MIDAS blew up my Jeep ...

[FlyNNN]

Drilling the two holes is fine, if there is not already a jiggle valve hole. Just be careful where you drill the holes, not in a gasket seal area or too close to the moving piston overlap area in the center.

OK, I'll put in a couple. I'm going to use the 180. It's a MotoRad, made in Israel, seems like a clone of your Murry. I'll then change to the 192 I have in the fall (or earlier if need be). I pulled a 195 from the existing system and tested the it on the stove and ... it opened open up only about half as much as this new one. Could just be the manufacturer type, we'll see. On to the install ...

 

[Ecomike]

I pulled a 195 from the existing system and tested the it on the stove and ... it opened open up only about half as much as this new one.

That is exactly what I was expecting!!!! Sounds like it was going bad, and not completely toast, but close. Hope the new one solves the issues. Good luck.

 

[FlyNNN]

Well, the hot temp. continues and is more into the red now. I encountered something different when I followed the steps below;

If you leave the upper radiator to T-Stat housing hose connection disconnected, and hold the open hose end up high, and disconnect the small heater hose near/at the T-stat, the highest one (not the lower one), and then fill the bottle to the top, the system will bleed itself completely in minutes and actually fill the radiator. When coolant starts flowing out the small tube connection near the T-stat, reconnect the heater core hose. Then quickly reconnect the radiator hose, then fill the bottle about 50-70% full.

At the spot where you say "coolant starts flowing out the small tube connection", is this flowing out of the hose or flowing out of the hose connection on the thermostat housing? In my case the coolant started flowing out of the heater core hose and I had to stop there. Did I miss something?

I drained the rad from the petcock. Filled up my catch pan which I don't know how much it holds. I then did a 50/50 mix in a container of 3.78l(1 US gallon) and used all. So, am I 1 gallon short?

A few things I noticed;

1) took a little longer to warm up.
2) once the thermostat opened I measured some lower temp values;

head - 120, down from 128
bottle - 31, down from 42
upper rad - 90
lower rad - 48

The lower head and bottle values may have been caught early. I was not able to even take a spin around the block because of the high temp. I quickly had to shut the vehicle down because of the higher dash temp. I did not do any inspection for exhaust leaks.

 

[FlyNNN]

I drained the rad from the petcock. Filled up my catch pan which I don't know how much it holds. I then did a 50/50 mix in a container of 3.78l(1 US gallon) and used all. So, am I 1 gallon short?

I've confirmed my catch basin is about 1.5 gallons. So it looks like I'm .5 gallon short on the fill. I also noticed my overfill bottle is empty.

I await EcoMike's clarification on his fill steps as I mentioned in my previous post.

 

[bigalpha]

I don't recall seeing, but did you check for proper CTS function?

 

[Ecomike]

Well, the hot temp. continues and is more into the red now. I encountered something different when I followed the steps below;

At the spot where you say "coolant starts flowing out the small tube connection", is this flowing out of the hose or flowing out of the hose connection on the thermostat housing?

Depends on where you disconnect the heater hose, either is OK, Good.

In my case the coolant started flowing out of the heater core hose and I had to stop there. Did I miss something?

No, sounds like you did it right. BUT, from your comments, it sounds like you were, or are still a 1 to 1/2 gallon low, or more on the total fill.

You did the small heater hose trick right from the sound of it. But did you twist, elevate, and move the upper radiator hose around to try and help air escape from the radiator, and then lower the radiator hose to see coolant run out, just before reconnecting to the T-Stat housing? Keep in mind that air rises and liquid falls, density, gravity....and air can get trapped in high pockets if has no way to escape by rising. Air will not go down through liquid to escape.

One more thing to do on yours is to make sure the heater is turned on at the dash and make sure the heater hose vacuum valve does open so that the heater core fills with coolant.

Then the final trick is to keep the coolant bottle about 90% full, with the cap off while running the engine to let the bottle top off the engine block before and as the T-Stat opens. Once the T-Stat opens and the temps reach about 185-190 F then put the cap on drive it (or just run the speed up to 2500, and cycle from idle to 2500, to push the remaining air out of the block and into the bottle. Then let it cool, and then check and fill the bottle to about 60% full, as needed, and repeat till the coolant bottle level is stable.

It sounds like air from the block got back into the radiator, so I would start over on the fill process, since it sounds like it is still missing a gallon or so of coolant. The top of the radiator is a high spot, higher than the block.

I drained the rad from the petcock. Filled up my catch pan which I don't know how much it holds. I then did a 50/50 mix in a container of 3.78l(1 US gallon) and used all. So, am I 1 gallon short?

