1989 318 overheating at idle

I have a 1989 318 that is overheating at idle. 173000 miles Haven't driven it because of this. So don't know if it will cool off while driving.

Noticed when I bought the truck that the water pump and timing cover had excess amounts red RTV. Someone was in there.

I replaced the thermostat with a 190 degree. Found a 160 in there.
Replaced the radiator cap with a 16 lb that tested to 14lb.

Used a scope camera to look in the radiator. Not super bad but used radiator flush twice. Camera showed some rtv stuck . Removed radiator and reversed flushed. Now clean and had good flow.

Thought that the wrong water pump could have been installed. Hard to tell with the scope camera. So I removed it. It was a six blade impeller like for a/c. The pump rotation is clockwise.

Opened up the timing chain for inspection. The crank had three keyways. It was set on the center or 0. Both marks on the gears were at 12 o'clock with #1 cyl @ TDC. The marks are 6&12 when #6 cyl is at TDC.

Not reassembled due to not finding a creditable cause.

I did have some moisture puddle under the tailpipe when the truck was running. Don't drive the truck much it a backup. Wanting it to be come a reliable back up.

Also I have a freeze plug on each side showing signs of some leaking.

Would you pull the motor to fix the freeze plugs replace head gaskets and inspect?

Or

Would you just reassemble and replace the thermostat with ones that has a bypass holes drilled it it? The 190 That I installed had the little brass wiggler bypass. Then do compression check to test the head gasket? And go from there.

it isnt uncommon for heads to crack on the magnum motor----i would check to see if the radiator has too much pressure---then put a known reliable temp gauge on it....

replace the freeze plugs while the coolant is down then button everything back up & take it out & run it. if it starts to overheat before you get up to "speed" pull over & let it cool then continue on. How hot is it getting? confirmed with an accurate gauge or there is no doubt that it is running hot? You said you ain't driven it cuz it is overheating at idle, more info, has it always been like this since you acquired it? #1 what do you have for fan (fixed or clutch)/shroud/fan fore/aft spacing. Your pump is good the rad sounds likely (maybe) good, you replaced the stat & I'll assume it is good (& yes you want an 180 or higher). I'd want at least 15 initial (what do you have?). way less likely is a vac leak & block could be crudded up & a person could pull the freeze plugs & car wash wand blast it out (trailer it to/from) but I would definitely not bother cuz if it is OK at speed then the prob is elsewhere. Short version: if the initial is adequate (& I'm assuming that it is) then IMNHO: radiator/air speed/water speed, in that order. EDIT What Savoy64 said, you can get a "tank valve" from O'reillys for less than $3 & screw it into the coolant temp sensor port (1/8" NPT) & pump it up to 10 lbs & see if it holds. With your tire psi gauge in hand hit the fitting with your air chuck for a split second at a time cuz with coolant in there & little dead air space it will reach 10 psi FAST. You can also put a psi gauge on that port & start it & see if it jumps up somewhat high fairly quick which it will if combustion is leaking into the coolant. Those cheap psi gauges are about $5

An 89 318 is not a magnum engine.

When you say overheating how did you decide that? Does it puke coolant? Or is the dash gauge what you are going by? Or do you have another temp measure device you are using?

Overheating at slow or no vehicle speeds are usually airflow related. Fan clutch, wrong (CCW) fan, gunk in the condenser or radiator, or both. No shroud. Idle is when the engine is least stressed so it is not making as much heat.

I'd double check the cam timing because someone has been in there. Replace all the freeze plus because it one or two are weeping they all will be soon. Put it together, get it running check timing (retarded can cause overheating), look for vacuum leaks (lean can cause overheating) and see what you have.

Correct not a magnum, a LA roller.
The over heating (Boiling over) is after I pull the truck out of the barn and let it idle.

I forgot to mention that this is a Shelby Dakota, it has two 11" electric pusher fans. They both work as should.

Timing is controlled by the computer. The distributor(thing) is set with an initial timing of 10 degrees.

The few times I have driven it the temp would creep up when at a stop.

Is there a catalytic converter on the truck still? If so have you checked to see if the exhaust is so clogged it's overheating the engine. I've known it to happen.

I'm assuming you have watched to see if clutch fan is operating properly, otherwise good suggestions from RapidRobert and SuperCuda.

Still has the catalytic converter. The insides are loose and rattling around. Hand on the exhaust has plenty of presser.

My thoughts now are to:

Pull the spark plugs and do a compression check with no coolant in the system.

Reassemble so it can be running again.

Recheck test the compression.

Repair catalytic converter.

Test for overheating.

Thanks for the input everyone. Can anyone see doing some thing different/

At idle how many minutes till it is boiling? It kinda sounds like airflow except for the fact that it sounds like it is boiling over QUICKLY at idle (plus 10 initial ain't much) but I cant say if that is a problem or not. More just thinking out loud.

Does it have a belt driven fan as well as the 2 electrics?

