Intake gasket leak or head gasket

[vfour65]

I have a chevrolet impala 2002 v6 3.4l ohv engine. My temperature is always high, just before middle or above in trafic, last week i had to park on the side because it was almost in the red section. One mechanic guy told me it was problely the intake gasket or head gasket. It's losing a little prestone like 1 liter every 300 km. I just ordered intake lower and upper gasket and will change when they arrive, should i change the head gasket too, how can i make sure it's leaking at the intake. I know these engine have ploblem with intake gasket. Is there a test or something to check where it's leaking. Thank you.

[sarotara]

If it's an external leak you can look around the engine bay with a flashlight after driving the car for a bit and try to find where the coolant is leaking from. Carefully, because the engine will be hot. If it's an internal leak, you will get some white smoke out of the exhaust. There might also be a distinctive coolant smell after driving the car. If I had to take a guess, I would say that it's most likely the lower intake manifold gasket that's leaking. Make sure that you bought the revised gasket.

[vfour65]

Ok, thak's for the fast answer, i will change these gaskets soon.

[vfour65]

I changed my intake gasket but when i installed the fuel line on the fuel rail the pipe did'nt have any o-ring. So i tought it was ok but after the job was finished i try start to the car and it smell a lot of gas under the hood and it's leaking just under the fuel rail entry. Can anyone tell me if there is an o-ring at fuel line connection to rail. I tried to buy the o-ring at GM but they only sell the fuel line for $70, what a deal, i want to be sure there's a o-ring there, thank you.

[Colt Hero]

I replaced the intake gaskets on my Impala and there is DEFINITELY an O-Ring on BOTH rails (slightly different sizes, if I remember right). It didn't happen to me, but I remember reading somewhere that when you pull the fuel line out of the rail, sometimes the O-Ring goes flying off. Maybe that's what happened to you.

You can DEFINITELY buy these O-Rings separately (at the dealer), but they're not as cheap as you might think. Looking at my records, I think I paid $22 for them, and I think they came in one set. The injector O-Rings (if you are replacing those too, as I did), came in their own set (~$14 for that). I remember walking out of the dealership with the 2 O-Rings thinking "what a rip-off" but I think this was the only part I bought at the dealer that made me feel this way. Everything else seemed pretty fairly priced.

By the way, I believe there is a test that can be performed to determine if there is a leak. I think they call it a "leakdown test", but I'm not certain of that (and I've never had it performed or know how to do it). Sorry about that.

[vfour65]

Hey thank's a lot for your answer, i guess here in CANADA they don't sell just the o-ring but the complete pipe, that's what they told me before ordering the part at GM since this dealer did'nt have in stock. Last friday i bougth the injector's o-ring from then but they never told me i would have to change the pipe to rail o-ring. Thank's again.

[Colt Hero]

I'd bet the guy behind the counter is mistaken. Try another person, or even another dealership. The guy at my dealership had a hard time finding the part number of these two O-Rings for me. Those sketch drawings they look at with the long lines and part numbers are hard to discern sometimes. I had to turn the monitor to look at it myself to make sure the guy was looking for the right part. There's just no way you should have to replace the whole pipe. Either the parts guy is a rookie, or he's trying to run up your bill (and his bonus)...

[vfour65]

Ok, i'm going to gm dealer tuesday morning, monday is holiday but you don't happen to have the part number of these 2 o-rings, maybe you gept the bill, thank's again.

[jetta90]

vfour65, as ColtHero indicated there is most definately 1 o-ring per rail. I am in the process of doing the intake gasket job myself and the spigot that screws into the rail closest to the fire wall was pretty tough to come out, and when it did was without an o-ring. I was a bit surprised but figured the engineers who designed the system new what they were doing.
So later what do I see on top of the thermosat housing..................yea, you guessed it ................an o-ring. Fits real nice on the spigot too !! It must have popped off when the spigot finally came off the rail.

[vfour65]

Well, everything is finish and i test drive the car, was 30c degree, same d.. thing the temperature gauge is haft way and more. I did'nt find the problem i guess, maybe there's something else, can anyone help me, i out of solution, i don't know what i'm going to do with this f..... car. impala 02, 216000km, 3.4L V6 ohv, my next step will be to go at a GM dealer for inspection $$$$$$. Thank's for help.