Few questions about the 5.9 Magnum

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Yeret

The Village Drunk
Joined
Oct 2, 2014
Posts
938
Reaction score
178
Location
Under the hood fixing/breaking something.
Ram Year
1999
Engine
5.9 Magnum
Hey all, got a few general questions regarding the 5.9 Magnum engine in my truck.

1. My engine has excellent power at low RPMs and partial throttle, however is quite flat post 2,500 RPMs and especially when I give more than half throttle. I do know my engine has the so called ECM "death flash" which apparently changes the ignition timing (see question 2)? Also, I suspect my intake manifold has the ubiquitous plenum leak as my engine loses about half a quart of oil every 100-200 miles (!!!). I know it sounds kind of obvious, but would either of these two cause a significant reduction in mid-range power?

2. What exactly does the "death flash" change? Does it reduce the amount of ignition advance across the RPM range or does it flatten the ignition advance curve so it takes more RPMs to achieve a certain degree of advance? From what I've read, this "upgrade" seems to do more harm than good (less power and fuel economy) so I would certainly want to reverse this if practical (re-tune ECM?).

3. Are the Magnum engines prone to be dirty? I barely make it 2,000 miles between oil changes before my oil looks like a melted Hershey bar and this time I have less than 800 miles on a Valvoline 5-30 (cold weather is here) change with a Purolator filter and my oil is brown-ing already. I bought my truck at 156,000 miles and currently have 170,000 and have changed the oil almost religiously every 3,000 miles. This last summer I was running Valvoline 10-40 and interestingly enough it seemed to "age" better than the 5-30 I'm running now...

4. Next year I'm looking to upgrade the ignition. I've been looking at Accel and MSD tune-up kits which look nice but while browsing Summit Racing, I spotted a kit by Davis Unified Ignition...

http://www.summitracing.com/parts/dui-dgetkkt-bl/overview/make/dodge

It's a bit more money, but the 45,000 volt coil going to 10mm wires and all-brass-contact distributor cap and rotor look really groovy. Has anybody used this set on their engines?

5. At the moment, I'm running an open-element round air cleaner (broke my airbox attempting to remove it last year. Don't ask, I was a *******...). My cleaner in question is 10x2 and works fine (and looks really cool) but I'm curious, if anyone here has done a similar modification, if a wider cleaner would be any better. I can't go much taller due to clearance issues, but I can go a few inches wider...if it's worth doing.

Thanks for any and all answers/input! :favorites13:
 

dodge dude94

Millennial Boomer
Joined
Sep 5, 2013
Posts
27,745
Reaction score
6,426
Location
East Texas
Ram Year
1998 Ram 1500
Engine
5.9 Magnum
Hey all, got a few general questions regarding the 5.9 Magnum engine in my truck.

1. My engine has excellent power at low RPMs and partial throttle, however is quite flat post 2,500 RPMs and especially when I give more than half throttle. I do know my engine has the so called ECM "death flash" which apparently changes the ignition timing (see question 2)? Also, I suspect my intake manifold has the ubiquitous plenum leak as my engine loses about half a quart of oil every 100-200 miles (!!!). I know it sounds kind of obvious, but would either of these two cause a significant reduction in mid-range power?

2. What exactly does the "death flash" change? Does it reduce the amount of ignition advance across the RPM range or does it flatten the ignition advance curve so it takes more RPMs to achieve a certain degree of advance? From what I've read, this "upgrade" seems to do more harm than good (less power and fuel economy) so I would certainly want to reverse this if practical (re-tune ECM?).

3. Are the Magnum engines prone to be dirty? I barely make it 2,000 miles between oil changes before my oil looks like a melted Hershey bar and this time I have less than 800 miles on a Valvoline 5-30 (cold weather is here) change with a Purolator filter and my oil is brown-ing already. I bought my truck at 156,000 miles and currently have 170,000 and have changed the oil almost religiously every 3,000 miles. This last summer I was running Valvoline 10-40 and interestingly enough it seemed to "age" better than the 5-30 I'm running now...

4. Next year I'm looking to upgrade the ignition. I've been looking at Accel and MSD tune-up kits which look nice but while browsing Summit Racing, I spotted a kit by Davis Unified Ignition...

http://www.summitracing.com/parts/dui-dgetkkt-bl/overview/make/dodge

It's a bit more money, but the 45,000 volt coil going to 10mm wires and all-brass-contact distributor cap and rotor look really groovy. Has anybody used this set on their engines?

5. At the moment, I'm running an open-element round air cleaner (broke my airbox attempting to remove it last year. Don't ask, I was a *******...). My cleaner in question is 10x2 and works fine (and looks really cool) but I'm curious, if anyone here has done a similar modification, if a wider cleaner would be any better. I can't go much taller due to clearance issues, but I can go a few inches wider...if it's worth doing.

