Overheating and already replaced all the usual suspects

[Qban]

Finally made some progress.

So I put everything back together with the champion radiator (I'm stuck with it), two holes in the tstat, replaced all spring clamps with worm gear and still have the heater core bypassed.

So the machinist/mechanic at my company took a look. He found I still had air in the upper radiator hose. So he machined a pipe with a petcock and we put it in the highest point of the upper hose and we bled it that way.

I ran the jeep on the highway at about 65mph for over 10 min and had a consistent temperature of 205. =) yay!

Now I'm going to try taking the 605N from long beach to the 14 with the ac on at 65mph which is how I overheated the very first time.

Hopefully air is the only problem. The disappointing thing to me was that I spent the time and did my research which led me to believe that using a lisle spillfree funnel with the jeep on an angle while massaging the upper radiator hose was enough to burp the system and purge the air. I guess it's not enough sometimes =(

Here's a learning point for anyone. Shake the upper hose and listen for water splashing to see if you have air. I pinched the hose and thought it felt good but I was completely wrong.

 

[mako my day]

Thanks for the constant updates, and the shaking hose step.

I'm going to shake my upper hose tonight, and hopefully get a reaction.

I don't recall, but did you test the exhaust manifold for any tiny cracks? Mine was shooting hot exhaust on the block, and causing heat spikes while under load.

 

[Qban]

Thanks for the constant updates, and the shaking hose step.

I'm going to shake my upper hose tonight, and hopefully get a reaction.

I don't recall, but did you test the exhaust manifold for any tiny cracks? Mine was shooting hot exhaust on the block, and causing heat spikes while under load.

Thanks man =) I'm glad to hear that I'm not just rambling, at the very least I'm hoping my stupidity can serve as a sign post to others =)

I didn't test the exhaust manifold. I only did a block test on air from the radiator. Mr. Machinist/Mechanic from work said lets just do one thing at a time.

Which brings me to my next learning point that I failed at. I shouldn't change more than one thing at a time unless its something like rebuilding an engine =) I would have created less issues if I wouldn't of over thought things and decided to change 20 things at once.

Once I have my issue completely resolved I'll write a final post describing my problems and everything. Hopefully it helps someone else.

 

[techno1154]

So you burped or de-air (if there is such a word) the 1998 XJ. Anything that work for you is good. I have heard of others doing this with success.

I had a 1994 XJ before the 1996 I have now and never burped any of them even though I serviced the cooling system several times in both of them including replacing defective radiators. I simply fill the radiator (and engine block), screw on the radiator cap then fill the coolant recovery bottle to the top, until it could not take any more. I then run the engine in the drive way until it is up to normal temperature then shut it off and let it cool for a few hours. Then it is time for a run around the block about a mile then let it cool again. Usually by this time the coolant in the recovery tank would have fallen to the correct level i.e. the engine and radiator would have self bleed (burped) and the air in the system would be replaced with the extra coolant from the recovery tank.

IIRC, the non Renix XJ,s do not or should I say should not require burping. However, burping would not hurt and in your case, it seem to help.

Your case seem to have the experts and novices (like myself) on completely stumped. I hope that this very frustrating and lingering problem go away sooner than later.

 

[Tony_SS]

Oh man... air bubble!

Best way to fill and burb antifreeze... point the front end up..take off the cap, start the engine, but the heat on high..fill the radiator, install the cap. Run it, drive it, let it cool down, check the level, top off the overflow.

 

[bugout]

I've always pointed my front end to the sky "literally" at temperature to get the airbubbles out....I'm glad sombody found an easier way...I've heard of this before but I've always found something else to do that seems more important at the time.

Thanks for the constant updates:exclamati:exclamati:exclamati

 

[Qban]

I've always pointed my front end to the sky "literally" at temperature to get the airbubbles out....I'm glad sombody found an easier way...I've heard of this before but I've always found something else to do that seems more important at the time.

Thanks for the constant updates:exclamati:exclamati:exclamati

Thanks!

Hmmm, I would have tried pointing my front end at the sky too. But one of the videos on youtube I watched about burping an XJ said not to put the front end too high. I guess now that I think about it, what the hell does that guy know either. hahaha J/K

 

[Qban]

Ok, so yesterday coming back from lunch I opened up on the fwy again with the ac on this time. I was about to overheat again. It wasn't a warm day and I watched my temperature quickly head up to 230 degrees.

I showed my companies mechanic again. He found that my new radiator cap (Murray) that I had pressure tested at O'Reilly before I bought it had failed.

The way he found it was by squeezing the upper radiator hose and listening to cap. It kept making a click noise with each squeeze. He pulled off the cap and held it in the air suspending it in it's normal position and looked at the center vacuum valve. There was a gap between the center vacuum valve and the lower gasket. It looked like the spring pulling the vacuum valve shut had detached somehow. If, this doesn't make sense, google radiator cap diagram and you'll see the parts.

He gave me another cap and said he knew this one was perfect.

The broken vacuum valve of the radiator cap also allowed air to get back in, so I bled again from the upper radiator hose petcock, and set off to test drive more.

