steeler

Strikeout with the 7th injector. No change. 

But I noticed while the engine was running the egr mass flow serious occasionally jump. It didn't look right with the valve commanded at 0%. I got digging and found where somebody had spliced a new connector on the egr diff pressure sensor, I checked continuity to the ecu abs found they had 2 wires spliced backwards! I have high hopes that'll fix it. 

Pm sensor they replaced at well. Pretty much everything has been replaced before it came to me. BUT I noticed last night they put the wrong 7th injector in it. Fingers crossed! 

On 10/31/2025 at 11:25 AM, fjh said:

I'm happy to see you are not a parts cannon supporter my self! I wonder if maybe  the turbo is is not sticking! if it can't go full stroke it maybe seeing there is not enough air to function correctly! ??maybe pull the servo and check the sweep and lever for being sticky!

Turbo is new, they did that along with injectors and cam. Ahi has not been replaced, but it's opening and passing the test in tech tool like it should. For some reason the ecu just isn't telling it to start dosing during regen. 

Also I should add that the soot level will skyrocket during regen. If you call what is doing a regen... If I reset soot level, it'll go from 19% to 160 in about 30 minutes. No engine smoke, runs fine until it derate fire high soot. Filter has been pulled and replaced 3 times by customer during this diagnostic nightmare and it's clean. So, from what I'm seeing, it's not really sooting up, it just thinks it is. Dpf diff pressure looks good at....    . 12 during regen. 

I'm trying not to parts cannon. The customer has already launched a boat load at it with no luck lol. 

7th injector is good. Swapped the acm with no change. Head scratcher! 

2 hours ago, fjh said:

I wonder if the previous part putteroners did relearn data resets ! just thouing that out there!

Yeah that was my first thought. I reset everything with no luck. Swapped ecu with a different truck, still nothing. Getting ready to swap acm and try that! 

2021 mp8. The truck came to us for not completing a regen. Using tech tool I start the regen but it never commands the hi to start dosing. Engine idles up, exhaust temps look good in the 550's and I can see the ahi module go thru it's checks.. Then it just sits there. Never starts dosing. 

Before it came to us it had new injectors, turbo, manifold, and the entire 1 box is new.. 

I'm getting, or maybe I already am.. Stumped! 

I had a customer that had put new injectors in a epa 10 mp7, but somehow put epa 10 mp8 injectors in it. It came to me because it ran HORRIBLE! In my case the mp7 did not like mp8 injectors in it at all! I had no knowledge that they had even put new injectors in it. Chased that one for a couple days before I discovered the problem. 

So... They might not have been mp8 injectors, but they definitely could've been the wrong mp7 ones lol! 

13 minutes ago, fjh said:

Do even replace the Valve cover gasket? 600 bucks for two wine corks Pretty pricey bandaid! For a mistake on the engineering side! Something that should have been a recall! Much like the bull gear feasco! If it doesn’t break before warranty is up don’t fix it!Volvo trash!

Agreed! That 600 is the delete kit, and the updated rail pressure sensor and rear injector harness. If the sensor and harness have already been updated, then probably way less than 600.

Yup, that's the difference between big city dealer vs mom and pop in Kentucky! 😂 

At least they won't have you down for 2 weeks like some shops around here. 

45 minutes ago, fjh said:

Yup you could be putting 2000 in you’re jeans buddy ! Or you can go home with a clear conscience! 
you chose right!

I guess it depends on his location. I assume big city dealerships are way more expensive than small city mom and pop shops. 

Yeah I do a lot of these deletes. I'm not sure what the parts cost, but it's a really easy fix other than updating the software for the accessory kit. 3k sounds high! 

Edited to add... I had to check to see what we charge for the delete. About $1000. Dang maybe we are too cheap! Parts are less than 600 bucks, and the job only takes a couple hrs max. 

A little late to the party but I was going to say it was the water pump. I've seen 2 so far that turned the coolant purple/black due to the fins rubbing. Surprisingly neither were leaking though. 

Glad you found the problem! 

I ran across one like that, hollowed out, but not deleted.... Go figure lol

3 hours ago, Joey Mack said:

Well, in my limited knowledge every Eaton i have serviced that was after 1990 got 50-W synthetic oil... 

Same here. We have customers that run 80 90 without issues in them, but unless the customer requests otherwise, we fill all rebuilds with 50w synthetic. 

6 hours ago, jimbo40 said:

There was no rust.  Instead of just  removing the cover, can I pull the cylinder off too and try to manipulate that piston manually to see if it is just stuck?

You probably won't have much luck locking the range cylinder in by hand. It takes a decent amount of pressure. But if your problem isn't with the cylinder/stuck piston, then you'll be removing the auxiliary section anyway. Assuming it isn't an air pressure problem. 

The larger piston is your range cylinder, smaller is reduction. In high range the large piston will be pushed towards the front of the transmission, to the rear for low. Like Joey said, you can remove that whole range housing by removing the air lines, 5 bolts and 2 nuts on the pistons. The shift forks will stay in the transmission and won't go anywhere. 

They make a kit with gaskets and o rings to service the housing. 

Was there any gunk/rust in that deep reduction cylinder? I've seen many that are rusted up and not used often, then when they get used they stick and have your exact issue... I've built 100's of 8ll's. I could almost do one blindfolded lol. No joke

11 hours ago, fjh said:

So not including labor how much money did this wild goose chase cost steeler just wondering how much Volvo gets to make on this adventure !

I think it was around 10k in Volvos pocket! 

Just a final update. Almost a month later and no problems, so...... Aftermarket Dpf, was the culprit. For whatever reason, this truck did not like it and wanted the big $$ oem! 

Yeah, going to release it to the customer and let them run it and see what we've got. I'll post the result in a few days! 

Ok, went with oem filter, test drove same route as before. Probably 50  miles. Soot level with oem filter went from 5 to 31 after drive. With aftermarket filter I went from 0 soot to 77......

Big difference