My '94 Ram is getting another motor installed (5.9) due to A/F in oil and out of tailpipe. The motor I'm putting in it has no place for an EGR valve like the one I'm taking out. Can I install the newer motor ('01) without the EGR set up or do I have to change the intake and right side exhaust manifold for the EGR? Will the computer not let the motor run if the EGR is not hooked up is what I'm trying to find out.

My reading of the Online Lending Library (Rockauto) shows there is an EGR transducer that measures flow. I guess that's because EGR passages are known to carbon up.
So IMHO you'll need to dress the new engine the same way.

R.

One also wonders what other parts may be different and not compatible with the computer's expectations.

Assuming your pulling out a '94 5.9 (or 318 cid), my gut instinct is to use the intake & exhaust manifold from the '94 & possibly some other of the '94 bolt on parts.

fyi- on my '96 "brand-X" car, I installed a '04 motor, but used all the '96 bolt on parts. It just made installation soooo much easier.

On a 94 truck it should still be OBD1 which means the PCM wont check the EGR system. After 1996 with OBD2 the PCM will turn on the EGR and test it by looking at the short term addaptive memory and 02 sensor to check if the EGR is working and will eventually set a code for the EGR if its not working. But your 94 PCM wont do that so you should be fine. If the eng going is was made with no EGR then it should run ok and not have any ping with the right fuel. If someone fooled with the eng going in and it had EGR at one time then I would use the intake and EGR from the old eng. Good luck , Ron

My OBD-I computer on my 1995 Magnum 360 V8 has a quite extensive EGR system checking process that comes on when the engine is fully warmed up and rpm and vehicle speed has been relatively steady, like when you are travelling at a steady speed on an Interstate.

The PCM turns the EGR off, and watches for the O2 sensor to indicate a “blip” of leaner Air/Fuel ratio as fresh air replaces oxygen deficient exhaust gas at the same rate of fuel injection.

The PCM then turns the EGR on, and watches for a reverse “blip” of richer Air/Fuel.

If the PCM does not see these two A/F blips correctly,
It repeats the test two more times.
After three failed tests it rurns on the “Check Engine Light”
AND
( this is the attention getting part)
the PCM sends a command that turns on the EGR flow
ALL THE TIME
Even when the engine is at low rpm and low throttle opening like at idle.
This causes the engine to run very rough and frequently stall,
which I guess the EPA thinks will get the owner to bring it to the dealer.

I am 99% sure a 1994 “Light Duty” Magnum 360V8 is the same.

There was a little sold
“Heavy Duty Magnum 5.9V8”
in the years 1994-1995
that had a different emissions equipment setup with a belt driven air pump and was installed in a few 2500-3500 series Rams. Its PCM might be different.

If this helps any, I swapped a 1999 5.2 magnum into my jeep and to do it I used a 1995 harness and ecu. The 1999 doesn't have EGR so I just didn't hook it up at all. I didn't hook up the evap either. The only mods I had to make was the 99 used different plugs on the throttle body so I had to swap the sensors over. Also had to drill and tap the intake manifold for a coolant sensor the 95 uses that the 99 doesn't have. Fuel injector flow rates changed so swap those as well. Runs great.

You may want to inquire about emissions requirements in your area before deleting the EGR. Many municipalities perform a visual inspection for the EGR and it's accessories, ie transducer, vacuum lines, etc. Along with a lit MIL lamp on the instrument cluster giving reason for a failed emissions test.

Also, a non functional EGR will reduce fuel mileage, sometimes noticeably. And finally, a non functional EGR increase a nasty little gas into the atmosphere that we breathe called NOx, Oxides of Nitrogen. Known to cause difficulty in breathing among the young and elderly and everybody in-between.

Thats what I would do. Mismatching parts is asking for problems. Use the different engine but all the manifolds and sensors that were on the original engine.

