2.5L performance?

[quicksand97]

Well atleast thats a good plus 20 to 30 degrees cooler. I think it was also a good idea to use the fan shroud with it, I believe it also plays a big roll in air movement and presure, such as a tunnel/funnel affect. So I have another question, does the fan run constantly while running the jeep or do you also run a relay for it to shut on and off at certian temps?

 

[abe]

Its always on as long as the key is on.

 

[quicksand97]

That sounds easy, not to rain on your parade but my concern would be in colder weather will the engine warm up enough to proper operating temps. There is a IAT sensor INTAKE AIR TEMP sensor, that senses the air temp and then adjust fuel delivery to fuel injectors as engine heats up. If the engine does not heat up enough you might be running rich which equauls more fuel comsuption. But maybe the ECU might make the adjustments on fuel delivery on its own, and make proper fuel trim. Or as far as air/fuel ratio goes according to engine temp. I might be concerned if the electric fan is running constantly, it sould kick on when your engine reaches about 180 to 190 or so. Which would mean running it through a thermostat/relay which would read and tell the fan when to come on according to engine temp. I am not a expert just my concerns/opinion. You might even be concerned of the life span of the fan running constantly. Do not get me wrong, I hope this works for you in the long run. I say all this because I care for my fellow jeepers rig. Keep me posted on how its working for you as far as fuel , power, etc. Just maybe its all good. O yeah what part of the states do you live. I wish you the best and Happy 4 Wheeling.

 

[jfrabat]

There are many controllers for the fan out there... Delta Current Control, Flex-a-lite, etc... With those, you can have the fan come on only when the AC is on or when the temp reaches a certain level (which you can pre-set). As for the thermostat, if the engine does not reach operating temperature (don't remember the exact number!), it will function in open loop, which means it reverts to the pre-set fuel trims, and will not use the O2 sensors to modify the mix, which means, you WILL run rich. I have had this debate in the past (2 times; consider that down here, there is NO winter!) and always ended up going with the 190* one. It's my experience that the Robert Shaw Thermostats tend to fail in the open position, while the cheap ones tend to fail in the closed position (just some food for thought). I am on my first stock one, so we'll see how that one works out.

 

[abe]

That sounds easy, not to rain on your parade but my concern would be in colder weather will the engine warm up enough to proper operating temps. There is a IAT sensor INTAKE AIR TEMP sensor, that senses the air temp and then adjust fuel delivery to fuel injectors as engine heats up. If the engine does not heat up enough you might be running rich which equauls more fuel comsuption. But maybe the ECU might make the adjustments on fuel delivery on its own, and make proper fuel trim. Or as far as air/fuel ratio goes according to engine temp. I might be concerned if the electric fan is running constantly, it sould kick on when your engine reaches about 180 to 190 or so. Which would mean running it through a thermostat/relay which would read and tell the fan when to come on according to engine temp. I am not a expert just my concerns/opinion. You might even be concerned of the life span of the fan running constantly. Do not get me wrong, I hope this works for you in the long run. I say all this because I care for my fellow jeepers rig. Keep me posted on how its working for you as far as fuel , power, etc. Just maybe its all good. O yeah what part of the states do you live. I wish you the best and Happy 4 Wheeling.

Um I live in florida south west I think it'll b ok. And I did look into that relay if I need to I will.

 

[jfrabat]

I used to live in Miami, and it would still work in open loop; I would not go to 180*...

 

[quicksand97]

Good info guys, I have been looking at a ford tauras fan and want to make sure I have all my ducks in a row before I purchase anything and install to quickly. Still debating if I will gain any HP or MPG with a E-Fan. Then I also have to think of dependability, life duration, or access to replacible parts.

 

[quicksand97]

opps posted twice

 

[quicksand97]

There are many controllers for the fan out there... Delta Current Control, Flex-a-lite, etc... With those, you can have the fan come on only when the AC is on or when the temp reaches a certain level (which you can pre-set). As for the thermostat, if the engine does not reach operating temperature (don't remember the exact number!), it will function in open loop, which means it reverts to the pre-set fuel trims, and will not use the O2 sensors to modify the mix, which means, you WILL run rich. I have had this debate in the past (2 times; consider that down here, there is NO winter!) and always ended up going with the 190* one. It's my experience that the Robert Shaw Thermostats tend to fail in the open position, while the cheap ones tend to fail in the closed position (just some food for thought). I am on my first stock one, so we'll see how that one works out.

I wish you the best on the stock thermostat, how long have you been running that one?