The 89 Shelby Dakota had no mech fan, too tight to fit. I would make sure the fans are blowing the correct direction. A piece of paper hung in front pof each one in turn will easily verify that. Temp creeping up at a stop tends to verify an airflow problem. I don't know how sensitive the Dak is to air dam presence, some vehicles will not properly cool if the air dam below the radiator support is missing.

5- 10 minuets and it would over heat by boiling out of the overflow. Got worse the more I ignored it.

The 10 degree is specification on the under hood chart. This setting is what the computer bases the rest of its calibrations upon.

Yes.
I checked the fans with paper before repair also after removing them. Both rotating the same direction. Checked amp draw. One of my fans had the quick connector eliminated, it was hard wired. This fan showed less amp draw. Both were close to each other. I won't mention how big a pain it was to do. One reason I want to get a game plan.

The housing that the fans are in acts like the shroud. I noticed that on the underside, of the duck bill section, on top of the inside of the shroud, looks to have HAD a rubber gasket that would seal to the A/C condenser. There are a few small push in Christmas trees that looked to held the rubber in place. I plan to remake this missing rubber.

The front bumper was also removed during this over heating repair. I cleaned and straighten the fins on the A/C condenser. Also cleaned the oil cooler fins and replaced the 4' of rubber hose Shelby installed. Made hard lines for this.

The lower air dam air deflector support was in place.

5-10M from dead cold? To me that sounds like something way more serious than (lack of) air flow.

boiling out the overflow is a head gasket leak--or a cracked head----there is test for it...

I was afraid of that.

^^^ that's what I was thinking. If there is an emissions testing stn closeby you could ask em to stick the probe in the air space below the coolant level & it'll register any hydrocarbons. Easier, I would get the O'reillys $3 fitting & pump it up to 10 psi and or the cheap psi gauge. EDIT meant to say above the coolant level!

I have a tester with gauge. Will add this to the lost of things to do.

Yeah, that quick a puke out the overflow isn't overheating, it's something else. A quick look at teh plugs might narrow down the cylinder.

yep----the super clean plug is the bad cylinder---steam cleaned...

Today my plan is to:

Pull the plugs and have a look at them.
Do a compression check with out any coolant in the system.
Reinstall timing cover and water pump.

If a plug looks clean and the pressure in that cylinder is low I'll just start pulling the motor. This will be to address the freeze plugs and possible head gasket.

If the plugs look good (dirty) and cylinder pressure all check ok. I'll finish installing the coolant system and then do a pressure check.

Next I'll go after the catalytic converter and monitor the freeze plugs.

Fingers crossed some something shows the correct path to repair.

I think today's plan is a good one. Good luck and keep us posted please.

Today's work included: no lunch and

Pulling the plugs #6 was white on one side all the others were black.

Got half way thu the compression check when the needle stopped moving on my gauge. Had to fix that so Im not sure if the numbers are I got are accurate.

On the second go around the #6 was 20 lbs lower.

So I then took a flat head screwdriver and poked at the weeping freeze plug. It easily went tru causing a hole.

With that I decided to pull the motor with the transmission attached.

I cut out the catalytic converter. The core was tight on the motor side but was loose on the rear end side. It will be replaced.

With the radiator out. I was able to get the engine and transmission out with the hood on. By myself. I don't think it will be going back in that way. Shelby must have removed the core support. I guess I could do that but I'm running out of space to parts.

Next week end I'll find time to remove the heads.

^^^ I wish I had your ambition!

I read your thread a little too late to have you check the radiator temp in all of the location to see if there were any colder or lower temperatures in any location. I had an overheat issue with my Road Runner and went through pretty much the same checks as you, even flushing the radiator. I'm at my friends place and just pulled into his driveway and had told him about the overheating issues and what I had tried. He walks back into his garage and comes out with his infrared heat gunn, opens my hood and within a matter of seconds shows me how 75% of my radiator is almost ambient temperature and the other 25% is really hot. "plugged" radiator down inside the veins where you really couldn't see even with a scope. With the radiator out I don't know if you can fill it with hot water and find where it doesn't raise the radiator temp or not. It was real obvious with engine running to see the difference in radiator (coolant) temperature. Had me fooled as the radiator was restored on the outside and looking new but was badly plugged and flow restricted on the inside.....new radiator core fixed it as it was so badly plugged. Oh and there is a method to check the coolant to see if there is a compression leak getting into the coolant.......works "most" of the time.

One other issue could be a plugged exhaust system. I know you checked the converter, but there could be a problem somewhere else in the exhaust system. (Restricted / plugged muffler, pinched pipe, etc.)

If you can do so, run the engine to see if it overheats before hooking up the exhaust. I doubt this is the problem, but sometimes strange problems occur.

A converter that has a piece broken off can plug the exhaust if the broken pieces turn the wrong way. The converter piece has small holes the exhaust passes through. When it breaks, it can roll and block off the exhaust flow through part or all of the holes in the the surface. Rattling inside the converter means those pieces are flopping around at are blocking at least part of the exhaust flow some of the time. Your exhaust flow can be part of your problem.

A partially plugged radiator could also be part of your problem.

