Getting Discouraged with my MJ (radiator issues)

[Smokeyyank]

The knock off aluminum rads fail.....a lot. There's a reason the mishimotos are stupid expensive, but still not 100%. Open conversion is easy should be a write up in DIY section. As for a new pressure bottle.

I believe you can use the Volvo one. Add replace mine years ago and I'm pretty sure that's what I did. 

 

Also echo what others have said about getting your own tools. Harbor frieght is great for decent and cheap tools. You don't need to have a full on tool box but a couple hundred bucks there sets uou up nicely. Good simple hands tools work wonders.

 

[acfortier]

21 minutes ago, Classy Comanche said:

What do I need for a true open set up? Now I'm super super lost on what I need since I thought I had open system this entire time. Man I feel so dumb now

Honestly, don’t need much, and it’d be simpler than what you have now. Here’s one of the writeups: 

 

[rokinn]

Understanding how systems work is 3/4 of the battle.  You're going to have to spend a lot of time understanding an visualizing the animal you are dealing with.  You tube videos will give you a visual.  Others will give you a how to in terms of how to repair.  I don't know where you are on the curve of all of this and your talents but drive ability is the first thing if you want any sense of payback and pleasure for all of your efforts.  All the other is just (don't she look good).  Focus on learning how understand the issues and how to deal with them in your vision and the time line expectations.  Time and experience go a long way.  The alternative is to sell it if it is too overwhelming.  Something like this a little later in life may well be a different story.  Challenges are great is you can handle them, overwhelm not so much.  It ain't t the be all end and end all by any stretch.   Comanche addicts may likely disagree.  Unfortunately I have the addiction as well, but it ain't the first addiction I've had to deal with in life.  Good luck!

[Classy Comanche]

OK I read the write-up. Maaaan it sounds so complicated yet so simple...the part numbers....didn't exactly line up. But I got a hit on a radiator potentially which I have posted below. I am worried about it hitting something or not being able to go in correctly. So. To my understanding of my....deal. is that I need a radiator that has a cap on it. My Monte carlo has one. Get a pressure cap that has a heat gage on it that tells temp (Absolute lifesaver since I got dummy clusters) and get a overflow tank which I already have as seen hooked to my Mac tank. Now. The hoses. Is there anything that needs to be re-arranged when doing this? I'm getting a sense of hope back here and not feeling like running it into a ditch being hopeless and uninterested. So far everything is clear and like I sort of understand how this stuff works. I essentially am blowing out my own radiator.....wasting my hard earned money. Its just the hoses and bottle I'm unsure on...I've wasted my money so far. I want to ensure this indeed will work

[Classy Comanche]

I also watched a bleeping jeep video on how to do the conversion. The part where you cut the heater control valve. When it comes to stuff like that I get nervous. However I will say even with the heat off I will occasionally hear a small squeak sound like something moving on my passenger side inside my dash and I can feel heat like blow through very gently. 

[Big_Mark]

It seems odd that you would have so many defective radiators, I know you're discouraged enough but if you have a bad head gasket blow by could be sending pressure into your cooling system, causing the radiators to fail.

You indicated there is a lot of oil coming from your engine, this can also be a sign of blow by (more likely rings than radiator for oil).

Sorry to add more to the pile.

[gogmorgo]

Unless you’ve got a rad cap that’s not doing its job I wouldn’t worry about head gasket. You’re not going to overpressure the cooling system if the pressure can get out somewhere. Take it one issue at a time. 

[coheed]

As others have said, back off and think about how future you would feel about letting the truck go. There were many times I thought about selling my grandad's MJ, what with frame warping, title issues, and rust. Eventually I turned into a trailer, and now I still have a cool thing that has sentimental value. I'm also very glad I didn't sell it.

 

My current truck has just been sitting for a while and only going to the dump on occasion. The front axle u joints are bad. Like missing all the needle bearings bad. But I don't wanna spend the money on swapping them because I plan to throw in the 4.10 axles from my old truck. But I don't want to do that unless I have all the parts to do the larger lift. Measuring my ride height the other day it's sitting at factory height with a Chevy drop shackle, so I don't think it'd be worth it to try the AAL I've got. So I need money for new springs.

 

Stuff on project vehicles adds up really fast and can get overwhelming. But making decisions in the moment that future you would be disappointed by sucks way worse. 

[Classy Comanche]

Oh I am. I'm going to just stop driving it a bit and just think. Like I said I just feel kinda dumb for sitting here telling people "oh yeah I have a open cooling system" when in reality I don't. So what I am thinking I'm going to do is do exactly what Johnny Cash did. One peice at a time. When I get my car back I'll go to autozone, advance auto and pick the stuff the conversion calls for. The napa radiator I currently have costed my just over $300. I was online looking at parts and the rad I posted above was like 152, the radiator cap with the temp gage was like 40-50 and the hoses were dirt cheap, connectors too. While I'm also out I'll pick up a valve cover gasket since it does leak from the top of the motor on my driver side. I do believe those have rubber but I heard somewhere they had aluminum ones? Are those any good? I had a good sleep last night and have really thought about it and if I can just accumulate the parts overtime it'll get me ready (I think) to get the job done and get my truck right. Are valve conver gaskets hard to change? Is there anything that could go super wrong? Does the bolts have to be torqued to factory spec or do they just have to be "tight"?

[acfortier]

You should be able to return those radiators that are leaking, no?

