03 Impala coolant leak

[Maebandy]

My 03 Impala has been overheating and leaking coolant. We changed the thermostat, the lower radiator hose, the water pump. It is still leaking. Now they are saying it is probably the cast aluminum housing that surrounds the water pump. Can we change this housing ourselves without affecting the timing or is this a job for a Certified Chevy mechanic? Also, it had been starting with difficulty before this problem reared its ugly head. Has anyone else had these problems, and if so, how did you heal them?

[bermis519]

Well i found out the other day that my car needs a intake manifold gasket on it because it's leaking antifreeze all over the engine. I dont' know if it's mixing with the oil or not but i have been checking to make sure it's not. I was told the oil will turn a milky white when they mix (oil and antifreeze) I have a warranty on mine and it's going to cost about 900 bucks to have it done. It starts very rough, sometimes i have to hold the key for about 5 seconds, i dont' know if thats from the gasket leaking. Its going in tomorrow and i will let you know what the outcome is too...there is also a loss of power too....

mike

[db17]

The chevy 3.4 is notorios for the intake gasket leaking. There is actually a factory tech bulletin on this problem as they are aware that the problem exists. If you have 3.8 it may also have a leak there but it is more rare on this engine. It will cause a lack of power as well as the engine is no longer fully sealed

[richtazz]

If it's a 3.4, it's an intake leak, if its a 3.8, it's a cracked upper plenum near where the throttle body mounts. Both are common problems, and both are relatively easy for a decent home mechanic

[missie1234]

I have a 2000 Impala 3.4 and am having the intake manifold gasket replaced. I called GM because I found a service bulletin for this problem on the internet. I was told that my car does not apply because this letter only went out to people who have a 3.8. I just think this is soooo wrong. If I would have received this letter in 2003 when it was sent out I could have had it replaced under warranty. I don't know how they can just guess at which cars they think might have this problem. They told me there was nothing they could do for me!

[bbeaven]

i have an 01 and in the neck of the radiator there is a muddy-like brown gunk.
is this normal for these cars, (3.4L) and if not could it possibly be oil?? or any related problem?

[bermis519]

I had this problem also. I found the nasty brown gunk by the radiator cap on the inside. This is from someone adding the green antifreeze with the pink antifreeze. You need to have your system flushed before it causes problems with your thermostat and your water pump. Make sure you DON'T mix the green and pink antifreeze together...it's either one or the other!!!!! I know chevy recommends the pink fluid in it.

Let me know,
Mike

[WGP]

I checked the coolant level on my 04 yesterday and I also found the brown gunk on the radiator cap. This car has 11k miles and I'm the only one who has ever touched the engine since I bought it with 14 miles in March 04. I know about the problem with mixing green/red coolants but I would think there would have been no "green" coolant added (??) unless the dealer topped it off when it was new (??). I was planning on flushing the system myself with distilled water and replacing the coolant with fresh Dexcool (which I do annually on all my vehicles) but now I’m wondering if I should show the gunk to the dealer since it still under warranty (??). I added a coolant filter on my 03 Duramax 2500HD and when I changed it after 16 kmiles it had quite a bit of black scale in it. I wonder if this black stuff we are seeing on the radiator cap is left over clay/casting sand from the block (??). I also had the lower intake gasket go bad on my 01 Malibu’s 3.1 (same basic block as the 3.4)) so I have been watching for any telltale signs of intake leaks – coolant or oil. Any thoughts on this? Should I just flush the cooling system myself or take it to the dealer (it’s still under warranty)?

[public]

Search around. The Dexcool is horrible. A lot of people have the sludge and there had NEVER been any green anti-freeze in there. GM says it is from running low coolant levels at high temps.??? I flushed out the dexcool on all three cars and replaced it with regular green coolant over a year ago. No more problems. Good Luck.

[bigrod118]

yeah I must agree, dexcool kicks trhe bucket. good old antifreeze is the way to go.

[jdb6075]

I have 2002 Chevy Impala. It's experiencing the same problems... I've noticed that the Radiator has brown and white scum on the surface of the water. So, I'm wondering if there is oil mixing with the coolant or vice versa. Alos, when drive I've noticed steam coming from around the engine? But can't locate the source. Does anyone have any ideas?

[WGP]

jdb6075,
Sounds like it could be that the lower intake manifold gasket is leaking ... common problem with the GM 3.1/3.4 V6's ...

[MI2600]

If you want a real eye opener do a Google search on Dexcool. Tons of complaints and GM has not been receptive to paying for expensive repairs. Instead they blame the owner for some oversight.
I drained and flushed (twice) my system. There had been evidence of the "brown sludge" in the radiator neck and overflow tank. I went back to the green antifreeze and have not had any problems.

[bermis519]

Well...after reading all these and haveing my intake gasket replaced about 4,000 miles ago, i have now noticed the sludge crap at the top of the radiator cap, i also noticed that the coolant level is going down and i have no idea why, i have a problem with the temperature gauge going up to like 220-240 in the temp gauge when it's just idleing. Why is it increasing so much, why can't it maintain the same temp as when i'm going down the road. Is the coolant causing this problem. I have mixed feelings about the dexcool now. I still don't know if its safe to put the green stuff in it or not. I would like too but not sure. This car is the biggest piece of shit i have ever owned!!!!!! I just dont' care to take it in anymore, i think in the year that i have owned it, it's been taking in 16 times for problems, CHEVY SUCKS!!!!!!!!!!!!! Any advice???

mike

[myknsteph]

I have a 2003 Impala 3.4L V6 that I just got back from the shop. I took it in to have the coolant flushed due to dark brown fluid in the overflow reservoir and they told me I have an intake manifold leak that is leaking oil into my radiator.

Is this common for the leak to go this way?

Are there any inexpensive fixes for this?