A few things I noticed;

1) took a little longer to warm up.
2) once the thermostat opened I measured some lower temp values;

head - 120, down from 128
bottle - 31, down from 42

Using the IR to measure head temps: Try and get close to the head ( the IR sees a radial circular area that grows in diameter as you get farther away from the target) and make sure you are seeing the head and not an exhaust pipe, try to stay closer to an intake pipe / head area and not near the exhaust pipe head areas when measuring the head temps. See if the readings are lower or not. You want a spot between the valve cover and intake port on the head. Also the head right under and near the T-stat is a good spot to read it.

upper rad - 90
lower rad - 48

The lower head and bottle values may have been caught early. I was not able to even take a spin around the block because of the high temp. I quickly had to shut the vehicle down because of the higher dash temp. I did not do any inspection for exhaust leaks.

On the upper, lower rad readings, did you mean drivers side and passenger sides, or what. Do you have those temps backwards if it is upper and lower? If yes, then the air that was in the block is now in the radiator, due to a lack of coolant fill the first try.

Otherwise, the bottom half of the radiator has NO FLOW, and the tubes are all blocked with crude!!!! (I had this on a Renix I bought once, needed a new radiator).

Are the tanks on your radiator plastic or metal? If metal we need the right and left side tank temps at the top, and at the bottom!!! 4 temps in all. If plastic, you need try and find spots on the core to check it. Metal areas.

 

[Ecomike]

I don't recall seeing, but did you check for proper CTS function?

He has tested the head temps with an IR gauge and they seem to confirm and match the dash gauge.

 

[FlyNNN]

I don't recall seeing, but did you check for proper CTS function?

I will hook up my Snap-On MT2500 and see what I can find.

Depends on where you disconnect the heater hose, either is OK, Good.

I only disconnected at thermostat housing.

No, sounds like you did it right. BUT, from your comments, it sounds like you were, or are still a 1 to 1/2 gallon low, or more on the total fill.

I've got a gallon of mix I'll try to get in.

Also the head right under and near the T-stat is a good spot to read it.

This is where I have been taking my measurements at close range.

On the upper, lower rad readings, did you mean drivers side and passenger sides, or what. Do you have those temps backwards if it is upper and lower? If yes, then the air that was in the block is now in the radiator, due to a lack of coolant fill the first try.

upper = passenger side, lower = drivers side. I did notice something odd that may provide another clue. When the thermostat opened up, the half of the upper rad hose had hot coolant whereas the other half close to the rad was cold and took awhile before I felt hot coolant.

Otherwise, the bottom half of the radiator has NO FLOW, and the tubes are all blocked with crude!!!! (I had this on a Renix I bought once, needed a new radiator).

Existing rad is less than 1 yr. old.

Are the tanks on your radiator plastic or metal? If metal we need the right and left side tank temps at the top, and at the bottom!!! 4 temps in all. If plastic, you need try and find spots on the core to check it. Metal areas.

Not totally sure. The petcock was plastic. There are some metal vertical rails that are visible near each of the hose connections that I target when using the IR gun.

I don't believe there is any false temperature sensor reading going on. I notice that the engine is getting extremely hot and visibly sweating and discoloration in some areas. See pictures below. I also threw in a picture of the new thermostat. Thanks again ALL for your feedback. I'll get back out into the garage and do some work.

 

[Ecomike]

OK, based on that feed back, it is either still way underfilled with coolant, and or the 1 year old radiator is clogged up badly, which can happen!!!!!

Lets get it full of coolant, for sure first. Then if the data is unchanged, try using no T-stat, then if the data is the same, either the water pump is no longer pumping (impeller came loose on the shaft? But that should make noise, and I doubt that is the case here), or the radiator got clogged up with old crud from the engine block that slowly came loose, or you have an exhaust leak that lowered the coolant pH (CO2 reacted with coolant ingredients) , and precipitated scale on the radiator tube walls killing the one year old radiator.

 

[FlyNNN]

OK, good news ... going in the right direction but not back to normal. Was able to take a good spin and it looks like I could actual drive it now ( ... and pick up some groceries, I'm getting hungry). See dash gauge below;

Here's what I encountered;

1) I didn't fully understand EcoMike's instruction and did not "disconnect the heater feed hose from the water pump" the first time around. I had disconnected the other heater hose on the thermostat housing. Then selected heat on dash and put the rear of the vehicle on ramps. Following this step I didn't have to put much coolant in before I was getting air out and finally coolant coming out from the water-pump port. I then installed the hoses, filled the coolant bottle and was able to get about 3/4 gallon in.

2) Turn vehicle on, selected heat on dash and monitor. No leaks or anything else bad. I noticed the coolant bottle heat up a lot quicker. Upper rad hose more uniformly heated up. Some temps I measured;

Coolant bottle 34
Upper rad hose 59
Top passenger side rad 60
Lower rad hose 31
Top driver side rad 29
Last coolant measurement before I went for a spin was 193F, as read from the MT2500. See picture below. As I mentioned at the top, things are better now but the engine is still running too hot as compared to before I brought it into "you know where". I'm going to go for a run now and pick up stuff! Its been a couple weeks of riding a bike.

