Engine Overheating

Tiny
ELVISED77
  • MEMBER
  • 2003 CHEVROLET IMPALA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 85,000 MILES
My car has been overheating for about a month. It will be fine then all of sudden jumps up and says "hot coolant temp". Then after a couple minutes or so it will go back down. I have changed the thermostat, the timing cover gasket and the bypass hose (which had two tiny holes in it) and it is fine for awhile and then right back to overheating. I would open the cap and usually run it until all the air/air bubbles would stop and then put cap back on. Well. Now all I get out of the filler tube is steam and it was the temp gauge will not come down off of "hot coolant temp". What else could I be missing? When I had the timing cover gasket replaced and the bypass hose. They did all that already. So I am still at square one of why it still jumps to "hot coolant temp" and now will not come back down. What else could it be? Somebody told me the water pump. Could that cause it or no? I change water pump radiator hoses the thermostat radiator and put engine block sealant and the temp Gage still goes up and down sometimes when the Gage goes down I get heat then when the Gage goes up I lose heat
Friday, May 8th, 2009 AT 7:52 AM

81 Replies

Tiny
MIKE H R
  • MECHANIC
  • 3,094 POSTS
Most common problems with vehicles overheating is one, the thermostat. Two, a clogged system. Try draining the coolant out of the vehicle saving it in a container, then back flush the radiator and engine with water using a hose. Make sure the engine is cool when you do it. If that does not work then do a compression check on the engine to check if there is other problems.

This guide can help as well.

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run down this guide and report back.

Cheers
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Friday, May 8th, 2009 AT 8:19 AM
Tiny
MIKE H R
  • MECHANIC
  • 3,094 POSTS
Also with the temperature going up then suddenly going down I would check the head gasket because this is what the car does when it is bad.

Here is a guide to confirm the issue:

https://www.2carpros.com/articles/head-gasket-blown-test

Please run down this guide and report back.

Cheers
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Friday, May 8th, 2009 AT 9:33 AM
Tiny
ELVISED77
  • MEMBER
  • 2 POSTS
Bad news, it tested positive for the blown head gasket. The shop is going to charge me $1,200.00 to do the job. Thanks for your help though at least I found out.
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Friday, May 8th, 2009 AT 1:17 PM
Tiny
MIKE H R
  • MECHANIC
  • 3,094 POSTS
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
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Saturday, May 9th, 2009 AT 10:21 AM
Tiny
LINNEX MILES
  • MEMBER
  • 8 POSTS
  • 2003 CHEVROLET IMPALA
  • 3.4L
  • V6
  • FWD
  • AUTOMATIC
  • 200,000 MILES
First and foremost, I wish to give a quick shout-out to the community with my previous issues. Keep up the great work.

New issue on hand. Was driving home and have made it to the last mile. All of the sudden, it got incredibly hard to steer. At the onset of the problem, I did a mental check of previous troubleshooting steps. I have already have replaced the power steering pump and inspected the pressure line (I can come back to replace it later on if need be). As I was wrestling the car back in the driveway, the engine started to overheat.

I began to research the problem. From what I gather, the issue of the hard steering was deducted to a bad rack. I have the part on order already. However, I need to investigate the overheating aspect as well. Could it be due to the rack's malfunction, or could it be another issue entirely?

Hard steering:
Replaced power steering pump.
Inspected power steering pressure line on both ends.

Engine overheating
Replaced radiator reservoir and hose as it was cracked. And that did resolve the issue. However, with it overheating due to the steering issue, I have to cover my apples.

I look forward to hearing your wise words.

Thanks!
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,330 POSTS
First clear up my confusion. It sounds like you replaced the power steering pump previously for some other problem. Is that right?

The rack and pinion steering gear can cause loss of power assist when the Teflon rings on the spool valve leak, but that never comes on suddenly as you described. In fact, GM had a real big problem with what we call "morning sickness", in the late 1980's and early 1990's. The symptom always is the same. No power assist first thing in the morning for the first ten to twenty seconds, but only when turning in one direction. Over the next few weeks or months, it will take longer and longer for the assist to come back, and eventually turning the other way will be affected too.

Given the overheating at the same time, I would suspect a belt problem, specifically a rusted spring-loaded tension-er that is not keeping the belt tight.

