Jeep 4.0L rebuild

[NW99XJ]

Uh oh,
What code did it throw?

[Mudderoy]

I'm not sure if I mentioned this...

I sent back the damaged Crane CAM to AMAZON. Yesterday I received an e-mail from them stating they had received it and there would be a follow up e-mail about any refund.

Shortly after I received a second e-mail saying that $116 had been credited back to my Visa and a $30 restocking fee was deducted from the $146 total. Numbers may not add up, I'm just using approximates.

So I contacted them today, via their CHAT interface. Told Muhammad Ali, yes I'm serious, that the cam was damaged by the lifters that I bought from them.

There was a lot of additional work that had to go into replacing those lifters and cam, and being charged a restocking fee for something I would have been more than happy to keep was adding insult to injury.

The refunded by $30. I also made sure that the cam was going back to Crane since I wanted the tech to be able to see the damage, but mainly to see those lifters that did the damage.

Amazon hasn't received the lifters yet. I'll probably be getting on chat again when they do those. Crane lifters were like $75.

[bluedragon436]

Glad that they are backing up the products that they sell.. Hope you get the XJ up and running properly soon.. I know Matt will def work is hardest to get it there!!

[NW99XJ]

...and not every one can say they spoke to Muhamed Ali!!!!
lol

[Mudderoy]

Okay so the 2 row all aluminum radiator is installed. I had to cut off the transmission fluid line that attaches to the top of the radiator. The fitting wasn't the same. The provide two tubes that you slip a hose and clamp over. Cut off the line and slide same hose and another clamp over it.

Not a big deal, just takes a little bit longer to install.

[Mudderoy]

First 5 miles it was about 203 degrees. Then I hit a long stretch where I could do 50 mph. Came to a stop and it went from 210 to 212, 215, 217. Got moving again about 40 mph (mile or so) 220. Pulled over into a closed store parking lot to look for leaks. Nothing.

No A/C so no electric fan running, at least not until the 217 (unconfirmed). So I turned on the electric fan bypass. As soon as I get the engine off of idle the temp drops a couple of degrees, almost like a switch.

As I drove 30 then 50 mph on a long stretch, temp dropped 217, 213, 210. A couple more miles, even stopped at lights, it continued to drop to 203/204. It pretty much stayed there all the way in to work.

Briefly dropping to 199 a couple of times.

You know the heavy duty Grand Cherokee clutch feels good and solid, plus makes lots of noise but I'm starting to wonder now if maybe it has a problem. It has to be at least 4 years old. I'll have to go back and look at the post I made about it to get the exact date.

When the engine is hot and I try spinning it, it won't spin more than a 1/2" To me that's good.

Hotter outside now (lunch time). I drove it about 4 miles to a restaurant. Never made it to 210. Windows down, electric fan bypass on.

Also it seems to be running better. No more P1391 since the one just after the CPS CMK were replaced. Shifting normal (as I recall it) as well.

Gas mileage is still noticeably bad. First 1/8 of a tank was 45 miles!!!!

I may have to get the computer more time to adjust. I'm thinking about replacing the O2 sensor with a brand new one though.

Also still need to check the gaps on the plugs and replace the cap and rotor. Do the basics.

[OrangeXJ]

looks like you are going in the right direction

[Mudderoy]

This is beyond frustrating!

Coming home, windows down, electric fan bypass on. 203 most of the way then at about the 8 mile mark, average speed maybe 35 mph, it starts going to 212, 215, 217. I drive another 2 miles and it varies between 219 and 215.

As I turn out onto a major road, with lots of room in front of me I start collecting some data (hopefully! I haven't reviewed it yet). I wanted to record engine RPM and Timing Advance.

The engine seems to be preforming normally now with two exceptions. The running warm and it will absolutely not go over 4,100 rpm! It's not missing, it spinning like hell, but the "G" force feels like it goes to 0. No acceleration.

I spent another 2 minutes, maybe, uploading the collected data, and I noticed the temp gauge, way over.

I switched back to the Torque screen that shows me engine coolant temp, 240 degrees! As I was turning on the heater, I saw it increase to 242.

Slowly the engine coolant temp came down. A few miles and it was back down to 230/232. About 3 miles from home it dropped to 215, but by the time I got to the house, it was running 224 degrees.

Does anyone have any ideas? I think I'm going to loosen up the exhaust and verify that there isn't an obstruction, however I didn't have this problem with the old engine so I doubt it's going to give me any clue as to the issue.

[Mudderoy]

In my frustration, I needed to speak with someone to see if they had any idea. I thought of Mark, xj4life2, who doesn't have an XJ any longer, but I digress.

His two mechanics say clogged cat. He wanted me to check the level of AC coming from the alternator.

So I attached the digital multimeter to the battery...

