Another overheating rant

Sorry for what is going to be a long post but I have to vent because I am about to kill someone or this Jeep.

So anyways, about 2 months ago I noticed that my 97 XJ was starting to weep coolant. At first I couldn't figure out where it was coming from. Then one morning while stuck in traffic the gauges went completely dead. A few good whacks on the dash later and the gauges came back but the temp gauge, that was at 210, suddenly jumped to 260. I quickly got off the road and popped the hood. It was definitely hot and I was finally able to see that the leaking coolant was coming from the water pump shaft. Since that point I haven't had any more massive overheating issues but I have also been running with the heater blasting.

So fast forward to a little over 2 weeks ago. I got a high flow water pump and a radiator cap with a temp gauge built in from Summit Racing and a high flow thermostat housing and thermostat from Hesco. Since I was trying to enjoy my vacation, I dropped the Jeep and the parts off at a local shop. Two days later and one non-high flow water pump (Summit sent me the wrong one), my jeep now has all of the parts I got plus a coolant temp sensor, upper and lower rad hoses, and a new serpentine belt in addition to a full flush and fill. So I get it home, pop the hood, check the work, and promptly get sprayed by coolant. The freak'n mechanic decided to reuse a hose clamp and it let go at the precise moment that I was in the line of fire. After ripp'n the guy a new one over the phone, he came out and fixed it. Since that point the thing has been running good. Not super cool but good. I also can't turn on the AC because it isn't triggering the Efan but that has been the only issue.

And now fast forward to today. On the way home from work the temp gauge literally jumped to 250 and the check gauges light came on. So I pulled over and checked the temp gauge in the radiator cap only to realize that it is bleeding just a little bit of coolant off because they didn't seal it properly. However, it is still stating that the coolant is at 180 but I could tell that the engine was warmer then it should have been. So I creeped it along and the temp gauge falls back to 220. Then a short while later it jumps again right to 260. I pulled over to find that it is puking out of the reservoir tank like all hell. Since I was next to the place that I bought it from, I just pulled in and told them to have fun with it.

So at this point I am insanely pissed off, Jeepless, and broke. The only other issue that it has is a header leak. The rest of the exhaust is brand new (including the cat). I don't know what the frick could be wrong with this damn thing.

Just

Empty

Every

Pocket

That sums it up!!

High flow water pump+high flow t-stat+high flow t-stat housing = too much flow. The coolant doesn't have time to absorb the heat from the engine before moving to the radiator where it doesn't have time to disepate the heat before cycling again. There is a link on a previous thread that has a write up for a cooling system restrictor that may do you some good, I'll try to find it and post again. Also what PSI is the new cap? Water in the oil? This is why you should only change one part at a time that way you have some cause and effect.

forget it...

88 Wagonman is absolutley correct.. TOO much flow or flowing too fast it actually HURTS you overall..

So your electric fan is NOT working? or its not being triggered by the sensor and thats why your running the heater?

make sure you have no air in the system... the rapid jumps your describing are kinda freaky... make sure you t-stat is actually working properly... if in doubt, get a new one (non high flow) and put it in. If those are good i know its not magic but "Water Wetter" does help... Make sure you dont have too much debris clogged in your front end blocking flow of air to the radiator... how is your fan clutch? maybe put some washers/square tubing inbetween the hood/hinges to help vent out some of that hot air.

goodluck and keep us posted...

JOe

You need to get that efan problem solved.

I replaced...
fan clutch
radiator cap
thermostat (180 degree high flow)
thermostat housing (high flow)
water pump
all hoses (including heater hoses)
radiator (3 core)
temp sensor
serpentine belt

I guess everything but the efan, it works fine. :S

My two core (replaced the factory plastic end cap in 2000) had a tiny leak that would make my temp gauge do that same little dance you were describing about every 4 months.

The radiator was my solution to my problem.

88 Wagonman said:

High flow water pump+high flow t-stat+high flow t-stat housing = too much flow.

Click to expand...

Sorry, my post may have been confusing on that point. I had ordered a high flow water pump BUT Summit sent me the wrong one. So what it actually has right now is a good ol' OEM water pump and a high flow thermostat housing plus a balanced thermostat from Mr Gasket. I did a lot of searching on that and from what I found people weren't ever able to get enough coolant flow through the block to be too much but they could get too much through the radiator. Either way, it doesn't matter because the coolant flow right now should only be marginally more then stock.

As for the Efan, it is coming on when it over heats but it doesn't come on when you use the AC... so I just haven't been using the AC.

At this point, my only thoughts are there is a blockage or air pocket somewhere. Granted I have not replaced the radiator or the fan clutch yet, but I have never seen them cause such a rapid temperature spike. Although if you have seen a bad rad cause this Mudderoy, maybe that is it.

And the reason why I replaced so much at once is because there was only one reproducible problem. I was hoping all of the new parts would resolve the intermittent issues.... but man was I wrong.

