Keeping My Cool

Time for a new post updating my cooling situation. See the previous post for more information if interested. Two things were left on the table to do, those were coolant flush and auxiliary fan override switch.

No pictures of the first item, it was pretty much just a boring process of filling and draining the radiator. I went with a fill/run till warm/drain/fill/run till warm/drain...repeat ad nauseam method using the cleaner you leave in your radiator for 3-6 hours of runtime. No particular reason but after about the 5th cycle I was wishing I had done a simple power flush. For the first couple of drain steps, I also ran some water through via the hose that connects to the top of the thermostat housing...a little mini-flush if you will.

The first cycle was very dirty, so I accomplished a little bit at least. The second cycle was cloudy with each subsequent cycle get more clear. The 4th cycle looked pretty nice, so I switch from tap water to distilled at that point. I basically put a total of 5 gallons of distilled though the system with the final cycle leaving about 1.5 gallons of distilled in the system to which I added the antifreeze to top the system off. Ended up with about 55/45 water/coolant mix.

Unfortunately the new coolant by itself didn't really solve anything. After enough time sitting at idle the motor still gets hot enough to kick on the auxiliary fan. It did seem to possibly cool it down quicker than before though...no hard numbers on that though. But again, it was needed maintenance so no real loss.

So, given that when both fans are on pulling air through both halves of the radiator the cooling system seems capable of keeping the temp in check, it seems to me that the answer is to be able to turn the cooling fan at will. I found some instructions and set to work making the modification. The basics of it is that the PCM brings a wire to ground when it want to trigger the fan, so we splice into that wire and put it to ground with our switch.

First I found the magic wire in the PCM wiring harness. I just stripped back a little of the insulation and looped another wire around it and then stuck a huge ugly glob of solder on it to hold it tight(need new soldering iron tip...at least that's the excuse I'm going with). A quick test of turning the key in the ON position and touching that wire to ground showed that it indeed works as the fan kicked on...

So that leaves me just in need of a switch. After brainstorming a bit, I decided to raid my computer graveyard in the attic and pulled a switch from an old power supply. It fit perfectly in the small section at the top/bottom of the filler panel to the right side of my instrument cluster in my '96.

Only drama here was getting the instrument panel bezel off. It was tight...I'm probably missing some trick, and I need to figure it out before I take it off again...

All was well until a couple days ago when I noticed the Jeep not warming up again...the failsafe thermostat had apparently tripped. I'm not sure what the triggering condition is, but I decided I would rather deal with a normal thermostat failing closed once in a blue moon versus the failsafe tripping every other day, so I just replaced it with a normal one. Problem solved.

Tested out my fan and it worked great. Played around in the yard and let it idle for 30+ minutes and with the fan on the temp guage was steady on 195. Still have to see how it reacts in the summer heat, but I feel good as of now. My only problem is that the switch ended up throwing a CEL because the PCM doesn't like that wire being grounded when it's not expecting it. I've found a fix involving a relay that will be my next little project.

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J ust E mpty E very P ocket part 2

Okay, part two of my catch up post. After getting the fluids changed and leaks fixed that I wanted, I decided I wanted to take a look at the coolant system. Actually the temp gauge needle sweeping past 210 while waiting in a drive through prompted me to look at the coolant system.

So time to collect our data and try to reach conclusions about what might be going on...

• Going down the road temp is fine...actually seems to run cool. With the exception of the night I drove it home. It ran around 210 on the interstate.
• At idle it eventually goes above 210.
• Don't really notice much fluid movement at idle with cap off. Once at temp blip throttle and coolant moves.
• Top radiator hose never really gets hard or feels like it has water in it...but it must...
• Spin test of manual fan clutch shows fan harder to turn when cool than when warm.
• Elec fan never comes on.

So first thing I do is buy a new radiator cap as the old one looked rough. I'm pretty sure the old one wasn't holding any pressure. No difference made. Everything I've read points to the fan clutch. This makes sense if it's not turning fast enough as it gets warmer at idle it wouldn't move enough air.

From 1996 Jeep Cherokee

I was certainly hopeful when I saw the old clutch. It was certainly nasty enough to be causing a problem. Unfortunately no real difference. I can tell the fan is moving faster, it roars on cold startup like it's supposed to so I think it needed to be replaced, but it's not the root cause.