 

[abe]

I know I replaced mine about 2 years ago b4 I moved to florida with a lower opening temp and its worked well so far. I do need a flush and fill since I've been down here though its been a while since that I know I haven't done it. Since I've owned the jeep and that has been 4 years now. My radiator fluid does look like it needs it.

 

[quicksand97]

I remember once a long time ago I tried a low temp thermostat from jet and my rig felt more responsive at first, then about 50 miles later it started bucking real bad, and hesitating so I but the stock one back in and all was fine. Who knows? That was before my cold air, accel coil, bigger TB, spacer and stuff. I might work today. But If I am happy with my performance now why mess with it.

 

[drivers]

with a electric cooling fan i personally would run it off a toggle switch so i can shut it off while doing deep water (prevents alot of splash into the air intake) also i live in sask canada so i like to keep the fan off till it warms up in the winter
this is just my opinion but it seems to work well as long as you dont forget to turn it on or off lol

 

[MoparMatt77]

with a electric cooling fan i personally would run it off a toggle switch so i can shut it off while doing deep water (prevents alot of splash into the air intake) also i live in sask canada so i like to keep the fan off till it warms up in the winter
this is just my opinion but it seems to work well as long as you dont forget to turn it on or off lol

Power the toggle switch off an ignition source. So if you forget to turn the fan off when engine is off the battery won't get drained by the fan.

 

[Shephard10]

Can somebody tell me what size/kind of relay they used or recommend

 

[56cj5]

I would say at the very least a 40amp relay!! That should do the trick...

Sent from my iPod touch using Jeepz

 

[M G D]

I pulled up this post from February 2006 in an effort to educate myself of the pros & cons of rebuilding my 2.5 or swapping in a 4.0. I really don't need more power or torque when I'm crawling but driving the highways to my favorite ORV park is a drag on 32x11.5x15's & a weak #3 cylinder. I'm leaning toward rebuilding the 2.5 and adding the standard hp helpers but the known hp gain of a 4.0 is tempting, I've read conflicting strong opinons not to bother because its a pain to swap and others say its simple and well worth it. What say you, any jeep veterans with the straight skinny for me, Bounty Hunter and Steelhead any pearls of wisdom? Thanks to any that can help with your experiences. MGD.

 

[jfrabat]

To go to a 4.0L, it is just easier and faster to take out everything you like from your Jeep and buying a 4.0L then transfering all your goodies... If you are gonna do an angine swap, do not go for the 4.0L. Of course, you can always put a turbo or a supercharger in the 2.5, or simply regear to make the best of what you have. With 4.88, the 2.5L should be liveable with the normal mods. I run 33's, and I can use 5th gear (sometimes; not going uphill, though).

 

[O_M_Jeep]

Nothing personal JFR I absolutely hate that answer "just buy a 4.0", I love my Jeep, it has history and love and memories and things I cant unbolt and just put on something else.

That being said, the 2.5 to 4.0 swap is easy if you have a decent well equipped shop and are mechanically inclined, if you arent, its probably the hardest thing you will do, this is why-

you have to cut off the 2.5 motor mounts and weld new 4.0 mounts on your frame, measure 27 times and weld once, still you may be a little off lol, its hard to find a good place to measure from is the thing, next, you cant just swap in the engine, you need the AX-15 transmission or the R42LE, with the AX-15, you need the transfer case too, the input splines are different from the one you have. the donor vehicle should be present, you will need the ECM and ALL WIRING ! ! I cant stress that enough, you have to change to the 4.0 engine control module and the wiring harness is different, so the donor harness has to be run through the firewall as well as the engine and sensors, depending on your gauge cluster you may have to switch that too but Ive only heard that, never seen it needed myself. There are a lot of very very good write ups that get more in depth that I just did, its worth the reading.

There are good ways to get more from your 2.5, electric fan is the best and most effective, if your running large tires, re-gearing is the best.

I can tell you I run a 2.5, 33"x12.5s and 4.10s and I can spin all 4 tires on rock, and all Ive done is electric fan and CAI (most will say they dont help, they maybe right).

Good luck in deciding, just read all you can, the more you know, the less surprised you will be when it isnt 'easy'.

 

[JohnnyO]

I finally got around to putting an Airaid intake on, it seems to hold speed on the highway a little better.

 

[cali_92]

im thinking about turbo charging my 2.5! im waiting to officially decide after this weekend when i do my elec. fan conversion. what does everyone think about that. im doing it for improved highway speed not for trail purposes.