Summer temps - XJ Starting to run hot.

[Mudderoy]

dang same problem here... aux fan kicks on.. and its cracked so it vibes like a hoe

Vibrating hoes? Interesting...

 

[Ecomike]

A/C really shouldn't make a motor overheat. It's putting a small drag on the motor is all.

IF the E-Fan does not work or the radiator or the water pump is compromized, running the AC WILL quickly add enough heat to the radiator to overheat any engine! Also, an over (or undercharged) AC system can overheat the engine via the condensor which dumps its heat right in front of the radiator.

Once the cooling system is marginal, as in your case, any weak points that leak any coolant at all, like the "Rad or Bot CAP", that fail to hold full system pressure can cause the coolant temperature to run away too.

Muckleroy,

Be sure to use a new cap and new Rad hoses with that new radiator, and you should see it drop down to 210 max.

What part of Houston are you in? I am near S.H./Pasadena.

 

[badron]

You are not overheating because your Efan comes on this is normal operatrion. Don't fix what ant brocken. The fact is any of his temp reading are well with in normal. Don't fix what ant broken.

 

[Mudderoy]

IF the E-Fan does not work or the radiator or the water pump is compromized, running the AC WILL quickly add enough heat to the radiator to overheat any engine! Also, an over (or undercharged) AC system can overheat the engine via the condensor which dumps its heat right in front of the radiator.

Once the cooling system is marginal, as in your case, any weak points that leak any coolant at all, like the "Rad or Bot CAP", that fail to hold full system pressure can cause the coolant temperature to run away too.

Muckleroy,

Be sure to use a new cap and new Rad hoses with that new radiator, and you should see it drop down to 210 max.

What part of Houston are you in? I am near S.H./Pasadena.

Hey thanks, thats a good idea. The cap is pretty new but it makes sense to replace it with the radiator. I'll do the hoses to, wth...

I am looking forward to the new 3 core and putting this chronic problem to bed once and for all. After this I'll do an electric fan replacement for the mechanical, I like the idea of the constant air flow as opposed to the variable based on engine RPM.

I'm in Katy. lol Pasadena is the only place I've been where I had a gun pulled on me. Many many years ago. Be careful over there.

 

[Mudderoy]

You are not overheating because your Efan comes on this is normal operatrion. Don't fix what ant brocken. The fact is any of his temp reading are well with in normal. Don't fix what ant broken.

I've learned the hard way that when the temp starts to rise to this point, the first hash mark after 210, it will instantly jump to the first red hash mark and the instrument cluster warning bell will sound.

I've also learned the hard way, $950 repair, that you cannot drive it far enough to get off the interstate without warping the head.

I think the system is losing coolant slowly over time (about 3 to 4 months). I don't see coolant anywhere including the oil. So I am thinking it is running out the over flow tube of the over flow bottle. Slowly the radiator loses more and more coolant as the bottle fills, over flows, cools, and is siphoned back to the radiator.

Hmmm it might be time to buy a really good water pump. The water pump was the original problem. So far I'm on my 4th water pump in 10 years.

I left it alone before, it was expensive. I understand your comment though, but believe me fixing the cooling system isn't my attempt to find a new hobby.

Actually maybe the water pump has a small leak and it is so small it evaporates from the heat of the engine. I DUNNO. But I will figure it out.

 

[langer1]

A/C really shouldn't make a motor overheat. It's putting a small drag on the motor is all.

True about the load, but the air temp coming off the condenser gets real hot, and all that hot/heated are cuts down on the cool are going through the radiator.

 

[Ecomike]

Hey thanks, thats a good idea. The cap is pretty new but it makes sense to replace it with the radiator. I'll do the hoses to, wth...

I am looking forward to the new 3 core and putting this chronic problem to bed once and for all. After this I'll do an electric fan replacement for the mechanical, I like the idea of the constant air flow as opposed to the variable based on engine RPM.

lol Pasadena is the only place I've been where I had a gun pulled on me. Many many years ago. Be careful over there.

I hope it wasn't me that pulled the gun! :gag: LOL, Just joking.

Lived here since 1978, moved over to this side of town after I go tired of Galleria Westhiemer traffic, where I was born and grew up.