Next is the thermostat, technically this should have been first, but I just assumed it must be working since it runs cools down the road. I actually hypothesized it was sticking open and that was the reason it was running cool down the road, and hoped maybe it was stickign closed sometimes and causing it to run warm. So I get it out and find this...

From 1996 Jeep Cherokee

Not so much stuck open as cracked open, but definitely open. This explains why it runs cool going down the road. Also could explain the one time interstate warming if the parts got turned wrong and blocked water flow. But could it explain the heat at idle? Maybe if obstructing the slower water flow...nah, I'm not that lucky. So that leaves me with the following observations...

• By design the small fan that only covers 1/2 of the 12" tall radiator isn't going to do the job by itself. The auxiliary fan is needed at idle and it isn't kicking on when it should...
• Gauge is off a bit and it's not actually getting up to 220 where the fan would kick on anyway, so that would mean a) the fan relay is fine and b) it's cooling "well enough" anyway.
• Water pump isn't effective at idle. He supposedly changed it recently... Giving some revs at idle does help a tiny bit, but not anything spectacular.
• Radiator has lost effectiveness, works okay with forced air at speed, but the fan at idle isn't moving enough air for the radiator working at lowered efficiency... So I could either a) try to flush or b) just go ahead and buy new 3 core radiator...

Took the kids for ice cream and observed the following.

• Thermostat working correctly while moving. Needle stays about 3 needle widths from 210, you can see it rise a little then fall as the thermostat opens.
• Waiting in the drive through, the temp started to rise. So I let it continue to rise a little and at around 4-5 needle widths past 210(apparently this is where 220 is), the electric fan kicks on and the temp drops back down to 210. Not sure how much lower it might have gotten cause I started moving again after that.

So that leaves us with the following.

• It's an airflow/cooling efficiency thing. While moving it cools fine, so the radiator isn't completely clogged. By design the manual fan only covers half of the radiator and the electric auxiliary covers the other half. Once the electric kicks in it will cool back down to 210, so that is working correctly.
• If it was 100 degrees outside I would just call it good and deal with it, but the ambient temp was closer to 60, so once it warms up I'm not sure the system will cope.
• I've found scum/buildup signs of previous bars-leak in the radiator, so I'm hoping there is scale buildup reducing efficiency that an over the counter cleaner can help with and that is what I'm going to attempt first.
• I'm also going to wire in an override switch on the electric fan as I would rather it kick in sooner and prevent the temp going to 220 instead of just cooling it back down.

These fixes/changes will be taking place this week and we'll head into summer and go from there. Fingers crossed.

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J ust E mpty E very P ocket part 1

I had planned to make daily posts of where I was at with my Jeep, but then got frustrated about my lack of progress and didn't end up posting anything. But there has been some progress made, so here is the catch up post. First of all, I have to comment that 4L makes getting the vehicle up on ramps very, very easy. With a 2wd vehicle, I'm constantly worried about giving it too much throttle as I'm trying to go up the ramps. I just put the jeep in 4L and up the ramps it creeped...no throttle required.

From 1996 Jeep Cherokee

Nice pink "drop cloth" isn't it. I really need to get the garage cleaned out so I can move the show out of the dirt and pollen. In fact that has been set as my goal. Lift kit can be purchased once garage has been cleaned...I now have motivation.



So, first thing on the list was fix leaking transfer case seal. So I dropped the driveshaft and then realized, that my transfer case didn't look like I expected it to. Apparently '96 models got the newer style transfer case that '97+ models have and thus there is this housing that is pressed on the shaft. Well, after hitting it a few times with a screwdriver/hammer, I decided it wasn't going to easily come off and quit for the night. I thought I would google the "proper" way to get it off, but didn't find anything. So the next day I went after it with the screwdriver again. Bent the lip enough to get a good angle with the screwdriver and a few taps later it was off. Unfortunatly it was also unusable and I still need a replacement now. But it's fine without it currently...just would make me feel better before going offroad.
Anyway, after remove a washer and lock ring(which I actually bought a tool for that made it really easy), a little more time with my screwdriver and hammer released the seal from it's location and a quick visual inspection after slipping the new seal from it's box revealed that I didn't have the correct part.