Thanks for any and all answers/input! :favorites13:

1. I would wager you not only have a blown plenum, but a clogging cat as well. Try this: start the truck, put the transmission in neutral. Let it run for a couple minutes then try revving it. See how fast it will rev, if it doesn't want to rev much past 3000 rpm, you have a clogging cat. Shut the truck off, let it cool down and remove the pre-cat O2 sensor (it's actually in the cat, but whatever), start it again but immediately try and rev it. If it revs past 3k or tries to, you've found your problem.

2. The Deathflash just ******* the ignition timing all across the board. There is no turning back once it has been done as your dealer likely can't even do the Deathflash now, let alone go back to an older tune. Your only course of action would be to buy a flash tuner such as a SuperChips or an SCT tuner.

3. I've found with my personal engine that a blown plenum can actually cause the oil to get dirtier, sooner as the plenum uses oil and creates carbon. That carbon gets washed down by the oil and thus makes it dirtier. Before my plenum was fixed, I found the same thing with mine. My plenum is fixed, I'm running a PCV oil catch can and using 5W40 Rotella T6 and my oil still looks good even after its June change.

4. To be completely honest with you, super-powered coils and 10mm wires are ******** on a stock engine. A regular old cap and rotor kit with brass terminals and quality 7.5mm wires are all you need. Just route the wires per the TSB and put good plugs in it and you're good. Just don't run them rare-earth plugs like Platinum, iridium or the E3s, very few trucks actually run worth a crap on them. These trucks prefer old school copper plugs. Factory plugs work just great in MOST applications. An upgraded plug you might consider is the NGK V-power, not G-power as those are platinum.

5. You can run a 14x2 just fine on these trucks and you can run a 14x3 with a little massaging. There is actually a thread in the DIY section on installing a 14x3 air cleaner. And, personally, when it comes to the round air cleaners, I'm a huge proponent for running as big a filter as possible. ;)
 
OP
OP
Yeret

Yeret

The Village Drunk
Joined
Oct 2, 2014
Posts
938
Reaction score
178
Location
Under the hood fixing/breaking something.
Ram Year
1999
Engine
5.9 Magnum
Thanks for the answers, dude. I actually did have a plugged cat a couple months ago (engine wouldn't rev past 3,000 RPM even at WOT). My down pipe was shot anyway so I had a cat-back job done. The Turbo Thrush muffler I had installed gives the engine a nice, meaty note without calling to every cop within two miles, LOL.

I was afraid I would need a tuner to reverse the "death flash." The SCTs I'm looking at go circa $400, but it'd be worth it to me. Maybe when tax return time comes around...

I've also read the "death flash" can also reduce fuel economy. Would you say this is generally true? Last I tested, my truck averages a little over 12 MPG.

It appears the Hughes Engines plenum repair kit is the most popular option and doesn't sound like a bad price ($120).

Thanks for the tip on the ignition stuff. I kinda figured a stock engine wouldn't benefit a whole lot, but never hurts to ask, right? I had a BWD Select cap, rotor and wires installed a couple years ago and earlier this year I installed Autolite 3923 sparklers. From what I've read, they're a "cooler" plug and my truck does ping less than with the Champion RC12Ys I was firing. My truck was a pinging beast when I first got her, but ever since I've been running BP 91 it's been almost non-existent, even better with the cooler plugs. It's nice to be able to run 2,500+ RPMs getting up to highway speed without the "can of marbles" racket. :favorites13:
 

dodge dude94

Millennial Boomer
Joined
Sep 5, 2013
Posts
27,745
Reaction score
6,426
Location
East Texas
Ram Year
1998 Ram 1500
Engine
5.9 Magnum
Thanks for the answers, dude. I actually did have a plugged cat a couple months ago (engine wouldn't rev past 3,000 RPM even at WOT). My down pipe was shot anyway so I had a cat-back job done. The Turbo Thrush muffler I had installed gives the engine a nice, meaty note without calling to every cop within two miles, LOL.

I was afraid I would need a tuner to reverse the "death flash." The SCTs I'm looking at go circa $400, but it'd be worth it to me. Maybe when tax return time comes around...

I've also read the "death flash" can also reduce fuel economy. Would you say this is generally true? Last I tested, my truck averages a little over 12 MPG.

It appears the Hughes Engines plenum repair kit is the most popular option and doesn't sound like a bad price ($120).

