Not what I'd hoped for my first thread......So my son bought this super-sketchy WJ..........

I'd always hoped that my first thread would be fir my very own Miata project, and it almost was, but alas, my employment situation took a drastic turn and now I'm basically a (really old) college freshman (starving student) instead.   So, making zoom-zoom-zoom noises in my garage as I wrench on my long anticipated Miata project will have to wait.

So, probably to keep me from getting bored and lazy, my 23 year-old son went out and bought a 2001 WJ that has seen some.....interesting....repair work by the PO.  I really wish he'd sought my advice before making this purchase, I could have found him a vehicle in much better condition for the same $$, but he didn't, so now I've got to deal with this thing.  My son has many talents and abilities, but mechanical aptitude isn;t one of them.  He tries, but he just missed out on that gene I guess.  Lucky for him, I do have that ability.  I grew up wrenching (farm kid) and while I'm not as good as a lot of the GRM members, I'm not too bad. I'm also old enough to know what my limits are.  

The car in question is a 2001 Jeep Grand Cherokee Laredo, 2WD with the 4.0 I-6.  I have very little Jeep experience and none at all with the WJ platform.  About the only thing I do know is that the Jeep 4.0 is one hell of an engine that will probably outlast just about any vehicle it's ever been put in.  They have a pretty legendary reputation, which seems to be a common thread for American inline sixes in general.  It runs well, and the transmission, which as I understand can be an issue in these vehicles seems solid.  So far, so good.

That said, there are some issues......  Rather than root around on the various Jeep-specific forums , I thought that the GRM hive would be a better source for helpful advice.  I know we have some Jeep WJ guys here, and after years of lurking here (thanks to  Mazdeuce and his legendary R63 thread for getting me hooked), I just have more confidence in the information I get here than that from most other forums.    So bear with me, as you might have already noticed, I tend to get a little wordy.......  

I've already sorted out various annoying electrical issues, like intermittently non-working taillights, turn signals that sometimes don't....um...signal, and like that. Also replaced the high pressure power steering hose that was spraying fluid all over the place and going through about a quart of fluid every 50 miles or so.......

So here's what's next and also some of the questions I have that I'm hoping the GRM hive can point me in the right direction on.

The biggest issue with this sterling example of Jeep/Chrysler engineering is that the radiator shroud was butchered by the PO when the radiator was replaced at some point.  Rather than removing the shroud the correct way, which I'll admit is (according to my youtube research) a bit of a PITA, he instead chose to basically cut off the entire bottom half of the shroud. Apprently and unsurprisingly, overheating became an issue at that point.  The WJ has 2 cooling fans, one mechanical and one electric.  Perhaps this is a common arrangement, but I can't honestly say I've ever seen it before, but most of my experience is with older (60's and 70's) American cars/trucks or with the same vintage Italian, German and British machines. 

So now we get to the "sketchy" aspect of this WJ.  To "solve" this over-heating problem he'd created by mangling the shroud, the PO turned to the electric fan.  I'm guessing that, as designed, it was intended to be for supplementary cooling when the mechanical fan wasn't enough, particularly when the AC is in use, but that's just a guess on my part.  In itself this isn't a terrible strategy, if you are too incompetent or lazy to just replace the shroud, like a normal person would.  Most taking this route would use one of the many, cheap and easy to get universal fan controller/relay combinations available on Amazon for less than 50 bucks.  But the PO wasn't "most people".  His genius solution was, I kid you not, to wire the electric fan directly to the battery, I'll post pictures later, you have to see this.....  One wire straight from the fan to the ground terminal of the battery, no connector, just wedged the wire in between the battery cable terminal and the post.  Another wire was run from the positive battery terminal (using the same awesome connection method), through the firewall into the passenger compartment.  A third wire from the passenger compartment to the other side of the electric fan completed the modification.  Seriously, that's it.  Not even a switch, much less a relay.  When the fan was needed, the operation method was to twist the two wires, laying in tha passenger side footwell, together......and voila!!!  Fan!!!!  Quite possibly the sketchiest "repair" solution I've seen in a long time, outside of a demolition derby that is....   I literally spent about 30 min alternately laughing maniacally and staring in stunned disbelief.  Wow.  Just wow.  I really need to get this solved, warm weather is coming and this is the Alabama Gulf Coast, if your cooling system isn't up to scratch, you are not going anywhere from May through October!!  

