Engine overheating

One way to test for a bad water pump is to squeeze the upper radiator hose when the engine is hot and idling. Careful, because the hose will be HOT! If you do not feel much coolant circulating through the hose when you rev the engine, the pump may be bad. The other cause might be a bad thermostat that is not opening properly (remove and inspect the thermostat), or a clogged radiator. It sounds more like you have a coolant leak and it allows the cooling system to get low, here are two guides we can go over to fix the problem.

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


and

https://www.2carpros.com/articles/car-is-leaking-coolant

Please run down these guides and report back.

Thanks for the guides I found the water pump was leaking so I got a new one for $114.00 and fixed it I love this site.

Engine Cooling problem
2003 Chevy Blazer 6 cyl Four Wheel Drive Automatic

this vehicle has an issue with running hot to the point of boiling in the coolant resevoir. they have had a new radiator and thermostat installed at a shop. i have drained the green coolant out and installed the dexcool coolant, also i have replaced the fan clutch. the temp at the thermostat housing after driving is 220 and the temp guage agrees with that. i am just wondering what im missing. also,while driving there is a "gurgling" sound during acceleration coming from the heater core area, and i was very careful to make sure there was no air in the system.....or so i thought.

At this stage of the game you have probably developed a blown head gasket from one of the previous overheating episodes.
A side note here........ Once you have green coolant in the system, unless you can flush every drop of it clear, the Dexcool benefits are all lost and you only have the effect of green coolant anyway.

hook a pressure pump to the radiator... i believe the cap is 15psi, so crank your pump to 15.... put a pair of vise grips on the overflow hose just under your radiator cap.... watch for a drop in pressure... if u see any leaks, then u know what to fix, however if u dont see any, u said maybe heatercore, check the passenger floor for dampness.... if its dry, its most likely a lower intake gasket, head gaskets are pretty rare on the 4.3, unless it got overheated.....

Hello,
I have a great little blazer that is still my favorite to drive but it is runnig screwy and I need some hints.

1. Everyday I have to add water to the radiator always 16-32 ounces. I don't drive far 20 miles round trip.

2. When I stop at the lights the car shudders and feels like it misses.

3. It runs fine down the highway but in slow moving traffic it boggs down.

4. It over heated today Tuesday the 22, First time in over 16 months.

5.The thermostat is fine it was wide open when the mechanic to the assembly apart. It collapsed in mere seconds after being exposed to the cooler envionment.

6. I have 20w-50 synthetic with a Lucas additive just changed 4,000 miles ago. I used the Fram exra guard filter. Today when I checked the oil it was milky, looked like coffe with creamer in it. Very upsetting but not the end of the world. I will change the oil tomorrow, but how will this affect my lifters? What is my potential downfall here.

7. The mechanic shop said "I have a blown head gasket and it will be a three day job costing 1,500 dollars. Wow to my supprise I figured bad water pump something simple not a head gasket.

8. What kind of test can be run to diagnose the problem properly? I do not wish to just give money away to people. If there is a 100 dollar diagnostic test that can be run I would prefer that. Is there really a way to deterine if it is a head gasket or are you supposed to take the at their word. Economics being what they are now can you really take someones word when the overhead is so high and the revenue so low?

9. I hope this is not too much information but I figure the more you know the better the guess. Thank you for your time.

take truck from that shop because the guy is inexperienced or overcharging, in my opinion. anybody who has worked on these trucks before knows your problem is a leaking intake manifold gasket not a head gasket. this is such a common occurance i cant believe the mechanic thinks its a head gasket. the gasket for the lower intake manifold is made from plastic and rubber which in all cases the plastic gets brittle and breaks causing the gasket to split out, thus causing your leak. get another opinion. dont drive it anymore until you replace the gasket or you will do damage to engine. hope this helps shed some light on the problem. oh yeah this lower intake job should not cost more than 750. and at 750 thats on the high side. ps they redesigned the gasket into rubber and steel so it wont happen again. good luck

Just a little help for the uneducated in car lingo. What is the differance and how do I sound like I have a clue? Is the Head Gasket failure rate common along with the Intake Manifold Gasket. Where is this located and what type of repair is it in relation to the head gasket? I am confused. Can this be fixed and then have the head gasket go son after because now there ismore compression and it will seek a ne weakness?

sorry. i have worked for gm over ten years and worked on my own for several more. i have never seen a head gasket go bad on one of these trucks, its always been the lower intake manifold gasket. the difference is the manifold gasket takes much less time to replace and although it is possible for a head gasket to go bad, i have never seen one fail, its always just been the intake manifold gasket. in my opinion i think if you just replace the intake gaskets now you will have no further problems with the engine.

A month ago my engine began to overheat. It never reached red line because I pulled over and let it cool before it did. When I opened the hood the reservoir had a brown gunk in it. So I got my radiator flushed and filled with more DexCool coolant. That fixed the problem. Now fast forward to now. The car is starting to run hot (3/4 of the full temp guage) when the car is at a stop light or in park. When the car is in motion, at all, the temp. goes back down. Also when the car is accelerated there is a water flowing/bubbling noise that can be heard. I don't really know if it is getting hot though because when it gets hot I'll turn off the car and listen and there is no classic hot water bubbling noise nor smell or steam. I think that it needs a new water pump. What do you guys think?

its possible but it could be a couple of other things to . like a bad engine coolant temp. sensor. or a bad thermostat. is there a engine light on? well whether it is or not I suggest that you bring it to autozone or your local parts store for a free computer analysis . if its a sensor then it will show which one or at least rule it out. keep me posted

Thanks for your time and answers. Where is this intake manifold gasket located? How do I direct the mechanic to observe the failure possibility of this particular gasket instead of the head. Can the manifold be removed without compromising the integrity of the seal? Can the head be removed with out ruining the structural integrity of the head gasket? Can they the machanics do a gasket check or compression check to determine which specific area is damaged and replace that gasket? I appreciate the fact that you have never gad one go bad.