Another thing to look at is the vibration damper. On many engines, the outer ring is the drive pulley for the serpentine belt. If the gel that is bonding that ring to the hub lets go, it can spin and not drive the belt.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
LINNEX MILES
  • MEMBER
  • 8 POSTS
I will gladly clear up any confusion for you. In the regard to the hard steering, it began with upon start-up as it would be difficult to turn when getting out of the drive way. I first checked the power steering levels as they were low. I replaced the power steering fluid accordingly. For a time, it worked. However, I soon find myself having to put it in more often. Also, there was a leak now that you mentioned. After researching the issue, and going through my Haynes repair manual. I was advised to inspect the power steering pressure hose and replace the power steering pump. And for a while, it worked as it no longer leaked as well. When the full-blown issue happened I was starting up the car as I was leaving post office which is less than a mile home. As I was backing out, that is when the difficulty in steering came back. Did some research, reached out to a few mechanic friends they stated that it could possibly be a bad rack. It is my hope that this clears up any confusion for you.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,330 POSTS
Yes, thank you. Anything is possible, but this does not sound like a bad rack. If it is, you would have had hard steering in just one direction. I am still leaning toward a belt issue. After that, a recently-replaced part, (the pump), has a better chance of failing. I have run into pulleys with center holes wobbled out and the pulley was not turning the pump's shaft, and I have had two with a shaft that snapped. The pulley appeared to spinning normally, but with the engine stopped, it and half of the shaft could be pulled out by hand. Both of those were permanent failures, meaning the power assist never came back.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
LINNEX MILES
  • MEMBER
  • 8 POSTS
Thank you for your advice. Okay, I will take your angle at this. Besides, trial and error, right? As I am taking the DIY approach, please direct as in the regards to what to look for, the parts, and links to any correspondence with instructions as to how to go about performing this task. Having replaced the belt before, this will be familiar territory. By no means am I an engineer as I am a computer geek, but I have to give credit to the GM engineers. I like the modularity of their design of the 3.4L engines as to how easy it is to get to some of these parts compared to other engine layouts. I am really enjoying being in control of my vehicle's maintenance. I humbly await your instruction.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,330 POSTS
Here is a photo of what your vibration damper looks like. The green arrow is pointing to the outer ring, which is the pulley. The blue arrow is pointing to the bonding material that holds the ring to the hub. Sometimes you will see that bonding material looks like it melted and/or sprayed around the area. Sometimes they look perfectly fine, even when the ring is broken loose.

To check for that elusive cause, put a chalk mark or piece of tape on the center hub by the red arrow, and another one on the outer ring, by the green arrow. Now run the engine for a least a minute or two. When you stop the engine and inspect those two marks, they should still be lined up like they were when you planted them. If they have move in relation to each other, that bonding material has let go and the assembly must be replaced.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
SUB STEVE
  • MEMBER
  • 6 POSTS
  • 2003 CHEVROLET IMPALA
  • 162,000 MILES
3.4 Liter engine was recently overheating. I took it to a Chevrolet service center. They replaced the thermostat (as well as flushed the coolant and new spark plugs). It now is very erratic. It may or may not overheat (up to red on the gauge), but the problem continued.

Just tonight I took it for a drive. When I was working the engine (driving up a hill or going seventy) it seemed to blow really hot air, then when I was driving slow or idling it seemed to blow cooler air, but then I got home and idled it and it was blowing hot with the temperature steady.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Have the air blend door/actuator checked out.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
WAVETOOL
  • MEMBER
  • 2 POSTS
Sounds like it is air-locked. The blend actuator will not change dependent on rpm change. If there is air in your coolant system it will do exactly as you are saying. Check your coolant level, and top up as needed. When your dealer changed the thermostat they drained some coolant and refilled, prob did not get all the air out.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
DOUGLAS ROBERTSON
  • MEMBER
  • 1 POST
  • 2003 CHEVROLET IMPALA
  • 3.3L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 10,006 MILES
Overheating and I changed radiator and bled the system.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
Rent a pressure tester at auto parts, make sure coolant is full then pressure check for blown head gaskets.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
STEVE W.
  • MECHANIC
  • 15,233 POSTS
I take it the car was overheating so you changed the radiator and bled the system and it is still running hot?
Other items that can cause overheating are a bad thermostat, bad water pump, bad head gasket, cracked head, or block.
Here are a few things to check over:
https://www.2carpros.com/articles/engine-overheating-or-running-hot
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
ELVISLOVER
  • MEMBER
  • 3 POSTS
  • 2003 CHEVROLET IMPALA
  • 3.4L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 250 MILES
So my car over heated the other day we have changed the water pump the thermostat, the heating and cooling sensor on top of the engine, radiator cap. The radiator is full, overflow is full, fans are working and we have burped the system once. Do you think it could still have air in it or could it be something else? It is still over heating.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
When engine is hot, disconnect fans by pulling fuse or relay so they will not start, then feel radiator if you feel cold spots it is bad, if you are using coolant then have the system pressure tested for head gasket/intake. If you see oil in overflow tank then have it checked for head gasket.
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Wednesday, August 1st, 2018 AT 7:50 PM (Merged)
Tiny
ELVISLOVER
  • MEMBER
  • 3 POSTS
The radiator has good flow through it. All the hoses feel good it is not smoking when it started, so we do not think it is a head gasket.
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Wednesday, August 1st, 2018 AT 7:51 PM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
Guess you know what's best
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Wednesday, August 1st, 2018 AT 7:51 PM (Merged)

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