Base2001

Heats up fast, but rarely over goes over 155 degrees, even on long trips.
The heater blows 115 degrees when it is 50 degrees outside and it does not.take long at all for the engine to warm up (Less than a mile)
When, on the rare occasion the temperature gauge climbs to 170, the heater can blow 140. (That is HOT, let me tell you).

I am quite sure this car has a thermostat.
It warms up like it has a thermostat.
But, it will not climb to 200 ever.
New car to me, so I do not know what to expect.
Sounds to me like the thermostat opens early and does not shut..
I have not removed the cap and watched the flow of water, but now that I think about it, this would probably show when the themostat opens and closes.
Have never had a car run this cool..
Does not heat up, even on long trips (200 miles)

Is it possible this Impala has a fail safe thermostat?
I need to read up on those..
The theromostat is a pain on this 3.4 V6.
Besides, I just flushed and filled the radiator 7 days ago.

What are your thoughts?

I would rather it hit 195 or 200 and stay there.
Isn't that what it should do?

Even if someone put a 165 THermostat in there, it would have to heat up to at least 165. RIght?

I am frustrated..
Do not want to drain the radiator and change the Thermostat, but it looks like I am going to have to.

Just looking for your thoughts.
It will be two weeks before I will have time to work this out.

Waving hi to everyone..
Just signed up 10 min ago..

tech2

check for a p0128 code. it sets when the car does not come up to temp in a set amount of run time. if it has this code, replace the t-stat. if you do take it out, ensure the correct temp stat is installed. sometimes people replace the correct temp stat as a way to "fix" other problems. You do not want a cold running stat...promotes engine sludge build up and poor mpg.

kevinkpk

Yep, you can install a higher temp stat. It is not failed open, I can attest to that. You do want to replace it with a fail safe open, and it's a little "jewel" to get at.

Base2001

The 3.4 does take a 195.degree thermostat and yes, it is quite the jewel to replace, but with the right tools, time and patience this problem will go away.
Need to clean the EGR also.. No one likes complicated, but it is a part of life..
Might just put ithe Impala in the shop and have them do the intake gasket, might even go further and have them replace the head gaskets also.
Trusting the mechanics is a hard step for me, but I'm not as young as I used to be.
Thank you for your help and advice.

tech2

why headgaskets...very very rare that these car need headgaskets. intakes yes, hg nope.

Base2001

Glad you said that.
Checking for a blown headgasket is quite easy and mine seems fine.
What I do not have is a good test for an intake gasket.
Is there a simple test other than observing an oil/coolant/air leak?
I have cleaned the block where it appears to have an oil leak, but until it leaks again, I will not be able to pin point where the apparent leak actually is..
The engine does not seem to be leaking any antifreeze.
It also does not have any oil in the antifreeze.
Luckily, there has been no antifreeze finding its was into the oil.

The simple car fix would be to change the thermostat.
Additionally, I will be removing/cleaning and/or replacing the EGR.

The oil leak was not heavy nor was it dripping, but the backside of the engine (near the fire wall) was covered in an oil film and there was evidence of heavy oil film caked on a hose underneath the engine and near the firewall.
Might have come from the oil sending unit for all I know.
Would like to check the intake manifold gasket without having to go though a lot of effort.

Head gaskets are easy to check..

Perhaps there is a simple check for the intake..


Over the next few days I will drive it and take note of where the oil may be leaking from.
Sadly, I have put some Lucas Stop leak in the oil, so it may take a while for the leak to reappear..
The cold weather has slowed me down, but this project will need to start soon.
My life would be simplier if all the engine actually needs is a thermostat and an EGR valve.

tech2

post some pics of the intake manifold ...where it meets the heads

Base2001

working on pictures

Base2001

Okay, the weather has mellowed..
Changed the thermostat..
After testing, the old thermostat worked perfectly..
The problem was the old rubber gasket allowed the coolant to bypass the Thermostat.
Took me an hour to get to the thermostat.
1/4 turn at a time to remove the bottom bolt
.
Had to remove the bolt, could not remove the gooseneck until the bolt dropped.
Made a tool out of a coat hanger and a rare earth magnet to get the bolt started back and again, 1/4 turn at a time to tighten the bolt.
Took two hours total, but now the engine runs at 185 degrees.

the thermostat tested at 195 degrees.
185 means the cooling system is working perfectly..
Warms up and stabilizes at 185..

I need a camera to post pictures..
Still looking for a way to post pictures..

next project will be the egr valve..
Note: This was not an easy job to do..
Almost impossible..
The bottom bolt could be impossible..
Trust me, I was lucky.
YMMV.