Ghosts and Goblins got my MJ 4.0 on Halloween, now what??

[89MJComanche]

Well, the ghost and the goblins of halloween got to my MJ last night.

 

I stopped off to meet my fiance for dinner in Mt. Pleasant PA at Leo's Rt31 Grille, and everything was just fine. I got in the MJ to drive the 9 miles from there to our home after being at the resturant for well over 2 hrs and it over heated on the way home. I think that I only drove about 1 mile after the heater quit blowing hot air so I had some other kind of internal failure.

 

After it steamed over, and all steam had stopped, the engine was still hot as hell.

 

I'm going to thank the IDIOT LIGHT Dash for this one, as the lights never, and still have not come on to indiacate any problems.

 

I can't junk this MJ because it is so clean and because I have replaced nearly everything else on it. It only has 60,000 origional miles. I also just sold 2 perfectly fine 4.0 HO engines to others from this forum for way less than I am going to have to spend to solve my own problem now.

 

Here is what I want to do.

 

I want to get a new cerfitied remanufactured engine installed with a Warranty of many years and many thousands of miles.

 

I'd like to convert the old no HO engine over to a HO setup with a 1999 intake manifold and Gale Banks Tube for similar engine. I have intake manifold already with a set of good injectors in it.

 

I'm not a 4.0 engine expert but I know that there were some differences between the 1987-1990 Renix deals and the 1991-1999 vintage HO and later model HO, before the distrubitorless ignition changes in 2000.

 

I need to get a motor put in this ASAP by some one reputable who can solve these issues and give me back a fresh powerhouse in this great little MJ. Radiator and other engine peripherals were recently replaced or rebuilt so I don't think that much other stuff will need to be source.

 

Budget, as low as possible, and prefer not to be over $1800. I'd do a used HO swap, if only I had one of the two good (that I drove) low mileage engines that I have sold for pennys on the dollar of what it is going to cost me to repair/replace this problem

 

Anyone suggest anyone that can help me?

 

Here are the symptoms. Ran real freaking hot, heater was burning up inside, inside heater went cold indicating low fluid for a mile or two, then got hot again. Then it steamed over under the hood, still running, I stopped and let it cool down. It completly boiled out of steam and was still HOT HOT HOT. It blew a bolt off the front of the manifold, and it blew out a few chunks of manifold gasket.

 

Now it starts, runs, sounds good, and idles fine. Take it for a 1 or 2 mile spin around the block and it pushes tons of boiled over fluid out the overflow (1987 with open system conversion, right now with no over flow bottle) I don't have any crank case foam, but I do have steam venting from the top/under the valve cover.

 

I need a 4.0 expert who knows which model year of engine to order for the swap to get the HO thing right, or some one who is not going to waste my time with trying this and that without it working right.

 

What should I do??

 

Next I'm going to pull the Thermostat out and fill it back up with fluid and see how it runs after that??

 

AMS

[Pete M]

Sounds like you're cooling system needs some TLC. Do you have access to an infrared temperature gun? And a swap to a full gauge cluster sounds like a good idea too.

[FxRacing282]

sounds to me like a t-stat is what you need. the water pump does not make noise correct?

[89MJComanche]

sounds to me like a t-stat is what you need. the water pump does not make noise correct?

 

Water pump no noise.

 

I did not pull the T-Stat yet. I'm going to pull it first thing in the morning when I can get some housing sealer. Anyone think that I can make a gasket with a bisquick box for the housing so that I don't have to buy one to test the T-stat?

 

I doubt that it is the problem, but I guess anything is worth a shot.

 

It starts and idles fine, and sounds normal, it takes about five min to get really hot past the point where it can't hold the extra fluid when it pushes the spring on the cap out to leak.

 

Head Gasket exterior on passengers side is not leaking any oil or appear to be bad, manifold gasket is toast, and one manifold bolt, front lower is broken off from the over heat.

[Catatonic Comanche]

I am not convinced that you need to spend $1.8K on a replacement 4.0 to stay on the road. Spend about $100-$200 on your cooling system instead! The H.O. can wait aboutten more years when you will REALLY n eed a replacement 4.0.