Thanks for the tip on the ignition stuff. I kinda figured a stock engine wouldn't benefit a whole lot, but never hurts to ask, right? I had a BWD Select cap, rotor and wires installed a couple years ago and earlier this year I installed Autolite 3923 sparklers. From what I've read, they're a "cooler" plug and my truck does ping less than with the Champion RC12Ys I was firing. My truck was a pinging beast when I first got her, but ever since I've been running BP 91 it's been almost non-existent, even better with the cooler plugs. It's nice to be able to run 2,500+ RPMs getting up to highway speed without the "can of marbles" racket. :favorites13:

Good deal. I have a Thrush Turbo as well and I like it. Took it about 4500 mi to break in but it sounds great now.

Yep, tuner is the only way to go. SCT is by far the best for power, but it can be rough on the computer if you're changing the tune all the time.

Yeah, it can, actually. By reducing the ignition timing, you're reducing the highest possible amount of power the engine can make as it's running richer and you also have to open the throttle more to get it up to speed and make it up hills.

Hughes isn't a bad kit, just slightly overpriced. lol I personally bought my plate from a Dodge enthusiast on eBay...he's not making them anymore to my knowledge, but it's a damn nice plate. I think Hughes is your only option again.

No problem. 3923s are indeed about 2 heat ranges cooler than the stock plugs, and they're also a "short reach" plug, meaning the insulator is not as far down into the combustion chamber as a regular plug. If the 3923 has reduced the spark knock, a new plenum will make it feel completely different. :naughty:
 

Derek_marburger

Junior Member
Joined
Dec 2, 2014
Posts
8
Reaction score
3
Ram Year
98 and 99
Engine
Both 360
I wish I got 12 mpg
I got one truck that gets 5mpg and one that gets 8.5
Both 360's both auto's....
 

Stegs

Senior Member
Joined
Apr 7, 2014
Posts
301
Reaction score
137
Ram Year
1998 Dodge Ram 1500 4x4
Engine
5.2L 318 C.I.
I wish I got 12 mpg
I got one truck that gets 5mpg and one that gets 8.5
Both 360's both auto's....

are you running a lift or big rims/tires?

when i had my 5.2 bone stock with a good tune up was just shy of 16 mpg

winter it went to 13-14 mpg

when i added bigger tires i was at a consistant 12-14 mpg

now with all the mods, 10 if im lucky.....she seems to like the fuel
 

Derek_marburger

Junior Member
Joined
Dec 2, 2014
Posts
8
Reaction score
3
Ram Year
98 and 99
Engine
Both 360
are you running a lift or big rims/tires?

when i had my 5.2 bone stock with a good tune up was just shy of 16 mpg

winter it went to 13-14 mpg

when i added bigger tires i was at a consistant 12-14 mpg

now with all the mods, 10 if im lucky.....she seems to like the fuel



My 99 1500 has 265/70/16 tires,
And my 98 2500 (8800 gvw) has 285/75/16

No lifts no nothing.
 

Merc225hp

Senior Member
Joined
Jan 13, 2013
Posts
5,145
Reaction score
3,130
Location
NA
Ram Year
truck
Engine
gas
^^^ Comp test on both motors is in order, then plenum gasket, full tune up to go with the rest of the work.
 

michaelcolligan

Junior Member
Joined
Nov 29, 2014
Posts
16
Reaction score
0
Hey, mike here. I just acquired a real nice 99 ram 1500 4wd. After running a while I noticed the oil consumption is ridiculous. It uses a quart every tank full. I suspect it is the valve seals 360 has 140k on it. I was wondering if anybody out there has had the same situation and how long it took to repair it. The parts are cheap, it's the labor that will kill you I suspect. What am I looking at $ wise. It's getting expensive to keep adding oil all the time. I'm running valvoline full synthetic. $8 a quart. It's a nice truck( rust free) in NY that's rare. Most of the old Rams I see are rust buckets, so I feel this truck is worth saving. Any input would be appreciated. Thank you. Mc


Sent from my iPad using Tapatalk
 

Johnn123

Senior Member
Joined
Sep 23, 2013
Posts
2,090
Reaction score
1,099
Location
Ontario
Ram Year
2010
Engine
5.7L Hemi
Hey, mike here. I just acquired a real nice 99 ram 1500 4wd. After running a while I noticed the oil consumption is ridiculous. It uses a quart every tank full. I suspect it is the valve seals 360 has 140k on it. I was wondering if anybody out there has had the same situation and how long it took to repair it. The parts are cheap, it's the labor that will kill you I suspect. What am I looking at $ wise. It's getting expensive to keep adding oil all the time. I'm running valvoline full synthetic. $8 a quart. It's a nice truck( rust free) in NY that's rare. Most of the old Rams I see are rust buckets, so I feel this truck is worth saving. Any input would be appreciated. Thank you. Mc


Sent from my iPad using Tapatalk

Start your own thread instead of posting your questions in other peoples threads.

OP DD94 has you covered.
 
Top