Have you cleaned between the AC condenser and the front of the radiator? I've seen an amazing amount of stuff accumulate between the radiator and the condenser. That will also cause over heating at an idle.

If you are replacing the freeze plugs, there are 2 on a small block between the motor and trans. I would replace both of those as well.

Shelby probably didn't have the front sheet metal on the truck when they installed the motor. Gene

You'll get it all sealed up and running good now that it's out, I'm sure. Did that with the 360 in my Power Wagon. Freeze plug at rear meant either engine or transfer case had to come out on mine, and engine seemed like the way to go. So much more could get done. Before and After.

Update us. Are you plugging and painting

Sorry for not updating.
With the engine out and on a stand I pulled the intake and heads.
Removed the freeze plugs and cleaned out the block passageways with compressed air.
Reinstalled freeze plugs.
The original head gaskets were installed.
Pulled the valves and cleaned them and replaced the seals.
No machining was done.
New felpro head gaskets were installed along with ARP head bolts.
The gaskets blocked the top front water thru the head. Felpro states improved cooling. We will see. Re installed intake.
Pulled oil pan cleaned installed new gasket.
The engine was not painted. It would make the rest of the truck look bad if it was painted.

Installed motor by its self. Then installed transmission.

Things were on a roll.

I had two weeks vacation starting the week of Christmas. Two days before I came down with the flu. It hit me hard, I don't do the flu shots. No one else in the family got sick. After 5 days of not sleeping and not eating my fever broke. I drank a lot of water so not to become dehydrated. Then I think because of my fever I had open sores in my moth and throat. This was called a virus at the doc in the box around the corner. Another five days of not eating.
So I made my self go out and work on the truck before the weather changed.

I finished installing the radiator hoses and such. Corrected some vacuum lines. I left off the air pump and blocked the ports on the manifolds. I plan on keeping the EGR system in place.

All this work out in the cold barn kinda made me not recover so much, didn't feel energized.

Took a break.

I still need to:
Weld up some pipe to connect the Y-pipe to the muffler.
Fill fluids.
Install grill.
Test temperature gauge -have a home made deal wanting to try out.
Fire up

Plan on using a temp gun to check for hot cold spots in the radiator at start up.

Sorry for the late update. Maybe I will get to work on things tomorrow.

pretty ingenious way of installing the transmission !
got a close up shot of how you mounted the transmission jack saddle on the engine lift tube by chance ?

Great progress! Sorry you got hit with that virus. A bunch of people at work knocked down with one. Keep up the good work!

This is how I made my transmission jack:
I work alone so I have to work smarter.
I bought a harbor freight transmission adapter for a floor jack. It has a steel peg out the bottom. So I just used a hole saw to cut a hole in the top of the arm of the cherry picker. To make sure the adapter does not come off I drilled and tapped a hole for a bolt to hold it down. In combination with the two post lift my cherry picker is now a versatile machine that does more than take up space. Some days I think of quitting my job and start rebuilding Mopar transmissions because this makes it so easy.

If this is not close up enough let me know.

X2 tho I dont think it would make me wanna quit a day job!

pic shows what i needed to know. thanks !

I enjoy the community of Moparts that's one reason I post and up date my posts.

So all things buttoned up and the truck runs. Only ran it for a few to check for leaks.

One thing I did notice was that there was water from the tail pipe.

Sorry no picture

I checked my log book and the last time I fueled up was 7-14-18.

Next weekend I hope to have some tile to run it around and to get it up to temperature.

I'll take a picture of the water from the tail pipe also.

hopefully, the tailpipe water is just condensation.

Ok.
I was able to fire up the truck and let it run.
Before start up I placed a clean sheet of cardboard down under the tail pipe. At first I did not touch the throttle. No water from pipe. Now I did not let the truck fully warm up. Could not see any exhaust.
I then revved up the truck some not to much. Water from the tailpipe and could see the exhaust. This continued all the way thru warm up and the fans turning on.
See pictures.

Well on the cardboard there was water with a little soot in it.

I had to know was it water or antifreeze. So I tasted it. No taste-water.

So as suggested I used a temperature gun all around the radiator. Hot at the top and cold down below. One or two spots on the ends at top that were not as hot as everywhere else.
The thermostat was holding its own at 195 degrees. Moving the temp gun around the heads and freeze plugs things looked acceptable.
O yeah the out side temps were in the mid 20's.

If I can borrow the temp camera I will see what it shows.

My plan is to drive it so the old fuel is removed and add fuel- tron additive to the next tank. I all ways run premium.

If any thing else comes up I'll past again.

Looks like "cold smoke" to me. Condensation in the exhaust system causes it and the water that drips out of the tailpipe. Normal.


Tim

I've seen cars dripping like a faucet in traffic (I would think no eng problem from the # of em I have seen). On a side note I drill a very small hole in the lowest bends of the exhaust front to rear so water can drip out & not set there & rust tho I have never had an ex system rust out.

I fit don't smell like burning coolant (assuming you have coolant in the cooling system) I don't worry about it.