Grand Waggy Cooling Issues...

[MonsterZ]

So here I am with another Wag (just can't help myself sometimes), I get to drive it for 1 day, it develops some issues (no surprise) and I get sent on temporary duty to North Carolina. Drat!!!

However, I am now on my way back home, 4 months later. Here is what I've got to deal with:

Cooling - I can't keep this running for more than about 30 minutes before my temp essentially takes a hard spike and over heats. It isn't gradual either, which to me is a little wierd, it will run cold for about 20-25 minutes, and then shoot to over 250 deg. Almost like my thermostat is culprit, though I am pretty sure I don't even have one in there, at least according to PO. Haven't had tme to dig into it yet. My plan is to run a jug of CLR through the Block (has been sitting for several years now) change thermostat, and possibly water pump at the same time and see what happens from there. Fan is working and the radiator doesn't appear to be leaking anyways.

Carb - It will not idle correctly and no amount of tweaking thus far will get it to perform correctly. I've checked my ignition system, it has a newly installed GM HEI conversion, timing is set at 8 deg, and when it does get gas it fires over and will run on high idle quite well. However, it will not kick down to low idle at all after the engine should be warm, and if put under a load at all will usually stumble and die. I am pretty sure that I am facing two issues with this. I am pretty sure that my carb is dirty and tarnished. I will be pulling it off, pulling it apart, cleaning and rebuilding it first thing when I get home in a day or so. Second is I am not sure that my timing is correct for HEI, but don't really know what it has to be at. Will research the archives, as I am sure I can find an answer there.

I hopefully will be able to have something to report soon. I am actually very excited about this, as it is an otherwise very clean G-Wag, and have been wanting to drive this for several months now. Wish me luck!

[letank]

Could be a defective temp gauge sender or gauge.. it is a 75 right.... best is to use any temp measuring tool... cooking or better infra red thermometer.... how is tbe return hose....... cooler to fhe touch.... it is usually 40 to 50 degrees cooler .... a little less above 85 degrees ambient temp. Of course results may vary
Better than clr use the prestone neglected treatment and fllow with a flush using their kit with a garden hose..... wait after the chemical flush before you add cold fluid... you want to avoid heat shock.

I need to think about the carb issue.... make sure that the idle solenoid is not binding or the throttle stop screw on the driver side is not keeping the throttle open.

Timing was specs at 5....for smog purposes... But it does run better at 12... this what I have on the 74.

[Carnuck]

Clogged cat or stuck stat?

[MonsterZ]

Ok, so a little more updating. This has now gone from simple to entirely frustrating. This is an 1988 Grand Wagoneer. Exhaust is almost brand new. Still has the Motorcraft 2150 carb. Was not able to get carb rebuilt as the Army has decided NOT to pay me what I am owed, yet again. So, still have some idling issues. That aside, I pulled the thermostat, and low and behold, not functioning correctly. Wouldn't open until about 210 degrees, keeping my water at a boiling point. Great, so I decided why not just run it without it for a little bit? Sure, I would never get hot, or very warm for that matter, but I wouldn't be boiling my antifreeze everywhere either. Shock of the day, that didn't solve a thing!! I can see that I have plenty of water flow through the radiator, so I am not concerned as of right now that my water pump isn't working, no end play on the pulley shaft or leaking water either. Fan is spinning and moving air, so I am a little stumped. I am pretty sure that my water jackets are clear, ran some CLR through the engine and got virtually nothing as far as debris out of it. This is the original radiator and fan. I know that they tended to be a little anemic stock, but this Jeep has 172K on it now, so I seriously doubt that in proper working order that it wouldn't be enough, was for the last 24 years. Does anyone know how to check if my fan is still moving enough air? That is about the only thing left that I can think of. Really want to get this going, as it is about the cleanest G.Wag I have ever seen. HELP!!

[FSJunkie]

2150's have a habit of clogging their idle passages, soak it in carburetor cleaner and blast out all the passages with compressed air. Cured my idle issues.

[MonsterZ]

Had planned on replacing all my gaskets and seals when I clean it. I could probably get away with not, but the kit is cheap and I'll already be into it when I do get paid. I think I am going to go ahead and just bite the bullet and order the crossflow aluminum radiator and high flow pump from bj's and do them now. Will also look for and replace my fan with an electric job while I am at it. Don't know much about that, I have heard of people using ones from a Taurus? Will have to look into it. The last thing I need to deal with on the side of the road in Alaska is an overheating engine. Temperature extremes in the winter between hot engine and cold air can do some wicked things to metal. For now, I will be in North Carolina for the next thee weeks or so. If there happens to be anybody in the Ft. Bragg area that could use an extra hand turning wrenches on their rig or just wants to hang out and talk Jeep, I am down.

[grandjeeper]

I think I am going to go ahead and just bite the bullet and order the crossflow aluminum radiator and high flow pump from bj's and do them now. Will also look for and replace my fan with an electric job while I am at it

I think going to all that expense and trouble before you isolate the current problem is not the best idea.

