MIDAS blew up my Jeep ...

There is nothing Midas did to make your head gasket fail by putting on a cat-back(as much as I'd expect to see another incompetence thread). Some other condition/malady reared it's head at a coincidental time. Maybe the aux fan isn't working so a no moving idle caused it to overheat(not their fault). Look up the higher psi Volvo cap p/n and buy it.
 
gradon said:
There is nothing Midas did to make your head gasket fail by putting on a cat-back(as much as I'd expect to see another incompetence thread). Some other condition/malady reared it's head at a coincidental time. Maybe the aux fan isn't working so a no moving idle caused it to overheat(not their fault). Look up the higher psi Volvo cap p/n and buy it.
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I think he has a metal bottle with a standard radiator cap. I already suggested he change it to at least 16 lbs, or test the one he has with a pressure tester, but I get the impression he is not listening.

A totally blocked exhaust will not damage a head gasket. It will simply kill the engine.

Overheating can damage the head gasket, but that takes a complete meltdown and loss of coolant and further running of the engine with no coolant to do that.
 
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FlyNNN said:
A local NAPA has something similar for $23. I've got to get on a bike and get over there before they close.
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It is about $4 in Houston. Do prices go up exponentially as you head northeast from Houston?

I doubt you need a new head, just a new head gasket, the set is about $50 in the US. Includes the intake-exhaust manifold and throttle body gaskets too IIRC, and new valve stem seals. Just get a machine shop to clean and test the old head. Unless the head is a 99-01 head, they rarely crack.

This is a Renix Jeep IIRC.

If you have a real head gasket leak into the coolant, I strongly recommend changing the coolant (use 50/50 green silicate based old style antifreeze/DI water) since the CO2 from the exhaust may lowered the pH of the antifreeze to the point where silcates precipitate as boiler scale on the inside of the radiator and engine block!!!!

Change the coolant before adding the bars leaks!!!!
 
Ecomike said:
I think he has a metal bottle with a standard radiator cap. I already suggested he change it to at least 16 lbs, or test the one he has with a pressure tester, but I get the impression he is not listening.
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I am listening. Thats why I am hear is to listen to the wisdom that may be imparted. I am your eyes and ears into this little corner of the world.

A clarification is required. When I say "overheat", I mean anything above normal. Normal for me is 100. I guess I should say HOT. It appears your definition is different and a meltdown condition would be coolant temperature pinned to right and coolant overflow. I have not let it get into a meltdown condition but it is there if I let it. So any references to cap pressure is not relevant in this situation.

jeeprunninghot2.jpg


Could not find Bar Leak around here but NAPA recommended this stuff for $23;

headseal.jpg


And here's what I had for dinner on the way back, $3 CAN. Good day for a bike ride and a Klondike.

dinnern.jpg


While I was NAPA, I checked on the head gasket set and it was $120. No head bolt set was found, is this mandatory?

I am now going out to the garage and use some of this wisdom I have gleamed here today.
 
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It's the 00-01 head actually - I've never heard of a 99 head being problematic, except very rare cases probably stemming from abuse.

FlyNNN, that gauge cluster was a trip for me until I remembered you guys talk in Centigrade.
 
Kingkong0192 said:
Did you just update that? Care to explain the flaw in the 99 head? Are you referring to the 0630 or the 0331 head in the 99s?

You probably remember my 99 0630 head cracking, and i'm rather curious on your explanation behind it.
Click to expand...

The only threads I have seen and read that had a confirmed cracked head, was a 99, 00, 01 year head. Most were 0331 heads. I have never heard any one here replacing a cracked Renix head. Head gasket, yes, head, no.

I am not sure what that leak sealer is they sold you, or what is in it. The products on the market vary a lot, and some can do more harm than good, especially if you do not use it right!!! The dry pellets from bars leaks, I have never seen damage or plug up a system. In fact OEMS used them on all new cars for about 75 years!!!!

Some of the heavy duty sealers can replace one problem with another, so read the label carefully, post us a link to the product formula and instructions on line if possible.

What I am trying to tell you on the radiator cap, is that if the cap will not hold peak pressure, it can cause higher running temps. It may not leak liquid, yet, but it also needs to seal in the gas in the bottle as well on a renix, or operating temps will climb!!!!!

On an open system the cap is deisgned to bleed liquid back and forth, on the Renix Closed system the bottle-and cap MUST BE AIR TIGHT as well as liquid tight. If the cap leaks any air at say 10-13 lbs, the gauge temp will rise!!!! It may leak gas till it hits 245 F, then say at 250 F start leaking liquid finally, just it starts to boil over.
 