DC engine off
625

DC engine on
626

AC engine on
627

I think I'm okay.

[bigjim350]

Usually if a cat is clogged it will glow bright red and get super hot during a long drive. Also you would notice the jeep being much quieter. Although it couldnt hurt to replace the cat, but I dont think thats the problem. But I can get you a magnaflow high flow cat for around $50

[XJ Wheeler]

Since you're hard up for suggestions.

Is there a possibility that something with the trans is holding it back? Torque Converter?

[Brasscatz]

Since you're hard up for suggestions.

Is there a possibility that something with the trans is holding it back? Torque Converter?

It's funny, my mind went to torque converter as well. When I put the new 350 in my old truck, there was something we forgot to hook up with the torque converter and I had similar symptoms. though, I ended up trashing the tranny and needing a rebuild before we figured out what happened.

[Brasscatz]

Usually if a cat is clogged it will glow bright red and get super hot during a long drive. Also you would notice the jeep being much quieter. Although it couldnt hurt to replace the cat, but I dont think thats the problem. But I can get you a magnaflow high flow cat for around $50

That's an amazing price! The brick in mine is loose, so if you can get your hands on more than just that one for Tony, I may have to hit you up for one.

[xj4life2]

Sorry Its been a while to get back to you, but over the weekend I spoke to several top mechanics and did some on line research for ya. If disconnecting the cat has no effect , I will agree with the above two comments and go back to what we talked about on the phone. Transmission, you stated that you had some work done on it and they over heated the motor, sadley the trans probably got hot also. My suggestion would be to change the fluid and filter in it and see if it helps at all. I believe that you have some burned clutches in the trans, possably the torque converter also. Good luck and keep me posted .
Mark

[Mudderoy]

Interesting read... :link: (http://jcs-pcs.com/Jeep%20Hesitation%20Fix.htm)


When we first bought our Jeep Cherokee (4x4, 5 Sp. Standard Transmission) second hand we loved it! Only problem was each time we tried to push it, it would start to go then suddenly at about 2200 - 3000 RPM it just went BLAAAAH, as in Nothing! it just slowed right down! It had a major dead spot that seemed like it might be a vacuum leak.

[NW99XJ]

Indeed.... makes me want to go poking around my OWN engine bay just to see whats up....

[xj4life2]

Interesting read... :link: (http://jcs-pcs.com/Jeep%20Hesitation%20Fix.htm)

Interesting but I think he was just masking a bigger issue, and wouldn't a simple one way check valve do the same thing ? I enlarged the size of my PCV line and used a one way check valve on it to cure some unrelated issues. my biggest question if there was a vac leak why only at high RPMs when the engine produces more vac.

[Mudderoy]

Hmmm I didn't update this thread. I wonder where I posted about the open exhaust test?!?!?!

Put about a 1/4" gap in the exhaust between the header and the exhaust.

http://youtu.be/4Y4hU_ctXYk

Took her out for a 4100 rpm run, and made it to 4800! So there is a problem with the exhaust, but where?

After calling the muffler shop and asking how long it would take them to replace the entire exhaust system, you know worse case, they said two hours, then the guy said, "But I really don't think you have a blockage in that exhaust."

I told him at the start of the conversation that my 4,100 rpm limit was gone, yet he held to his belief that the exhaust was fine.

I got off the phone and thought about it. Screw those guys, I'll just fix it myself!

So not knowing where the problem was, I ordered a muffler from Amazon, for over night delivery along with some clamps.

That was Tuesday. For some reason the muffler didn't come in until Thursday. I was dog tired, so I didn't install the stuff until tonight.

So I took the Sawzall to the exhaust just in front of the cat, and here's what I found.

678

So I cut off the welds and removed the bits of left over pipe, so I could slide the pipe in/over the new muffler, and cat.

679

680

690

After getting cleaned up I took her for a test run. I was still concerned I would have a problem. I guess it's just that it's taken so long to find the issue.

http://youtu.be/jCUZSySDUQk

Success!

She's still running a little warm, well 220 and drops to 217, back and forth. I guess it's really normal, but that was at night. Still a little worried about the temp.

[Dredwolf]

Awesome that you found it!!!

I have several competent mechanics in my area, but its almost like they get MORE stubborn when you are trying to help them ID the problem with careful observations to HELP them solve the problem you are paying them to fix.

My father told me once this was what made him become a DIY guy, having to fix things the professionals he paid to help did not actually fix as he asked.

[Cheromaniac]

Glad you found the plugged up cat Tony and solved the 4100rpm "rev limiter" problem. I guess you won't need to upgrade the valve springs after all. :D

[Mudderoy]

Glad you found the plugged up cat Tony and solved the 4100rpm "rev limiter" problem. I guess you won't need to upgrade the valve springs after all. :D

Not willing to leave well enough alone, I'm still considering it.