 

Sorry that this experience interefered with your night out with the significant other...that part sucks...

 

V/R

 

:cheers:

 

Paul

[aerocorey]

Anyone think that I can make a gasket with a bisquick box for the housing so that I don't have to buy one to test the T-stat?

 

You can buy cheap blank sheets of gasket material to cut your own gaskets from. Seriously, though, t-stat gaskets are like $2. :roll: You're willing to spend $1800 on an engine, but not $2 on a gasket?

 

Pressurization is the key to cooling system. You have to figure out where yours lost its pressure. You say when you drive it now boiling coolant runs out of the overflow bottle. Did you top the cooling system off after it overheated? If you did, and it's still bubbling out of the overflow, your radiator cap probably failed and caused this whole mess. I'd try that before a t-stat, or possibly both at the same time since a new radiator cap, a new stat, and a gasket will only be like $25. The trouble is when it overheated and blew out your intake gasket it made more pressure leaks. What's the bolt that came out of the intake go to? If it got hot enough to spit a bolt out and blew out the intake gasket I'd be worried about every gasket in the system (including the head gasket), and possibly the condition of the intake manifold (is the mating surface warped?). I'd take a deep breath, hold off on the new engine, and roll up my sleeves. Pull the intake off, replace the gasket, and put on a new intake if you can't verify the straightness of the current one. Replace the stat and the radiator cap. Replace all of your hoses, and clean the fittings before installing the new hoses. Do a pressure test and see if you're losing pressure anywhere. If it passes a pressure test you're probably good from there, but check your coolant level regularly and be vigiliant about coolant in the oil. It might not be a bad idea to run a compression test. I don't see you spending more than $200 on this. Good luck. When it's back on the road you can spend the $1600 you have left over on a lift kit and then break more stuff!

[Wildman]

OK......I read your story, twice, and the way I'm reading it........your going to junk a 4.0 engine that has 60k on the clock, because it over heated? :huh???:

 

Yes, I read that you replaced the radiator, and other items, but how do you know that you just didn't blow a heater hose or the expansion tank, some thing simple, and now think you need to install a HO with the '99 intake :???:

 

Unless your 4.0 was really neglected over the years, I wouldn't think that the internals would just crap out and cause you to steam over. Yes, it's possible, but take a step back and start checking and doing some diagnostic what the problem could be. Like a compression check, and ever do a cooling system pressure check. It could be just a bad head gasket that's causing your problem.

 

I've boiled out my coolant on my Ford 351W several times, blown hose, water pump implosion, 3 year old radiator letting loose. Old radiator exploding going up a "hill" in West Virgina. Red lined the temp gauge, and as of the past week, it turn 265K on the clock. And this is pushing 11k+ pounds down the road every day :yes:

 

It just sounds like you want to upgrade to an HO 4.0, so go for that, and re-wire the complete truck, and make all the changes that are needed for the HO to work. And that is a LOT of work to make it click.

 

I want to get a new cerfitied remanufactured engine installed with a Warranty of many years and many thousands of miles.

 

The only one I can think of is Jasper, unless someone else had a better source.

 

I think the guys here that are pushing 300K on there 4.0 would have your problem :doh:

 

Anyone think that I can make a gasket with a bisquick box for the housing so that I don't have to buy one to test the T-stat?

 

I think it would be better to spent the 57 cents and get the proper thermostat housing gasket :roll:

 

It might be better to step back and check what you have now, solve the cooling problem, or as your story goes, spent about $5K to make the conversion to what you think you need, and run this MJ for another 30 years ;)

 

Oh.......and unless you have some old spirits living in your 4.0, I don't think the ghosts and goblins got to your cooling system :shake:

[89MJComanche]

 

You can buy cheap blank sheets of gasket material to cut your own gaskets from. Seriously, though, t-stat gaskets are like $2. :roll: You're willing to spend $1800 on an engine, but not $2 on a gasket?

 

I made the statement about the bisquick box because it is 22 miles from my house up here in the mountains to the autoparts store and I was thinking about pulling the T-Stat and putting the housing back on as a test measure to see if it still boils over.

