Todd71106

I’m on my way down there right now. That’s the first thing I’ll check. That makes sense because I replaced the starter a few weeks ago and had the batteries disconnected.

Greetings. I have a 2013 Mack granite with an MP8. Yesterday, the DEF gauge and the oil temperature gauge started bouncing back-and-forth and the engine brake started acting erratic. Sometimes the engine brake works sometimes it didn’t. It’s not slowing the truck down like it normally does. All three events started simultaneously not sure where to start, I’m guessing it’s something electrical. Has anyone had a similar experience?

Are you running aftermarket LED headlights? If so, you may need a load equalizer.

I put the Doorman 8885126 & 8885127 in my 2013 GU713. I went with high quality LED Bulbs and load equalizers / anti flicker canbus decoders. They really light up the oil field lease roads at night !

They said they did not see any soot in the fuel tanks. what I saw it coming through the return line was a lot of diesel fuel evidently. He said there was some algae in the bottom of my fuel tanks.

Finally got the truck back, and after 1 day of hauling 130 barrels of salt water around the issue seems to have been resolved. A couple weeks before I had the injectors and cups replaced, I replaced the fuel filter housing with a cheap Chinese Amazon replacement. The primer pump on the cheap replacement would not fully seal when locked down. This caused the loss of fuel pressure under load. Luckily I still had the original Mack housing. They swapped it back out and the fuel pressure issues were gone. I saved $200 on the part but lost thousands in down time. I won’t be replacing any critical parts with cheap Chinese stuff ever again !

I’ve had the same problem with my 2 outside marker lights. I believe it turned out to be a connection problem on the power distribution block under the hood on the drivers side firewall.

I finally got the truck back 3 weeks ago. It ran good for a day or 2. It was loosing power at higher RPM's as the fuel tank level decreased. There are no more bubbles returning to the fuel tank. Instead there is now soot flowing back into the fuel tank. I took it back to the shop and they have had it now for 3 weeks. They all ready got my $6500 so they were in no hurry to fix the problem. They just started working on it yesterday. They are telling me there is zero PSI fuel pressure under load. They don't seem to want to address the soot problem. Would a loose injector cause soot to flow back into the tank? maybe re-using stressed fasteners?

Right now, my biggest fear is that he will replace one or some of the injectors, but charge me for all 6. But, at some point you have to trust someone.

Just an update here. The diesel repair shop replaced the injector cups and the truck actually runs worse when and if it starts up. Lots of bubbles in the fuel tanks. They now plan to replace the injectors with a discounted labor rate. I have not paid them anything yet. They quoted me $6000 for everything. Starting to wish that I would’ve attempted this job myself.

Interesting. Are you talking about Cascade automatic dishwasher powder detergent ?

I’ve actually researched this quite a bit lately. I have learned that the $300 kits you see on Amazon and eBay are single use kits at best. They may or may not hold up long enough to finish the job. I was considering doing the job myself because my buddy had a brand new kit he got off of Amazon. I heard a few stories about the tools failing halfway through the job. In the end, I took it to a shop due to the cost of the real deal tools, and my timeframe constraints.

The local Mack house here in Shreveport actually agreed to do the job. I was upfront with them and told them it’s an oil field truck and has been deleted. Those lease roads are extremely rough on trucks. I am in there every week buying parts, so they see me a lot. They’ve got the best prices in town on brake system, suspension parts, and batteries. Even before my discount. Anyway they quoted me $3400 for the 6 pack and $1700 labor, which I thought was fair. Only problem was the 2 week wait. The independent shop is actually $300 more, but the turnaround is only 2 to 3 days. Based on my past experience with the shop, that actually means one week. Lol.

Thanks everyone. I would like to do the job myself, but can’t afford anymore downtime. The guy that deleted my truck is going to change out the injector cups for $2040. I’ll reply back if this solves my problems.

Will the injector cups eventually get bad enough that the truck just will not start up anymore?