On my 1995 at highway cruise in the 1600 to 1800 rpm range with a manifold vacum of 11 to 8 inches Hg my Actron OBD-I Scantool shows the spark advance is quite high: 42 to 48 degrees BTDC. I think this is because EGR slows combustion speed and requires more advance. I have even seen as high as 52 degrees.

I do not know if the OBD-I pcm is “smart enough” to not dial in this much advance if the EGR is not functioning.

Chrysler did away with EGR in 1996 when more efficient 3-Way Catalytic converters became available.
Non-CA EPA Tier 1 regs for the period 1992 -2003 can be met without EGR if the guts of the CAT are efficient enough. Light duty gasoline trucks over 3750 lbs to 5750 GVW only had to meet 0.7 grams/ mile,
versus the passenger car limit of 0.4 NOx grams/mile in that period.

Chryslers 1995 CATs were pretty fragile.
There was a recall.
My original factory CAT began rattling around 50,000 miles.

The 2nd dealer installed CAT suddenly failed around 110,000 miles and nearly plugged the exhaust. The extra backpressure blew out the internal bellows of the “EGR Modulating Valve” and I did not discover this until the first long trip on the aftermarket 3rd CAT. This is when my CEL light came on and I read the Ram FSM sections about how to troubleshoot and fix the EGR system.

Now that you say that I do believe I remember a 94 Intrepid that did test the EGR even though it was not OBDII yet which I believe was standard by 1996 on Mopars and some 95 Neons had OBDII. I remember this 94 Intrepid set a code for EGR failure. I also remember Mopar dropping the EGR on the 3.3 for a few years and then we were getting 3.3 engines failing the NOX emission test. Mopar was telling us to replace the CATs on the cars that failed and we found nothing wrong. But a few years later they went back to EGR on the 3.3 eng and then we had no failures. I don't remember what year it was when they dropped the EGR on the 3.3 and I don't remember on their other engines without looking it up. I just remember some other engines that also dropped the EGR. I also saw many of the vacuum transducers melt the hose under it that brings the exh pressure to it and many vacuum transducers melt from clogged CATs and exh. I saw a lot of the Mopar engines showing a lot of timing that the PCM gave it at different times. And I was surprised to see so much sometimes as it was more then I was thinking I would see at times.


The PCM will turn the EGR off when it meets the test parameters to test it as it looks for the 02 to go lean and the short term adaptive to go rich to see if it is working. I believe "360view" is correct as I had forgot that some cars did monitor the EGR before OBDII. But if the eng was built without EGR it may be ok but if the eng in the car had EGR the PCM may be one that monitors the EGR and may set a code with no EGR working. Ron

I believe those who say that you can do an engine transplant with an OBD-I pcm and wiring harness while leaving the EGR parts off.
The PCM will not shut the engine off if it fails EGR testing,
it will just turn full voltage on to the wire that is supposed to go to the EGR modulating valve. If nothing is attached to that wire, nothing harmful happens. The Check Engine Light may light and a code set in memory.

I also suspect that having the EGR valve integrated in the rear of the Kegger style Magnum intake manifold heats up the aluminum in the rear of that manifold and makes the air to cylinders 7 and 8 hotter.
#8 cylinder seems to ping first,
and many report that #7 has more head gasket failures.
That D@&& plenum gasket tends to fail in the rear corners too!

If he leaves the EGR off and the PCM looks for it then it should set a code after a few trip failures and turn on the CEL lite. In Md where I live the 95 and older cars I believe still get the tailpipe sniffer as 96 and up they just scan the vehicle. But even if it gets tailpipe tested if they see the CEL on they will fail it. I believe in Md where I live that year will get tested on the rollers and get a drive test. Some older years I think still get just the idle test but I have been out of it (retired) since 2011 and I don't remember what years get only an idle test.


Its funny "360view" that you mention it can turn the erg on by grounding the EGR solenoid as I forgot about that it can do that if it keeps failing.