I didn't have time right then to replace the shroud, also I didn't have one to replace it with, but I wasn't about to let him drive this thing as it was.  I love my son, evn if (or perhaps because) he really frustrates me sometimes.  I had a 15A SPST toggle switch lying around from something I'd built at some point, so on with some ring terminals (soldered of course, I hate crimp terminals), drill a hole in the panel right there to the right of the steering column and mount the switch right there.  Horray!!  The "WJ of death" is now at least 10% less sketchy.

A quick trip to my local pull-a-part netted me an undamaged fan shroud with the electric fan still attached, a bargain at $20. I think I'm going to become intimately familiar with this yard's inventory of WJ's in the near future.  Lucky for me, they seem to have a good inventory of them.

So this weekend, on Sunday, I'll be continuing the "de-sketchification" process and replacing the fan shroud.  I found a great YouTube video, 2 videos actually, the shows the radiator removal/replacement process very clearly and thoroughly. Awesome.  Also not awesome.  As I feared, it's going to involve a lot of disassembly/reassembly, pretty much the entire front end of the car, but it's all pretty simple stuff.  I know from experience that getting the mechanical fan off of the water pump pulley will probably be a bit of a PITA but I can bodge up a pulley holder from a piece of flat-bar and while I don't own a 36mm open-end wrench, I do have a big freaking adjustable a 2lb hammer and a large vocabulary of curse words.    Barring unforeseen disaster, always a possibility, I should be able to replace the shroud without too much difficulty.

If you've read this far, and I really can't imagine why you would, so thanks for that, I do have some questions that I'm hoping someone with some WJ experience can answer.

First, since the PO's "repair" pretty much trashed the stock connections and wiring for the electric fan, should I attempt to recreate/rebuild that circuit or would an aftermarket fan relay and temperature switch be a better way to go? Ideally I'd like to restore the stock wiring.  I'm sure I can source the parts and connectors I'd need from the junkyard.

That brings me to my second question.  Does anyone know where I can find a decent wiring diagram for this thing?  I really have no idea how the electric fan is supposed to be wired, but I'm an electronics guy by trade and training.  Give me a good diagram or schematic and I can figure it out.

Third, this WJ has ~175K miles on it.  Since the access will never be better than during the shroud replacement process, should I consider replacing the water pump, belt tensioner and idler pulley "as long as I'm in there"? It would truly suck to tear this thing down, replace the shroud, then have to tear it all apart again a short while later to replace one of these items.  My son is trying to find out from the PO if these have ever been replaced before and if so, when.  I think that at this point, it's better if the PO and I remain strangers. I'm not sure I could refrainfrom asking snarky questions about his level of mechanical competence.  I know some work on the cooling system, beyond the radiator replacement has been done, the filler neck has obviously been removed or replaced at some point judging by the copious amount of orange RTV seen there..... I can't really tell about the water pump, it's kind of hard to see down there.

And lastly, for now anyway, what are the other common failure items on these WJ's that I should be looking at?  For good or bad, he's going to have to dive this thing for the foreseeable future,  I'd like to get a head start on anything that is known to be problematic.

Thanks everyone for reading!  While this is not the way I wanted to get my GRM thread history started, it is good to finally be posting my own thread.

I promise, there will be yet another Miata thread in the future, a genuine "build thread" with, most likely, all sorts of silliness and questionable decisions..... 

Mike

For a 01 4.0L it might be a good idea to pressure test the cooling system. 00-01 had the 0331 head which is known to crack. PO could have been chasing an over heating problem that's truly caused by the cracked head. Local Autozone or whatever should have a loaner cooling system pressure tester.

In reply to PseudoSport :

Good to know.  Probably not, from what my Son tells me, the radiator was replaced due to a cracked end-tank, but a pressure test can't hurt. It hasn't shown any tendency to overheat in the 4 months that my son has owned it, and the cooling system seems to be holding pressure just fine but you never know..... I think I actually have a pressure-test kit around here somewhere, unless I loaned it out at some point and never got it back.

If time allows I'll probably do a compression test on the engine too, just for giggles.

Thanks for the suggestion!!  

