I know this unit a truck forum but I have and 89 318. When I got it the motor would puke all of the coolant out into the resivour. I replaced the water pump, hoses, and radiator. Drove it 700 miles to Florida. Here lately it has started doing it again except it puts it on the ground. It only does it after you turn it off and it set for about 10 minutes. I have replaced the radiator cap several times. Blew air through the resivour hose in both directions. I’m no master mechanic but I do work on all my own vehicles and I’m a fairly proficient mechanic. The motor is bone stock. The smog u it is not hooked up but I don’t think it is part of the problem. I’m gonna do a compression test today or tomar. It doesn’t run hot but it does seem to have excessive pressure in the cooling system. Cracked head? Blown head gasket? It runs really smooth and there is no water in the oil. Or vice versa. Any thoughts would be appreciated. Yes it is a throttle body.
1989 318 coolant issue
- Thread starter Dan s
- Start date
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Is the thermostat in the correct way ?
Professor Fate
Push the button, Max...
Radiator should be full to top, reservoir bottle should be between MIN and MAX marks- if overfilled, it will push coolant out of the overflow onto the ground after shutoff. You do have the factory reservoir and not a smaller aftermarket one, right? The reservoir bottle does NOT get filled to the top- it needs the extra volume to contain the coolant during heat cycles.
Is the engine actually overheating, or is it cooling normally?
Is the engine actually overheating, or is it cooling normally?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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The thermostat sets the
MINIMUM
coolant temperature.
When the coolant temp
FALLS
below the rated opening, the stat closes, in an effort to keep the engine warm. The stat has absolutely NO effect if the coolant temp is hotter than it's rated set point. It just sits there WIDE-OPEN, waiting to see the coolant temp fall to less than it's set-point, when it jumps back into action.
However, if the stat fails it's job and gets stuck closed/or near-closed ; now you got trouble.
The pressure-type rad cap does nothing but raise the boiling point of the coolant, so the auto-manufacturer can run a smaller rad, with an inferior coolant,in a smaller liquid capacity system; it's all about saving a couple of bucks to them.
That cap should never blow-off, unless the pressure rises past the blow-point, in response to the liquid being too hot; which, if it happens at speed, points directly at an efficiency failure (except as already noted, that you over-filled it.)
If it happens only at idle or low-speed operation, this then includes; the fan, the shroud, the water-pump speed, and belt slippage; and above all;
Air-flow thru the fins and water-flow thru the core.
So your first defense against overheating is to check to make sure the rad freely passes air thru the fins, and water freely runs out the bottom hose very near to the same rate as you can pour it in the top.If you have an A/C condenser in front of the rad, it too must freely pass air thru it.
After that; is to check the operation of the stat, or just replace it; they used to be like 3 bucks...... so in a shop setting we just threw them away.For diagnostics, you can take the stat out and break the guts off it, then re-install the disc. If it still overheats, then you have other issues.
The next thing, after that if you have one,comes the fan-clutch the hotter the reservoir gets, the more difficult it should be to rotate the fan. Some are designed to fail closed; so when the reservoir is cold, it can also be difficult to rotate. Between NOT cold and NOT hot, the fan will vary it's resistance between slipping a lot, to not slipping at all.
All this assumes your engine is NOT blowing compression into the water-jacket, as already mentioned. A compression test will reveal a problem mostly in the top-most inch of piston travel. It will not always find a problem lower than that.
But, if you gut the stat and put just the disc back in,then fire that beast up, if there exists a pressure dump into the cooling system, yur gonna see the bubbles in the top of the rad, together with stinky steam, almost right away. Resist the urge to light the steam on fire.
That's all I got.
Oh wait; you said 89. You still got the lean-burn?
If yes, then prove the diaphragm in the V-can is still functional. If it fails, your engine will run FULL-TIME retarded timing. It will be gutless, suck gas bad, and overheat; and no amount of cooling system diddling will cure what ails it.
So after proving it holds a vacuum; you still gotta make sure the thing advances the timing.
If you don't have a LB, then map out your timings and make sure the engine is seeing adequate Part-Throttle timing. And make sure TDC on the balancer is actually TDC on the piston.
Adequate timing will vary with the application, but I suggest 10* at idle, and a minimum of 32* @3400@WOT, less if it detonates at "normal" engine temps of 180 to 200. And in between the Vcan should be pulling full timing ASAP, usually 10 to 15 degrees by 1800rpm at small throttle settings. This is my opinion. If the engine accepts more without detonating; give her what she wants. If dshe will not accept these "adequate" numbers, you got some other issues. Start with cleaning out the heat-crossover under the carb, and proving the heat-riser, and EGR system, and restore the heated air intake system.