I had a Caravan around a 1996 with a trans problem and I remember when I brought it in the shop that it ran bad and had no power. I knew the trans had to come out so I figured I will fix that first and then check the running problem. But after I went through the trans I pulled it out to drive it as it was now running ok in my bay. And the Caravan ran perfect now that I had cleared the codes and set Quicklearn and repaired the trans so it was not in limp-in mode. It seems Mopar programmed the PCM to limited the rpm to about 3000 when the trans was in limp-in I guess so you wont hurt the trans. That was the first one I had ever worked on that did that and when I got others like that I knew what was going on. Funny as I noticed how every year they could make the PCM's smarter and I always tried to find out all I could in training about any new tricks the PCM could do. Info like that I usually could never find in any books. Ron

That would be an interesting test with an OBD1 reader!

It was a kinda interesting “test” to see that I got about 2 MPG less on the trip I made when the EGR was not flowing because the EGR bellows was blown out. I had made this same trip dozens of times before.

EGR was not invented to reduce NOX.

EGR was invented in the 1920s to extend the range of gasoline engined aircraft.
The extra inert gas in the intake manifold raises manifold pressure when at less than full throttle power, like when a Bomber is at high altitude cruise using less than full horsepower needed at takeoff with a full load of bombs. The higher manifold pressure “helps” push the pistons down on the intake stroke. The lower peak combustion temperature also lets less heat leak away through the cylinder walls and cylinder head. For awhile EGR was a “secret military technology.”

It was only later in the early 1970s that engineers seeking new pollution reducing techniques realized that the lower peak combustion temperatures led to less chemical NOx creation.

I don't have to worry with the sniffer and testing, I only use this truck for snow plowing my own driveway, it's not on the road for inspections.

Not sure where you found that (polished turd) gem, but no, not even close. EGR does not raise manifold pressure. EGR does not help push the piston down. EGR does not let "less heat leak away through the cylinder walls and cylinder head".

It does lower peak combustion temps which helps prevent knock and Nox formation.

That's just what I was taught in auto shop class and other training classes through my years. I have no idea who or when EGR was first used I just know car manufactors use it to help control NOX emissions. And that's because NOX is created when combustion temps get to high. The EGR inert gas wont burn so it helps lower combustion temps to keep NOX down. I have also heard some call EGR "The cheap mans octane booster" since it helps keep combustion temps down and helps stop any other flame fronts from starting so it helps to fight detonation. I don't know when it was first used and dont care I just know car manufactors used it to help in emission control. Ron

The EGR lowers pumping losses. It's essentially a vacuum leak minus the O2. So, ya, it raises manifold pressure (less vacuum). It also allows for greater throttle opening angle which results in even less pumping losses on the intake stroke.

Help push the piston down? Semantics. 360view is correct on this, the wording is just...unconventional. I don't know about the heat transfer thing.

You ever hit the highway in a throttle cabled car w/EGR and notice a few minutes into the drive that you have to push the accelerator pedal down a little further to maintain speed? That's when the EGR opened.

2-4 mpg in about normal.

Moparteacher,
my comment
“that it helps push the piston down”
is unconventional.
but I have found in the past
it helps get across the the efficiency benefit that occurs in general terms, but not strictly scientific ones.

EGR (and also very lean air fuel mixtures)
both get the throttle more open at a given power output,
raise manifold pressure
and therefore reduce “pumping losses”.

It is a thing of beauty to trace the non-ideal Carnot Cycle of “real world” engine processes on a P/V diagram and see the various areas representing useful work and various losses, with the added surprise that clockwise and counterclockwise movements show work and waste.

I understand scientifically that there is only positive pressure,
no “negative pressure”
despite the common everyday expression of “vacuum.”

Two very famous American men of the past could explain
EGR, leaner A/F and pumping losses.
MIT trained PhD General Jimmy Dolittle, and
largely self-taught engineer Charles Lindbergh.