So looking at where Edminton is on a map and where I usually am on a map, I'll happily drive you up a new engine for all the sceptre MFCs I can carry home :)

But anways, looking through the thread, I think EcoMike is probably going in the right direction. Typically, the sign I look for in a blown head gasket is coolant in the oil, or oil in the coolant. However, no matter what even running for 5 minutes you should not be seeing such a dramatic rise in temperature.

Out of curiosity do you have an IR thermometer? I've spent hours chasing down gremlins in cooling systems only to find out it was a bum temp sensor. However, I have very little faith in the skill or honesty of most chain auto service places. Most places I take my car I watch them like a hawk, usually to make sure they're performing the required service to my satisfaction, however this also gives me pause to see if they're up to no good.

On a side-note, doing work on the head was a big step for me the first time I did it also, however while it's a greasy and somewhat confusing job, it's not as difficult as it sounds, and if you're serious about it, a total rebuild isn't too far away from a head swap. But when it comes to such things, I'm really lazy, and like to just pull the motor out of the car. I'm getting ready to take on a full rebuild in the next few months on a spare motor I just got. (1990 XJ Renix)
 
Ecomike said:
I am not sure what that leak sealer is they sold you, or what is in it. The products on the market vary a lot, and some can do more harm than good, especially if you do not use it right!!! ...Some of the heavy duty sealers can replace one problem with another, so read the label carefully, post us a link to the product formula and instructions on line if possible.

What I am trying to tell you on the radiator cap, is that if the cap will not hold peak pressure, it can cause higher running temps. It may not leak liquid, yet, but it also needs to seal in the gas in the bottle as well on a renix, or operating temps will climb!!!!!

On an open system the cap is deisgned to bleed liquid back and forth, on the Renix Closed system the bottle-and cap MUST BE AIR TIGHT as well as liquid tight. If the cap leaks any air at say 10-13 lbs, the gauge temp will rise!!!! It may leak gas till it hits 245 F, then say at 250 F start leaking liquid finally, just it starts to boil over.
Click to expand...

Thanks for your feedback Ecomike. The leak sealer I used was recommended and I went with it. See link for details;
http://www.irontite.com/store/index.php?main_page=product_info&cPath=1&products_id=2

I added the sealer this evening. I did not replace the existing coolant. I may pick up some of the green silicate based old style antifreeze you suggested tomorrow. How many bottles do I need? I've never flushed the coolant on this RENIX so it looks like it will be another first.

I idled the engine for about 15 minutes and did not see any change in symptoms. I drove around the block and the needle was in the middle red already. See picture below;
jeeprunninghot3.jpg


Regarding the radiator cap on my bottle, it is rated @ 16lbs. Thanks for additional explanation. It does not leak any coolant and appears to be air tight as well. Could it still be bad?

djgrayxj said:
Note from DJ I suggest you add a Vacuum gage to your tool collection and post what you observe. We may get some ideas from what the needle is doing.
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I do not have a vacuum gauge and was unaware of the troubleshooting capabilites. I will keep this in mind but will initially follow up with some of the other suggestions first.


BulletMaker said:
So looking at where Edminton is on a map and where I usually am on a map, I'll happily drive you up a new engine for all the sceptre MFCs I can carry home

But anways, looking through the thread, I think EcoMike is probably going in the right direction. Typically, the sign I look for in a blown head gasket is coolant in the oil, or oil in the coolant. However, no matter what even running for 5 minutes you should not be seeing such a dramatic rise in temperature.

Out of curiosity do you have an IR thermometer? I've spent hours chasing down gremlins in cooling systems only to find out it was a bum temp sensor.
Click to expand...

Yes, I am located in Edmonton, 500 miles north of Montana. Whats the deal on sceptre MFCs??

Regarding discoloration, the coolant did not look milky. I'll take a look at the oil tomorrow. The temperature only starts to go above normal once the thermostat opens. I did take out the IR thermometer and measured 85c on the passenger side rad, 38c on the driver side of the rad. I was monitoring the e-fan as well and it was behaving normally as mentioned earlier by "gradon".

I thought about a "bum sensor". I may have one around here, I'll have to check. The readings don't appear to be erratic. How could the IR thermometer check that?

I also have a Snap-On MT2500 that I have not hooked up since this problem started. I'll hook that up tomorrow as well and see what I find with that.

This really is a two headed beast thread; 1) being whether MIDAS has any culpability and 2) how to resolve the problem without spending $3800. I appreciate everyone's participation.
 
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Shoot the IR gun at the thermostat housing and then compare what it says with what the jeep says.