An 88 Grand Wagoneer should cool just fine if all of the stock equipment is working correctly.

Many other posters have pointed this out. While there are certain situations (high ambient heat at low speeds in low gear ranges) that benefit from enhancements, under normal driving conditions an 88 GW shouldn't overheat.

The cooling check list includes:

Is it really overheating?
Is the system low on coolant?
Is the fan shroud present?
Is the fan clutch working correctly?
Is the fan (number of blades,etc.) correctly matched to the application?
Is there a temperature differential between the radiator inflow and outflow hoses?

Probably some others I have forgotten.

[jsinajeep]

I would not put all that new stuff on until I solve the problem.
Use a cooking therm. in the fill neck of the rad. to verify that it is over
heating first. It sound like the fan clutch is not working right when the engine is hot.

[fulsizjeep]

Crikey, figure out the problem before you throw a bunch of money at it like me.

[Carnuck]

Sounds like the stuck stat may have cooked the head gaskets OR the cat is clogged and backing heat up into the engine.

[letank]

The cooling check list includes:

Is it really overheating?
Is the system low on coolant?
Is the fan shroud present?
Is the fan clutch working correctly?
Is the fan (number of blades,etc.) correctly matched to the application?
Is there a temperature differential between the radiator inflow and outflow hoses?

2x on the last item, the temp differential is a good indicator of working radiator and running waterpump.... You can do the feel test, watching for that moving fan.... On a good radiator the temp difference between the upper and lower radiator hoses is around 40 to 60 degrees , depending on ambiant temp.

With the radiator cap off, you should see the coolant flow moving when the temp gauge reaches the green band... Remove before starting so you do not burn your hand or face.

[MonsterZ]

Ok, so I'm finally home, and got the cooling issue solved, but developed another. The time away gave me a chance to come back to the problem fresh. I ran some better cleaner through the engine, much different results this time. I had so much junk flow out of the engine that I repeated this three times before I got clean water through the block. That done I reinstalled a new thermostat after inspecting my hoses and seeing that they were still good. Pump was fine, no end play, and good flow. Radiator no leaks, fired it up and TA-DA! Worked like it should. Gradually warmed up to just under 200, stat opened and temp dropped off to almost 120, then climbed back to about 190-200 range and stayed there just like it should. Was very happy about this!

Then this happened: after idling for about 30 minutes it started to develop a tap. Was quiet at first and very hard to locate. It grew a bit louder, and sounded like it was coming either the top end of the engine or from possibly the front. My ears are kinda shot anymore from too much shooting with no ear plugs (infantryman, I'd wear on patrol if I could). Then the engine just shut itself off. Will not fire up now. Turns over great, but it was like someone had just turned off the key.

So I went back to basics. Fuel, air, spark, compression. I had the carb adjusted well once I got it running, so I think I am good on air and mixture. I've got spark at the cylinders and timing was on when it shut off, nothing has moved so I'm pretty sure that spark is good. I am thinking its my fuel pump that failed as it seems to make the most sense, but I feel like I'm forgetting something. I tried pouring a little gas into the carb throat, and it would kick over and try to run but it acts like its starved. I haven't yet pulled my fuel filter and I don't really want to tear into the carb if I don't have to, but same thing with pulling the pump, as getting to it is gonna be kind if a mother in my garage. Is there a way to check my pump and does anyone have any ideas? Thanks everyone.

Edit: the tap almost sounded like a lifter that wasn't pumping up correctly or like a valve out of adjustment. Was very strange, a very experienced friend (Dad) suggested that it may have been the arm on the pump failing that caused the tapping, but I have t pulled this as of yet.

[rockrollin]

SeaFoam may cure a sticky lifter, could be exhaust leak. I use a wrapping paper tube to isolate engine bay noises. Kinda like an ear lazer lol. Pull the gas inlet hose at carb and place in glass bottle, to see if your getting fuel while turning over (unplug the coil + first). Change the fuel filter

[letank]

Congratulation on cleaning that cooling system.

Not too sure about the tapping.... do you have enough oil?

if you suspect a fuel issue... and of course it does not run.... dumping a little more gas makes the engine run barely 2 secs... been there, done it... just a little coughing...

remove the carb top or air horn and see if you have fuel.... otherwise one of the vent on the top of the air horn is connected directly to the carb bowl of the 2100 (forgot which carb you have) so you can connect a small hose and fill the bowl....

otherwise a fuel pressure gauge Teed to the inlet of your fuel filter (on the 75 you only have the one sitting above the valve cover and no return line to the gas tank..?) crank and see if you built pressure... hope that you have a good battery...

should I ask if you have gas in the tank... been there done it (1/4 tank in an FSJ stored in full sun for a 6 months... the gas evaporated... but I am not in Alaska)... disconnect the fuel line at fuel filter and blow in line.... you should hear bubbling.... If you have ethanol in the gas... it does strange thinks to the fuel filter.... blocking it with whatever... gel that restricts the fuel flow... we are at 4 to 5.5 psi....

[jeeper54]

Just curious... what was the better cleaner that you used to flush the cooling system?