pumps to circulate raw water through the heat exchangers to lower the engine coolant temperature. The pumps are attached to adaptors that are bolted to the flywheen housing and are driven through couplings attached to the rear idler gears. The idler gear driven pump driver shaft is carried on a double row ball bearing located in the pump housing flange end. The pumped water lubricates the impeller. To avoid possible impeller damage, do not run the impeller dry for longer than normally required for the pump to prime itself. One raw water pump type has an impeller that rotates against a bronze cam in the impeller housing. The other type includes polyurethane cam and liner. A rotary style seal assembly seals against leakage along the shaft.

The pump can operate clockwise or counter clockwise. Raw water is drawn into the pump through the outlet opening. Both openings are located on the top of the pump housing.

How to Prime a Raw Water Pump on a Series 149 Detroit

To prime the raw water pump: (1) Remove the pipe plug from the water inlet elbow. (2) Pour in at least a pint of water. (3) Replace the plug.

How to Remove the Raw Water Pump

(1) Drain the water system. (2) Loosen the hose clamps at the outlet elbow and intermediate tube, and slide the hose along the tube. (3) Loosen the hose clamps at the inlet elbow and the inlet tube, and slide the hose along the tube. (4) Remove the bolts and lock washers holding the inlet and outlet elbows to the pump and lift the elbows from the pump. (5) Remove the gaskets. (6) Remove the adaptor to flywheel housing bolts and lock washers. (7) Tap the adaptor edge with a soft hammer to loosen the pump from the flywheel housing. (8) Withdraw the pump straight out from the flywheel housing while disengaging the drive gear from the coupling. (9) Cover the pump opening in the flywheel housing with a clean cloth to prevent foreign matter from entering.

Raw Water Pump Repair on a Detroit 149 Engine

Once you have removed the pump, you can disassemble it to and use one of our repair kits, if the pump is still repairable. Use the following steps as a guide (bronze cam pumps instructions):

(1) Remove the cover screws and lift the cover and gasket from the housing. (2) Use pliers to grasp a blade at each side of the impeller, and pull the impeller from the shaft. The spline plug will come out with the impeller. (3) Insert two wires, each with a hook at one end, between the housing and the seal, with the hook over the edges of the carbon seal. Pull the assembly from the shaft. (4) Insert two wires, each with a hook at one end, between the housing and the seal seat and gasket, with the hook over the edge of the seat and gasket. Pull the assembly from the shaft.

Once the seal is removed, proceed as follows:
(1) Mark the housing and the adaptor for reference when reassembling. (2) Remove the bolts and lock washers and separate the adaptor from the housing. (3) Clamp the drive gear in a soft jawed vise and remove the retaining nut and lock washer from the shaft.
(4) Take the gear from the vise and, using a suitable puller, pull the gear from the shaft. (5) Remove the woodruff key from the shaft. (6) Remove the bearing retainer from the groove in the housing. (7) Support the pump housing in an arbor press with the mounting flange resting on the press bed and the splined end of the pump under the press ram.
(8) Use a brass rod between the shaft and the ram, and press the shaft and ball bearing from the housing. (9) Remove the slinger from the housing. (10) Pull the bearing seal from the pump housing. (11) Use an arbor press and a suitable sleeve to press the shaft from the bearing. (12) Remove the bolt and lift the cam from the housing. (13) Lift the wear plate from the dowel.

Should You Replace Your Detroit 149 Water Pump?

Remove the water pump and disassemble it: Are there worn or damaged parts? Do the bearings bind? Is the cam liner too thin? If yes, then replace. Consider using a repair kit or replacing the entire pump.

Coolant Specifications

Coolant temperature should be between 71 – 81 degrees C or 160-177 degrees F.

Detroit Series 149 Blower

The air intake system consists of the air cleaner, air shutdown housing, blower, blower bypass valve, turbocharger, turbocharger intercoolers. In the scavenging process, a charge of air is forced into the cylinders by the blower to sweep out all of the burned gases through the exhaust valve ports. This air also helps cool the internal engine parts. Air entering the blower from the air cleaner or the compressor discharge of the turbo is picked up by the blower rotor lobes and carried to the discharge side of the blower. Fresh air from the blower enters the cylinder block air chamber and sweeps thought the intake ports of the cylinder liners. The angle of the cylinder liner ports causes the intake air to swirl as it enters the cylinder. This motion continues thought the compression stroke and facilitates scavenging and combustion. The engine blower supplies fresh air for combustion and scavenging. Two hollow three lobe rotors revolve with close clearances in a housing inside the cylinder block, between the two cylinder banks. To provide uniform continuous air displacement, the rotor lobes are helical or spiral shaped. A single blower is used on 8V engines. Two tandem blowers are in use on 12V and 16V engines.