Just for fun, I tried googling "jeep wj wiring diagram," and I got a bunch of suggestions, including these guys

https://www.scribd.com/doc/239887718/Jeep-Grand-Cherokee-WJ-Electrical-Wiring-Diagram

who said something about a 30-day free trial.  NMNA, but I like the sound of "free trial."  (Of course, there may be other sources that are free forever.)

In reply to Stealthtercel :

Awesome!!  Sometime back I stumbled on a sort of monthly-subscription type thing that is supposed to give you access to service and repair guides, including wiring diagrams, for multiple vehicles.  It was pretty cheap, but like an idiot I didn't;t bookmark it and now I can't seem to locate it again.  I'm considering purchasing a good service manual for this particular vehicle since I anticipate it becoming a regular visitor to my garage for the forsseable future...  Can anyone suggest a good one?  In the old days Haynes and Chilton's were always good choices, but I've been very disappointed in their more recent offerings.

FWIW I just had to do belt tensioner, idler, and water pump on a 160k mile ZJ, so if you feel like doing them while you're in there it probably won't hurt anything. Of course, I have the V8 so it you may get different service life out of the I6 parts.

I've heard of the head issues repeatedly on those, and the taillight problems, but not a ton outside of that.

 On my '97 ZJ, I have found a lot of answers just using the search function in the appropriate forum of jeepforum.com, but the people here are much more helpful and are generally much better mechanics. The older Grands Cherokees are cheap enough that most of the people working on them are young kids that mean well and know nothing, or meth addicts that just need to get as far as their next PO appointment. There's a LOT of sketchy, trashed trucks out there.

You may also be able get loaner tools for the fan removal at your local Advancepepzone type store if you're buying some parts from them.

In reply to NOT A TA :

I'm considering that, particularly if I replace the water pump. There is a brand-new Autozone just down the road, been open less than a month, so they should still have a full compliment of loaner tools in almost new condition.  I've removed this type of fan before, several times on different vehicles without the "correct" tools but I'm sure that it's much easier with tools designed for the job.  I usually take a piece of flat bar stock, drill a hole, remove one of the pulley bolts, use that to attach the bar to the pulley, wedging it against the hub, and the proceed with the big freaking adjustable wrench and hammer method to loosen that 36mm nut.  I did find a 36mm wrench on Amazon for $20, part of me says that's probably a smart investment, the other part says, that's $20 and you've done it before without.......

In reply to ultraclyde :

I'm leaning hard toward doing the water pump, and probably the idler pulley (it's really cheap) while I'm in there anyway.  I may leave the tensioner as is as long as inspection doen't reveal an obvious issue.  Of the 3, the tensioner appears to be the easiest to replace without excessive disassembly. 

I'll be pressure-testing the cooling system, just in case, probably do an engine compression test too.  If they are solid, then hopefully the head is OK.  It actually runs very well, kind of a miracle as it's very apparent that it's been used hard and subjected to a lot of dubious "repairs" over it's life.   

You are right about the taillights.  Tons of threads out there about those damn things, terrible design!!  Even before searching forums I'd surmised that they were problematic, after visiting 3 junkyards, checking over 30 WJ's and finding not a single undamaged taillight in any of them.  Finally found one in an old-school (non u-pull-it) junkyard, but I had to drove about 45 miles to get it.  Even then I had to work on it a bit to get it to work consistently.

Is is just me or is Jeep/Chrysler just terrible at wiring and electrics?  Every one (Mostly Chrysler/Dodge, not many Jeeps) I've ever worked on has had strange issues with wiring and some design features, like those taillights the left me wondering what the designers were smoking..... 

Nothing particularly useful to add other than to +1 the coolant pressure test. My experience with later model 4.0s is generally related to running hot and cracked heads are not at all uncommon. Usually replacements are cheap from a local machine shop if that turns out to be the case. I am a big fan of the 4.0 though. Not really refined or particularly efficient but if kept cool and properly lubricated they just run forever.

Looking into the cylinder head cracking issue, the issue seems to be with the "0331" cylinder heads fitted in 2000 through mid to late 2001 when the casting was modified to address the issue. 

