I have a 1990 xj. did the hcv delete thing but didn't change the radiator. I'm putting in a radiator hose filler which is a radiator cap for the upper hose, " cheaper than a radiator" I was going to buy an overflow res but after I took off the shelf for the old pressurized res I found this just sitting under the shelf. I'm guessing someone used that for a res before I got ahold of her. my question is is can i use that temperately for my overflow until i can get a real one? thanks.

 

The coolant looks good.
It's new too.
I did it all this summer.
As far as going down the road,it runs a lot cooler than before.
At highway speed,it runs at 190
Before I did anything,it ran from 205 to 210 all the time.
It only heats up,if you use the air.
If you let it idle,it will do like before,get up over 210,kick on the third fan,and stay there.
It mainly only overheats with the ac.
That's why I don't understand it.
It runs 20 degrees cooler on the highway with no ac.
I just redid the cooling system cuz I redid the rest of the Jeep,you know?
Thought I was buying the best.

 

Mishimoto is just not a good option. I sadly got roped into this as well. If you ask 00t444e and he has the patience to explain why for the 100th time then you will get a better idea of why Mishimoto is terrible. Generally though you will not get a different response from anyone that has been on this forum for any amount of time. Now people that haven't been on the forum long will tell you Mishimoto radiator is great because Mishimoto spends tons of money advertising that the XJ radiator they have is an upgrade. At some point, I will have to do a write up on this because I've actually put quite a lot of research into this. For example that triple electric fan setup you have there you'd think all those claims they've made about how much of an improvement it is was tested in some sort of wind lab, it wasn't and when I do my writeup I'll quote Mishimoto saying that they put them in three XJ's located in Arizona and did real-life testing. This in no way tests all of the severe scenarios that you should test to make the bold claims they make.

I have heard of some weird things about high flow water pumps as well. I will be running a high flow water pump myself so we will see. If I have any issues with it I will reach out and say so.


Basically what I'm saying is sell that Mishimoto and you'd be surprised your issues may just "Magically disappear"

 

That's not good.


That is exactly where itshould be. That is correct operation, as designed by the factory, for the best operation of the 4.0. It is not a problem that needs to be solved.

You spent $1200 doing exactly the wrong thing.

 

I put on of the cheap big aluminum ones ebay on mine. My factory radiator was leaking.
https://www.ebay.com/itm/303799112039
I've been nothing pleased with it..

I was running on the warm side 180-200 when my clutch fan failed. Replaced and it never gets much over 180
normal temp is 150-160 checked with temp gun because I didn't believe it.

I noticed my parts jeep has a electric fan on the open side of the radiator

I've never had ac so no idea if Temps would go up 20deg.

For some reason my cummins also runs 150-60

A radiator that has a radiator cap is the only way to go. I gutted all the bull**** extra lines and fabbed the stand pipe from the waterpump to work much cleaner under the hood and simpler

I have a good temp gun and have found it invaluable for trouble shooting everything from cooling systems to figuring what cylinders dead and bearings that are running hotter than the rest.

 

The temp gauge on my XJ NEVER hits the 210 mark unless its the middle of summer and I've been driving for quite a while and then come to a stop, then it'll hit 210 or a little higher. So my system is either in immaculate working order, or my temp sensor is a little off....

 

I have a feeling this thread is not going to be about helping this guy anymore XD.

 

I feel like he possibly got a decent answer that he is going to run with by now... hopefully.

Any decisions made?

 

I appreciate it guys.
It helped.
I'm gonna leave it like it is for now.
It's winter,I'll be straight.
You live you learn.
Thanks.Yall take care.

 

Hopefully it straightens itself out for you. Its always a bummer to spend some extra cash and not fix what was wrong....

 

How much would it cost you to put factory 2.5l clutch fan and shroud back on? Or 4.0 clutch fan.

If you have these parts still youl only be out time to swap and test.
then go through it changing one part at a time elimating it as a cause.

 

The other thing about these older XJs with cast iron engine blocks and heads is that they likely have a good layer of rust inside the water jacket that's limiting heat transfer from the engine to the coolant. No amount of new parts will ultimately fix that until you tackle the rust chemically.

 

My xj actually runs merry brown looking coolant definitely has **** in there coating everything. It runs cold so I havent messed with it.

My cummins however is running so much crap. I flushed it about 10 times this summer then payed a shop with a machine to flush it.. still merky and scaley chunks come out.. look like paint chips..

I now run distilled water.. will not ever run tap water again.. git be the iron and minerals in my well water working wonders on growing stuff inside

I'd probly have a fluid analysis done to determine whats going on in there and what chemicals to use to go after them.

 

Yeah, that'll do it.

 

HI
Thanks for putting up with my questions. I just thought an update was in order here. I did most of what was suggested.

Added the injector covers on 3 and 4 to stop heat soak. They did not fit right bit they did stop the heat soak problem. Perfect.
Added a trans oil cooler. Put it on after the existing one for may effectiveness.
Used a cooling system cleaner and refilled with fresh antifreeze and distilled at a better than 50/50 rate.
Verified that the fan clutch was working. I do have the metal blades too.
Verified that the electric fan works. I did buy the kit to turn the fan on with a switch but havent put it in yet.
Radiator is already new.
Left the 0331 head on. Heard that if they make it to 120000 they would be OK besides I wond up with about 3 grand in 4wd mechanical stuff so I am broke.
Changed all fluids with the best I could find.

We have been in Death Valley going to all of the places we could not get to before. Yesterday it was 100f and we went up Echo Canyon from sea level to 3,000ft. It was loose sharp gravel most of the way with some fun twisty bits. I was surprised at how much clearance we seemed to have. No complaints from the trans, the engine just squeaked over 120 for a minute and came right down. We were using AC for most of the ride till the outdoor temps dropped with the altitude. Not a problem at all. I am very glad I asked here. Tomorrow we will move up to the northern end with more difficult roads. We named it the Big Horn Sheep because it is white, follows the RV around all of the time and has big horns.