Engine running warm - what to replace?

[romanella]

I recently had my 2.5L rebuilt & bored out to 2.7L. Still running stock radiator, fan & shroud, and water pump. Engine sits always a notch over 210F, often getting near the red lines. What should I replace to keep the temp down? Going to need to do something soon... Hasn't overheated yet, but I'm sure its coming with the warmer weather.

Have replaced temp sensors, new coolant and a radiator flush less then 1000 miles ago.

Thanks!

[terron gregg]

start cheap maybe replace the thermostat go with a lower cooling one

[romanella]

I put in a new heavy duty 195F thermostat when I did the rad flush & new coolant.... Any other ideas?

[probable cause]

fan clutch? seven blade?

[SavageSun4x4]

Dunno if this applies to you or not but:

http://www.savagesun4x4.com/oem_7-blade_tj_fanclutch_in.html

[romanella]

I have a 5 blade fan on the YJ... Could be the fan clutch. Any way to check?

[probable cause]

something to do with spinning the fan by hand....i believe if you spin it with your hand and it spins more than 5 times you're supppose to replace it.

[SavageSun4x4]

Not sure about the 5x spin but still and in a similar fashion when your grasp the fan blade it will feel loose and go back and forth with ease...meaning very little resistance. You best bet is to compare it to another fan blade (anyone will do) and note the difference...

[probable cause]

yeah i just changed my fan clutch about a month ago and my tj runs under the 210 temp.

[romanella]

Would that have such a detrimental effect w/ the temperature? I'll check tonight as I have another fan sitting in my garage somewhere. Wondering if it could be due to the fact that the engine was overbored, but the shop said it should be sitting right around 195F, hence my investigation as to what could need to be replaced...

[romanella]

yeah i just changed my fan clutch about a month ago and my tj runs under the 210 temp.

What was it running at before you changed the fan clutch?

[probable cause]

right above 210 this is still with a five blade

[romanella]

Will check & report back when I get home from the office around 6. Thanks for the help!

[romanella]

Fan seems fine... Hardly spins at all. Top radiator hose is hotter then @*!&, bottom one is cool to the touch. What next??

[probable cause]

sorry i'm not sure somebody else will have to chime in

[Fire Ball]

First thing to do is varify that the temp you are reading is correct :)

Then start working on air flow issues (fan, radiator fins, fan shroud, belt is tight), water flow issues, (water pump, thermostat, corroded radiator) Since you just redid some engine work, make sure the level is still up in the system.

[romanella]

make sure the level is still up in the system.

What do you mean by this?

Just checked the fan shroud, was somewhat loose. Tightened everything back down & drove around: temp hasn't changed. Belt felt fine, coolant levels good & full, no oil in coolant and no coolant in the oil...

What a PITA!

[shaggy914]

who did the work on the engine?
what all was exactly done?
do you have a five gas analyzer?
what about a scanner?
any engine codes?
how long ago was it rebuilt?
if you have a scanner be sure to check the monitors for a pending lean 02 sensor code.

with the porsche engines i work with a stroker kit can do things like this.

[romanella]

A1 Engine of Arizona did the work. It was long-block rebuilt and bored out to 2.7L. I have no idea what a "five gas analyzer" is, nor a scanner. No engine codes since the rebuild. Rebuild was done at the end of December, dropped in the very beginning of January. I know how to read the engine codes when it does throw one... But it hasn't thrown any.

[Fire Ball]

Level I meant coolant levels :) Sorry.

[DirtyYJ]

Haha maybe you just drive too fast???

[romanella]

Hahaha... Possibly!

Could it be a leaking exhaust? Muffler is hanging down at a very odd angle. WRENCHING PARTY?!

[DirtyYJ]

You can usually hear exhaust leaks..
When does it usually overheat?

[romanella]

It doesn't overheat, just sits dangerously close to the temp red line and doesn't back down. Its unnerving, and I'm sure it'll get worse with the summer heat.

