rizmonkey

I just replaced my thermostat on my 2001 Grand Cherokee and topped off the antifreeze.......... now the last couple mornings the interior overhead info center pops up my coolant low signal? The radiator is full and the overflow reservoir is at full/ hot.

What's the deal?

Thanks in advance,

RIZ

dave1123

Probably your float sensor is shot. $15 at rockauto. Just unplug it for now.

rizmonkey

I replaced that a few years ago and it didn't fix the issue??? Do you think it's because I had the upper radiator hose off to replace the thermostat and it got air in the system or something? Does it need to be burped?

RIZ

dave1123

Well...gee...no. The only place that signal comes from is the reservoir float. It could be stuck with crap. Take it out and check it for function.

rizmonkey

I'll check it out when I get home and let you know what I find out. The heat doesn't seem to be pumping out like it should even though I can feel it on both the driver and passenger sides down by the center console.

RIZ

dave1123

I'm not saying you don't have air in the system. What I'm saying is the VOIC only reads the float in the reservoir.

The easiest way to remove air is to remove the temp sensor and fill the rad until coolant flows out the hole, then re-install it.

rizmonkey

Well son of a beotch........... my reservoir was low ?!?!? I must have a small leak somewhere? It never dropped before. Ideas?

RIZ

dave1123

Fill it up, record the mileage, and find out how long it takes to trip the warning again. There are so many places it could be going without obvious leaks it's hard to tell. You DO have that 0331 head; not to frighten you, but check your oil for signs of coolant and look down the filler cap for the infamous crack. The water pump has a "weep" chamber that holds a tiny bit of coolant that is allowed to evaporate when the shaft seal starts leaking. When this weepage gets large enough, it will be thrown off the pulley on start-up, but stops afterwards.

These are in addition to the obvious radiator, hoses, and heater core problems. There are soft core plugs in the block as well. IDR if there's one in the back of the head or not.

I have a history of slow coolant loss with my 4.0. It started with the water pump seal that got worst over time. After replacing that, it was good for awhile, then I had lots of steam from my exhaust and water dripping from the tailpipe after long periods of idling and rapid loss of coolant. Since I had no coolant in my oil, I decided to change my head BEFORE that became a problem. Everything was perfect for a long while, but now I've got increased oil consumption, a slow coolant loss, and more than normal steam from the tailpipe. The newest thing is a misfire on cylinder #4. Just after the head change, #3 had a misfire code but that was a cracked insulator on the plug. #4 wasn't obvious until yesterday when I could feel it at idle. I'll have to pull that plug and see what the problem is. I do notice less steam now that the plug is misfiring, so it's possible one head bolt got mistorqued and now I've got a head gasket leaking. Who the **** knows?

rizmonkey

Ok, so I filled the reservoir Saturday morning and now Wednesday morning the low coolant went off again, it was low...... I filled it Wednesday afternoon and now watching it to see when it goes off again. Where do I look first? I don't think I see coolant on the ground?

RIZ

bigbadon

It may be that you did not completely fill the coolant system when you replaced the thermostat. If that were the case (most often it is) it will take a number of heat/cool cycles to purge air into reservoir and then SUCK coolant out of reservoir to fill system. If this is the case just keep adding coolant until level stabilizes.

dave1123

I don't think so. I gave him a couple of areas to check that are known causes of coolant loss. He needs to eliminate those first.

Riz, you can check the water pump by putting a dry piece of cardboard under the front of the engine in the morning before you start it up. Then start it and see if it gets wet. If it does, it probably will stop in about 30 seconds. That's the shaft seal.

I put about 2 qts in about every 2 weeks or 500 miles. 2 qts above the low level is about 2" from the top of the reservoir. I'm trying to nurse it until the weather gets warm enough to work in my driveway. I'm also using a qt of oil every 300 miles without any visible leaks except a small stain around the oil pan gasket. 3 hours of idling shows a quarter-sized spot of oil on the ground. Obviously NOT the rear seal. The drain plug is new. There is no visible smoke in the exhaust, but it smells odd. There is a little greasy carbon on the tailpipe tip, but I'd expect that at 187K miles.

OH....and my heater core isn't leaking.

I have about 10K on a new cylinder head. I thought the oil usage might caused by putting new valves on top of worn rings, but the crankcase breather and CCV valve are clear and dry. The head came assembled and I'm wondering how good the valve seals are.

rizmonkey

Well, I spent $500 to have my water pump replaced since they said that was the problem. I drove it for 3 days and my low coolant warning came on again. I took it back to them and they called for me to pick it up a couple hours later........ told me to drive it and see how it does. They said they put a bunch of stop leak in the radiator. 3 days later on the way home from work the heater vents blew ice cold and I notice smoke from under the hood a bit as I was driving... then the temp gauge slowly started climbing and I got home before it got into the red at all. Overall about a 7 mile drive. ...... After I got home I opened the hood and there was coolant everywhere in the front of the engine bay........ once it cooled down, I opened the radiator cap and it was solid thick of stop leak... no liquid even while poking around with a screwdriver. Then I took off the oil fill cap on the valve cover and poked a screwdriver in there and there is stop leak sand in there too...........

What do I have? I'm assuming a blown head gasket......... since it was the same symptoms my dad had on his truck other than the stop leak gunked up mess. It's my daily driver and I haven't taken it back to the shop that did the water pump since I don't want them touching it again. I have a private mechanic I may take it to...... he always fixes it the first time. The only reason I didn't take it to him this time is I have to make an appointment a week or two out for him and the other shop could get me in right away. I just asked them to determine my coolant leak so when they came back with the water pump I just had them do the work ( they are also the other big garage in town that seems to have a good reputation and I have had them do work before with good results.

Is my 4.0 motor shot? Is it a head gasket? Is the radiator shot? What do you think I'm looking at? How much do I have to shell out to get it back on the road? I don't wipe my *** with hundred dollar bills.

RIZ

dave1123

Well, I'm sorry to say I think you have a cracked head. The stopleak in the valve cover was the clincher. If you google Clearwater Cylinder Heads, you get a website from Odessa Cylinder Heads who has a new heavy casting of the 0331 head for $455 complete with valves and shipping BOTH ways (core return).
It's also guaranteed not to crack for 5 years unless severely overheated. There's a heat sensitive melt tag on it so they know. I got mine in 3 days because they happen to have a warehouse in NY. It weighs 85 lbs whereas the original one is 78 lbs. You have to return the core in 30 days but they are pretty flexible on that. If you don't return it, you get billed for an extra $100.

You should be able to go back on the shop that put the stopleak in it. I'll bet the heater core is plugged AND the radiator has popped a seam.

The last time I used stopleak was on a junker winter-rat and as soon as the radiator stopped leaking, I flushed it out of the system BEFORE it plugged anything else.

SatiricalHen

With how long you've been running it with coolant leaking into the oil, especially with stop leak in the oil system the engine might just be trashed.

rizmonkey

Everything I find on both Clearwater and Odessa heads are they have a horrible reputation and a very bad Better Business rating...... honestly, I just went out there and searched them both and nothing but bad revues came up for both. WTH ?!?!?!

RIZ