 

[Ecomike]

Keep in mind the MT-2500 is reading the temp sensor in the lower drivers side block, tucked under the exhaust manifold. The Dash gauge reads the sensor in the top, rear, drivers side of the head!!!!

Regarding the picture below, the T-stat when closed (cold) shuts of any real air or coolant flow out the two open lines in the picture, the left one and large middle one, but the heater hose on the right side BYPASSES the T-STAT, and having it open is the KEY to getting air out of the block an getting the entire system filled, the second key is having the large upper radiator hose disconnected at the T-Stat, and the hose elevated so air can escape the top of the Renix Radiator (tie a string to it, or use a helper).

 

[Ecomike]

You may just need to top the bottle off now on a couple of drive and cool down cycles. Can't wait to see the next MT-2500 data!!!!

 

[FlyNNN]

Went for a good drive and was pleased with cruising temperatures but not so pleased with the idle temp. once I returned. The e-fan is not kicking on because that side of the rad is below the switch-on threshold. First picture is my dash while driving around 30mph. Second picture is idle temp. when I returned.

EcoMike, could you please provide clarification on some of your previous comments;

#1

If you leave the upper radiator to T-Stat housing hose connection disconnected, and hold the open hose end up high, and disconnect the small heater hose near/at the T-stat, the highest one (not the lower one), and then fill the bottle to the top, the system will bleed itself completely in minutes and actually fill the radiator. When coolant starts flowing out the small tube connection near the T-stat, reconnect the heater core hose. Then quickly reconnect the radiator hose, then fill the bottle about 50-70% full.

#2

...but the heater hose on the right side BYPASSES the T-STAT, and having it open is the KEY to getting air out of the block an getting the entire system filled, the second key is having the large upper radiator hose disconnected at the T-Stat, and the hose elevated so air can escape the top of the Renix Radiator.

#1 & #2 was the method I did the first time around. I found another thread on this site where you mention "Also, you need to disconnect the heater feed hose from the water pump, at a spot between the two, to let air out, and disconnect the upper radiator hose at the T-Stat housing then fill the bottle to the top and let it drain into the radiator and the head & block". This is what I did the second time and seemed to be more successful.

If the T-Stat is open, and you are getting those temps, then either the radiator is plugged up already, or the Water pump is not pumping like it should, or both. A new radiator and good pump should read about a 5-6 C delta T (10-12 F) , temperature differential. If the coolant flow is too slow, you get a large delta T temperature drop!!!! But not enough flow to cool the engine.

So knowing the results we now know with no known unknowns (where have I heard that before?), are we leaning towards a new rad and pump?

 

[Ecomike]

The two small hoses are both connected the the water pump, one is suction, the other is pressure. The pressure one on the drivers side bypasses the T-Stat IIRC, and the other one has passages, twists and turns in the water pump that slows or blocks the bleeding process. All I know for sure is the drivers side heater hose is the one you want open to the air to the air out easily.

Ignoring the other data, overheating at idle, and running cool while driving at a decent speed, say 30-60 mph, is usually a sign of a bad fan clutch!!!

It tends to say the radiator and pump are OK, so I am a bit puzzled now because of the idle temp data you posted, makes me suspect some kind of error in the IR measured data?

But its getting hot at idle, and cold drivers side radiator and no E-fan turning on makes me think there is a flow problem. If you have plastic tanks your radiator temp data may be no good.

Lets suspect a bad fan clutch for now and maybe a bad E-fan temp switch as the next targets!!!

I gave up on the E-fan temp switchs (bad location, late response, and it gets worse as the cooling system gets older, and HO 91 jeeps gave up on them too, went to a T-stat temp trigger....) and I went to a toggle switch, winter/summer manual selection, on mine.

I think you solved part of the problem with the new T-stat!!!!!

 

[FlyNNN]

Ignoring the other data, overheating at idle, and running cool while driving at a decent speed, say 30-60 mph, is usually a sign of a bad fan clutch!!!

It tends to say the radiator and pump are OK, so I am a bit puzzled now because of the idle temp data you posted, makes me suspect some kind of error in the IR measured data?

But its getting hot at idle, and cold drivers side radiator and no E-fan turning on makes me think there is a flow problem. If you have plastic tanks your radiator temp data may be no good.

Lets suspect a bad fan clutch for now and maybe a bad E-fan temp switch as the next targets!!!

I gave up on the E-fan temp switchs (bad location, late response, and it gets worse as the cooling system gets older, and HO 91 jeeps gave up on them too, went to a T-stat temp trigger....) and I went to a toggle switch, winter/summer manual selection, on mine.

