99 explorer intake gasket replacement

[Dono]

If the leak isnt real bad, there wont be enough misfires to cause a code.
This might be a case of expansion and contraction. Motor heats up and seals off most of the seepage, then when it cools...seepage city

I am just guessing though

 

[kycycles]

there was coolant inside the plugs. it is a lot of moisture. i will check it out when i get to the shop this morning. hopefully its fixed

thanks for the help

 

[kycycles]

coolant

at what point should coolant start working its way into the over flow? because mine does not seem to ever back flow, not even when the truck was overheating, i got no back flow today. i could hear the system boiling. i actually ended up opening the cap with some towels and relieved the pressure from the system. a lot of coolant came out of the cap when that happened. coolant that i would think should be back flowing into the over flow.

any thoughts??

 

[Dono]

When the new lower intake gasket went on, did you use sealant around the coolant ports? Both on top, and bottom of the gasket.

I dont know when coolant pushes to the coolant tank. I just make sure there is coolant in the tank, and drive for a few days. Then looking in the resevoir, you will have a pretty good idea if you are loosing coolant.

Sorry about the issue, the thought of taking everything apart again really blows.

 

[Dono]

Whats with the overheating? Whats going on there? Overheating the OHV with factory heads usually means you now have a cracked head.
Oh man.

 

[kycycles]

i did use sealant per the book. i dont believe the book said to use sealant on both sides around the ports. i do know that it said to put sealant on both sides in the corners and a small area in the front and back.

 

[kycycles]

no signs of cracked heads...it was just an observation from the past. the gauge never made it in the red as long as i have owned it.

however.....because of the issue with the radiator not relieving pressure, i got the idea that maybe the build up of pressure was forcing the coolant past the gasket onto the plugs. obviously the coolant is not getting there while driving, only while sitting(as i still do not have an engine light and the truck runs great once started and i have not actually fouled any plugs)

so, my idea was to remove the spring from the radiator cap and keep the system de-pressurized. so far this has worked. i let the truck set for a few hours and it started right up. this would not have been the case before.

lets see what happens in the morning, after the truck has sat all night. then we can discuss the pros and cons of this trick....if it in fact continues to work for me.

 

[Dono]

So, where's the coolant coming from?
Im no help to you.

Can you get a good look at where the heads meet the block and look for any seepage?

How many spark plugs look wet when you pulled them out to have a look at them?

Since the coolant ports to the lower intake are on the ends, id expect the middle cylinders to not have coolant in them if its the lower intake gasket.

 

[Dono]

You might be on to something with the pressure.
Hope so.

You get heat in the cab from the heater core when driving?

 

[kycycles]

plugs

all six plugs were wet, and i mean soaked. yesterday, i only pulled the upper intake off to re-torque the lower intake bolts. i cannot see any signs of any leaks anywhere.

i am pretty confident this little fix will work(at least for a little while) considering the truck would have been almost impossible to start after a few hours.

 

[kycycles]

You might be on to something with the pressure.
Hope so.

You get heat in the cab from the heater core when driving?

absolutely....i did lose some coolant after de-pressurizing the system, but the temp gauges is staying right were its supposed to.

 

[Dono]

All 6 plugs, and it was coolant not Gas...
Umm.....
Dono dunno.

Now, say a coolant port to the Lim blew open running to the middle of the motor would that cause coolant leakage to get to all cylinders? Im just trying to remember what the lim configuration would be against the heads.
I think that the coolant would be leaking in to the oil. Can you remember?

btw, hows your oil look?

 

[kycycles]

All 6 plugs, and it was coolant not Gas...
Umm.....
Dono dunno.

Now, say a coolant port to the Lim blew open running to the middle of the motor would that cause coolant leakage to get to all cylinders? Im just trying to remember what the lim configuration would be against the heads.
I think that the coolant would be leaking in to the oil. Can you remember?

btw, hows your oil look?

no signs what so ever of coolant in the oil(that baffles me)

it did not smell like gas, it did not ignite when i put a lighter to it, but my allergies are bad right now , so my smell is not all that good.

tomorrow morning will be the true test.