[DirtyYJ]

I had the same problem one time a couple of summers ago.. It was right after I put in a new water pump. After that I went through and practically replaced the entire cooling system just short of the radiator. Turned out I bolted the fan on backwards!
What are you doing Friday night.. wanna wrench?

[romanella]

How the heck do you bolt a fan on backwards???

And yeah, Friday sounds awesome. My girlfriend is gonna go see the va**na monologues... I'd like nothing more then to skip out on that "adventure" :) Friday works great! What needs to be done w/ yours?

[DirtyYJ]

Probably because it wasn't labeled front and back... that or lack of attention?
I just have to do a motor mount

[GRUNT]

Hey Chris, when you had this done I asked "Billy 4 HP" since he works at an engine shop. He asked if the checked the block walls before they bored it out. With the small block, the tolerances change when you remove material from a block that is small to begin with. The first thing he mentioned is that if A-1 didn't do their homework and x-ray(don't remember the technical term) the block prior to boring to find potential thin spots in the cylinder walls then you would have a temp issue. He said you may be in for trouble come summer.

I would contact Billy4HP to get him to elaborate.

HTH. I also hope it is just your fan on backwards! :D

[shaggy914]

did the modify the fuel system?

whats the normal corse of action for a 2.7 build?
have you done anything to raisethe fuel pressure?
if the fuel injection cant compensate for the extra needed fuel then it will run lean.
a lean mixture means a hotter burn and you will have a hotter running engine.
you would be able to tell this with a 5 gas analyzer.
if you get an engine code that says o2 sensor always lean or a monitor thats o2 sensor always lean then you know you have a fuel problem.
there are more things to look at besides just codes. the vehicle will only throw a code when the car goes way beyond limits and come compensate on its own.
in a perfect world youd have a 5 gas analizer a build sheet and a scanner.
you really need a 5 gas print out and a snap shot of the engine.
a build sheet would be nice but at this point it isnt necessary, it would only make the diagnosis process less dificult.

without a build sheet and some numbers to work with i really cant do anymore than guess at what it could be and thats not really any way to diagnose a problem.
the last thing i want to do is tell you to start unnecessarily throwing parts at it and cost you money on top of a new engine.

sorry i cant be of more pratical help but if you get a real scanner or a 5 gas i can analyse the results.

[Billy 4 hp]

Hey Chris, when you had this done I asked "Billy 4 HP" since he works at an engine shop. He asked if the checked the block walls before they bored it out. With the small block, the tolerances change when you remove material from a block that is small to begin with. The first thing he mentioned is that if A-1 didn't do their homework and x-ray(don't remember the technical term) the block prior to boring to find potential thin spots in the cylinder walls then you would have a temp issue. He said you may be in for trouble come summer.

I would contact Billy4HP to get him to elaborate.

HTH. I also hope it is just your fan on backwards! :D

My work sheet for a hot running engine:

Is the base ignition timing set properly or if a bigger than original CI engine, advance a deg or two.

What is the airfuel ratio at part and wide open throttle, adjust if possible. Nothing leaner than 15:1 is acceptable IMO.

Was this block sonic tested before the overbore, was a minimum of .125 obtained? Since it's too late now, go to the following.

Add Redline Waterwetter or a equiv. product.

Is it possible to overdrive the waterpump up to 10% to increase waterflow?

Does the temperature "creep" at an idle or is it just when cruising around town or at a constanst freeway speed.

Is a larger, more efficient radiator available? If so, get pricing.

Check the fan clutch, upgrade and replace as necessary.

Other than the obvious, fluid level, collapsing lower hose, etc. That's about it... My old school trick is when it get's the hottest, crank up the heat (passenger) and see if the heater core is enough to help cool the engine off. If it does, you have a chance of correcting the issue with either a better, radiator, fan clutch, etc or a combination of everything I mentioned wouldnt hurt.

