davida

Just a note: The Anti Freeze works both ways, it keeps the water from freezing and from boiling, if you have run all the AF out, The water will boil in a system that has a overflow tank or in a system does not, when the cap is removed. AF really does not keep your engine from overheating it keeps the water in a state (liquid) that allows it to cool the engine. Higher operating temps are normal on most cars nowadays.

darknezz

Yeah I know it needs AF to work properly, I did a 50/50 mix and added more AF when it boiled over. And as for having that high of an op temp for newer cars my bmw has a 165 degree tstat and never gets hotter than 180 when its function as it should.

goneboating06

jeeps like hotter temps like said before... i have a 89, with all new cooling components, and a 195 tstat. It runs close to 210 all the time, but never goes above 210. My new suburban runs at 210 all day... engines are more efficient at higher temps, as long as its controlled. now if your jeep starts getting at temps like 220 or 230, i would start to worry about it. Dont know if this helps, its just my 2 cents.

95Cherokee

MY water doesn't boil over at 212 because I use coolant which raises the boiling point.

davida

Maybe your bmw is running cool I looked over at the bmw forum (they claim they have the biggest bmw forum) and the census seems to be that they run between 198 & 212.
http://forums.bimmerforums.com/forum....php?t=1113686

Of course you have to convert from Celsius to Fahrenheit to know what they are talking about, but then they are BMW guys!
(Notice I never used the name "bimmer", I see that it's reserved for owners)

davida

X2

djb383

I never said anything about what temp it was supposed to run and this time of year they don't run a steady 200F, more like 190F-220F. Summer time coolant temp yoyo's up/down depending on speed, ambient temp, air flow thru rad, a/c use, condition of the cooling system, etc., etc. During winter cold months, coolant temp will run very steady, probably right at whatever temp t-stat is used.

If you will look at the pic I posted you can clearly see the ScanGauge displays closed loop (clsd lp) and coolant temp (wt) is only 94F when I snapped the pic. Again, there's no reason for the system to wait 10-15 minutes to run lean and clean when it can do so with-in a few seconds after start-up because the O2(s) are providing the ECM/PCM with the info it needs to run lean and clean.

darknezz

Its just the way he said it, of course coolant raises the boiling temp.
Also my bmw is using a 85c (185) degree tstat so I guess its higher than I thought. It stays right at center where it should.

Anyway thanks for all the info, if it continues to overheat on the pass over 210 I will investigate further.

1987 new toy

OK just to start this off as far as your coment (yes water does boil at 212) But antifreeze raises the boiling point! On top of that look it up IF you dont belive the reason your radiator system is pressurized is because for every pound of pressure it raises the boiling point of that fluid a few degrees! So if you had 5 pounds it might raise your boing point to 220, if you had a 15 pounds it will raise your boiling point to 240. THAT IS WHY THEY ARE PRESSURERISED SYSTEMS. Now if your cap was the problem it would then explain why you boiled at 212. Also on your older system you need to fill your bottle with the engine running at operating temp and your heater on because of the valve that closes off your heater core. Perferably with the engine at a higher rpm then idle so that you are moving the water through faster and eliminating air pockets while you fill it. If the cap did not fix it you could have a small crack in one of your exhaust ports in the head that does not allow water to go through but will allow( exspecially on a steep grade) ehxaust to enter your cooling system. HOPEFULLY THE CAP FIXED IT FOR YA.

davida

I checked out your BMW pics, Smooth Very Smooth!

djb383

That's the way factory idiot gauges are designed to work.....needle stays right in the middle. Our Saturn Vue (Honda VTEC V6), the needle stays right in the middle......same way with our Toyota Corolla. Plug the ScanGauge in and watch coolant temps yoyo, especially this time of year. At least the XJ factory gauge has a few numbers, most factory gauges have a C and H with some marks in between, like our Saturn and Toyota. Now that's a genuine idiot gauge for ya.

darknezz

^^ eh I do have to agree with this. the BMW has a VERY slim margin of operating temperature. The gauge could be replaced with a light when if its over heating, cause if its ever over half way YOU BETTER PULL OVER FAST. BMWs tend to get DESTROYED by over heating pretty easy. BUT I STILL LOVE EM :P

Sorry for the length.... But please read to understand whats been happening.

Anyway back to the Jeep, made it home from cali today. Before I left I wrapped electrical tape around the threads on the expansion tank and the cap fit pretty snugly cause it was still just spinning on their and not tightening down. THIS IS WITH A NEW CAP.

As per advice from here I just let it sit at 210 and it was doing fine for awhile until a real big hill again and it got between the 210 mark and the next line. Sat their for awhile then shot up and I by the time I could get off I5 freeway it was in the red. It popped the cap again and boiled out all the water....

I let it cool and refilled it with 50/50 mix AND wrapped duct tape around the bottle and over the cap, lol, and set off again. It was fine for around another 100 miles sitting at 210 and a little over on hills. I pulled off at a rest stop to take a break and check it, well most of the water was out again and it was hissing around the cap. I refilled it and re duct tapped it and made it home the rest of the 150 miles ok.

So wtf. Im thinking I want to just ditch the stupid plastic bottle and go to the open system. Do I just attach the hose that comes out of the bottom of the bottle to the heater valve where the hose goes into the bottle? and get a new radiator? Could somone post a link to a write up or tell me what to do? While I'm at it I'll get a GOOD radiator and electric fan and ditch the clutch fan. Was also thinking of ditching the a/c compressor and condenser for it as its in front of the rad restricting airflow. As well as the compressor putting strain on the engine.

Whadda yall think?

darknezz

^^^ READ ABOVE POST TO!

I didnt even see this before. First just so everyone knows I DO know antifreeze AND pressure raises boiling points and that's why the systems are pressurized. I DID NOT KNOW to fill it while the engine was on all the time, I DID do that when I flushed the system to bleed it out, but as for just adding water recently I have not been doing that.

As far as a crack in an exhaust port.... Thats litterly a crack in the head or the head-gasket? And not just the manifold gasket right cause I know I need that and thats alot easier.... I suppose I should test the coolant for exhaust gasses. I hope this is not the cause however.

But right now its still not holding pressure due to the cap so I am still aiming at that first.

1987 new toy

The way it sonds to me is you just are not holding pressure in the system. Yes a crack in the exhaust prot will be in the head . Now as far as changing it over wich I just did to my 87 two days ago. If you have a pick-a-part would be the best You will need as follows Radiator, overflow bottle, and the heater control valve( pay close attention how thwe lines are hooked up on the heater control vavle.), and the bracket off the newer model that the overflow tank bolts to. I will go out and take some pics because you will need to relocate your coiland move your relay juction so you can install the bracket for the overflow.

1987 new toy

Also on the radiator swap the older radiator has the electric fan sensor in the radiator and the newer model has it in the thermostat housing I chose to wire my electric fan on a switch so i can turn it on when I'm 4x4ing if you want to put it in the sensor you will need to get the thermostat housing. Also look at your upper tranny line and make sure it has a female fitting on the line if it has a male thread on the line you will need to get the line when you get the radiator.