Detroit 60 Series Diesel Engine - 60 Series Specs, Reliability, Problems

Detroit 60 Series Diesel Common Problems

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The Detroit Diesel 60 Series engine began production in 1987 and remained until 2011. It’s an inline-6 four stroke diesel engine and was the first heavy duty diesel engine with full electronic controls. The Detroit 60 Series earns much praise for its great balance of fuel economy, performance, and longevity. However, no engine is perfect and there are no exceptions here. In this article, we discuss 60 Series engine specs, reliability, problems, and more.

Detroit 60 Series Diesel Engine - 60 Series Specs, Reliability, Problems

Detroit 60 Series Background Info

As a large displacement, heavy duty engine the Detroit 60 Series diesel engines have widespread uses. They were popular engines in class 7 & 8 on-highway trucks and buses. Other uses include heavy-duty off-road and marine applications. The 11.1L Series 60 engine was popular on many USA buses. Once the 11.1L was discontinued in 1998, the 12.7L became the primary motorcoach engine. 14.0L Detroit Diesel engines became the popular semi-truck option once they were introduced in 2001.

Anyway, outside of uses, there’s a lot of other background info to cover when it comes to the Detroit Diesel 60 Series engines. One important topic revolves around the DDEC electronic control.

Detroit Diesel Electronic Control

There are countless benefits to the electronic control of the 60 Series diesel engines. Again, this was the first engine to begin using full electronic control and it wasn’t until several years later than other manufacturers followed. This control is referred to as Detroit Diesel Electronic Control (DDEC).

DDEC allows for diagnostics, shutdown timers, speed limiting, cruise control, and many other functions. Ultimately, owners are able to view valuable engine management reports. This helps Detroit 60 Series owners avoid engine abuse and improve fuel economy among other benefits. DDEC did go thru multiple updates over the years, so we’ll break that down quickly below.


DDEC I was the original system in 1987 and lasted until 1992. It was a 2 box system with an ECM in the cab, and an EDM in the engine. The EDM on the engine was responsible for operating the fuel injectors.


In 1992, the DDEC II system began replacing the earlier version. Rather than two-box, this system uses a single box mounted on the 60 Series diesel engine. The DDEC II system was a good improvement and was very popular with fleet operators.


The DDEC III system came out in 1992 along with the II version. A primary difference with DDEC III on 60 Series engines is that it introduced dual voltage 12V/24V ECM units. This made it easier to install into a variety of applications, such as marine and industrial.


1997 saw the introduction of the DDEC IV control system. This was mostly to incorporate other Detroit 60 Series engine changes like a waste-gated turbo. Otherwise, the DDEC IV system was meant to improve power, torque, and performance.

60 Series Diesel Specs

Displacement677 CID (11.1L)778 CID (12.7L)858 CID (14.0L)
BlockCast Iron, Wet linersCast Iron, Wet LinersCast Iron, Wet Liners
HeadCast Iron, DOHCCast Iron, DOHCCast Iron, DOHC
Compression16.0 : 115.0:1, 16.5:115.0:1, 16.5:1
Bore x Stroke5.12″ x 5.47″5.12″ x 6.30″5.24″ x 6.62″
Engine Weight2,675 lbs2,800 lbs2,800 lbs
Horsepower250-350 HP380-455 HP425-575 HP
Torque (lb-ft)1,100 – 1,250 TQ1,350 – 1,550 TQ1,550 – 1,850 TQ
Max RPM2,100 RPM2,100 RPM2,100 RPM

*The 60 Series peak horsepower occurs at 1,800 RPM across all engines. Torque peaks at 1,200 RPM for all engines as well. In some continuous duty applications the engine speed is limited to 1,800 RPM.

All variants of the 60 Series engine are well respected. The 11.1L and 12.7L engines were very unique for their time in 1987 as they were the first heavy-duty diesel engines with full integration of electronic controls. However, the 14.0L 60 Series engine is especially well-known in the heavy-duty segment. With 500+hp and 1,650 lb-ft the 14.0L Detroit engine delivers great performance.

Anyway, these engines are from the same 60-Series family and that’s shown in the similar specs. They’re all large displacement, inline-6 turbodiesel engines. They also share the same cast iron design with 4 valves per cylinder, wet cylinder liners, and 7 main bearings.