Your carb is calibrated to run air at a certain temperature, and it ain't more than 200 of underhood air, nor ambient . IIRC it is calibrated for a constant air-temp of less than 100*F, 80/85* rings a bell.
MINIMUM
coolant temperature.
When the coolant temp
FALLS
below the rated opening, the stat closes, in an effort to keep the engine warm. The stat has absolutely NO effect if the coolant temp is hotter than it's rated set point. It just sits there WIDE-OPEN, waiting to see the coolant temp fall to less than it's set-point, when it jumps back into action.
However, if the stat fails it's job and gets stuck closed/or near-closed ; now you got trouble.
The pressure-type rad cap does nothing but raise the boiling point of the coolant, so the auto-manufacturer can run a smaller rad, with an inferior coolant,in a smaller liquid capacity system; it's all about saving a couple of bucks to them.
That cap should never blow-off, unless the pressure rises past the blow-point, in response to the liquid being too hot; which, if it happens at speed, points directly at an efficiency failure (except as already noted, that you over-filled it.)
If it happens only at idle or low-speed operation, this then includes; the fan, the shroud, the water-pump speed, and belt slippage; and above all;
Air-flow thru the fins and water-flow thru the core.
So your first defense against overheating is to check to make sure the rad freely passes air thru the fins, and water freely runs out the bottom hose very near to the same rate as you can pour it in the top.If you have an A/C condenser in front of the rad, it too must freely pass air thru it.
After that; is to check the operation of the stat, or just replace it; they used to be like 3 bucks...... so in a shop setting we just threw them away.For diagnostics, you can take the stat out and break the guts off it, then re-install the disc. If it still overheats, then you have other issues.
The next thing, after that if you have one,comes the fan-clutch the hotter the reservoir gets, the more difficult it should be to rotate the fan. Some are designed to fail closed; so when the reservoir is cold, it can also be difficult to rotate. Between NOT cold and NOT hot, the fan will vary it's resistance between slipping a lot, to not slipping at all.
All this assumes your engine is NOT blowing compression into the water-jacket, as already mentioned. A compression test will reveal a problem mostly in the top-most inch of piston travel. It will not always find a problem lower than that.
But, if you gut the stat and put just the disc back in,then fire that beast up, if there exists a pressure dump into the cooling system, yur gonna see the bubbles in the top of the rad, together with stinky steam, almost right away. Resist the urge to light the steam on fire.
That's all I got.
Oh wait; you said 89. You still got the lean-burn?
If yes, then prove the diaphragm in the V-can is still functional. If it fails, your engine will run FULL-TIME retarded timing. It will be gutless, suck gas bad, and overheat; and no amount of cooling system diddling will cure what ails it.
So after proving it holds a vacuum; you still gotta make sure the thing advances the timing.
If you don't have a LB, then map out your timings and make sure the engine is seeing adequate Part-Throttle timing. And make sure TDC on the balancer is actually TDC on the piston.
Adequate timing will vary with the application, but I suggest 10* at idle, and a minimum of 32* @3400@WOT, less if it detonates at "normal" engine temps of 180 to 200. And in between the Vcan should be pulling full timing ASAP, usually 10 to 15 degrees by 1800rpm at small throttle settings. This is my opinion. If the engine accepts more without detonating; give her what she wants. If dshe will not accept these "adequate" numbers, you got some other issues. Start with cleaning out the heat-crossover under the carb, and proving the heat-riser, and EGR system, and restore the heated air intake system.
Your carb is calibrated to run air at a certain temperature, and it ain't more than 200 of underhood air, nor ambient . IIRC it is calibrated for a constant air-temp of less than 100*F, 80/85* rings a bell.
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I checked the.thermostat. It’s good. Rad is full. New pump. I don’t understand why it only does is when u turn it off and it sits for about 10 minutes. Then it pukes. Aj as usual I’ll have to read your post a couple of times. That’s a lot of info. My wife is about to drive it to town. We will see what happens. It seems to me that when it gets shut of it heats up (which is natural) and builds pressure. It never runs hot even when just setting and idling. I let it idle for over an hour the other day and it didn’t even try to get warm. As far as the lean burn system goes. I was really wanting to keep it as factory as possible. It is really a clean truck. But it does suck gas and is a sure enough dog as far as pose goes. So I may have to delete it. I’ll post some pics today of the engine compartment and I need to read the thread on deleting it. I saw it the other day but didn’t look at it.
You need to find someone that can do a pressure test. It sounds like you are loosing pressure as it sits. You said you replaced the cap but it could be something as simple as that. Or a head gasket. Does it smoke excessively? Check your oil to make sure it doesn't have antifreeze in it.
Smog pump (AIR pump) not related to coolant. The coolant does not need to be at the bottom of the radiator neck. The bottom right photo looks ok to me. Reservoir is too full.