With the dual row all aluminum I'm a little confused by the coolant temps though. I'll be looking into it more today. May be time to change the heavy duty grand cherokee fan clutch, even though it appears to be fine. But some trained exhaust people said my catalytic converter was good too...

[gary63]

now the you rebiult you motor and you board out the motor 10 or so the cyl. walls will be alittle thinner and you will run alittle hotter a 5 or so over reg. sometimes. also you may have a bad thermast and it is sticking off and on .

[Cheromaniac]

now the you rebuilt you motor and you board out the motor 10 or so the cyl. walls will be a little thinner and you will run a little hotter a 5 or so over reg. sometimes.

I think it's time to put this internet myth to bed once and for all. Overboring the cylinders does NOT make the engine run hotter and it's been proven many times over. :)
The maximum overbore is limited by the cylinder wall thickness, and most 4.0L blocks will tolerate a +0.060" overbore without issue.

[Mudderoy]

I'm seeing my long term fuel trim in the negative percentages. I believe this means it is running lean. I'm thinking that this might be why its running warmer than I would like

I drove about 10 miles today in 77 degree temp. Most of the time it would cycle between 222 and 217. If I turned on the electric fan (override switch) it would run 210/215.

That was driving about 40 to 50 mph. I haven't tried it on the highway yet.

Also the P1391 came back during heavy acceleration.

[Mudderoy]

After changing out the restrictive exhaust, I was hoping that the coolant temps would drop. They did but not where I had hoped.

So off to diagnose more issues.

Temp would cycle between 222 and 217, with 224 being the high.

Now this was with A/C off and electric fan bypass off. So just mechanical fan and computer controlled electric fan. I'm quite sure that when it would drop from 222 to 217 it was the electric fan kicking in. It would drop fast.

So even though I wasn't seeing the magical 210 I could tell things were better, but with all the time and expense I wasn't completely happy.

Yesterday afternoon, just after starting the engine in the parking garage I made the command decision to hit the bypass switch for the electric fan to run 100% of the time. I was well over half way before it reached 210. Now keep in mind that it currently has a 160 degree thermostat in it. It's a test, I'll probably go back to a 195, or at least a 180 after getting all these bugs worked out.

Now I noticed that when I drove 40 to 50 mph the temp would increase, 208 degrees, but at a light the temp would drop quickly, rise slightly and then drop quickly when I left the light. I'm sure this was due to the water pump spinning faster and causing the coolant to flow.

By the time I was less than a mile from the house (about 19 miles total) I hit 212 for less than a minute, then it dropped to 210 then 208, sitting at a light.

I was a little disappointed that it hit 212, but this was much better than before.

So here is the working theory. The GC HD fan clutch ain't working right, and at higher speeds it is causing the mechanical fan to act as a block to the air flow.

So I have ordered the NAPA 272310 Heavy Duty Grand Cherokee fan clutch. They don't have it in the store, so they ordered it from the warehouse. $43.81 I believe.

I'll pick it up this evening on the way home from work.

I briefly considered just getting the electric fan setup from DirtBoundOffroad (an :xjtalk: vendor) but then I remembered the 1999 and figured I could always put this new fan clutch on it later.

I suspect the 3 electric fan configuration would solve this problem, but I'd like to keep the changes small right now, and find the solution.

So let this be a lesson to you. Changing out a motor is difficult and time consuming.

I focused on the parts that I thought were the most likely to cause a problem with the swap, and the exhaust was a major issue, and now it appears that the fan clutch is another.

Spending just $150 more would have saved me weeks of headaches.

[NW99XJ]

I suppose lessons like this is what people like you and me get for being such cheap bastards. lol
Well it looks like clear sailing is on the horizon for you and your XJ, I think your ultimate test is going to be a day on the trail. Any chance you'll be getting out for some wheeling anytime soon?

[Mudderoy]

I suppose lessons like this is what people like you and me get for being such cheap bastards. lol
Well it looks like clear sailing is on the horizon for you and your XJ, I think your ultimate test is going to be a day on the trail. Any chance you'll be getting out for some wheeling anytime soon?

Well that was my point. Nothing about this was cheap. I went thought a great deal of thought, and bugging Matt in the process, about every little detail, and I was still bit by it.

Wheeling? I have to reinstall my transfer case skid, which means getting some nutserts. Should be pretty simple. Also I want to get the slyders welded on. Right now just bolted in place. I wanted to get the rocker panel dent out before welding them on then the engine swap came, etc...

I suspect that I'll be going out when Matt gets his 97 up to 100%

[XJ Wheeler]

Good to hear some progress going for ya, Muddy.

Hope that fan clutch is the fix. I'm sure after all these problems you've been having you can appreciate when an issue has an easy solution.