As you installed a 195 deg F thermostat, it should run "on the thermostat" this time of year. If it doesn't well there will be issues. But in all fairness the thermostat should be tested as most are way off (put a piece of string in the thermostat opening when it's cold, heat the thermostat in boiling water hanging from the string (or just under boiling for a 195 deg F thermostat), use a candy thermometer and record when it opens and releases the string.

HTH

[romanella]

I'll pick up some water wetter today after work. Can I just drain a few ounces out of my radiator and then add the Redline Water Wetter?

Fan clutch seems good, kinda difficult to turn... Not sure if its seizing up. I want to add the water wetter regardless.

Thanks for the reply Billy!

[Billy 4 hp]

I'll pick up some water wetter today after work. Can I just drain a few ounces out of my radiator and then add the Redline Water Wetter?

Fan clutch seems good, kinda difficult to turn... Not sure if its seizing up. I want to add the water wetter regardless.

Thanks for the reply Billy!


Just make sure you add the Water Wetter to the radiator and not the overflow tank...

[romanella]

What do you take me for??? Hahaha.

[romanella]

I added some Red Line Water Wetter a little while ago. Let the Jeep idle for a bit with the heater on full, then drove around to get it mixed in nice and good. A very tiny difference was noticed.

http://www.cmcgems.com/etc/jeep/gauge.jpg
Here is where my gauge is sitting now. Fluctuates a little higher and a little lower depending on speed & outside temp.

What next?

[Billy 4 hp]

I added some Red Line Water Wetter a little while ago. Let the Jeep idle for a bit with the heater on full, then drove around to get it mixed in nice and good. A very tiny difference was noticed.

http://www.cmcgems.com/etc/jeep/gauge.jpg
Here is where my gauge is sitting now. Fluctuates a little higher and a little lower depending on speed & outside temp.

What next?

My work sheet for a hot running engine:

Is the base ignition timing set properly or if a bigger than original CI engine, advance a deg or two.

What is the airfuel ratio at part and wide open throttle, adjust if possible. Nothing leaner than 15:1 is acceptable IMO.

Was this block sonic tested before the overbore, was a minimum of .125 obtained? Since it's too late now, go to the following.Call the folks that built your engine and start asking questions
Add Redline Waterwetter or a equiv. product.

Is it possible to overdrive the waterpump up to 10% to increase waterflow? Call the folks that built your engine and see if they either know of an overdrive pulley setup or a high flow waterpump for your application
Does the temperature "creep" at an idle or is it just when cruising around town or at a constanst freeway speed.

Is a larger, more efficient radiator available? If so, get pricing.

Check the fan clutch, upgrade and replace as necessary.

Other than the obvious, fluid level, collapsing lower hose, etc. That's about it... My old school trick is when it get's the hottest, crank up the heat (passenger) and see if the heater core is enough to help cool the engine off. If it does, you have a chance of correcting the issue with either a better, radiator, fan clutch, etc or a combination of everything I mentioned wouldnt hurt.

As you installed a 195 deg F thermostat, it should run "on the thermostat" this time of year. If it doesn't well there will be issues. But in all fairness the thermostat should be tested as most are way off (put a piece of string in the thermostat opening when it's cold, heat the thermostat in boiling water hanging from the string (or just under boiling for a 195 deg F thermostat), use a candy thermometer and record when it opens and releases the string. Takes some time as you will have to remove the already installed thermostat, but at least you will know if the new thermostat you installed is defective or not. In a racing application we don't even use a thermostat. We simply use a orifice that slows down the coolant flow enough to allow the radiator to do it's job.
HTH

Please re-read... Worst case scenario take it to Bob Ream's at B&R Automotive or Hopper's Automotive and get them to put in on a 5 gas analyzer to check A/F ratio.... B&R is nice as I know they have a chassis dyno so they can test the vehicle without it moving down the road...

[romanella]

Billy, what about this bad-boy?

http://www.quadratec.com/products/51212_58.htm

[Billy 4 hp]

Billy, what about this bad-boy?

http://www.quadratec.com/products/51212_58.htm

Sounds like it may be your lucky day...


:D