The Car Garage

[gmendoza]

This is a room for information for automobile problems.

If you have a auto problem, please post.
If you know a solution to a posted auto problem, please post.
If you found a solution that is common/uncommon knowledge to a posted auto problem, please post.


My first problem: Car overheating. Mercury Grand Marquis 1996.
Bought both temp sensors, thermostat, coolant flushed, new reservoir cap, checked all hoses.
2nd problem same as first, still overheated.
checked oil for milky substance-none
checked if radiator leaking-none
left reservoir cap off and ran car, it bubbled
head gasket problem-none
ran car
3rd problem same as 2nd and 1st. overheated

solution: took out thermostat

cons of taking out thermostat:
less mileage efficiency
no heater (until car warms up)
open coolant system

pros: wont overheat again
ran car to work today: didn't overheat, didn't even come close.

Uncommon knowledge: gutted the innards of faulty thermostat (bought two of same brand and maker, both faulty). installed the thermo-cap back into the housing making it have some resistance.

car is 1/4 to 1/2 temperature, had heat from heater.

the real fuel efficiency problem is that gas prices are not fuel efficient.

 

[ChickenCanoe]

Good idea.

I've found new thermostats that were faulty. When you buy one put it in boiling water (above the set point of the thermo) and see if it opens.
I've also had cars that would overheat without the thermostat. The reason is that the engine will heat the water as it comes to temperature then if there are inefficiencies in the cooling system it will continue to climb. With the thermostat, after the engine reaches temp it gets a surge of radiator cooled water dropping the temp and thermo closes again. This is usually more common on small less well designed systems like an MG or Triumph.
Not likely to be an issue with a Mercury.
If it isn't losing water, I'd check for blocks in the heater core or radiator. A flush won't always fix that.

 

[rebelcowboysnb]

This is a room for information for automobile problems.

If you have a auto problem, please post.
If you know a solution to a posted auto problem, please post.
If you found a solution that is common/uncommon knowledge to a posted auto problem, please post.


My first problem: Car overheating. Mercury Grand Marquis 1996.
Bought both temp sensors, thermostat, coolant flushed, new reservoir cap, checked all hoses.
2nd problem same as first, still overheated.
checked oil for milky substance-none
checked if radiator leaking-none
left reservoir cap off and ran car, it bubbled
head gasket problem-none
ran car
3rd problem same as 2nd and 1st. overheated

solution: took out thermostat

cons of taking out thermostat:
less mileage efficiency
no heater (until car warms up)
open coolant system

pros: wont overheat again
ran car to work today: didn't overheat, didn't even come close.

Uncommon knowledge: gutted the innards of faulty thermostat (bought two of same brand and maker, both faulty). installed the thermo-cap back into the housing making it have some resistance.

car is 1/4 to 1/2 temperature, had heat from heater.

the real fuel efficiency problem is that gas prices are not fuel efficient.

left reservoir cap off and ran car, it bubbled
head gasket problem-none

These two statements don't go together.. What do you mean it bubbled? That car as far as I can tell has no radiator cap an has a pressurized reserve correct?



Unless you just filled it up an its venting trapped air or it is actively overheating it should not bubble. If it is then you do have a head gasket problem.






You also said you got two bad thermostats. Did you test them off the car or did they just not work on the car? I usually put them on the stove in a pot of water. Air in the system will make a working thermostat act bad an at times an can make it actually fail.



Running the car that cold will keep it on the road but it keeps the computer in warm up mode. That means it is running rich of fuel an ignoring a lot of its sensors. This makes bad mileage will fail emissions tests. It also has the oil at a lower temp than it was formulated for. This sludges up the engine. Quaker-state had a rep for this but all oils do it if ran colder than spec.

 

[ChickenCanoe]

Also, did you try a new radiator cap? The pressure is important.

 

[rebelcowboysnb]

Also, did you try a new radiator cap? The pressure is important.

Thats one of those odd cars that does not have one. Said he replaced the pressure cap on the reserver though.

 

[gmendoza]

This car doesn't have any radiator cap.
I checked both thermostats by putting them in a pot of water and boiling the water. they didn't open. Not open = bad thermostat.
I don't have a water drainage problem, no leaks from the radiator, no milky substance from the oil, so no faulty head gasket, unless something else I didn't check for a bad head gasket. I also said I did replace "some" of the thermostat back into the car. Its mostly a restrictor now.


Running the car that cold will keep it on the road but it keeps the computer in warm up mode. seems to me the temp was reading 180 and the gauge was 1/2 way. optimal temp is 190 so im not too bad off.

That means it is running rich of fuel an ignoring a lot of its sensors. This makes bad mileage will fail emissions tests.
We dont have emission test in South Carolina, nor smog because this is an EPA clean state.

It also has the oil at a lower temp than it was formulated for. This sludges up the engine.
My oil temp reads 1/2 as well. was that way when the thermostat was on it.

Most likely I will install the premium thermostat on it this weekend.

remember! this is a 1996 year car with 200,000+ miles on it. Its not a new or a few years new.



Several common signs of a blown head gasket:

• Blue/white smoke coming out the tail pipe which indicates oil is burning-nope
• Dripping oil from the gasket itself-nope
• Excessive coolant loss with no obvious source of leakage-nope
• Loss of power or a rough engine due to compression loss-nope
• Water mixing with oil-nope
• Oil mixing with water-nope
• Low compression in 2 or more adjacent cylinders-nope
• Remove dipstick and let a drop of fluid fall on hot part of engine - oil will smoke water will "sizzle"-smoke only

correction: I meant the reservoir fluid didn't bubble, not did bubble.

 

[gmendoza]

Well I was wrong.It was a blown head gasket. ahhhhhhhhhhhhhhh!!!

It has been some time for an update but here it goes.

Last time I was trying to diagnose and found it was a blown head gasket.It took about a month to self-fix, and we are at the end of the fix.We don't have a covered garage or covered carport so we had to do it by good weather and God's good graces.

Removed and installed new head gasket, timing belt cover gasket, water pump o ring, both valve cover gaskets, intake manifold gaskets, exhaust manifold gasket, egr valve gasket, throttle body gaskets, new head bolts, new spark plugs, and misc stuff.

next weekend is new oil, new coolant, mmo for fuel and oil.

The car fired up this weekend. Cranked great. Timing was spot on and needed rechecked when we removed the valve.

Will update next weekend.

 

[gmendoza]

update:

car failed to start Sunday. a great noodle scratcher.

This past turkey day weekend, installed a new starter. was a bear to take out and put new one in.
car still didn't start
checked and re-gapped spark plugs
car still didn't start

wife came home Sunday, had her help me with spark check tool, all sparks are right on
cranks but car still didn't start

checked fuel button on tip of intake manifold, fuel came jutting out

car started

it was hydro-locked

saw an oil leak coming out of passenger side valve cover.
turned off car and took off valve cover
gasket was wrong type, got an exchange for exact match at advance auto
put gasket on

at 6th bolt of valve cover bolt, snapped off
a lot of colorful metaphors in a space of 30 seconds was blurted out loud.
went to U pull it and got 4 valve cover bolts
came back and put bolts on
started car, works fine, no leaks

car has a little shimmy, not very noticeable at all. wife is putting a full tank in because she put some fuel injector cleaner in a 1/2 tank of gas. problem solved.

driving it to worky tomorrow.