I drove it for an hour at 70mph up the 405N through LA which is where I had my first overheat with the AC on full. This sucked as it's not warm in southern California and every other night half the freeways are closed so it's like playing roulette as to where I test drive and If I get stuck on the closed fwy, haha.

It held up just fine usually staying at 206 with little short moments of hitting 208 and coming back down.

Things are looking pretty good, we'll see how the next couple of weeks fair.

 

[bugout]

Ok, so yesterday coming back from lunch I opened up on the fwy again with the ac on this time. I was about to overheat again. It wasn't a warm day and I watched my temperature quickly head up to 230 degrees.

I showed my companies mechanic again. He found that my new radiator cap (Murray) that I had pressure tested at O'Reilly before I bought it had failed.

The way he found it was by squeezing the upper radiator hose and listening to cap. It kept making a click noise with each squeeze. He pulled off the cap and held it in the air suspending it in it's normal position and looked at the center vacuum valve. There was a gap between the center vacuum valve and the lower gasket. It looked like the spring pulling the vacuum valve shut had detached somehow. If, this doesn't make sense, google radiator cap diagram and you'll see the parts.

He gave me another cap and said he knew this one was perfect.

The broken vacuum valve of the radiator cap also allowed air to get back in, so I bled again from the upper radiator hose petcock, and set off to test drive more.

I drove it for an hour at 70mph up the 405N through LA which is where I had my first overheat with the AC on full. This sucked as it's not warm in southern California and every other night half the freeways are closed so it's like playing roulette as to where I test drive and If I get stuck on the closed fwy, haha.

It held up just fine usually staying at 206 with little short moments of hitting 208 and coming back down.

Things are looking pretty good, we'll see how the next couple of weeks fair.

Though XJ sensors, senders and gauges are not know to be accurate, ALL of mine inside the cab came ALIVE by cleaning the firewall connector out. It is easy but time consuming. Get all of that nasty excues for electric grease out. Be prepared to go through a few cans of electrical cleaner. I even had to break down and use so brake cleaner because of how tar like the grease in there was. I uses an assortment of picks, small screw drivers and Q-tips to get everthing out and dry. I took a brass brush on a dremmel to freshen up the male spades. Then uses a flat micro file our of my armory kit to do the same to the female spades. Bent every male spade to one side (JUST A HAIR). Apply a light coating of fresh electrical grease and reassemble. Then apply a S%$@ load of electric grease to the outside of the assembly.

Also, Cruiser54's mostly renix tips under dash ground, http://www.jeepforum.com/forum/f11/cruisers-renix-tps-procedures-1280956/ who I promised to do a write up for as soon as I got a little more familiar with photo bucket,

helped alot even on my 96. EVERYTHING ELECTRICAL in my cab worked better after that.

My sensors went from sleepy and slow to :variety: just like that.

 

[mako my day]

Question that you may have the answer to... If you sit at idle, does the Efan ever kick on?
At idle will your temp hit 220?

I am trying to determine if it's normal for the engine to get to 220, and have the efan kick on. Normal, meaning 90% of XJ's do this.

 

[Tony_SS]

Murry caps SUCK. Mine leaked everywhere... I ended up getting a Stant cap with a pressure release safety... worked perfect.

 

[bugout]

Question that you may have the answer to... If you sit at idle, does the Efan ever kick on?
At idle will your temp hit 220?

I am trying to determine if it's normal for the engine to get to 220, and have the efan kick on. Normal, meaning 90% of XJ's do this.

Now that I have a new STOCK cooling system, fan clutch, radiator, water pump, thermostat and radiator cap, I have a hard time getting my rig to 220. I could idle in Neutral all day long now. It is possible to do however, in gear with my foot on the brake (in a long line at a drive thru) and the efan will come on pretty regularly though.

 

[Ex Jay]

I'm going to shake my upper hose tonight, and hopefully get a reaction.

If I had a dollar for every time I said that...

 

[mako my day]

Any update? I am still fighting my over heating issue while at fwy speeds. I can idle all.day, 4x4 all day, get get up above 50 mph, or drive up a hill I get up to 235 with the heater blasting. Its beyond frustrating.

 

[rockclimber]

Any update? I am still fighting my over heating issue while at fwy speeds. I can idle all.day, 4x4 all day, get get up above 50 mph, or drive up a hill I get up to 235 with the heater blasting. Its beyond frustrating.

have you flushed your rad/heater core?

sounds like not enough water flow/heat transfer.

 

[yossarian19]

Mako what year is yours? Could be hg issue.

 

[mako my day]

Should I start a new thread?

99 4.0
New tstat, pump, rad, hoses, and exhaust manifold (stock replacements)

Engine will idle and crawl all day( with no ac on)

When The engine works over 35% on the highway The temp spikes. Basically when we are trying to hold 60-65mph.

Down hill, the temp drops to 185 even at 70 mph.

Yesterday sucked. 4 hours home from the desert with the heater blasting just to keep temp at 220-225.

 

[mako my day]

....I use a scanguage plugged into the obd2 to watch exact temp, and engine load.

 

[rockclimber]

what brand is the radiator?

those are the same sympotoms mine had, turned out the replacement radiator was crap and the core was about .5" thinner than the OE rad.

 

[mako my day]

Napa. I have the zj fan clutch. Can I fit a bigger rad?