levi_v

So after my recent camping trip I started having issues again with my cooling. Been going after this problem for about 2 years now, as some have probably seen from my other posts. Was wondering if anyone had any bad experiences with flowkooler water pumps? Almost wondering if it is flowing too fast and not allowing the radiator to cool down the fluid. Or possibly the thermostat not keeping up with the water pump correctly? Found this old post on ifsja.org:

"FlowKool confirmed my suspicions by stating they double the water flow of conventional water pumps. I typed a long explanation of what is happening, but IFSJA told me I wasn’t logged in when I hit “submit”. I took that to mean my reply was too long and complicated, so I am now explaining it from a mechanical point of view… If you test a thermostat in a heating pot of water, you will notice that the thermostat slowly opens as the set point is reached. If you take a pair of tongs, and pull the thermostat out of the boiling water, it will slowly close as the temperature drops. On the other hand, if you remove the thermostat from the boiling water and place it in a pot of room temperature water, the thermostat will close very quickly. This is what is happening with the FlowKool water pumps- there is too much water moving too quickly to permit the “proper” function of the thermostat. This is causing the thermostat to close before the full cooling cycle was completed."

Any ideas?

sreeb

I'm going to call this "problem" a myth.

The thermostat isn't supposed to cycle, rather it should adapt to an appropriate flow.

If you have doubts about your thermostat, I would start by installing a replacement bought from your dealer with a real Chrysler part number.

Fred/N0AZZ

To high of a flow rate will cause overheating found that out yrs. ago on my race cars using aluminum racing radiators and CSI electric water pumps. You don't want a thermostat in them to restrictive but you must run aluminum restrictor rings to decrease flow. They come in different sizes I have a full set they fit where the thermostat went. The water must stay in the radiator a certain amount of time to allow it to cool properly.


A stock cooling system in a clean block/heater core are all that is necessary in all but the most hardcore Crawlers 95+% of the time.


JMHO

vank

I have a hesco pump, also twice the flow, and have zero overheating issues (now).

I agree with sreeb, with a proper thermostat and you won't have any issues with a higher flowing pump.

Fred's example is extreme and not applicable here. We're talking belt driven pumps in a box on wheels not drag cars.

levi_v

Would just an OEM Mopar thermostat be sufficient with a High flow water pump? I have had several 195 degree ones and currently on a 180 degree and all behave about the same.

Oh yeah and I also found this interesting: http://jeep-xj.info/HowtoRadiatorRestrictor.htm ...might try it since I have some scrap poly laying around.

vank

I'm using a Mr Gasket t-stat that I believe is rated as "high flow" was recommended in some thread when using the high flow hesco pump and t-stat housing. I do not recommend using the 180 t-stat. 195 is what the system is designed for and allows for the proper operating temp of 210.

What exactly is the problem you're having? Are you running hot or overheating? Getting hot at low speeds around town/traffic or when on the highway?

I too was running down issues with mine for a long time. I replaced everything (head gasket x2, cylinder head, fan clutch, thermostat x3, radiator x2, radiator cap, aux fan, hoses, pump, housing etc). I finally was convinced my head must be cracked (even though I had it magnafluxed and pressure tested and was told it was good) so I put another head on and have been good ever since.

levi_v

Overheating occasionally, mainly going uphill weather it be pavement or offroading. If I'm just driving around town ill be around 218-225. Going uphill ill hit 240 no problem, especially if I have AC on.

I've done 3x radiators, 4x thermostats, thermostat housing, high flow water pump, 2x fan clutch (one stock and one HD), lower radiator hose w/spring, upper hose, temp sensor, radiator cap, 50/50 fluid, water wetter, heater core, evap core, compression test, block test (blue fluid kind)... and I'm running out patients and ideas. Been a fun rig to play with but when I am fixing it and dumping more money in it than driving it, kinda gets old.

SteveMongr

Could be blocked passages in engine, not allowing coolant to flow. Seems like you tried everything else. Did you clear AC condenser of debris?
I also run a high-flow pump and 190 t-stat.

levi_v

Paid a shop to troubleshoot it a bit and they did do a flush on Monday. The AC condencer I cleaned out numerous times even while I had the radiator out. I also sprayed it with coil cleaner from home depot to get it really clean. I may look into doing a leak down test and see if that shows me anything out of the norm, but I'd be surprised since I have already done the compression test and block test.

vank

Wow.. this sounds exactly like what I went through. See my thread here:

https://www.cherokeeforum.com/f2/sti...ything-211712/

I even did the block test and compression test with good results. In the end everything was fixed by replacing the head. I now figure that I had micro cracks that were expanding as the head heated up and closed up when the head was cold. Therefore when the head was off the jeep (cold) the pressure test and magnaflux didn't show anything. I hate to be the bearer of bad news but this is just my experience.

The only two things I don't see on your list is (1) head gasket, so maybe start there first before replacing the head. A fel-pro is about $25. (2) Is your exhaust free flowing? A plugged cat/muffler can cause the system to heat.

I can relate to the frustration. I dumped a lot of money into mine trying to get it to cool properly. Fortunately I had another vehicle to drive, but I missed out on a lot of wheeling trips this summer. Gotta make up for lost time now. Once you get it running well it will all be worth it

levi_v

Yeah, I haven't done the head gasket yet. The muffler, cat, and o2 sensors are new. I changed exhaust parts out just before my cooling problems because previous owner had a busted thermostat, literally came out in pieces and was causing the system to run too rich which in turn killed the cat and sensors.

vank

Seeing as you've done everything else I'm thinking head gasket is the next step. When you have the head off I'd recommend getting it machined and tested.

One visual check you can do beforehand is look and see if you're getting any bubbling in the radiator filler neck. Bubbles indicate you're introducing exhaust gas. Just pull the cap and let it get warm while idling (watch and make sure you're not getting too hot). If you see bubbles once you reach operating temp you know you've got a problem.

freegdr

Try water outlet restrictor first. Ive been having a similar issue water flowing to fast radiator cant cool it down quick enough.

levi_v

Okay, I've pulled the head on a mazda miata before and that wasn't too bad... I am thinking that it is the head/head gasket causing me issues because I am seeing an occasional bubble in the filler neck of the radiator. Is it easier to pull the head with the exhaust and intake attached or removed? I've seen it done both ways and have heard it is a bit tricky putting the exhaust manifold and intake back on when the head is in the car. Also is just a standard head gasket from one of the parts stores adequate?

Tried this out last night real quick since it is a simple test. I used my drill press with a scrap piece of poly to make a flow restrictor. Didn't make any difference.

vank

I've always removed the intake and exhaust first. A few of the bolt holes underneath are hard to find when putting it back together but nothing is that hard to get to. Personally I only use fel-pro or victor reinz gaskets. They're generally not much more expensive and they're far better.