Have you a compression tester? I bought mine for $24 and it works a world of wonder. I also built a home made leaks down tester but a compression tester should be able to point you in the right direction as whether you have an internal engine problem or a sensor problem.

I just did a head job in my 99. Cost me about $550 for everything. I did all the work.
 
Kingkong0192 said:
Shoot the IR gun at the thermostat housing and then compare what it says with what the jeep says.
Have you a compression tester? I bought mine for $24 and it works a world of wonder. I also built a home made leaks down tester but a compression tester should be able to point you in the right direction as whether you have an internal engine problem or a sensor problem.
I just did a head job in my 99. Cost me about $550 for everything. I did all the work.
Click to expand...

OK, I can shoot the thermostat housing. No compression tester here. I'll add it to the list.

I have an idea that I would like to run by everyone here. How about disconnecting the exhaust and getting results. Can this be done for testing results and is safe for the engine? Instead of trying to troubleshoot the myriad number of things that can go wrong on the engine side of things, how about eliminating the thing that has caused the problem in the first place?
 
FlyNNN said:
I may pick up some of the green silicate based old style antifreeze you suggested tomorrow. How many bottles do I need? I've never flushed the coolant on this RENIX so it looks like it will be another first.

Regarding the radiator cap on my bottle...... Could it still be bad?


The temperature only starts to go above normal once the thermostat opens. I did take out the IR thermometer and measured 85c on the passenger side rad, 38c on the driver side of the rad. I was monitoring the e-fan as well and it was behaving normally as mentioned earlier by "gradon".

I thought about a "bum sensor". I may have one around here, I'll have to check. The readings don't appear to be erratic. How could the IR thermometer check that?
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1) One gallon of the pure antifreeze, and one gallon of DI water (mixed 50/50) is almost enough to fill the system. It depends on where and how you drain the system. I think it is 3 gallons tops, maybe 2.5 gallons to fill the entire system. May vary a little between aftermarket radiators. Down here most of the stores are pushing pre mixed, pre diluted 50/50 blends ready to use.

2) I thought you said earlier the radiator and water pump.... etc., were all new? Was the coolant reused? I am a little confused on your saying you have not changed the coolant before?

3) Yes the cap could be weak (thus bad). I had to finally buy a cap / radiator pressure tester (Most stores down here rent them), and I went through about 5 brand new caps all labeled 16 lbs at the store counter, testing each cap in their inventory, and 4 of them tested at 8-13 lbs before they leaked air, only one held till 15.5 lbs, and they were all labeled 16 lbs!!!:lecture:

4) How do you know what the coolant bottle liquid level is?

5) Renix plumbing is nearly impossible to get the radiator full. Norman fill methods leave the radiator half full of air at the top, as it has no exit. The upper radiator hose is convoluted in such a way that it acts like a plumbing P trap, that blocks the exit of air out the end of the hose. There is a trick to getting the air out. Ask for the tick later when you are ready.

6) I am concerned about the T-stat data you posted,

I did take out the IR thermometer and measured 85c on the passenger side rad, 38c on the driver side of the rad.
Click to expand...

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.

Also, the Renix E-fan is turned on by a temp switch in the cold side of the Radiator, so if the flow is blocked it comes on too late (never really sees the engine temp), and even when on, the coolant flow is too slow....The 91 HO Jeeps moved the fan switch temp sensor to the T-Stat housing and solved that problem.

The IR can verify the head temperature where the Gauge sensor is located, on the rear of the head, passenger side near the fire wall.

Use the IR tester to verify the top of the radiator temp, the lower inlet and outlet tank temps, and the head near the rear temp sensor, and the T-Stat housing temps, all with the T-Stat open, and post them up here!!

Verify the head temps near the head sensor and the T-stat temps versus the dash gauge for sure next!!!! Make sure there is a problem.

I will be back online in about 90 minutes. Gotta run.
 
Thank you Ecomike for the checklist. Answers to your questions;

2) I thought you said earlier the radiator and water pump.... etc., were all new? Was the coolant reused? I am a little confused on your saying you have not changed the coolant before?
I've always ended up getting some shop to do it for me. New stuff, just not put in by me. My bad.


4) How do you know what the coolant bottle liquid level is?
Cap off, visual inspection.


5) Renix plumbing is nearly impossible to get the radiator full. Norman fill methods leave the radiator half full of air at the top, as it has no exit. The upper radiator hose is convoluted in such a way that it acts like a plumbing P trap, that blocks the exit of air out the end of the hose. There is a trick to getting the air out. Ask for the tick later when you are ready.
I thought I knew what the trick was; nose down, remove coolant temp sensor at back of head. As I mentioned before, there is a lot of bubbling going on in the coolant bottle prior to the thermostat opening.


