Very odd, beats me, but may be easy to you, take a look!

[jaedee1]

I've been messing with cars for a while but I've never dealt with the following symptom:

My Explorer starts and runs strong with tremendous power and drives good. But after about 15 - 20 mins of driving it starts losing power badly and the engines tic-tocs / knocks -- and after a while it'll die and won't start back up. If left alone for a good 30 - 40 mins, it starts again and runs as if there's nothing wrong, no knocking or weakness until another 15 - 20 mins... I must say that the loss of power is gradual, it starts around 8 mins or so, and worsens from there, so does the knock.

I'm drawing to conclude that the vehicle is fuel-flooding, but why the knocking? Anyway, do you support that? If so, what should I look at first? Please throw in your two cents. I own a 1997 Ford Explorer 5.0 Limited Edition 4x4 automatic V8 w/ 160k.

Thanks in advance.

 

[Turdle]

It could be the fuel pump relay, however I bet the fuel pump is going weak. without driving it until the symptom ocurs with a fuel pressure guage, you are left with shotgunning with parts.

Try this-swap the fuel pump relay with another in the power box and see if this helps.

The knocking pinging is from the mixture going lean. Once the fuel pump cools off it is partially working again, however I bet it shows weak fuel pressure at idle.

 

[jaedee1]

It could be the fuel pump relay, however I bet the fuel pump is going weak. without driving it until the symptom ocurs with a fuel pressure guage, you are left with shotgunning with parts.

Try this-swap the fuel pump relay with another in the power box and see if this helps.

The knocking pinging is from the mixture going lean. Once the fuel pump cools off it is partially working again, however I bet it shows weak fuel pressure at idle.

So what I'm getting from the above is that it's not fuel-flooding but instead fuel-lacking?? Well, that might just make sense because I'm not smelling fuel when all of this is happening -- and after it dies, if I lift up the hood, no fuel smell.

It's weird with vehicles because too much fuel and lack of fuel result in the same effect when you try and start a car: it just cranks. So when my truck dies after this ordeal... when I go to start it, it just cranks... I never would assume it was, in fact, fuel-constraint.

OK, will go try switching the relay now... Thanks Turdle.

 

[jaedee1]

Well I switched the relay, and added fuel to help cool off the fuel pump, cause I was pretty low on fuel... for a good while I thought the problem was solved because it lasted a long while idling w/ no hesitation or knock, and didn't quit; but when put it on drive it died, I restarted and started driving it, the same thing happened: Got weak, got to knocking. The knocking is pretty bad, actually. The engine got supper hot this last time. And it looks like heat steam/smoke was coming out of the oil stick tube when stick is pulled.

So I let it cool off, started it again, and it ran strong again, no knocking, full power.

My thing is, if it's gonna do that, why don't it do that all the time. It seems to do it when the engine gets hot. I'm not sure my fans are kicking it.

 

[A Wise Guy]

I'll throw this out there. Are your cats clogged up? Fine when cold but when hot a whole different story.

 

[RomeovilleIL]

Well I switched the relay, and added fuel to help cool off the fuel pump, cause I was pretty low on fuel... for a good while I thought the problem was solved because it lasted a long while idling w/ no hesitation or knock, and didn't quit; but when put it on drive it died, I restarted and started driving it, the same thing happened: Got weak, got to knocking. The knocking is pretty bad, actually. The engine got supper hot this last time. And it looks like heat steam/smoke was coming out of the oil stick tube when stick is pulled.

So I let it cool off, started it again, and it ran strong again, no knocking, full power.

My thing is, if it's gonna do that, why don't it do that all the time. It seems to do it when the engine gets hot. I'm not sure my fans are kicking it.

What does your temp guage show during this process? Overheating will cause the symptoms you describe & its a guaranteed engine killer if not fixed.

 

[my98nnj]

I'll throw this out there. Are your cats clogged up? Fine when cold but when hot a whole different story.

My thoughts as well. Bet the cat's are clogged.

 

[JCat]

..

 

[jaedee1]

What does your temp guage show during this process? Overheating will cause the symptoms you describe & its a guaranteed engine killer if not fixed.

Weird that you should say... I noticed that it does overheat when that happens, and it goes all the way up to red. I just realized that last night and this morning.