 

I would think the best valve cover gasket to get would be the Felpro one: https://www.amazon.com/Fel-Pro-VS-50522-Valve-Gasket/dp/B000C2APC4

 

I can't remember the last time I did one, but I don't think it's super complicated on the 4.0.

 

For something like this, I'd torque down to spec. 

[Classy Comanche]

I see. Well I have no idea what the specifications are for the bolts. Like if I was to return the radiator from napa today I could very well possibly get everything I need plus the gasket without spending more money and just more or less using the money the rad costed me. And in a way this works out perfectly because those radiator hoses have to come off anyway for the conversion. So when those are out of the way it'll give more ease of access to everything I hope. I wish I knew what the spec was on the bolts. The only thing about this whole thing is cutting that heater control valve off and torqing the bolts down to spec. Last thing I need to do a strip a bolt or not tighten it enough since the back bolt will be kinda hard to get to

[acfortier]

This is going to be your friend: https://cdn.xjjeeps.com/pdf/en-us/1984-1993-factory-service-manual.pdf

 

Says 55 in-lbs (NOT ft-lbs). If you don't want to spend the $$ on a torque wrench, snugging them down with a 1/4" ratchet will be more than enough. I think there's a particular order that they should be tightened, found in that FSM above.

 

 

[Classy Comanche]

The mechanic is telling me it's just a different way of a conversion that I have now. The rad cap is at the highest point and shouldn't have anything to do with my radiator leaking except poor quality. Now I'm back at square one on what to do. My grandfather is also telling me no don't do it that the metal Mac tank is a pressure tank hence the radiator cap. Now I don't even know if that should be full because my grandfather is telling me it should be about half full or so

[jpnjake]

12 minutes ago, Classy Comanche said:

The mechanic is telling me it's just a different way of a conversion that I have now. The rad cap is at the highest point and shouldn't have anything to do with my radiator leaking except poor quality. Now I'm back at square one on what to do. My grandfather is also telling me no don't do it that the metal Mac tank is a pressure tank hence the radiator cap. Now I don't even know if that should be full because my grandfather is telling me it should be about half full or so

It should only be completely full if you have an overflow tank. If not when the system pressurizes it expands and if it were completely full it would overflow, that’s what the overflow\puke tank is for

[Classy Comanche]

Alright. So my Mac tank is full. It has a catch tank. Now I'm rethinking this. These aluminum radiators are just poor quality?

[jpnjake]

 

[Classy Comanche]

Yeah I got a plastic tank attached to my aluminum Mac tank. It does push coolant into there and keeps the aluminum one full

[Classy Comanche]

By the way. The rad cap on my mac tank is 16lbs of pressure. What's the factory pressure it needs to be if anyone knows by chance? I considered doing a 14. I ask this because my head gasket is leaking oil. Has been since I bought it. Even smells hot after driving it and walking by it. I almost wonder if exhaust fumes are getting in causing higher pressure 

[Airborne Janitor]

Took me 6 years from the time I bought it to where I could actually drive it. I've been there, I had my truck untouched for almost a year. The big things holding me back were time and money. So I made the time and I made the money to where my goal was I need to get this thing mobile and this is how much I'm willing to spend. I won't even tell you how much I spent to get my $900 MJ going, and it's still not done, but I'm glad I kept at it. Having a truck I wanted as a teenager, and now being able to drive around with my daughter in it is priceless.

[Classy Comanche]

Yeah I've definitely changed my perspective on selling it. That's for sure. Something I've had a question about is does the 4.0 have like a automatic choke on it? When mine idles it will run smooth and good but then it will idle back down kinda low then go back to normal and it does that if I'm sitting still. I'm trying to decide if it needs a head cover gasket. I have bought a felpro to have just in case. Its not running rough but I didn't know if when it idles down if that is something all 4.0's do or if that's a sign of something 

[rokinn]

FYI....Head gasket is between the head and the block.  Valve cover gasket is between the valve cover and the head.  Saying you have a leaking head gasket is entirely different than having a leaking valve cover gasket.

[gogmorgo]

Valve cover gasket is an easy job. Head gasket is a little more involved. Only thing a valve cover gasket will solve however is oil dripping down the side of the engine. If you do it, don’t overtorque the bolts. Get them snug, tight enough they won’t shake loose, but no more or you’ll distort the cover and you’ll never get it to seal correctly after that. Spec on them is so light it’s not within range of a typical small torque wrench. 
 

Taking a vehicle off the road to fix it is one thing, but don’t leave it sit for too long. I did that with my first MJ. It sat for two years before I got started, and I got interrupted partway through and three years later I still haven’t got back to it.

 

 

[Classy Comanche]

Gotcha. I'm doing my rad first then I'm deciding on doing the valve cover after that or do a whole upper engine rebuild/refresh

[Pete M]

wait, am I missing something?  why is the metal tank full?  either it should be roughly half full so the fluid can expand, or it shouldn't exist.      that plastic tank is merely a catch for if the cap pops because that's the only way fluid will get to it. 

 

 

[rokinn]

He says he is running it as an open system so that configuration would be correct.  There's no reason not to go ahead and do the valve cover gasket first.  Simple job.  I've read that 3 core aluminum radiators are prone to leaking.  I had a 3 core and it leaked pretty quickly.  I went to a 2 core and have had no problems since (several years).   It's all aluminum.