 

[Runnin'OnEmpty]

One thing I might add pertaining to the radiator
cap: It has two gaskets that have to seal to work
correctly. The bottom of the cap seals to the
overflow, and the top gasket seals to atmosphere.
If the top gasket isn't sealing, coolant will not
suction back into the radiator from the overflow tank.

Maybe also check the hose connections to the radiator
and overflow tank, since any break in suction will
prevent coolant returning to the radiator.

This probably dosen't have anything to do with the
coolant in the cylinders though, unless the cap isn't
releasing pressure at all, and forcing coolant around
the gaskets...?

 

[kycycles]

[/QUOTE]This probably dosen't have anything to do with the
coolant in the cylinders though, unless the cap isn't
releasing pressure at all, and forcing coolant around
the gaskets...?[/QUOTE]

the problem seems to be fixed. the truck fired right up this morning...it did not hesitate or sputter.....

it appears that the pressure was building up to the point that the coolant was being forced past the gasket. This would make sense considering that after a long drive with a full radiator, coolant would sometime blow out of the radiator cap.

i will go pick up a new cap this week and see if it allows the system to work properly..

after this, i will be posting up about my pesky air bag light(this is the only warning light i have left LOL)

thanks for all the advise guys. i hope this thread helps someone else out.

i would have never imagined a bad cap would cause me so much headache

 

[kycycles]

i am going to start another thread about the radiator(if the new cap does not work). i checked all the lines, but i am not sure why the coolant is not back flowing. maybe it has the wrong cap? it seems like the lower seal on the cap blocks the port for the overflow.

 

[joe doe]

i am going to start another thread about the radiator(if the new cap does not work). i checked all the lines, but i am not sure why the coolant is not back flowing. maybe it has the wrong cap? it seems like the lower seal on the cap blocks the port for the overflow.

this is correct and they way it should be .once the system gets enough pressure to blow past the pound rating on the cap ,the coolant will then flow past and into the overflow .
radiators are sealed systems .just be sure to get the right cap with the correct pound rating.

 

[kycycles]

well...a new cap did not work. 2.5 hours later, truck was very hard to start. sooo....obviously the possibility is there that i need to reset the gasket, or i have another problem going on. But since the truck runs so well, i think i will just keep my system de-pressurized and deal with it for a while.

i did notice that with my modified cap, the coolant was back flowing into the tank. but i could hear it boiling.

i just cant help but think that something is going on with my cooling system. even before i replaced the gasket, there were several occasions that a large amount of coolant blew out past the radiator cap(after i filled the radiator full). its almost like the system built up too much pressure.

the truck runs cool, the gas mileage has increased(almost 16mpg with trailer and motorcycle running 80-90 mph) i have not had a chance to gauge it under normal driving, but this is a huge improvement. the power feels better than ever and i have no warning lights.

i am just going to deal with this for a while. the truck has 180k miles. if i can squeeze another 50k out of it, i will be satisfied.

 

[joe doe]

radiator fluid should not be boiling ,it is boiling because you have it exposed to air .when the system is sealed it should not boil .
leaving the system open you will boil over .
have you checked the water pump?are both hoses pressurized(stiff) once the system is hot?
have you tried replacing the thermostat?

 

[kycycles]

radiator

radiator fluid should not be boiling ,it is boiling because you have it exposed to air .when the system is sealed it should not boil .
leaving the system open you will boil over .
have you checked the water pump?are both hoses pressurized(stiff) once the system is hot?
have you tried replacing the thermostat?

i kinda assumed that the boiling was from the air getting in. still not sure why i get overflow into the tank this way, but not with an UN-modifed cap

i will double check the hoses, but i would have thought the truck would overheat if the pump was in-op

i installed a new stat when i replaced the lower intake gasket.