 

Pressurization is the key to cooling system. You have to figure out where yours lost its pressure. You say when you drive it now boiling coolant runs out of the overflow bottle. Did you top the cooling system off after it overheated? If you did, and it's still bubbling out of the overflow, your radiator cap probably failed and caused this whole mess. I'd try that before a t-stat, or possibly both at the same time since a new radiator cap, a new stat, and a gasket will only be like $25. The trouble is when it overheated and blew out your intake gasket it made more pressure leaks. What's the bolt that came out of the intake go to? If it got hot enough to spit a bolt out and blew out the intake gasket I'd be worried about every gasket in the system (including the head gasket), and possibly the condition of the intake manifold (is the mating surface warped?). I'd take a deep breath, hold off on the new engine, and roll up my sleeves. Pull the intake off, replace the gasket, and put on a new intake if you can't verify the straightness of the current one. Replace the stat and the radiator cap. Replace all of your hoses, and clean the fittings before installing the new hoses. Do a pressure test and see if you're losing pressure anywhere. If it passes a pressure test you're probably good from there, but check your coolant level regularly and be vigiliant about coolant in the oil. It might not be a bad idea to run a compression test. I don't see you spending more than $200 on this. Good luck. When it's back on the road you can spend the $1600 you have left over on a lift kit and then break more stuff!

 

All good suggestions in your post thanks.

 

I know that I have steam leaking from my valve cover gasket and oil filler, and from along the manifold which tells me that the head is either cracked or gasket blown out.

 

I know that you can overheat a 4.0 something fierce and not damge it, I have overheated a few in my sig and have never blown one up to the point that it would not run to propel the Jeep at least across a parking lot. This time however is definatly the hottest I have ever gotten one.

[mvusse]

Did I read correctly you converted to cooling system to an open system without an overflow bottle?

 

Then if your radiator is full, and the engine warms up you push coolant past the cap onto the pavement. As it cools back down, it will suck in air to replace the extra volume. Now you have air in the system, which can cause cooling issues, especially if you end up with air trapped in the water pump, causing it to not move the coolant.

 

Not your current problem, but might have been the cause of it.

[aerocorey]

Did I read correctly you converted to cooling system to an open system without an overflow bottle?

 

Ooh, good catch. I missed that too. If there's no bottle that's absolutely a recipie for disaster.

 

If you've got steam coming out of your valve cover and oil fliter your head gasket is toast. Your cooling system is boiling over into your oil. Stop running the engine. Drain the oil and see if it looks like chocolate milk. I wouldn't jump at a cracked head or block just yet. Get a head gasket kit and all the stuff mentioned previously and go to work. Run a pressure test and cross your fingers.

[89MJComanche]

Did I read correctly you converted to cooling system to an open system without an overflow bottle?

 

Then if your radiator is full, and the engine warms up you push coolant past the cap onto the pavement. As it cools back down, it will suck in air to replace the extra volume. Now you have air in the system, which can cause cooling issues, especially if you end up with air trapped in the water pump, causing it to not move the coolant.

 

Not your current problem, but might have been the cause of it.

 

I had the overflow bottle on there... The overflow bottle plastic cap (newer style HO overflowbottle) It does not have one right now because the steam toasted it the other night. Melted like a chocolate drop on hot asphalt.

[89MJComanche]

OK UPDATE AT 11:00 AM TODAY.

 

Went to Autoparts Store to get Water Pump, Thermostat, Gaskets, Coolant and other stuff to try to solve my immediate problem of no driveability and sevear overheating problem.

 

I pulled the thermostat completly out, and re-installed the gooseneck thermostat cover without a thermostat behind it. I filled the system with water and went for about a five mile drive pushing the motor on a 2 lane highway. It did not overheat (and it did not push any water out of the overflow hose that is not connected to anything right now) The heater inside of the Jeep stayed luke warm the whole time.

 

It is sitting outside at idle right now.

 

I'm getting some leakage around the Thermostat Gooseneck Cover (from the quick RTV seal job to test it) and I am getting some seeping (sizziling) along the manifold/head area that can be seen from the top. It looks more like oil vapor now there than white steam. Of course with no T-Stat I'm probably running at what ? 160?