I think you solved part of the problem with the new T-stat!!!!!

- The fan clutch was a recent replacement (as well as the thermostat) by the same shop that wanted my $3800. Seems like warranty items which I probably won't be able to recover on.

- I'll get some new IR data now that we are heading in the right direction.

- I have been pondering the manual switch option for a number of years now. Although, in this case, if that side of the rad is cool it probably wouldn't make much difference. I'll troubleshoot that sensor first and do some research on fan clutch testing.

- No, I thank you and the other members who has participated in this thread. I'm sure the title peaked everyone's interest. I'm still trying to make sense of the results and where its going and how it all started.

- The "professionals" assessed that a $3800 blown head gasket repair was necessary. With the results produced so far, do you think the blown head gasket theory is still in play?

 

[Ecomike]

Fan clutch testing is not easy. I did some testing with a large frying pan and hot water, that worked pretty well. The clutch should be easy to turn at room temp, and very hard to turn at say 80 C. The ZJ clutch (Grand Cherokee 4.0 clutch) is a better, heavy duty clutch.

You could have a small head gasket exhaust leak, but that sealer you added may have helped already. Usually that kind of leak pushes gas out of the cap. And it would tend to be much worse while driving, and not as bad at idle!!!! The resent results suggest the head gasket is OK, or is resealing.

Exhaust blowing on the block was worse at idle on mine!!!!

I have seen fan clutches that were bad out of the box since the 1970's. They can fail quickly too, so can T-stats.

A single overheat (for other reasons) can kill a good T-stat!!!!

 

[FlyNNN]

Fan clutch testing is not easy. The ZJ clutch (Grand Cherokee 4.0 clutch) is a better, heavy duty clutch.

You could have a small head gasket exhaust leak, but that sealer you added may have helped already. Usually that kind of leak pushes gas out of the cap. And it would tend to be much worse while driving, and not as bad at idle!!!! The resent results suggest the head gasket is OK, or is resealing.

Exhaust blowing on the block was worse at idle on mine!!!!

I have seen fan clutches that were bad out of the box since the 1970's. They can fail quickly too, so can T-stats.

A single overheat (for other reasons) can kill a good T-stat!!!!

Whew! ... nice to have some breathing room now.

- I thought I came across some tips during my Internet travels for testing the fan clutch. Although, getting a new one is probably no where near the $3800 bill I was faced with a couple of weeks ago. I recall people's experience's with the ZJ fan clutch not so favorable due to the excessive noise and going back to stock.

- I guess that grey mess of sealant did something then, that is good. I'll make sure to grab that nice head I see at the pick'n'pull next time.

- I'll still see if I can discover anything on the exhaust leak side of things.

- I did notice that the coolant bottle is retaining pressure and temperature much longer after shutdown that before.

- I have a theory on how this situation came to be. It's a possibility that some problem had existed prior to post #1 without my noticing. We have 6-8 months of winter here with below 32F temps. The cool outside temperatures could have keep the engine cool enough not to notice anything. Then, when one of the first warm days arrived I then went to MIDAS to get the ball rolling. It still was working fine prior to my arrival. It still over-heated in their shop. That still does not get them off the hook for how they handled the situation once it played out, and is still playing out. Just a theory.

 

[Ecomike]

I think there are a lot more of us using the ZJ clutch, and being happy with it, then those that were not. Some of the ones with problems had the thicker one and a three row radiator, and engine mount issues, and the combo had the clutch hitting the radiator. My 87 has the hayden brand which is 1/4" less tall, and gives we a 1/4" gap to my three row radiator.

I doubt you have a thick radiator?

Installation is a little more work.

Just for fun, try a run around the block with the old bottle cap, and see how much the new bottle cap helped (versus just the new T-Stat).

 

[Ecomike]

Check out the last 3 posts, mirror with string!!! For finding an exhaust leak!!

http://www.naxja.org/forum/showthread.php?t=1100194

 

[FlyNNN]

I think there are a lot more of us using the ZJ clutch, and being happy with it, then those that were not. Some of the ones with problems had the thicker one and a three row radiator, and engine mount issues, and the combo had the clutch hitting the radiator. My 87 has the hayden brand which is 1/4" less tall, and gives we a 1/4" gap to my three row radiator.

I doubt you have a thick radiator?

Just for fun, try a run around the block with the old bottle cap, and see how much the new bottle cap helped (versus just the new T-Stat).

- This thread has covered a few topics and now we are on to the ZJ clutch which has a lot of coverage already. I'll have to start to get up to speed on this topic. Can you use the stock fan with the ZJ clutch?

- I don't know whether my rad is thick or thin, I don't have anything to compare with.

- The jeep stayed in the garage today. Tomorrow I'll go out and I'll put back on the original rad cap and get some new measurements.