For some reason the casting number on the outside of the head wasn't changed when they changed the casting to address the issue, and visually then only way to tell if a particular 0331 head is one of the affected ones is to remove the valve cover and look for the letters "TUPY" cast into the improved heads between cylinders 3 and 4.  Most of what I'm finding seems to indicate that, if the early heads crack, they do so between cylinders 3 and 4 and result in visible coolant in the oiling system, the dreaded "milky oil".  I haven't changed to oil in this WJ yet, that's also on tap for this weekend, but I've checked it multiple times and the oil on the dipstick looked and smelled perfectly normal.  I'll pressure test anyway, but I think I may have dodged a bullet on the head-cracking issue.  I may pull the valve cover anyway just to know for sure which variant of the 0331 head this Jeep has.  It will depend on how well/quickly the rest of the work goes whether I have time to pull the valve cover or have to wait for a different day.

Thanks everybody for your helpful comments and suggestions so far.  It's much appreciated.

.

I have never had a more love hate relationship with a vehicle than my wj. When it worked right, it was a phenomenal vehicle. Had head gasket issues, transmission issues, and death wobble issues. Got terrible MPG and then the AC broke. I miss it for all the wrong reasons. 

So I had a few minutes today to do a quick inspection and initial signs are promising.  

The best sign is that it is not losing coolant.  It was low the first time I looked at it about a month or so ago, and today the coolant level hadn't changed at all.  The underside of the oil filler cap is free of milky sludge, which as I understand it, can be another sign of trouble.   A visual inspection, looking down thru the filler port on the valve cover showed nothing unusual, but admittedly it's hard to see much that way. I was hoping to see the "TUPY" cast into the area between the rocker pairs of Cyl 3 and 4, Which would mean that this car has the "good" version of the infamous "0331" head, but I really couldn't see much of anything except oil.   I got it up to temp and spent several minutes looking thru the filler with the engine running and could detect no signs of coolant seepage, but it does appear to be oiling the top-end very nicely.  

I'm probably going to go ahead and get a gasket set, pull the valve cover and give it a good inspection.  Of course I'll also run a coolant system pressure test and probably a cylinder compression test, just to be sure.

If I have no crack, but do have the failure-prone head casting, then I'll probably just button it back up and hope for the best.  I don't think spending the money for a new/reman head is really justified in that case.  He only paid $1500 for the car (which is too much I know, but he didn't ask me before he bought it) and it's got 175K on the clock already.  The head and all the gaskets and hardware needed to do the swap would probably cost at least half that much.

mikedd969 said:

In reply to Stealthtercel :

Awesome!!  Sometime back I stumbled on a sort of monthly-subscription type thing that is supposed to give you access to service and repair guides, including wiring diagrams, for multiple vehicles.  It was pretty cheap, but like an idiot I didn't;t bookmark it and now I can't seem to locate it again.  I'm considering purchasing a good service manual for this particular vehicle since I anticipate it becoming a regular visitor to my garage for the forsseable future...  Can anyone suggest a good one?  In the old days Haynes and Chilton's were always good choices, but I've been very disappointed in their more recent offerings.

 

Could this be what you were looking for?  www.alldatadiy.com

It's $30 for the first car/year, $20 for extra cars, with cheaper pricing for five years.

I have used it for my newer cars and my father-in-law uses it for the family fleet (he's the handy one so he gets to fix the extended family's cars). I'm not 100% sure if it has wiring diagrams.

Edit: yes, it does have wiring diagrams, at least for the car I checked (11 Impala).

MazdaFace said:

I have never had a more love hate relationship with a vehicle than my wj. When it worked right, it was a phenomenal vehicle. Had head gasket issues, transmission issues, and death wobble issues. Got terrible MPG and then the AC broke. I miss it for all the wrong reasons. 

I'm already at that point with my ZJ and I've only had it 4 months. Hell, it's never even really let me down (yet), but...I always feel like it could at any given moment.

Haven't read the whole thread, so maybe it's been said. 

The bestest way to bleed a 4.0L coolant system is to pop the heater hose off the thermostat housing while filling. If you don't, it can take a while to bleed it. 

In reply to ValourUnbound :

That just might be it!!  In any case, it'll have what I need.  :)

In reply to DrBoost :

Thanks!  That'll certainly help me out on Sunday.  

mikedd969 said:

In reply to DrBoost :

Thanks!  That'll certainly help me out on Sunday.  

 

I was a tech at a Jeep dealer for years. This is how everyone did it, except the customers that replaced the T-stat or water pump DIY. Then they'd tow them in and we'd bleed it.