Normal gear wear causes a decrease of rotor to rotor clearance between the leading edge of the right hand helix (drive) rotor and the trailing edge of the left hand helix (driven) rotor. Clearance between the opposite sides of the rotor lobes is correspondingly increased. The blower’s rotors are timed by the two rotor gears at the rear end of the rotor shafts. This timing must be correct. Otherwise, the required clearance obtained by the use of shims behind the gears and between the rotor lobes will not be maintained. While the rotor-to-rotor lobe clearance may be adjusted, gear backlash cannot be corrected. When gear have become so worn that backlash exceeds 0.102mm .004 in, the gears should be replaced.

A flexplate coupling, consisting of three spring plates, adjusts for misalignment between the blower and blower drive gear. Each rotor is supported in the doweled end plate of the housing by a roller bearing at the front end and a ball bearing at the rear end. The blower bearings, timing gears and governor drive assembly are pressure lubricated by oil passages. A cup shaped oil strainer has been incorporated in the vertical oil passage at the bottom of each blower end plate to remove foreign material from the oil. Oil flows up, through the end plate, into the end plate cover. It leaves though a small orifice, spraying the splines on the drive couplings and drive shafts. Oil then splashes onto the bearings and timing gears. Oil that collects in the bottom of the end plates drains into a passage leading through the cylinder block to the crankcase.

When To Repair or Replace the Blower

First, remove the blower, disassemble the blower and clean it.

Are the bearings corroded, pitted or bind? Is the rotor shaft bent? Are the gear teeth worn or damaged? If yes to any of these, then replace the parts with a blower repair kit.

Are the discharge holes and drain cavities in good condition? If yes, clean or replace, depending on severity. Is the oil strainer vertical oil passages, orifice plugs plugged with oil? If yes, blow out with compressed air, or replace.

How to Remove the Blower for Series 149 Detroit Diesel
(1) On non turbocharged engines, loosen the constant torque clamps and slide the air inlet housing hoses back to disconnect the housing from the air cleaners. (2) On engines with turbochargers, disconnect and remove the air inlet and outlet tubes from the turbochargers. (3) Remove the eight bolts, lock washers, and plain washers securing the air inlet housing to the air shutdown housing. (4) Remove the air inlet housing and gasket. (5) Disconnect the wire cable from the air shutoff cam pin handle. (6) On multiple blower installations, remove the shutdown linkage between the air shutdown housing. (7) Remove the engine ventilating system. (8) Remove the 7/16 in bolts, lock washers, and plain washers securing the air shutdown housing to the lower cover plate. (9) Remove the air shutdown housings and gaskets. (10) Remove the governor control housing, blower cover plate, and gaskets. (11) Remove the fuel pump from the flywheel housing. (12) Remove the blower drive shaft from the blower drive gear hub assembly. (13) On engines fitted with formerly used hose and clamp connectors, 12V and 20V engines, loosen the two constant torque clamps securing the cover hose to the blower end plate cover and the blower drive gear support. (14) Slide the hose back over the drive support. (15) Remove the retainer clip, and slide the inner tube connection into the blower drive gear support. (16) Complete blower removal as follows: remove the four bolts and washers securing each blower to the block. Attach a suitable rope, belt or strap to the webbing of the blower housing. Using a hoist, remove it from the block.

On 12V, 16V and 20V engines, remove the rear blower first.

Detroit 149 Series Turbochargers

To avoid injury from contact with rotating parts when an engine is operating with the air inlet piping removed, removed an air inlet screen shield over the turbocharger air inlet. The shield prevents contact with rotating parts. The turbocharger is designed to increase overall engine efficiency. Power to drive the turbocharger is extracted from waste energy in the engine exhaust gas. The turbocharger consists of a radial inward flow turbine wheel and shaft, a centrifugal compressor wheel, and a center housing that supports the rotating assembly, bearings, seals, turbine housing, and compressor housing. The center housing has connections for oil inlet and outlet fittings. The turbine wheel is located in the turbine housing and mounted on one end of the turbine shaft. The compressor wheel is located in the compressor housing and is mounted on the opposite end of the turbine wheel shaft to form an integral rotating assembly. The rotating assembly consists of a turbine wheel and shaft assembly, piston rings, thrust spacer, compressor wheel and wheel retaining nut. The rotating assembly is supported on two pressure lubricated bearing that are retained in the center housing by snap rings. Internal oil passages are drilled in the center housing to provide lubrication to the turbine wheel shaft bearings, thrust washer, thrust collar and thrust space. The turbine housing is a heat resistant alloy casting enclosing the turbine wheel and providing a flanged engine exhaust gas inlet and an axially located turbocharger exhaust gas outlet. The turbine housing is bolted to the turbine end of the center housing. The compressor housing that encloses the compressor, provides and ambient air inlet and a compressed air discharge outlet. The compressor housing is secured to the compressor end of the center housing backplate assembly with a V band coupling.

