New member here, possible head gasket leak 01 expy

[nerdwrench87]

Hi, I'm Nick. I've been lurking here a little while, and great info! I'm also on f150online and yotatech forums, even though I don't have a yota anymore.

I need a little bit of advice on my " new to me" 2001 expedition XLT.

My dad was going to sell it because pep boys diagnosed a bad head gasket and or cracked block, but would NOT explain to him how they came to that conclusion, or how the block test works, nothing, except they wanted 2700 to tear it apart. So long story short I told him I'd buy it, and he handed me over the title and said happy birthday.

I immediately put a battery in it, as it had been sitting for about a year, hadn't started in about 4 months because the fuel pump died, and went to work on dropping the tank in the street. What fun...

Drove it to work for about a week and a half, no signs of overheating or a bad head gasket ( though I had to reseat a coil pack on cylinder 4 because they didn't put it on properly). Changed oil blah. Turns out pep boys didn't do a coolant flush, or at least properly, because the fluid is extremely watered down and kind of rusty, which they told my dad to get it flushed every 3 months to clear it out.

Fast forward to 5 days ago. Got in, and not even 10 minutes later, on the freeway, the engine starts chugging. So of course I look down again, and the temp is sky high and the overheat light is on. Turned on heater and pulled over and shut down.
Got out and popped the hood, there's a little bit of coolant leaking from the cap, but it wasn't hot enough to be overheating. (I took the cap off without the eruption and hot shower)
Upper radiator hose was hot, the lower one was cool. The temperature gauge read normal a couple of minutes later. I'm guessing thermostat. Also, the heater gets warm, blows hot for a few, then cools off. I'm guessing that's a clogged heater core, which I think could have clogged the thermostat.

I did do a block test at work, it turned from dark blue to a slightly lighter blue. No yellow or green. (Napa stuff)

Does this sound like a head gasket (as my boss says a bad head gasket can mimic a thermostat) or does it sound like I need to flush the heck out of the cooling system and replace the thermostat?

Thanks to all for your input !!

 

[Exia]

Ok if a headgasket is gone you will have either, water in oil or oil in water. If neither than its not a HG.. Check your heater core hoses make sure they are not leaking.. Than check the passenger floor board, if its water logged, heater core is shot....

For the over heat issue flush it and replace thermostat.. and if you can have Autozone run recent/previous codes..

 

[flyin]

all of the headgasket issues i dealt with were always for oil leakage. A multi layer steel gasket works well as long as the surfaces are flat. Could there be any leakage at the under body lines to the rear heater core? Are you losing any coolant? Tstat is easy enough to try but rare to fail hot on that model. It may be worth it to r+r the water pump to look at the impeller. It is also very easy.

Or

Lets verify that the engine is really overheating. Measure upper rad hose temp and thermostat housing and intake coolant passages. It should be around 190-210. You COULD have a bad cylinder head temp sensor or harness issue causing the computer to think the engine is overheated. The computer sees cht and calculates coolant temp and sends a signal to the gauge

 

[nerdwrench87]

No signs of a HG... No milkshake oil or coolant. Not losing any coolant or oil. Floors are completely dry. Upper radiator hose was hot and lower one was lukewarm. I'm guessing cylinder head temp sensor too... I'm just trying to think of work pep boys might have done that would screw up the sensor.

I have a code reader on my f150's ecu tuner, and i pulled a overheat protection code from it when it first overheated on my dad... A wee after pep boys supposedly did the coolant.

 

[Exia]

No signs of a HG... No milkshake oil or coolant. Not losing any coolant or oil. Floors are completely dry. Upper radiator hose was hot and lower one was lukewarm. I'm guessing cylinder head temp sensor too... I'm just trying to think of work pep boys might have done that would screw up the sensor.

I have a code reader on my f150's ecu tuner, and i pulled a overheat protection code from it when it first overheated on my dad... A wee after pep boys supposedly did the coolant.

Just an idea.. check the fluid and see if its extreme dark green... They may have not 50/50'd the fluid.. But thats also the same as everyone else said flush the system and replace thermostat. Also check the tension on the fan see if you can turn it by hand, it should require some umph to move, also inspect the blades....

The only reason I say check these first, is just a precaution and may save you hundreds of dollars. rad flush and thermostat DIY cost 15 - 25 bucks

 

[chuckh]

Take it to a radiator shop and have them pressure test it. Also, pull your spark plugs, if theres fluid in the chambers its time for a new engine....Believe me, I just went through this.

 

[Big White]

The hot/cold form the heater is usually a sign of low coolant. Make sure it is not blowing a cloud out the tail pipe either. (Smell/ or fog bank on cool day!)

 

[nerdwrench87]

They put on the receipt "customer advised to return in 10k miles for radiator flush"
The coolant looks like straight water. They gave him some lame excuse about how you need to flush it extremely often to get it to run clean again. Which I know, as I work at an automotive shop, is horse doodoo. I plan on flushing it within the next couple of days, as I'm not charged for coolant. I also plan to flush the heck out of the heater core, so we'll go from there.

Ill check the cylinders for fluid, great idea thanks.

No exhaust clouds, no sweet smell from exhaust

Tension is good, fan blades look great.

 

[nerdwrench87]

okay so it started "overheating" more and more. i replaced the thermostat, since the heater would blow cold then warm again, and the upper hose would be hot but the lower hose cold. overheated the next day on the way to work. so i did another block test, this time at guaranteed operating temperature. (when i did it before, i just waited for the temp to rise from cold to in the middle). used the napa blue block test fluid. turned yellow instantly with one squeeze.

heres what i dont get... it runs PERFECTLY. no misfire, no loss of power, (in fact its got more power than my lifted F150 of the same year and same motor) . oh well.. haha.

until I either decide if I want to sell it, because lets face it why would a single man be needing TWO V8's? or fix the HG, maybe even do a lightning swap and slap some THUNDER badges on it (in the far future), I'll be trying the 'head gasket mechanic in a bottle" ...my buddy who is a master tech used it in his girls cobalt with a cracked head, and it sealed it up nice and tight, and has held for 8 months so far. worth a shot i guess.

i guess i should have recognized the occasional air bubbles in the overflow for compression leaks, not just air bubbles in the cooling system from an improper burp

thanks to everyone who has helped me with this!

 

[kmh1596]

okay so it started "overheating" more and more. i replaced the thermostat, since the heater would blow cold then warm again, and the upper hose would be hot but the lower hose cold. overheated the next day on the way to work. so i did another block test, this time at guaranteed operating temperature. (when i did it before, i just waited for the temp to rise from cold to in the middle). used the napa blue block test fluid. turned yellow instantly with one squeeze.

heres what i dont get... it runs PERFECTLY. no misfire, no loss of power, (in fact its got more power than my lifted F150 of the same year and same motor) . oh well.. haha.

until I either decide if I want to sell it, because lets face it why would a single man be needing TWO V8's? or fix the HG, maybe even do a lightning swap and slap some THUNDER badges on it (in the far future), I'll be trying the 'head gasket mechanic in a bottle" ...my buddy who is a master tech used it in his girls cobalt with a cracked head, and it sealed it up nice and tight, and has held for 8 months so far. worth a shot i guess.

i guess i should have recognized the occasional air bubbles in the overflow for compression leaks, not just air bubbles in the cooling system from an improper burp

thanks to everyone who has helped me with this!

Not sure why a "Master tech" would use the head gasket in a bottle... He would know what that does to all of the other seals in that engine.... Not good!

Good Luck on your fix--post pics of whatever you end up doing.