93 Grand Voyager w 3.3 overheating

I keep having an overheating problem with this van. It's blown out a hose
(replaced), the fan seems to come on, I've removed the thermostat, plenty of
coolant, no leaks, etc. Any ideas? Thanks.

 

Is the thermostat in the right way? Are there any (improperly installed)
collapsed hoses? Could you have trapped air that was not purged (use the
bleeder at the thermostat housing)? Or, if you blew the hose and lost all
the coolant you could have also blown a head gasket. BTW, how old is the
radiator cap? It's cheap to replace and if more than a couple years old it
might be a quick fix. Last possibility would be a clogged radiator given
the age. Good luck.

Good luck.

Bob

 

How often have you flushed the cooling system and changed the
antifreeze? How many miles on the van? I'd guess a clogged radiator
core, but without more details that is only a guess.

Does it overheat while cruising at speeds above 40 or so, or only in
town or at idle?


Matt

 

Thanks for the help. Yesterday I removed the thermostat completely, it
overheated about four hours later. It seems to overheat when we're driving,
not at idle. BTW what is the easiest way to check for a clogged radiator on
this car?

Thanks again

patrick

 

If it is overheating at highway speeds with the thermostat out then that
pretty much rules out the electric cooling fans and, obviously, the
thermostat. Pretty much leaves a clogged radiator (most likely
depending on mileage and maintenance history - neither of which you've
yet mentioned), water pump impellor failure (highly unlikely), or head
gasket failure that is allowing combustion gases into the coolant.

I've never had the hoses off either of my minivans so I'm not sure if
you can see the ends of the tubes through the radiator cap or hose
outlets. Visual inspection is normally the easiest way to see clogged
tubes.


Matt

 

Do not rule out the Head Gasket. While it is not a common problem on
the 3.3, it does happen.

I had to do the head gasket on my 94 GC 3.3. I was luckier though, the
leak was visible from the outside of the engine. Based on feedback
here, even though I was skeptical, I had the head gasket done. No
quesiton, that was the problem. <whew>

I have not lost a single drop of coolant since the head gasket was
done. And no overheating either!

Good luck

 

Thanks again for your advise. The car (it's a taxicab) has over 300k miles
and has been well maintained. I've inspected and/or replaced all of the
hoses, reversed the heater core flow and flushed the entire system. I get
very good water flow from every connection on the system.
If it's the head gasket, won't my oil turn white?

Thank you ,
Patrick

 

You won't necessarily have your oil turn white. Remember that the oil
pressure can be 40 to 80 psi while the cooling system is 16 psi. I had a
head gasket go on my 1991 3.3 5 years ago. Haven't had a bit of a problem
since. If you've got a shop that has an exhaust sniffer you can have them
hold the sniffer over the filler neck & check for hydrocarbons. Their
prescence would indicate exhaust gasses in the coolant. Check the radiator
while the van is running & see if there are any bubbles in the coolant.
They might also be an indicator of a leaking head gasket.

Good Luck & God Bless,

Tom Heintz "Mopar Maniac"

 

I have never had the head off of a 3.3L so I can't say for sure, but
most engines have both water passages and oil passages running near the
cylinders. A head gasket failure can cause combustion gases to enter
the oil, the water, or both. Also coolant and oil can comingle. Do you
lose any coolant over time? Any oil? Most head gasket failures I've
seen go both ways - combustion gases into the coolant, but also coolant
sucked into the cylinder (intake stroke tends to cause lower pressure in
the cylinder than in the coolant). If you aren't losing coolant over
time, other than what is lost if you are getting to the boilover point,
I'd question if it was a head gasket leak. Another possiblity,
especially with the miles you have on the van, is a cracked head. I
haven't heard of this being a problem area for the 3.3 engine, but then
I'm not sure many have 300K+ miles on them.

Might be time to suck it up and turn the problem over to a competent
garage or dealer.


Matt