The turbocharger is mounted on the exhaust outlet flange of the exhaust manifold. With the engine started, exhaust gases flowing through the turbine housing cause the turbine wheel and shaft to rotate. After passing through the turbine housing the gases are passed through the exhaust system then into the atmosphere. The compressor wheel that is mounted on the opposite end of the turbine wheel shaft rotates with the turbine wheel. The compressor wheel draws fresh air, compresses it and delivers it at high pressure through the blower to the cylinders. The turbocharge responds to engine loads demands by reacting to the flow of exhaust gases. As power output increases or decreases, the turbocharger provides the necessary air supply. Lubricating oil for the turbocharger is supplied under pressure though an external oil line running from the side of the cylinder block to the top of the center housing. From this oil inlet, oil flow through the drilled oil passages to shaft bearing, thrust ring, thrust bearings and backplate or thrust plate. Oil returns though an external oil line running from the bottom of the turbocharger center housing to the oil pan.

Whenever a new or overhauled turbocharger is installed, prior to the initial engine start, the turbocharger must be pre-lubricated to avoid possible center housing bearing damage.

How to remove the Detroit 149 turbocharger

If one of two turbochargers feeding the same airbox should fail, both trurbochargers must be replaced. Replacing only one failed turbocharger may lead to overstress of the remaining turbocharger, resulting in overstress and possible failure of the replaced turbocharger.

(1) Disconnect the oil supply line and the oil drain line from the turbocharger. (2) Cover the end of each oil line inlet, oil line outlet, air inlet and exhaust outlet opening. This will prevent foreign material from entering the engine. (3) Loosen the two clamps securing the hose to the turbocharger and the air inlet tube, and slide the hose up over the inlet tube. (4) Remove the four bolts, nuts and washers securing the turbocharger to the exhaust manifold adaptor. (5) Remove the turbocharger and gasket, replacing the gasket with a new one when a new turbocharger is installed.

Specifications

(thread / torque lb•fl/ torque N•m
Fuel Pump coupling disk bolt 3/8-24 / 50-55 / 68-75
Blower hold down bolt 7/16-14 / 50-55 / 68-75
Blower hold down bolt 9/16-12 / 78-85 / 102-115
Blower timing gear and bearer retaining nuts 1 5/16-18 / 200-250 / 271-339
Turbo thrust bearing retaining screws M4X10mm / 30-35 / 41-47

The series 149 engines are V type, two stroke. Fuel is drawn from the supply tank through the primary fuel filter. From there, fuel is forced through a secondary fuel filter and into the fuel inlet manifold, then into the injectors. Excess fuel is then returned to the tank through the fuel outlet manifold and connecting line. The fuel also serves to cool the injectors. Air enters through the blowers, passes through an air cleaner or silencer and is pumped into the cylinders by way of the air box and cylinder liner ports. Coolant is circulated by the water pump, which is mounted in the front cover. Heat is removed by the radiator or heat exchanger.

Coolant, when properly maintained, could be operated up to two years, or 4000 hours, whichever comes first.

Detroit Series 149 Oil Filters

If you need oil filters, we have them here at Diesel Pro. We offer a premium spin on type, which can be found by selecting your engine, then clicking on the Oil Cooler group. Always change the filter when changing the oil. Oil is drawn from the oil pan through a screen and then into the oil filters. Then, the oil flows into the cooler (or bypasses) and then divides in the cylinder block. Part of the oil goes camshaft bearings and through the rocker assemblies. The rest goes to the main bearings and connecting rod bearings through the drilled oil passages in the crankshaft. The passes in the connecting rod push oil to the piston pin and the inner surface of the piston crown.

Regular drain intervals is extremely important for these engines. For agricultural, industrial and marine uses, the maximum interval for oil drains is 300 hours or 1 year, whichever comes first. For continuous use stationary units, the maximum oil drain interval is 300 hours or 3 months. Although diesel fuels containing 0.5% sulfur are considered high sulfur fuels, piston ring wear studies have shown that the combustion of fuels containing more than 0.3% sulfur significantly increases ring face wear rates. For industrial, agricultural or marine engines with oil TBN above 10, change oil every 150 hours or max of 1 year. For stationary units, continuous, with oil TBN above 10, change oil every 150 hours or 2 month.

New Oil Cooler on Detroit Series 149 Engines

Use the following to install a new oil cooler.

