TFitzPat87

Alright CF, I'm back with another question for you guys...

So like stated above, my temp starts to slowly climb if I'm going any faster than 65mph. If I slow back down to 60 to 65mph it cools back down and actually sits below the 210 mark. If I come to a stop, it does the same thing, start moving again and cools back down. Also if I have the heat running, the temp doesn't creep up unless I start pushing 75 or 80mph (which isn't often). Any ideas on why this would happen?

Within the last year I've replaced water pump (started leaking), tstat, hoses, fan clutch, and just this past Saturday the radiator with an OE single core (old one was leaking in cold weather). So everything should be up to par, the only change since everythings been replaced is the lower rad hoses doesn't have the spring. Which I read doesn't need it, as it was only installed for factory assembly reasons. I assumed it might be air in the system, but it sounds like an open system rids itself of air on its own.

Any ideas? This was happening before the rad change as well, but I figured it was cause of a leaky radiator. I did notice that the rad cap doesn't seem to be very warm after driving for a while, so that brings me back to air in the system.

As always, your help is appreciated!

IJM

Do you have lots of gunk in the block, or have you flushed it all out? Is you electric fan coming on around 218 as it should?

TFitzPat87

Flushed everything out as best as I could when I replaced the radiator. Fan is kicking on if temps get that high, but it usually doesn't get that warm. I'm just trying to get it situated before it gets real warm out, as I assume it'll be a little worse the warmer it gets.

BlueRidgeMark

How high does it climb?

TFitzPat87

I've only seen it climb a little above the 210 mark, usually have to slow down before I can see how far it gets, and then it cools back down at that point. It didn't used to do this, otherwise I would have figured it was normal.

While I have you guys, can a bad catalytic converter effect coolant temp? I have a feeling mine is bad, and in my searching I've seen that mentioned.

BlueRidgeMark

If it's just a little bit, I'd start with a good flush. Search on my username and "Amway".

No kidding. It works.

cruiser54

We don't have to go to meetings, do we?

cruiser54

No radiator cap?

TFitzPat87

Hahaha! Yes, there's definitely a rad cap. Speaking of which, it was actually warm when I got home today after work, so I feel better about that since it was pretty much cold the last two days.

Also, I happened to find my old lower rad hose, so I'm gonna pull the spring from that and put it in the new one, and see if that helps. Other than that, I'm kinda stumped but until it starts running real hot, than I'll just keep an eye on this.

Waynerd

I've read that a plugged cat can cause enough back pressure to keep the hot exhaust gasses in the head manifold area longer and cause higher combustion chamber temps which in turn would raise engine/ coolant temps

cruiser54

Is it new?

TFitzPat87

Sure is!

cruiser54

Ok then!!

TFitzPat87

Well, everything seemed ok this morning, though it was a little bit cooler out today. I kept the heat off and tried to stay at or above 75mph and it did get a warmer, but didn't go above the 210 mark this time.

Does it jive that the rad cap wouldn't be warm right after the jeeps turned off, but is once it's sat and things have settle for a little bit?

Anyway, if I'm just being paranoid I apologies for polluting the forum with another "high temp" thread.

robertj

You don't suppose you have any air trapped in the system, do you? I had a 2000 that would get warm after a thermostat and water pump change, so I put it on ramps to get the front end up and removed the radiator cap while it was running. I was able to burp air out of it and add more 50/50. It's worth a shot if you haven't already done that.