Ok. So the rad is almost completely full. The reservoir is a little over full. But by the time she gets to town it will suck it almost empty. That is a 16#cap. Brand new. It’s the third one I have put on it. As u can see the smog pump does not have a belt on it. When she gets back I’ll try to post a video of it while it’s warm. I’ll probly just go ahead and delete everything this afternoon. I’m trying to keep this truck as factory as possible. Thanks for the help
I suspect a head gasket
So if you do have a failed head gasket and small amount of exhaust in the coolant system, it will push water into the reservoir and probably over fill it and loose water. Ignore it long enough and it will run hot eventually. Testing for this isn't difficult..
And for the record, the copper colored head gasket fix from Barsleak really works. It fixed my 96 camry 4 cyl. well over 7000 miles ago.
And for the record, the copper colored head gasket fix from Barsleak really works. It fixed my 96 camry 4 cyl. well over 7000 miles ago.
that is not what I wanted to here but I think you may be right. But I would think it would do it while it’s running. Not when it is shut down. That is the part that has me perplexed.
i will this afternoon. I just got a new test kit I haven’t had a chance to use
It sounds to me like you're simply filling the cooling system too full. What you have is not a coolant recovery tank, but simply an overflow jug. There's a difference. A recovery tank is a part of the pressurized system. An overflow jug simply does what its name implies. You need to fill the radiator so that it is about 1" from the top. This will give it the proper room for coolant expansion. If the overflow jug has coolant in it and the radiator is slap full, discard the coolant in the jug and drain some coolant out of the radiator until it's 1"-1.5" below the top, then it will be filled correctly. Try it then and see how it does.
When an engine stops, some cylinders contain pressure while neither valve is open. All of that very hot cylinder pressure can go into the cooling system via a crack in a head gasket.
Well. This engine should have the 302 heads on it and I have wondered if maybe it has a crack. Unfortunately I will be leaving g to go to Wyoming this coming Monday and I don’t have time to do the top end of the engine right now. It will have to wait till I get back. May just have to park it for now. I’ll keep y’all posted on what it turns out to be. I’ll definitely do a pressure test this afternoon and post the results.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Don't miss post 17
But if the hose I see in that pic, that is
attached to that plastic straw;
if that straw goes to the bottom of the tank
on the outside of the tank
like mine does, then
it is a coolant recovery tank, and the cooling coolant in the rad, will in fact suck it back into the top of the rad, as long as the cap is working. And you will know the cap is working by checking the coolant level in the rad, when cold, after having gone thru at least one hot/cold cycle, and finding the rad as full as it gets.
In this type of system, a pressure leak into the cooling system will usually manifest as an oily brown frothy mess in the recovery tank.
But if the hose I see in that pic, that is
attached to that plastic straw;
if that straw goes to the bottom of the tank
on the outside of the tank
like mine does, then
it is a coolant recovery tank, and the cooling coolant in the rad, will in fact suck it back into the top of the rad, as long as the cap is working. And you will know the cap is working by checking the coolant level in the rad, when cold, after having gone thru at least one hot/cold cycle, and finding the rad as full as it gets.
In this type of system, a pressure leak into the cooling system will usually manifest as an oily brown frothy mess in the recovery tank.
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512Stroker
We are all here because we are not all there.
After you park it and it pukes what is the level in the radiator and the recovery tanks after it cools down to close to ambient temperature.
Like several hours later
Like several hours later
512Stroker
We are all here because we are not all there.
Were these pic's taken hot or cold engine temp?
That cooling system is over filled.
it goes to the bottom of the tank and it will draw fluid back into the tank
it was taken cold. And yes it was over full. My wife drove it yesterday about 60 miles round trip. Never had a problem. Maybe I just put to much in it. I haven’t done a. Compression test yet. Hopefully I will get to it today.
I;m not gettin into a pissin contest over technicalities. If it's not a part of the pressurized cooling system, it's not an integral part of the cooling system and has no bearing whatsoever on filling the radiator slam up. Call it a recovery tank, an overflow jug, a puke tank, whatever you want to call it. Unless it's pressurized with the cooling system, the radiator must have some space at the top of the coolant level for expansion. Period. If you're filling the radiator slam up, that could be what's wrong. Post #17 is a suggestion that has ZERO COST. THERE'S your clue. I always start with the free or low cost options, because 99 times outta 100 that's where you find the problem. But what the heck do I know? I swear, some of these guys have nothing better to do than come on here and make things so complex and convoluted, no one ever knows what the right answer is. The fact is this is the internet and nobody "knows" what your problem is, but the free/cheap stuff IS the place to START. Good luck. I hope you figure it out.
lol. Thanks for the advice. No pi$$ing contest here. I’m starting to think I just over filled it. Seems to be a pattern for me lately. More is not always better
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