(1) Using a new gasket, position the oil cooler, over the two studs and against the cylinder block. (2) Thread two stud nuts and lock washers over the studs, tightening the nuts finger tight. (3) Install the water inlet elbow and gasket, tightening the bolts finger-tight. (4) Install the water outlet elbows, spacers and gaskets. (5) Center the elbow flanges on the cooler flanges, and install the bolts, finger tight. (6) Install the inlet tube between the water pump and the oil cooler inlet elbow, without tightening the bolts. (7) Install the inlet tube brackets.

Then tighten the bolts as follows:
1. Tighten the water inlet elbow bolts. Start with one of the four top bolts on the water pump inlet elbow. Alternatively torque the bolts to 41-47 N m or 35-35 lb ft.
2. Tighten the oil cooler to block bolts and nuts. Start at the center and work outward. Torque the stud nuts to 113-126 N m, 83-93 lb ft. Torque the bolts to 96-102 N m, 71-75 lb ft.
3. Tighten the water outlet elbow bolts. Center the flanges and tighten the elbow to block bolts. Gradually and alternatively torque the elbow to cooler bolts to 41-47 N m or 30-35 lb.
4. Alternatively tighten the water inlet tube to water inlet elbow bolts.
5. Alternatively torque the water inlet tube to water pump flange to 41-47 N m or 30-35 lb ft. Tighten the water inlet tube bracket bolts.

When to Replace Camshaft Bearings on Detroit 149 Series Engines

Some Series 149 parts should be carefully maintained, and the camshaft bearings are no exception. The contra-rotating camshafts are located near the top of the cylinder block. In 8V149 engines, there is one set / two sets in the 12V149 and 16V149. Each camshaft is supported on upper and lower camshaft bearings or shells, and retained by bearing caps. A thrust plate is attached to one of the rear bearing caps. If they show any signs of being scored, then they should be replaced.

Fuel Filter in Detroit 149 Series

Fuel is drawn from the supply tank through the fuel strainer and enters the fuel pump at the inlet side, where it leaves the pump under pressure. The fuel is forced through the fuel filter or secondary filter. From the secondary filter, the fuel is directed to a junction block where it is then routed to the inlet fuel manifolds for each injector bank. From the fuel manifolds, fuel reaches the fuel injector by means of an inlet pipe. Surplus fuel returns from the outlet side of the injectors though the fuel outlet pipes into the fuel return manifold. The return fuel passes through the fuel junction block and back to the fuel tank. All engines are equipped with a restrictive fitting in the outlet manifold to maintain the fuel system pressure.

Detroit Series 149 Oil Cooler

To perform its functions satisfactorily the lubricating oil must be kept within proper temperature limits. Two oil coolers are centrally located on the right side of the cylinder block. A second oil cooler, mounted opposite side of the engine, is used to cool the lubricating oil used in a Torqmatic converter, or marine gear. To determine if there are any issues, use the following guide:
(1) Drain the lubricating system. (2) Drain the cooling system. (3) Remove the oil cooler and disassemble it and clean.
Does the cooler core have any leaks? If it does, replace it.
5. Are the housing bores corroded, pitted or worn? If so, replace.
(1) Assemble the oil cooler core. (2) Install new o-rings and a new gasket. (3) Install the oil cooler.

Detroit 149 Crankshaft Oil Seal

Failure to install the correct seal in relation to the direction of crankshaft rotation can result in seal damage, oil leakage, and possible engine damage by a reduced oil level.
(1) Place the bearing support on the bed of an arbor press. Do not coat the oil seal bore because the seal case is already pre-coated. Press the new crankshaft oil seal into the outboard bearing support with the lip of the seal facing in towards the bearing with the installer. (2) Install the outboard bearing support assembly. (3) Install the vibration dampers.

Crankshaft Main Bearings on the Detroit Series 149

The crankshaft main bearings are precision made and are replaceable without machining. The upper bearing is seated in the cylinder block main bearing support, and the lower bearing is located in the main bearing cap, anchored by a tang. The tangs on the lower shells are off center and the tangs on the upper bearing shells are centered. There is an oil hole in the groove of each upper end bearing shell. Use this guide to determine when to replace your main bearing shells:
(1) First remove and clean them. (2) Check to see if they are damaged, if the bearing shells are moving, or if the bearing shell thickness is not in limits. The minimum thickness is 3.922 mm ir 0.1544 in.
(3) If any of the above are true, then replace the main bearing shells. If not, continue.
(4) Is the connecting rod to bearing clearance not in limits? If so, replace the main bearings.
(5) Are the thrust washers worn? Is the crankshaft end play in limits? If not, then replace the thrust washers.