 

I'm going to drive the 60 miles home with it like this and use my inside heater as a monitor of the heat issue (since I have idiot lights) if it gets too hot, or completly cold, I'll stop and either refill the system or let it cool down and start over again.

 

I'm not 100% confident that replacement of the water pump, T-Stat, and fluid is going to solve this problem because I don't kow if the engine is going to be able to run at 220 like it is supposed to without pushing steam past blown gaskets.

 

Still no foam in engine oil under valve cover or on Dipstick. I'll change the oil in her as soon as I get home today.

 

I guess that in many ways this engine is probably not quite as toated as I thought the other night, but still overheating engough to break of a manifold bolt is HOT HOT HOT!!

 

If I paid for a Head Gasket, Valve Cover Gasket, Manifold Gasket job, anyone think that it would be wise to just get the oil pan pulled and DEGUNK anything else and go back with all new gaskets?

 

Also if I do that? can I do a simple swap to a 1999 intake manifold without major mods to this renix engine?

 

And last thing, PLEASE SOME ONE FIND ME AN AUTOMATIC COLUMN SHIF RENIX GAUGE CLUSTER>

[FxRacing282]

okay. older cars and trucks didnt have an over flow bottle. so that is ka-put. I'm pretty sure you need to do a head gasket. you oculd be warped to make sure. a 4.0 is allowed .006 of an inch of warpage. you can check this with a known accurate straightedge and a feeler guage. Hopefully its not warped.

the other problem. as i have learned from all the awesome guys on here and in school is that when you run an engine with no t-stat. it will most likely never heat up. and its gonna run like crap. you can get a rad. cap at autozone or vip or whatever that has a temp guage on the top of it for like $15. ive always wanted one but can't justify spending $15 on a cap. for you it may be a good idea.

[Pete M]

For what it's worth, my 4.0 has overheated 3 times now (2 of them very badly) and did not damage the head gasket.

[wolfpackjeeper]

actually, you will run hotter with no thermostat. the coolant flows too fast and does not stay in the radiator long enough to lose any heat.

 

i read it as a thermo that failed with catastrophic results. pull the head and replace the gasket. If the head is cracked, you could replace it with an HO head and manifolds, but there is a bit of work there as well. You would either need to convert the wiring over and use the new TB, or by an adapter to use the renix TB. Replace the thermo, and change the oil and coolant.

[Redramman]

:agree: with MVUSSE. Actualy all the posts you got are good advice but don't over look the simple things,and be sure to fix the manifold bolt and gasket that was damage from air pocket/low coolant causing an extra hot area.Do you have a preasure-vacume type radiator cap?you need this with overflow jug.

[HOrnbrod]

And last thing, PLEASE SOME ONE FIND ME AN AUTOMATIC COLUMN SHIF RENIX GAUGE CLUSTER>

 

I do not think Renix era full gauge clusters w. the auto shift indicator exist. They were in the some of the XJ Police Package models, but these didn't start until 1992 (electronic speedo). If the only reason you don't swap a full gauge cluster in is because of no shift indicator, you can do something like this. Works just fine.

 

[mvusse]

actually, you will run hotter with no thermostat. the coolant flows too fast and does not stay in the radiator long enough to lose any heat.

 

Urban myth.

 

Yes, it flows through the radiator faster, theoretically droping the temperature of the coolant less. But since it is dropping the temperature of more coolant per any amount of time, it is actually transferring more heat to the air, making the system more efficient.

 

Also, the coolant also flows through the engine faster, which again, won't increase the temperature as much, while transferring more heat per unit time.

 

the only reason to limit water pump capacity is to limit the amount of HP used by it, which will lower your mileage.

 

If I run hotter without a thermostat, then why did every car i have ever owned with a temperature gauge, in which I have temporarily ran without a thermostat for various reasons ran cooler then with. To the point of hardly having any warm air from the heater, and me being able to hold coolant hoses or radiator indefinitely without burning myself.