Detroit 60 Series Diesel Engine Problems

The Detroit 60 Series engines have all earned a good reputation as being reliable work horses. Detroit Diesel even initially recommended major overhaul intervals of 500,000 miles. However, that was raised to 750,000 miles after they proved to be strong, reliable engines. Still, no engine is perfect and that applies to the Detroit 60 Series diesel engine. In the next sections, we will cover some of the most common 60 Series problems including:

  • Wrist pin
  • Bearing issues
  • EGR system
  • Cracked exhaust manifold
  • Emissions system issues

Again, the Series 60 engines are reliable and offer good longevity. The above are some of the most common issues, but that doesn’t mean all engines run into these problems. In other words, we’re classifying these as the most common for good reason. It doesn’t mean the problems are truly common, but when things do go wrong these are a few key areas.

That said, we will break down these Detroit 60 Series problems in greater depth below. We’ll then wrap up the article with overall thoughts on 60 Series reliability and longevity.

1) Defective Wrist Pin

Wrist pin problems were a random issue that occurred on a number of 60 Series engines built before 2002. The wrist pin wasn’t totally defective as plenty of engines never ran into this problem. However, some wrist pins had a defect that causes the piston pin and crown to separate. The rod could also potentially disconnect in some instances.

Ultimately, wrist pins weren’t a very common problem on the Detroit Diesel 60 Series engine. However, damage could be pretty severe in the cases of defective pins. It could lead to components being thrown thru the block. Of course, a hole in the block isn’t a cheap ordeal and often results in the need for engine replacement.

2) Bearing Problems

One thing Detroit did to improve fuel economy was program the engine to idle at low RPM’s. However, it turns out, the low idle speed often wasn’t high enough to properly operate the oil pump. This would lead to low oil pressure at idle. In turn, the bearings would wear down prematurely due to oil starvation and poor overall oil flow.

This bearing issue specifically mostly affected pre-1997 engines. As such, Detroit 60 Series bearing problems are most common on the 11.1L and 12.7L variants of the engine. Detroit later increased idle speed slightly and improved oil pressure at lower RPM’s. That said, later engines can still run into bearing issues but it’s much less common.

3) EGR System Issues

Those familiar with newer diesel engines understand the hassles that emissions systems can cause. Later Series 60 Detroit engines used an EGR system to lower NOx emissions. There are a number of potential problems that arise from the EGR system. However, the primary cause of trouble is the EGR cooler.

Coolant leaks from the EGR cooler are a common issue on the Detroit 60 Series diesel engines. As a side note, coolant leaks in the oil cooler is also a potential problem. Anyway, white smoke, coolant loss, and overheating are potential symptoms of EGR issues. Overheating can be a serious symptom that can cause further damage and problems, so be on the look-out.

4) Cracked Exhaust Manifold

Exhaust manifold function is pretty simple – the exhaust manifold is meant to collect exhaust gases from the cylinders before merging into a common collector. One potential issue with the Series 60 diesel engine is a cracked exhaust manifold. It’s generally a fairly minor issue, but should still be addressed as soon as possible.

Look for symptoms such as excessive engine noise, power loss, or burning/raw exhaust smells from the engine bay. Once the manifold cracks, exhaust gases seep thru so you should notice the smell or hear that the engine is louder. However, symptoms can be tough to identify until the crack expands.

5) Emissions System Problems

As a final 60 Series topic, we’re sticking with generic emissions system issues on the newest 14.0L variant. The 60 Series engine was around for a long time, but the 14.0L didn’t come around until 2001. It remained in production until 2011 and emissions laws became more stringent during that period.

We already talked about EGR issues, and that’s a system found on the Detroit 60 Series 14.0L engine. Some newer ones also have DPF, DOC, and other emissions systems. Again, many familiar with newer diesels likely understand these emissions systems can be a hassle. The 14.0L 60 Series is still a great engine, but it’s more complex and has more room for failure compared to older Detroit Diesel engines.

Overall Reliability

Despite a few common problems and design flaws, the Detroit 60 Series diesel engine still delivers great reliability and longevity. It’s a popular and well-renowned diesel engine for good reason. Diesel Power Magazine even ranked the 60 Series as the second best diesel engine in their “Best Diesel Engine Ever” list.