So looks like time to head to the parts store. Unfortunately, they couldn't locate the right part number at all. Even drug up a giant binder from under the counter, but they didn't have any part listed for any Cherokee model that looked like this seal. So my work for this night was over.
I went to the dealership the next day and they had two possibles listed, one in stock...and it was thankfully the correct one. Unfortunately it was also $35 as opposed to $10 like the other. But it was what I needed. After working in the yard until dark, I drug out the trouble light and got the seal put in. Replaced the driveshaft and was finally able to have a feeling of accomplishment. I could now mark one item off my list. Well, by this point the weekend rolled around and it was a perfect Saturday for fluid change...as long as you don't mind copious amounts of pollen in your fluid. The wind was blowing an you could actually see the pollen flowing through the air...again need to clean the garage. The transmission service when fairly uneventfully. I drained the pan using the drain plug(first transmission I've had that ever had a drain plug), then added 4qts or so new fluid and started the Jeep up and let it circulate the new fluid a bit, then drained that mixed fluid again and dropped the pan to change the filter also. Had a little mishap, dropping a bolt into the oil catcher pan, but retrieval went well. Put it back together and added some fluid. Went to crank it to let it warm up to check the fluid level and...CLICK.

What? A battery issue? Well apparently, something was wrong with it. It would act okay until you put some draw on it and then nothing. Dug an old battery out of the boat and put it on and it cranked slow, but worked. So I assumed bad battery. Well, I was wrong. Went to Wal-Mart and they tested it as good. I bought a new battery anyway figuring their equipment must be screwed up and headed back home. Hooked the old battery up first and my Dad(who was there doing some welding for me) watched as I tried to crank it and saw a spark jumping from the + cable. Turns out it was a bad connection. Put on a new swanky chrome plated terminal I had bought I some point for a car amp install and it's been working fine since then.

Okay, time to back up a few hours now. The first part of the day was spent not on the battery, but on the oil filter mount. I had purchased an o-ring kit earlier in the week and set to work installing it. I knew it was going to be a pain getting to mount off, but didn't quite realize how bad it was really going to be. First off was the needed tools. I knew I would need a 60T torx bit and had already purchased one. I also knew it wouldn't actually fit on a ratchet in the space provided so I quickly went to cutting with my dremel. Now I had a bit that just happened to fit in a 12mm wrench. I have seen others make a tool and welding the bit in the wrench, but without a welder(Dad wasn't there yet) I improvised. I simply folded over a paper towel and wedged the bit in the box end of the wrench with paper towel. Had to redo it a couple time, but it worked. Only problem now is I needed leverage to break it loose. I didn't have anything to use as a cheater pipe that was large enough to fit over the end of the wrench, so I cut end off and used my jack handle. Worked like a charm...well it at least worked. Then it was just moving the wrench a 1/4 turn at a time to get it loose. All in all took about 2 hours to get off. A bit of mistake I made was that I had figured all of the work was going to take place from the top side of the vehicle, so I took it off the ramps...unfortunately this was not the case and I needed to get to it from underneath. Couldn't get it back on the ramp though, because the engine was sans oil. So I got to work in a tight spot...finally got it off though...



If you look at the second pic above you can see the main leakage point. The flattened o-ring just wasn't doing much anymore...

The rest of the job went pretty smoothly, just took some time to get the mount back on. Filled it up with oil and could mark another couple things off the list.

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What have I gotten myself into?

Well, once again I haven not completed Project Fisher and now I have a new project. I've always said I wanted a 4x4 vehicle, even said I wanted something I could fix up... Enter the XJ. For the Jeeping uninitiated that's a Jeep Cherokee. Mine is a 1996 to be precise. Had it for a week or so now, and am trying to begin maintenance on in in preparations for a lift/tires. So expect some activity on the blog again, this time Jeep related...


Well start out with a pic and a roadmap of what is to come.

From 1996 Jeep Cherokee

• Fluid/Filter change for transmission/transfer case
• Fix rear output seal leak on transfer case
• Fix oil filter mount fix
• Delete remaining side moulding/clean off glue
• 4.5" Zone Offroad Lift
• 31" Trxus MT tires
• 15x8 Cragar Soft 8 wheels
• "Fix" peeling/hazy clearcoat
• Coverking Neosupreme Seat Covers

That's definitely enough of a start. So far with trying to divide my evening time with other responsibilities I've only managed to get halfway done with the transmission service and finally got the transfer case seal in last night. I think I'll save that saga for it's own post.

Hopefully this weekend I can make some good progress on the leaks and be ready to progress from there...

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