krismoriah

I think its was a little under $300. My econovance actually went out but didnt fix the smoking on startup. THe driver of the truck said the jakes went out and i replaced both jake solenoids with no help..then i noticed that someone before I owned the truck had been hitting the econovance with a hammer for some reason..there was alot of tool marks on mine due to beating it. . i hit mine with a hammer and the jakes started working again..so thats what caused me to replace it... Right after I bought it new i found one in a junkyard for $100 but passed it up.

Same thing with a 1998 E7-400 here and another guy in the forum had the exact same problem. So far nobody has figured it out for a true "fix' I replaced the econovance with no help. If your truck starts and doesnt cut out or lose power when warmed up your econovance isnt due for a replacement yet. I am about a year on the heavy smoke at startup and rough running until it 'clears up'

yep there it is but on a different page..thank you http://combscustommfg.com/mack_truck_bumpers_and_chrome_parts

just picked up an older r model and bringing it back to life. where to get a grille like this?

like this..

This one has them too..but looks like more bars..

anyone know who sells or where u can get a grille like this?

The engine rebuild or swap might have replaced whatever engine was in it with a 300. Owner says it has no jakes which is not going to work for what the truck will be doing on a daily basis. Called up a friend who has a 300 mack with jake heads, new fuel pump and turbo for cheap..so that fixes that problem. The guy with the engine says he has run 300 macks for years and he could leave 425 cats and 400 cummins like they were standin still on the hills... but you hear alot of those stories. I think a good game plan is get her going for pretty cheap and work her on a daily basis until something major goes wrong with the engine.. she will pay for herself in a short amount of time... then repower with a 350 later on..

I am double posting this in another section.. I have to move fast on this deal on a truck im looking at.. just trying to get as much info as i can before i purchase. I just got a call about a 1980 superliner dump for sale. Talked to the guy says it has a EM6 300 that was rebuilt. Says it has pictures of a bulldog on a rebuild plate on the engine. Says it has a 13 speed road ranger with 4.17 mack rears. Radiator is leaking pretty bad..dont know how much that will cost..if i can even find one. Are the EM6 300 motors pretty good? I have a 1995 mack 400 and it does really well.. just wondering how gutless this truck will be in comparison...? Seller says it will do 85mph no problem. but its the hills that I have to haul that i am wondering about. Will be packing 25 ton regularly. Just wondering if this 300 engine can handle 77000lbs up hills without falling on its face.

I have to replace the studs and nuts occasionally on my granite quad axle.. Inspect your studs really well and your nuts to make sure they arent stripping or stressed. Also could be problem with someone installing too tight. Or someone not installing the nuts in sequence. There is kind of an art to putting on rims correctly. Been thru a few rims myself. Check the obvious first. Also a bad kingpin can cause alot of stress on that rim.

I had the same problem awhile back. The jakes werent working right, and it was derating. I replaced both jake solenoids..no help. I replaced the econovance and it fixed it. It has always smoked a ton at startup.. It clears up within 30 seconds. From what yours is doing..something says the econovance isnt getting the proper amount of oil to do its thing. It will derate by advancing or retarding the timing if the oil pressure isnt right. Have you looked at the lines going into the econovance? is it possible your new econovance isnt working properly? Have you tried pecking on it when its acting up to see if it clears up? I am by no means an expert but except for the smoking at startup (which i think is the timing related to the lack of oil pressure at startup at the econovance)... mine had the same problem and was an easy fix.

1998 Mack RD688 with E7400 Driver came in the other day saying the truck was missing... popped the hood and all the bolts were broken that hold the pump in place..only the bracket was holding it on... i drilled and tapped all new bolts... fired it up..now it has what seems to be a dead miss at idle.. it surges.. 800rpm to 900rpm up and down up and down.. After it warms up it runs fine. Could it be the ecovance? I replaced about 3 months ago with a junkyard ecovance...and it ran fine up til now. I know the ecovance retards the timing or advances based on oil pressure... Or did i do something wrong with putting my pump back on? Since it runs fine after it warms up..and starts fine..leads me to believe I should be looking elsewhere?

definately R models..there are 4 that I have counted so far in my area 1 is a dump truck and 3 are hauling coal. I have a 1997 RD688 and know what those headlights look like..I see R models all the time with the single round bulb...but these look like the exact same hood except they have dual rectangular headlights like the superliner..so maybe the coal hauling guys upgraded to superliner headlights to make their trucks look cooler? They look great from the front...makes them not look as outdated I guess.

I have noticed two older R model trucks here with square headlights they are twin headlights in place of the usual round one headlight..is this a particular model of truck that has this or is there a conversion kit? Looks like a r model with superliner headlights...but IDK..

No it did not fix my smoke issue either.. my mechanic thinks there is o-rings leaking under the injectors somewhere.. but mine only does it on startup. It definately fixed the de-rate and my jake brake issues as soon as I put the solenoid in.. I got by with $100 from the junkyard for mine. Whatever it is lets the fuel leak past the injectors after you shut it down. Which loads up the cylinders with fuel.. I was worried about vapor lock or washdown with the amount of fuel that must be loaded after shutdown.

I have a 1998 model with an E7400 that did the same thing..i think. Mine smoked a ton at startup then cleared up..then after awhile would lose power..and jakes wouldnt work. There was a solonoid on the side of the pump that someone had been taking a hammer to.. so i got to looking and the solenoid was nearly beat to death..and was sparking. I went to a junkyard and got a solenoid off an E7350 and fixed the derate and jake problems... still smokes like crazy at startup but after that runs like a champ. Replace the solenoid as cheaply as possible... will fix your power problems. As for the smoking like its on fire at startup... i still havent figured that out... I have heard maybe the puff limiter? I couldnt find any screens?? maybe someone can post a picture of the screens so I know what to look for?

I dont know what kind of oil you usually run...but i have heard when you first have signs of really bad blowby..to change weights to straight 40 and add a gallon of lucas..and you can get another year out of it. If it works you can start saving back for your rebuild or engine swap and keep earning. Also might be wise to pull the valve covers off and make sure the oil passages are all clear..i have seen them gunk up and cause blowby and give false signs of rebuilds.

My 1998 E7400 did almost the same thing...lost all power on the hills and the jakes acted up. There is a solenoid on the fuel pump towards the front of the pump..someone had had problems with mine before I got it..there was all kinds of hammer marks on it..then one day the wire shorted out and thats when I had all the problems. Maybe try banging on it to see if it helps you. The part was $500 thru my stealership...but i got a used one for $200 at a local junkyard.

Yes it does smell like fuel. I read where it could be lack of oil pressure to the ecovance..isnt there some small screens somewhere behind allen screws that if removed will help? I looked but didnt see any thing like that. It is only on startup..lasts about 5 seconds..then clears up.

Hello, I am new to the forum. I have 2 mack dump trucks (2005 granite and 1998 RD688SX) and 1 Ford LTL9000 dump with a 425 cat. On the 1998 RD688SX with an e7-400 on startup there is always a massive amount of white smoke out the exhaust then it clears up. What causes this? The engine has 300,000 miles. Thanks in advance.