The first time I saw the temp jump from 240(?) to the red area I was going down I-10 at 80 mph. I nursed it off the highway, and even waited for it to cool. Not long enough as it cost me $950 to have everything repaired. Head was milled due to it being warped. The culprit was the factory water pump. They used plastic fins, which were non-existent when they removed it.

About two months after all that the factory radiator developed a leak. I had it replace with an all metal 2 core. All was fine for years. Maybe 2 or 3 years ago I started having the same problem.

It was because the coolant level was low so the temp would raise cause more coolant to evacuate because of the increased pressure. I did the high flow thermostat (180 degree) and high flow thermostat housing. Seemed fine for awhile then I started seeing the temp creep up again. I had to add coolant.

I bit the bullet and bought the 3 core radiator ($170). When I was taking the old one out I saw a very small leak (wet spot) on the 2 core. So I would probably have been ok if I had just taken the old radiator out and had it repaired by a radiator shop. Frankly I'd rather have the 3 core. I'm going to get the 2 core repaired for a spare.

The 2 core was ahhh 8 years old I think, so it may be blocked with trash as well as having the small leak.

If your radiator is pretty old it might be a good thing to take it out and have a radiator shop go through it.

As Long as the thermostat is rated at 180 degrees, you shouldn't be having a problem with too much flow(as long as its working properly). From reading your original post, it seems like you've always had something weeping. even after repairs. This probably means that you've got an air lock. These things can be a right pain in the rear to get all of the air out of so after repairs there is always the chance that your guage will jump around a bit until the air has a chance to work itself out. If you have weeps in the swystem however, as it cools, it will suck air in instead of sucking water back from the overflow. Eliminate all leaks and ensure that there is no air in the system and you'll probably be fine.

Well I just got a call from the stealership and they say that the radiator is shot and not holding pressure. To me this still seems odd though. It wasn't leaking at all after the last repair, so I am not sure how a radiator that wasn't leaking caused it to overheat because it was leaking... damn I am confused.

Anyways, I am going to go cry now because they are going to kill me on the price of this thing.

You can buy one online for $160 and replace it yourself, or you can take your XJ to a radiator shop and have them do it, I think a lot cheaper than a dealership. Just my 2 cents.

If it is a OEM radiator I'd replace it. I WOULDN'T REPLACE IT WITH AN OEM RADIATOR!!!

Be happy, at least you know that the major component of your cooling system has a problem. Fixing that is almost certain to fix the problem.

Holy crap, I just got off the phone with the stealership and they want $685 to put an OEM radiator back in the thing!:scared:

Looks like I will be towing it home and doing it myself. I so don't have the time for this.

Wow, money for nothing and chicks for free.

Keep us updated on what happens.

Well, I put in a new radiator and it is still messed up. It will run at 210 then creep to the next line past that and stay there for a while. Then the temp gauge will suddenly jump to 260. But if I shut it off for a minute it will go back to 210. I am about to load this thing with C4.:gonnablow

that kind of sudden temp spike, after reaching operating temp, is very typical of a blown head gasket

you need to do a pressure test on the cooling system, and chemically test the coolant for a leaky head gasket

Dark Knight said:

Well, I put in a new radiator and it is still messed up. It will run at 210 then creep to the next line past that and stay there for a while. Then the temp gauge will suddenly jump to 260. But if I shut it off for a minute it will go back to 210. I am about to load this thing with C4.:gonnablow

Click to expand...

Did the stealership do a test for exhaust gases in the cooling system?

They only did a pressure test when I first took the Jeep in. It is now back with them and they are thinking that it is a blown head gasket or a cracked head. So I assume they will be doing whatever testing is required to prove or disprove that. Although if it is one of those two, why does the temp drop so fast after letting it sit just a couple of minutes?

I also did check the oil and I didn't see any coolant in it. At this point it really doesn't matter what they find because my bank account is dry.

combustion gases leaking into the water jasket will form superheated steam bubbles, which dissipate quickly after shutdown. Its also possible the leak is near the temp sensor, and is skewing the reading.

if you have a lever-vent radiator cap, you might be able to see some of these bubbles in the radiator neck before they dissipate

92DripCherokee said:

combustion gases leaking into the water jasket will form superheated steam bubbles, which dissipate quickly after shutdown. Its also possible the leak is near the temp sensor, and is skewing the reading.

if you have a lever-vent radiator cap, you might be able to see some of these bubbles in the radiator neck before they dissipate

Click to expand...

See now that makes sense! Thank you for explaining that!!

And I just got the call from the shop and they say that they are seeing pressure spikes in the cooling system on the compression strokes of the engine (or something like that). Which obviously means that it is either a blown gasket or a cracked head.... neither of which do I have time or money to replace. So it looks like I gots me a new lawn ornament.