Detroit Diesel produced over 1 million 60 Series engines. That means these engines are pretty easy to find parts for. There are also plenty of shops and mechanics familiar with the 60 Series diesel engine. As such, it’s an easy engine to maintain and upkeep even when you do run into the occasional issues.

The Series 60 engine is also simpler than many newer diesel engines. All of these factors combined with great power, torque, and performance make the Detroit 60 Series a great diesel engine.

What’s your experience with the Detroit 60 Series? Leave a comment and let us know!

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  1. I have a 2001 379 Peterbilt. With the Detroit in it my issue is . It backfires and spits and sputters and blows white some times blue smoke after it’s ran down the road for a while. But then clears up and jams down the road. I can not figure it out new injectors and still does it new fuel pump still does it I’m lost help.

    1. Christopher – if you’re getting white and blue smoke it sounds like you are probably leaking coolant and or oil into the combustion chamber. Blue smoke is usually caused by bad pistons or worn valve seals which will leak oil into the combustion chamber. A thick white or grayish smoke is usually from coolant leaking into the combustion chamber which could be from a blown head gasket. You could have a cracked block or cylinder head as well, but I’d start with checking the head gasket. A new fuel filter is probably a good idea if you have a new pump and injectors, but your smoking issue is going to be related to oil or coolant leaks, not fueling issues. But the last thing you want is an old dirty fuel filter to take out your new injectors.

    2. The fitting that goes to your return line outlet isn’t just a fitting. It has a 2mm orifice and is designed to keep your fuel pressure up. After that there’s a check valve so the fuel stays primed in the system when you shut it off. It smooths out on you once the air gets worked out of the system but will smoke like crazy till it’s all fuel in the rail. I can about guarantee both of those things are stock in your motor cause nobody knows they’re there

    3. Also if you have a Davao fuel filter put a shut off on the out port and shut it off when you shut the truck down. That’ll be a temporary fix cause it drains back that far and you’ll know you’re on the right track when it starts up the next day and clears out quicker

    4. Hi Christopher, I have a 2014 glider with a 12.7 Detroit in it. It had a fresh inframe done with a brand new PAI Brute head installed with fresh remanned injectors. At about the 60 thousand mile mark it developed a cold start misfire that would not go away until the engine was up to 180F, once warm the engine would run strong all day, If you tried to force it it would pop/sputter/smoke black (not blue or white like yours). Early on it would come out of the misfire all by itself as it warmed up but as time went on the only way to make it stop was to shut it off for 3 to five minutes and restart. Naturally we thought a problem that resolves through cycling the key was an electronic problem. I noticed at one point during warmup that #6 cylinder was completely cold so we changed out the injector but that had no effect. Eventually I noticed that when it was misfiring the intake manifold at the #6 port would get hot, much hotter than the rest of the manifold and too hot to hold my hand on. This was a diagnostic breakthrough since none of the gurus I spoke to previously could explain why it was behaving this way, they all want to plug into the ECM so the computer can tell them what’s wrong, except in my case there were no codes stored or active while it was misfiring for a tech at a Freightliner dealership. The hot intake told us there was a mechanical problem, by the way it behaved we ruled out weak/broken valve spring and narrowed down the choices to either valve train out of proper adjustment or sticking valve. I had the overhead rerun and that solved the problem, Now the engine runs smoother and is much quieter inside the cab. This may not help you but hopefully it helps someone.

  2. Hi could the throttle bushing cause check Engin light to come on or more likely the harness I chanchhes the sensor still same only at idle …..

  3. Hi I have Detroit series 60 Engine. It was parked outside during little showers. Now, its not starting. Can anyone assist me please. Looks like injectors aren’t getting command. Need urgent help.

  4. I have a DDEC 3 Detroit S60 engine, revs are not reaching 2100rpm. Only ending on 1440rpm. And of I try to drive like that I can feel as if the engine is loosing too much power and might die at anytime. What could it be

    1. Someone put the engine max RPM at 1400 as apposed to letting the engine run up to 2100 .A Comin practice when looking for better fuel economy. quick fix

  5. I’ve got a 1999 international what is 60 Series Detroit mine done the same thing when it got wet it quit come to find out though. I was having major trouble with my ground wires

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