6) I am concerned about the T-stat data you posted, 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.
Makes sense to me. I've thought along those lines but due to lack of experience not confident in taking decisive action. I've noticed that when the thermostat opens, the upper rad hose does not feel like there is a strong coolant flow. For some reason, I have been thinking water pump not pumping as strong as it should.


The IR can verify the head temperature where the Gauge sensor is located, on the rear of the head, passenger side near the fire wall.
Drivers side, correct? 1990 RENIX.


Use the IR tester to verify the top of the radiator temp, the lower inlet and outlet tank temps, and the head near the rear temp sensor, and the T-Stat housing temps, all with the T-Stat open, and post them up here!!
Verify the head temps near the head sensor and the T-stat temps versus the dash gauge for sure next!!!! Make sure there is a problem.
I'll get some temp data for this afternoon.

BTW, I called up MIDAS (most likely for the last time) and asked about the exhaust disconnect idea I had ... they blew me off. I truly believed in the cause/effort scenario but I appear to be beating a dead horse. On with the engine troubleshooting ...


 
When you're checking with the IR thermometer, you want to check the area where the temp sensor is (see if it's reading correctly) then check the T-stat housing, and then check the input area of the radiator, and then the outflow portion of the radiator (bottom drivers side).

These 4 numbers should tell you 1) if your sensor is reading correctly 2) if your T-stat is opening at the right temp 3) if your radiator is getting flow and 4) if your radiator is actually cooling the water.

Also, since it sounds like you don't do a lot of maintenance yourself, you probably want to maintain a higher antifreeze/water ratio, this antifreeze mix this will keep your block from freezing solid in the winter months, knowing how cold it can get that far north, I would recommend this. Typical renix radiator capacity is about 2-2.5gals. To get this mix, if you did 1.5gal of antifreeze and add another gallon of Deionized water you should be at about 60% mix which should provide freeze protection down to -52C for ethylene glycol AF (the green stuff). For the pink stuff you're down to -48C.

Another thing you want to think about is opening the radiator cap (when engine is cold) and turning it on, waft the gasses coming out of the bottle and smell for exhaust or gasoline fumes.

Let us know how that oil comes out looking, as that's the surest sign of a bad head gasket in my opinion. Also, I don't remember if you stated what the current coolant level is, do you see it in the bottle? (or when you open the cap) I think that's the one downside to having the nicer bottle.

Also, the Sceptre MFC's I was talking about are these http://www.sceptermilitary.com/fuel_containers/ Can't really get them here in the states because of EPA regs. was thinking about driving up to canada, slapping a "water" label on them, filling each with water and then driving back. The ones you can get are usually military surplus, which means they are trashed, usually having had engine oil or some other nastiness put in them prior to surplusing.
 
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Yes, the driver's side.

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.

The method you have read, works on the HO 91-01, but is a waste of time on the Renix.

The gas you are seeing in the bottle with the engine running is normal at elevated rpms, like 2000 to 3500 rpm, in fact is major bubbling.

A little bubbling is also normal at idle, but just a little. A lot of bubbling at idle may indeed be a head gasket leak. Has to do with the way it is plumbed up on Renix, 87-90.

Bulletmaker is right about upping the antifreeze ratio for your part of the world, unless global warming has solved that problem, LOL!!!!!!

FlyNNN said:
5) Renix plumbing is nearly impossible to get the radiator full. Norman fill methods leave the radiator half full of air at the top, as it has no exit. The upper radiator hose is convoluted in such a way that it acts like a plumbing P trap, that blocks the exit of air out the end of the hose. There is a trick to getting the air out. Ask for the tick later when you are ready.
I thought I knew what the trick was; nose down, remove coolant temp sensor at back of head. As I mentioned before, there is a lot of bubbling going on in the coolant bottle prior to the thermostat opening.

The IR can verify the head temperature where the Gauge sensor is located, on the rear of the head, passenger side near the fire wall.
Drivers side, correct? 1990 RENIX.
Click to expand...
 
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MSDS on the Ironite product you used is here:

http://www.irontite.com/msds/index.php

It is antifreeze (5-10% ethylene glycol) mixed with 5-10% Borax. I have no experience with that stuff, so I can not recommend it. It IS NOT the product I suggested, nor does it seem to even be similar!!!!

The product I recommended is 100% natural fibers, that seeks out leaks and gathers at the leak site to reform the fiber head gasket at the leak point!!!!

Borax probably reacts with the silicate in antifreeze to form a borosilicate glass seal at the leak sight, but I have no idea what drawbacks it may have, ie. possible nasty side effects.
 
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