I would stick with the mechanical clutch, yours is obviously still working! It gets tighter as the radiator heat gets hotter and thus runs faster at idle, like direct drive, then loosens up at higher engine rpms and higher vehicle speeds and when it sees cooler radiator air. It is self adjusting.

You will be amased at the new radiator.

 

[Mudderoy]

I hope it wasn't me that pulled the gun! :gag: LOL, Just joking.

Lived here since 1978, moved over to this side of town after I go tired of Galleria Westhiemer traffic, where I was born and grew up.

I would stick with the mechanical clutch, yours is obviously still working! It gets tighter as the radiator heat gets hotter and thus runs faster at idle, like direct drive, then loosens up at higher engine rpms and higher vehicle speeds and when it sees cooler radiator air. It is self adjusting.

You will be amased at the new radiator.

lol 1978 was about when it happened! I went to Deer Park High school, but lived near Baytown "Lynchburg". I was just out running around early one morning in my 1972 Nova.

Well I'm not doing anything else until I get the new 3 core radiator in.

 

[Mudderoy]

True about the load, but the air temp coming off the condenser gets real hot, and all that hot/heated are cuts down on the cool are going through the radiator.

That makes sense, and explains why things get hotter with the A/C running. I like that better than a slipping belt under A/C load.

Maybe with the new 3 core radiator it will compensate for the heat from the condenser.

 

[langer1]

One observation, my XJ never ran hot except one time when I raised the front up 2" making the front higher then the rear.
That changed the air flow so much it cut down on the air flow through the radiator.
Once a did the rear and the body was level or slightly nose down the temperature dropped 20 deg.

 

[Mudderoy]

The new radiator is here! The new radiator is here! The new radiator is here!

 

[Blaine B.]

Yeah the CSF radiators always seem to have the neck bent. Not sure why. Takes a second to unbend it and it's fine though.

 

[Mudderoy]

While looking at the old radiator and comparing it to the new radiator...

A couple of interesting developments.

1. I see a small amount of water next to the old radiator. Maybe I found a leak!

2. The "covering" or shroud that goes around the radiator is torn and missing a substantial piece on one side of the radiator! I bet it has been like this since they change the radiator about 7 or 8 years ago.

Too many assumptions. I should have looked more closely. Of course I saw everything better tonight, because it was dark outside and I was using a flashlight.

The new radiator goes in this weekend.

 

[89xjJe3per]

Yeah the CSF radiators always seem to have the neck bent. Not sure why. Takes a second to unbend it and it's fine though.

Thats because they like to drop them a few times before they get em to the box...

 

[Hammered]

Lebaron Vents

 

[bgred2]

You guys are making me glad I have an idiot light instead of a temperature gauge................But just to be sure I replaced about everything in the cooling system.

 

[89xjJe3per]

You guys are making me glad I have an idiot light instead of a temperature gauge................But just to be sure I replaced about everything in the cooling system.

The idiot lights are even worse u cant tell if its overheating tell it actually happins! Fu#k that i just did the conversion to get rid of the idiot lights and i am very pleased!

 

[bgred2]

I know but sometimes ignorance is bliss!

 

[Mudderoy]

You guys are making me glad I have an idiot light instead of a temperature gauge................But just to be sure I replaced about everything in the cooling system.

You do make a good point. As I said I am hyper sensitive to where the little bastard needle is.

I put the 3 core in today. Took it out the highway and put the cruise on 80 mph and drove out about 5 miles.

Exited and pulled over to look for leaks. Clean and the radiator had that "new hot paint" smell! lol

Ran 210 the entire 5 miles. After I pulled over to check for leaks the needle moved slightly above 210, technically the needle was still on 210 hash mark.

I got back on the highway going the opposite way. It took a couple of miles for it to drop back to 210.

I ran the A/C the entire time. I'll double check the coolant level tomorrow as I just topped off the new radiator before warming it up and then doing the test drive.

This coming week will be the real test, as we are expecting 90's in the afternoon, and that is always the time that I have issues. I am thinking about taking the old radiator to a shop to have them test and fix any leaks. It would be nice to have a spare.

 

[Mudderoy]

True about the load, but the air temp coming off the condenser gets real hot, and all that hot/heated are cuts down on the cool are going through the radiator.

Ok I'll show my ignorance once again. This was my first time to change out a radiator on an XJ. I was amazed to see how big the condenser was! No wonder it can impart a significant amount of heat to the radiator.

:flame: