I had this job about a week ago and thought it would make a good article. I’ve done many head gaskets over the years, and it becomes kind of a no brainer for me, but this is a common problem on the V6 engines so it deserves some recognition. The main problem on these engines when they do have a head gasket leak, is that they will normally leak at the back corner of the rear head. This is the most common place to see a coolant leak on these vehicles.
After getting the car in the air to do some diagnosing, I saw right away that it had the ‘usual’ leak in the back corner of the rear cylinder head. Now, this is a pretty big job as nearly the entire top half of the engine has to come apart to do this repair. Luckily for the customer, their Impala was still covered under the factory powertrain warranty so it would end up costing them nothing to get the car fixed.
Quite a few parts are needed to do this job as well, including a new head gasket set, intake gaskets, valve cover gaskets, coolant crossover gaskets, and a few others. New cylinder head bolts are required as well since they are known as ‘torque-to-yield’ bolts. This means that after a regular tightening to a specific torque reading, they require an additional tightening to a specific angle reading. A special tool, called a torque angle meter is needed to do this correctly. Please note that you should NEVER reuse the old head bolts.
I got the car apart pretty quickly since it’s such a familiar repair for me and found the leak was caused by a spot on the head gasket that was lacking some material. You can see in the included pic below that there is a blue material on the gasket and that it is worn away in the corner area of the leak. GM has redesigned the cylinder head gaskets for these engines that are a little beefier and better sealing. Always use the new design when doing this repair.
Some block and head clean up, and it was ready to go back together. These engines, for as long back as I can remember have used different length pushrods for the rocker arms on the intake and exhaust valves. Many times, people replacing the intake gasket or even doing a head gasket, end up getting these pushrods switched around. This causes an awful misfire condition and will usually have some odd noise as well. If you attempt a repair like this please keep everything where you’ll know how it goes back.
Using the new gaskets and new head bolts, it all went together just like normal and I didn’t have any issues getting the torque and angle readings right on the money. Installation of the intake manifold, coolant crossover assembly, and related accessories all came next and it was just about ready to fire. A quick oil change and coolant flush got it ready to run.
The car fired right up, which is always a good thing! It got to operating temperature, and I bled the air from the cooling system so it was good to go. Another big job down, and a satisfied customer! I’m sure I’ll be seeing another one like this very soon, as usual…
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21 Comments on "Chevy Impala Engine Overheating- Common Causes And Repair"
If you can fix my Chevy impala 02 give me a call 3235078917
2008 Chevy equionx resoivor start to fill up an loose heat unless motor is rev up
I have a 2005 Chevy impala and the engine seems to get very hot after 10 minutes of driving. What can be the problem and what should I do?
What should I do to engine in my 2005 Chevy Impala is getting very hot going to be 250 degrees and blowing white smoke
My engine gets very hot after about 10 minutes of driving. The engine temp gauge is right at the middle what can be the problem?
I am getting ready to do the head gaskets on my 2003 impala with the 3.8 motor. In regard the the torque angle meter. How do I use that?
whats the usual cost for a job like this for a 2000 v6 impala, my son bought a used impala and we just replaced the water pump, radiator and thermostat. it still seemed to be running hot, it will reach the half way point on the gauge. now i see leakage on the head. very upsetting.
Rough estimate for this repair is about $1100, depending on where you go. The dealers are higher of course.
Thank you. We had it repaired, $1200.
After you repaired it did you have any other problems? Thinking of repairing mine but don’t know if other problems will arise after.
2004 cavalier 2.2 echo Tec engine what would cause it to flood out the motor in the air flow hose going to the air filter hose?
If you mean that the hose is full gas, then I would check the fuel pressure regulator. They leakngas and flood out the engine.
My car keep overheating and keep cutting off on me and I don’t know the problem it’s like my engine smoking in the back. Chevy impala 2003 engine 3.8
If its overheating and smoking- GET IT TO A MECHANIC ! ! !
My 04 impala 3.4 engine runs hot. I have bought the head gasket set but haven’t put it on yet, could there be anything else?
I had all leaks and tubes replaced in my honda odysse for the ac. I had the compressor replaced. I had it charged and filled with freon. Driving from California to Texas the ac stopped blowing cool air. Now only blows hot air. The heater works well. I had someone say that it might be something behind the dash.
The problem could be a lot of things. First step is to have the freon charge checked. You may still have a leak somewhere.
my 2004 chevy max v6 engine temp guage is in the middle and goes between middle and red. is this normal, theres no sign of overheating i intend on havn it flushed it has 160k miles thanks jerry
My car is running hot and I noticed that the fans don’t even come on could this be a fuse problem?
ProTech: If the fans are not coming on, it could be something as simple as a blown fuse, yes. Usually though, if the fuse is blown, there is a reason for that. You could have a fan motor that is drawing too much current and blowing the fuse. There could also be a faulty fan relay. You might want to start by checking fuses, but if you don’t find one blown, you’ll have to investigate further. Check the fan relay(s), there could be more than one. Also, check for a seized fan motor, or even just a bad connection somewhere.
On my 2000 Chevy impala it is leaking antifreezze under were the belts are what could cause this problem.
Mechanic JK: This may be from either the water pump or more likely what is called the coolant bypass manifold. This connects the front of both cylinder heads. It can be hard to see, but they seap from the gasket that is on each cylinder head.
My Chevy 2003 impala 3.8 engine keeps excelerating and then it starts to overheat. …what do you think the problem is?