Before last night I dismissed overheating as the problem and never even paid attention to the gauge, because I've had plenty of experience with overheating vehicles and normally there's steam or a coolant issue; but there's none of that.

Why would it overheat with no coolant issue? I notice heat smoke coming off the oil adding and dip-stick tubes! What is likely to cause this, guys? My fans is kicking in and the cooling system seems good, except that the heater core has been bypassed.

My question is: Is the knocking causing it to overheat, or is the overheating causing it to knock? -- The truck runs amazingly nice before the knock/overheating starts, but amazing sh8ty when it happens.

 

[lounge lizard]

I'm going with cats as well!

 

[jaedee1]

What does your temp guage show during this process? Overheating will cause the symptoms you describe & its a guaranteed engine killer if not fixed.

Just how do you think of stuff like that!!!??? Well, it's a good thing you did, because you were right, overheating is seeming to be the issue. The rig was running bone-dry with not 1 drop of coolant (and I know a motor will terribly act up without coolant). The coolant reservoir fooled me as it had more than an adequate level of "water".
The motor and radiator didn't have one drop, which explains overheating with the lacking of steam. Why the motor had zero coolant, you ask? Well, it is not holding it; it flows out just as fast as I pour it in. Long story short: The guy sold me a lemon!

Now, to folks who commented earlier, thanks to all of you guys. I have the source of the problem now. I need to figure out the repair -- if even possible.

What are the most prominent places coolant would flow out so freely, so fast? Coolant is not going into oil. Truck seems to have great compression. I'm thinking if it were a freeze plug, truck would run pretty nasty... same is true for a cracked block.

So, beside a busted water pump, where else should I look?

Thanks again guys.

 

[Turdle]

Hopefully--freeze plug? Water pump--heater hose? heater core?

Check the oil cooler between the water pump and oil filter-

 

[jremington59]

I don't know how you went 8 miles with no coolant. It should have fried in about 8 seconds.

Where's it pouring out from? My guess is you overheated it and warped a head. It could have just been low on coolant this entire time. There's no way possible you drove it that long with no coolant. When you bought it didn't you check the fluids?

 

[hunterdan]

Missing the drain plug on the radiator? Otherwise, stick a garden hose in and see where its coming out.

Dan

 

[jaedee1]

Hopefully--freeze plug? Water pump--heater hose? heater core?

Check the oil cooler between the water pump and oil filter-

OK, Turdle. Thanks again. I'll try the oil cooler, heater core is bypassed - and i doubt it's a freeze plug based on how it drives.

 

[Scout3]

Just how do you think of stuff like that!!!??? Well, it's a good thing you did, because you were right, overheating is seeming to be the issue. The rig was running bone-dry with not 1 drop of coolant (and I know a motor will terribly act up without coolant). The coolant reservoir fooled me as it had more than an adequate level of "water".
The motor and radiator didn't have one drop, which explains overheating with the lacking of steam. Why the motor had zero coolant, you ask? Well, it is not holding it; it flows out just as fast as I pour it in. Long story short: The guy sold me a lemon!

Now, to folks who commented earlier, thanks to all of you guys. I have the source of the problem now. I need to figure out the repair -- if even possible.

What are the most prominent places coolant would flow out so freely, so fast? Coolant is not going into oil. Truck seems to have great compression. I'm thinking if it were a freeze plug, truck would run pretty nasty... same is true for a cracked block.

So, beside a busted water pump, where else should I look?

Thanks again guys.

Can't believe you ran your ex with the temp guage in the red without verifying whether you had a problem or not. At the very least you have put some serious wear on your engine. A bad freeze plug will not affect the way the engine runs at all, a cracked block may depending on where it is cracked. You say the water pours out as fast as you put it in. Well, where is is pouring out from?

Ed

 

[ranger7ltr]

I've been messing with cars for a while but I've never dealt with the following symptom:

My Explorer starts and runs strong with tremendous power and drives good. But after about 15 - 20 mins of driving it starts losing power badly and the engines tic-tocs / knocks -- and after a while it'll die and won't start back up. If left alone for a good 30 - 40 mins, it starts again and runs as if there's nothing wrong, no knocking or weakness until another 15 - 20 mins... I must say that the loss of power is gradual, it starts around 8 mins or so, and worsens from there, so does the knock.

