Jump to content
Keffer inc

MP8 still sucks at life

Recommended Posts

My truck has always had a mild misfire and it got worse this week. Now it starts missing really bad at 1300 rpm. I've been trying everything else like egr preasure sensors,  checking the tunes on the dpf diff sensor but I guess it's either bad cups or injectors, possible low fuel preasure? It used to normally act up at the 1500 rpm range and be intermittently missing. (Running rough for 60 seconds and smooth out for 120 seconds like it was an electronic malfunction. Also, the dpf has been going frequent regen and now wentry into limp mode. The warning (blue switch) went stright to blinking and later the red shut off lamp started coming on intermittent and then ATS needs service came up. Not the way it was to work as the manual says. What do you guys think is going on with the miss? I'm assuming I'm running rich if the dpf is clogged. I also checked the dpf preasure sensor tube and they are clear. Bad sensor for the warnings not properly working??

 

Share this post


Link to post
Share on other sites

I forgot to say that the computer isn't showing any miss fire codes. Non for individual injectors and the for multiple cylinders. Neither codes come up?

Share this post


Link to post
Share on other sites

In my opinion ya need to get hooked up ad do a compression test ( cyl  balance ) etc as much as you would like to avoid the shop you need th bite the bullet and do it could still be a wiring harness or a bad valve not unheard of, and 

Share this post


Link to post
Share on other sites

Did you have your local Mack brand dealer look at the truck and provide you with an in-depth diagnosis? If necessary, they could have their district service representative come in to look at it (I assume Volvo hasn't cancelled that Mack position).

Share this post


Link to post
Share on other sites

I'm going in the morning to at least fix the dpf. Would like to get home for the injectors so I can be with my family while I'm not working.

Share this post


Link to post
Share on other sites

So best case if all I need is a dpf cleaning,  it is $1,300 or $3,400 if the DPF filter is wasted and needs to be replaced. Also they say the injectors are what need to be replaced so they said the bill all together is $8,500. And down time I should be back out of the shop by tomorrow night. Almost sounds too good, is it?

Share this post


Link to post
Share on other sites

Yup the injectors likly took out the dpf 

Share this post


Link to post
Share on other sites

I just can't comprehend the cost of repairs on these new trucks!!! Scary. I barely have $8500 into my entire truck. 1985 MH.

  • Like 1

Share this post


Link to post
Share on other sites

Used to be able to do a complete engine exchange for 6-7 thousand bucks back in the 80's.

Share this post


Link to post
Share on other sites
9 hours ago, james j neiweem said:
Used to be able to do a complete engine exchange for 6-7 thousand bucks back in the 80's.


Yes I remember early '90s my boss doing Pedigreed exchange E6 for $7500 with my labor! I remember one time they tried to screw us out of the core, until I pointed out to the boss that the cracked block they sent back wasn't our core. The engine I pulled out had screw in expansion plugs, and the rejected core had press in plugs. I think the boss bought my lunch that day.

Share this post


Link to post
Share on other sites

Well it got worse, the cam shaft is ate up, all the lobes have at least a 1/4" groove dug through them. It's amazing the truck could function at all. Looking at $18,000 now to still do injectors, replace my bad dpf filter, and a new cam. I only paid $25,000 for that truck. This truck better run like a raped ape when it comes out.

Share this post


Link to post
Share on other sites

How many miles on this thing? A 2011 shouldn't be showing this much wear unless it was run almost 24/7!

Share this post


Link to post
Share on other sites

I thought it was premature too, the truck only has 733,000 miles on it. I think it had 675,000 when. I bought it and I didn't idle it over nights. So abuse from the first owners? I think the first owners were in Ca.

Share this post


Link to post
Share on other sites

I was wondering how badly I am stuck with thus truck but it sounds like I own it for life. It is what I want and set up as I wish. A little long on the wheel base for a tag axle would be nice but it's a good spec. It has to run good though with all this though. 

Share this post


Link to post
Share on other sites

Good luck, I hope you are satisfied with the end result. If you like the truck, keep it. My biggest issue with the new emissions trucks is the cost. After it is out of warranty, it is difficult to justify the cost effectiveness.

Share this post


Link to post
Share on other sites

Good luck finding a pre-emissions truck, they've had to meet emissions standards since the 80s.

Share this post


Link to post
Share on other sites
22 hours ago, TeamsterGrrrl said:
Good luck finding a pre-emissions truck, they've had to meet emissions standards since the 80s.


1985 E6, thank you very much. I suppose 4 valve heads and a puff limiter are emission components I can live with.

Share this post


Link to post
Share on other sites

The major effects of the early 80s standards were the end of the bigger naturally aspirated diesels. Sure you don't want to lose that expensive and troublesome turbo?

Share this post


Link to post
Share on other sites
21 hours ago, TeamsterGrrrl said:
The major effects of the early 80s standards was the end of the bigger naturally aspirated diesels. Sure you don't want to lose that expensive and troublesome turbo?


I drive my F model 673P so I can save wear and tear on my turbo MH.

Share this post


Link to post
Share on other sites

No way!  I don't want an automatic. I have an eaton 10 spd. Everyone lovee that M drive but I still don't trust it. Give it a decade and then maybe I'll be I'll trust it. 

 

As for my truck, I haven't heard any news for a while so Im going over to see what's up this afternoon 

Share this post


Link to post
Share on other sites

Let me re phrase that.  The Detroit diesel  8v-92  will be automatically  applying a oil coating to the bottom of your truck.   It is a Detroit diesel joke that they leak.

I wouldn't ever recommend or suggest such a thing as an automatic transmission in a Mack.  :) 

Sell the new Mack and get your self a nice Mack super liner.  For what you have in engine repairs alone you could have a decent old Mack and modify it to your liking. Then you would have something  more reliable and cheaper to maintain and repair.

 

 

Edited by 68-f-model
  • Like 1

Share this post


Link to post
Share on other sites

Really sorry to hear of your troubles Keffer, just a real shame. Ya go out and buy a rig to provide for your family and have this happen. Im in the same boat as you, big piece of me regrets buying this truck. Nothing but reliability issues, to much money spent on emissions garbage, and most repairs have you locked into Mack doing them. Like you, for the moment im stuck with it. Mine has 540,000 miles on it and i still owe to much to sell it.

Far to much complexity in these trucks. Its got me walking in fear everyday of the next multi-thousand dollar repair. Its as if they are "built to break". I have near zero confidence that this truck will live long enough to either sell or be payment free. Always 1 mile away from disaster.  

I've been trucking since 1989, and if any truck can take me out, this is the one.

I hope your troubles pass quickly and with good resolve.

  • Like 1

Share this post


Link to post
Share on other sites

I'm still in Amarillo Tx, Friday they completed the cam, injectors, and dpf. We went for a test drive and it was still missing badly, maybe even worse. At first they were thinking maybe a valve was damaged inside the head. But Saturday a tech decided that it may have been a fault injector that they got. Haven't heard anything yet but I hope that's it. I've been at a hotel for a solid week now.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...