Community Forums

Leehicks1 · 02-20-2017, 08:36 AM

Hello all, I'm a relatively new owner of a 2005 Monaco Executive with the Detroit Series 60. I've driven it about 4000 trouble-free miles so far, up until yesterday. I'll try to give as much information as possible to describe the problem, so thank you for bearing with me if you think you have some advice to give:

-Fuel level was just getting below 1/4 tank so we stopped for fuel. We were in Key Largo, so not many of the normal options where I would normally stop (e.g., large-volume truck stops). We filled the tank to about 5/8 full at a Marathon station that I doubt sees many larger vehicles but did sell diesel.

After driving about 10 miles, mostly about 50-55mph in 6th gear at ~1500 RPM - we got a small hesitation, or hiccup. About 10 seconds later, another one. No problems for 10 more minutes, but then quite a few hiccups in a row, all around 1200-1500 RPM. On a couple of them the check engine light flashed very briefly then went back off.

Pushing on, this continued off an on - sometimes I would go 15 minutes between hiccups, sometimes I'd get 10-20 of them back to back. Besides the very momentary loss of power during, the power delivery seemed normal. I noticed then that with each hiccup there was a puff of grey or white smoke coming from the exhaust. Hard to tell exactly, but it was not Black smoke like you'd see from old dirty diesel engines.

There seemed to be no long term ill effects from these hesitations, except for causing a bit of driver stress. I then decided to try running the engine at a bit of higher RPM. Downshifted into 5th and ran about 1800 RPM. Once I did this I never got another hesitation or hiccup for the next 100 miles of driving, including some slowing down for traffic congestion.

I have an appointment in a few days with a Detroit service center to check my codes and have a look - but was hoping someone here might have some advice on what may be happening. I'm hoping for bad fuel / clogged fuel filter but find it odd it would run better at a higher RPM in that case. I don't know when the fuel filter was last changed, but I do know it has not been since I've owned it, so not in the past 4000 miles.

Thanks in advance. Lee

OLYLEN · 02-20-2017, 08:44 AM

HAVE you checked for water on the first fuel filter? Sounds like a bad fuel load, change fuel filters and add an additive for possible water in tank. The shop can tell you what to add.

LEN

jimmy braden · 02-20-2017, 08:50 AM

might want to consider a biocide and get ready to do a set of filters. At least primary.

I guess it starts and idles normally?

Leehicks1 · 02-20-2017, 08:58 AM

It does start and idle just fine, yes.

Thanks for your comments so far - fuel filters are high on my list. I was just looking at them this morning, and it seems that the previous owner changed out the fuel filter, it is not the one as shown in the owner's manual. The original Monaco setup seemed to have a primary filter with remote panel for priming fuel and purging water. That system seems to be removed from my coach. I now just have a RACOR filter number S3225P that has a manual dump valve on the bottom, and no apparent priming abilities. No remote catch bottle either, and nowhere for the sensor to plug in to give me a water in fuel warning.

kketterling · 02-20-2017, 09:29 AM

I will be curious what you finally find the issue to be as I'm experiencing the exact same thing with my CAT engine. Plan to change filter once I get home. I would think if it was water in the fuel your issue would exist even when running it in 5th gear at higher RPMs.

Please let us know what you find out on this issue.

twinboat · 02-20-2017, 09:49 AM

Change or have the fuel filters changed.

The reason it ran better in lower gear is it needed less power to keep moving. Higher RPMs don't necessarily mean more fuel burn.

Same thing with the Cat engine.

I've been dealing with diesel engines for 45 years. If there is a power loss, 95% of the time it's fuel filters.

Diesel fuel is dirty and the engine recycles it continuously.
5 times more fuel is pushed thru the filters then the engine burns. The rest goes back to the tank for another trip thru.

Chargerman · 02-20-2017, 05:19 PM

I have a 06 Executive also with a Series 60 engine. Mine was also missing some components to the Racor priming system. I changed the filters the first time without it working and learned a hard lesson. It was impossible to start the engine after the filter change because I could not prime the fuel system no matter what I did to try to remove the air. I purchased what was missing from Racor and also installed a shut off valve on both sides of the Racor unit so that it would not dump all of the fuel from the motor or fuel tank when the filter is removed. Detroit may have a method to prime it without the Racor but I would not remove the filter myself without having it in place and working.

Good Luck!

DWMeatloaf · 02-20-2017, 07:34 PM

In adition to my rv i own a small trucking company. Most likely you got dirty fuel and a bunch of water. I would would look for a shop that has a filter system that can "sweep" your fuel tank and remove any water or contaminats. Chang your filters and buy an extra set. As your motor is older you sould be fine but water in the fuel can cause big problems for new rigs. Most important try to get your diesel at some place with a high volume turnaround. I have lost a ton of money to mom and pop diesle fuel problem repairs. I love mom and pop stores but not there fuel.

**TonyDi** · 02-20-2017, 09:03 PM

Sounds to me like you have picked up some bad fuel or water. As suggested, change all fuel filters and check the water filter as well.

I rarely let my fuel get under 1/2 tank. This way I'm not obligated to buy fuel where I would otherwise pass on it.

Leehicks1 · 02-21-2017, 05:26 PM

Hi everyone and thanks for responding. I took the bus over to Florida Detroit Diesel this morning. The diagnostics had stored codes 59 times last Saturday for a faulty TRS, or timing reference sensor. The tech described the symptoms of a problem like this would make it feel like the engine actually shutting off momentarily - which is exactly how it felt. This works in conjunction with a SRS or synchronous reference sensor. I had them replace both sensors (about $25 each plus an hour of labor).

I also had them go ahead and replace both fuel filters - just because I don't know the age/mileage on the current filters. I know it is bad troubleshooting method to replace two things at once - but I feel pretty confident that the 59 fault codes stored on Saturday would be the source of the problem.

jimmy braden · 02-21-2017, 05:30 PM

No, you did good.,,when it comes to sensors you need to replace all that are calling out codes - that way you dont pay labor 2x, and sensors arnt $. And since the filters are an unknown, good to get them done also.

Should be flawless now, baseline your mpg and live the good life.

Thumbs up

Chargerman · 02-24-2017, 06:48 AM

Congrats on the repair at a VERY reasonable cost. Curious to know if they mentioned how they prime the system without the Racor pump?

Leehicks1 · 03-08-2017, 05:20 AM

Sorry for the delay, I had troubles with the website redirects when logging in. I'm not sure how they primed it, but on the invoice it says "Prime Detroit, Start engine and check for new fault codes. "