I'm drawing to conclude that the vehicle is fuel-flooding, but why the knocking? Anyway, do you support that? If so, what should I look at first? Please throw in your two cents. I own a 1997 Ford Explorer 5.0 Limited Edition 4x4 automatic V8 w/ 160k.

Thanks in advance.

As you notated, the engine ran fine for 15-20 mins then starts to lose power...That is about the amount fo time it would take to overheat the engine on extremely low coolant and the amount of coolant in the engine block to stop transferring heat from the engine and begin that cycle of losing power, knocking and dying...

I would always check fluid levels, air pressure, and suspension AT THE BARE MINIMUM before starting to drive a new used or new vehicle...But I am a bit of a perfectionist ...In this case it is difficult to point the finger at the PO since you can't verify that the coolant was topped off in the radiator;instead all you looked at was the coolant recovery tank...And the oil in the engine has been heat cycled enough to require replacement as well...Oil actually removed a significant amount of heat from the engine but if the coolant is non-exisent the oil will absorb more heat than normal and degrade a lot faster...And I forgot the tranny fluid will have been overheated as well in this case...

BTW the cooling fan on the 2nd Gen Explorer is driven by the engine so unless the fan clutch is dead or the fan is missing the fan will be attemting to cool the fluid flowing through the radiator...

But there MIGHT be a bright side to this situation;Yes you have a major coolant leak somewhere that is fixable... Hope it is not a crack in the engine block...If it is something less major, fix it and move on...With the engine still runnng and running strong you might not have cracked a head or blown a head gasket...But you definitely used up some of the remaining life of this engine by overheating it...

And the 5.0 liter is less vunerable to cracking heads than the 4.0 liter OHV is...Though I am not saying that you didn't or can't crack a head on these... They just stand more abuse and punishment than the 4 liter will without damage...

Good luck on fixing the leak...Let us know where the coolant is running from...And the outcome of the engine after the leak is fixed...

 

[RomeovilleIL]

Finding a leak shouldnt be that difficult, especially if its a large one as you described. At this point I would use just water so you arent dumping antifreeze everywhere. Fill the radiator and overfill tank and see if there is an immediate leak. If so you likely have a very simple fix as an unpressurized leak will probably be a lower hose or the radiator itself.

If it isnt leaking already, with everything full start and run the engine until normal operating temp is reached (you want the thermostat to open, maybe 5-6 minutes in summer). Keep the hood open and look for anything obvious on the front of the engine like the waterpump or the hoses, especially the short one right above it.

Turn off the truck, jack up & place on stands and go looking underneath if you havent spotted it already. Any major leak should be quick to find. It's the little seeps that are hard to pin down. By the way, since we already know its a big leak, this should be mechanical repairs only. Do not try to use leakstop products - even if it seals up it will only be temporary and sure to start again at a bad time later.

As others have mentioned, you need to change the oil and probably the transmission fluid after this episode. There is no telling how often it was overheated or to what degree by someone before you bought it.

 

[jaedee1]

I don't know how you went 8 miles with no coolant. It should have fried in about 8 seconds.

Where's it pouring out from? My guess is you overheated it and warped a head. It could have just been low on coolant this entire time. There's no way possible you drove it that long with no coolant. When you bought it didn't you check the fluids?

You are right, it would've fried driving 8 miles... I didn't drive it 8 miles, it sorta idled and a bit of drive for about 8 mins.
The water is exiting the bottom by the oil pan it looks like, but I'm sure it's come from atop somewhere.
I check the coolant reservoir, the oil, and tranny... I bought non test-driven (key was absent, battery was dead)... took the guys word for it! -- yea, I know, go ahead call me a fool... but it wasn't too expensive!

 

[jaedee1]

Can't believe you ran your ex with the temp guage in the red without verifying whether you had a problem or not. At the very least you have put some serious wear on your engine. A bad freeze plug will not affect the way the engine runs at all, a cracked block may depending on where it is cracked. You say the water pours out as fast as you put it in. Well, where is is pouring out from?

Ed

Well, the car would idle fine, then the noise would start mildly, the whole time I'm thinking, fuel? rod knock, I'm not thinking overheating... the temp gauge would be in the middle and then I guess when I'm not looking it just sorta jomps to red or something. Not sure where water is coming from.