 

79 Ford F100: 195 thermostat between 190 and 205. Without thermostat between 150 and 160.

91 Geo Prizm: 195 thermostat up to 195. up to 210 in hot weather stop and go with A/C blowing. Without thermostat ~120.

94 Suburban: 195 thermostat between 185 and 205. Without thermostat between 160 and 165

87 Comanche: 195 thermostat between 190 and 210. Without thermostat between 150 and 165.

 

Also had an 84 Olds 98, an 82 LeBaron and an 81 Caprice. Never ran the Olds without a thermostat and the other two had idiot lights.

 

My data does not support the flawed theory.

[FxRacing282]

actually, you will run hotter with no thermostat. the coolant flows too fast and does not stay in the radiator long enough to lose any heat.

 

Urban myth.

 

Yes, it flows through the radiator faster, theoretically droping the temperature of the coolant less. But since it is dropping the temperature of more coolant per any amount of time, it is actually transferring more heat to the air, making the system more efficient.

 

Also, the coolant also flows through the engine faster, which again, won't increase the temperature as much, while transferring more heat per unit time.

 

the only reason to limit water pump capacity is to limit the amount of HP used by it, which will lower your mileage.

 

If I run hotter without a thermostat, then why did every car i have ever owned with a temperature gauge, in which I have temporarily ran without a thermostat for various reasons ran cooler then with. To the point of hardly having any warm air from the heater, and me being able to hold coolant hoses or radiator indefinitely without burning myself.

 

79 Ford F100: 195 thermostat between 190 and 205. Without thermostat between 150 and 160.

91 Geo Prizm: 195 thermostat up to 195. up to 210 in hot weather stop and go with A/C blowing. Without thermostat ~120.

94 Suburban: 195 thermostat between 185 and 205. Without thermostat between 160 and 165

87 Comanche: 195 thermostat between 190 and 210. Without thermostat between 150 and 165.

 

Also had an 84 Olds 98, an 82 LeBaron and an 81 Caprice. Never ran the Olds without a thermostat and the other two had idiot lights.

 

My data does not support the flawed theory.

:smart: :clapping:

[wolfpackjeeper]

actually, you will run hotter with no thermostat. the coolant flows too fast and does not stay in the radiator long enough to lose any heat.

 

Urban myth.

 

Yes, it flows through the radiator faster, theoretically droping the temperature of the coolant less. But since it is dropping the temperature of more coolant per any amount of time, it is actually transferring more heat to the air, making the system more efficient.

 

Also, the coolant also flows through the engine faster, which again, won't increase the temperature as much, while transferring more heat per unit time.

 

the only reason to limit water pump capacity is to limit the amount of HP used by it, which will lower your mileage.

 

If I run hotter without a thermostat, then why did every car i have ever owned with a temperature gauge, in which I have temporarily ran without a thermostat for various reasons ran cooler then with. To the point of hardly having any warm air from the heater, and me being able to hold coolant hoses or radiator indefinitely without burning myself.

 

79 Ford F100: 195 thermostat between 190 and 205. Without thermostat between 150 and 160.

91 Geo Prizm: 195 thermostat up to 195. up to 210 in hot weather stop and go with A/C blowing. Without thermostat ~120.

94 Suburban: 195 thermostat between 185 and 205. Without thermostat between 160 and 165

87 Comanche: 195 thermostat between 190 and 210. Without thermostat between 150 and 165.

 

Also had an 84 Olds 98, an 82 LeBaron and an 81 Caprice. Never ran the Olds without a thermostat and the other two had idiot lights.

 

My data does not support the flawed theory.

 

had the same situations where I have had to run a car without a thermo to get home:

Stroker - ran around 225-230 with no thermo, pinned on 195 with thermo

LS1- ran about 210 without thermo, 180 with thermo. (expensive and a pain to replace btw)

 

 

my data does support it. Not calling you a liar, just saying we seem to have an impasse, could be the different locations, driving styles ect. I do know that when I worked parts, I saw more overheating problems fixed by adding a thermostat than by removing one. The urban myth is supported by 3 ASE rated parts pros, one of whom has about every rating you can get.

The other factor is an increasingly common mod I am seeing. People are adding a washer type disc to the upper rad hose in order to reduce the flow rate further.

 

 

kinda a silly thing to argue about since we both seem to agree that a thermostat is a necessary part of your cooling system anyway.