Mine is doing the same thing. I've noticed too when it overheats I lose all heat to the interior compartment.

you need to remove the intake to see that it is bad. **im sure it is bad**. this gasket was so poorly designed that they updated it two times before they made one that would not fail. the original intake gasket is made out of plastic surrounding a rubber gasket. needless to say that over time the plastic cracks and the rubber gasket spits out. the new updated gasket is hard rubber molded over steel so we wont have this problem anymore. basically the intake manifold has to be removed before you can reach the head. im so sure that when he removes the intake there will be no doubt that the intake gasket is gone. sometimes its hard to detect a bad gasket but these fall apart so bad it can not be missed.

start with your thermostat then.

My Radiater has coolant in it.(when engine is cool, I remove radiator cap and liquid is to the top). However the engine is overheating on me this afternoon. I do live in Phoenix, Az and the current temp is 112.Any suggestions. I do have an appointment set to look at it first thing monday morning.

Try replacing the thermostat and see what happens

I am takign it to a shop first thing monday to have them look at it. I trust these guys my brother has used them and they are nice. I have talked to someone else about this and they agree it might be the thermostate. I have read its and inexpensive replacement plus labor might run me aroud 75. Does that sound about right. I hope that is the issue. I just put new tires on the fron this morning i dont feel liek dumping alot of money into it. But it does get me around and i do need it.

what causes the s10 blazer to boil over into the expansion tank?

many different things, a stuck thermostat, bad fan clutch. plugged radiator, bad head gasket, a bad water pump. is it leaking anywhere.

thank you for your reply. no it's not leaking. i'll just have to start replacing items. at least i have a starting point.

Just replaced the rad cap and so far the boiling over problem has stopped.

Hope you can help with this issue, I recently had my Blazer in the shop for a failed distributor and rotor. ( approx ) 1 month ago). Well, 3 days ago my temp guage shot straight to the top while coming home from work, then it dropped to zero, this occured several times as iI looked to pull over. I also ni=oticed my valves clattering just as pulled over and shut off the engine. No bursted hose just a bit of coolant were I stopped. Oil was maybe a quart low. I had it towed to my local dealership and after a day they called and told me I needed a new radiator, hoses, and I should also change the water pump and the lower intake gasket also needed to be replaced. Seems that the Dexcool inthe system had turned to gel inside and fouled up the system. Here is my real question, I was called back 2 days later and the shop told me that when they went to test the vehicle after the repair they noticed the the engine was missing, when they tested the engine they found a cylinder was miss firing anf then scoped the cylinder. They told me that there was a hole in the top of the piston and that the plug was also damaged. They said this was caused by the overheat, and that I now needed a new engine. The engine was perfect before this incident, I have never had any major maintenance, and the car was running maybe for a minute before I shut it down when the overheat occured. What may have caused the damage to the piston and was it caused by the overheat. My cocern is that they may have dropped something into the intake manifold when working on the lower seal for the intake manifold and possible fouled the piston when they started the engine back up after replacing the radiator , water pump and the lower seal. They quoted me about $4800 for a used engine replacment and approx. a grand more for a new engine. What do you think about the cause of the engine damage and the estimate for the repair, I am currently $1500 into the ar for the radiator, water pump, and seal work.

hi sorry to hear of your troubles , im going to tackle this one short but sweet , the overheat concern you had could have caused alot of things , first when the engine overheats as bad as you said it willl expand the cylinder walls causing a loss of compression and aso overheating the oil making it too thin to protect the engine and cause bearing damage but unless you broke a rod or rod cap , or wrist pin the only way to have a hole in a piston that way is to drop a valve or for a plug to break off and strike the piston or like you stated to lose something in the intake , all statements are possible the only way to find out for sure is to tear it down , but either way check around for engine prices and also see if the dealer will work with you since you spent soo much already, where i used to work we would have given the longblock at cost and charged for small parts and labor and i was at a small dealer . and to be honest they should have checked it out first , im sure the tech drove it in the shop

good luck
jim

Thanks alot, this will be very helpfull in making a decision.

Fantastic response

no problem

My 02 Blazer has a heat issue. It over heated the other day. I checked to see if the thermostat was opening by removing the radiator cap. The fluid seemed to be flowing fine so I'm sure the thermostat and pump are fine. I then had the cooling system flushed and refilled with new fluid and had the cap replaced. It still overheated but not as quickly or as bad. My question now is should the clutch fan spin easily by hand and should the coolant have a burnt rubber smell? I suspect the clutch fan and the lower radiator hose needs to be replaced. If you can help me with this puzzle I would greatly appreciate it.

when the engine is running is the air flow good or hardley at all from the fan

The air flow is fair but I am questioning the fan because when I spin it their doesn't seem to be enough resistance. I have replaced the thermostat and lower hose and this has helped quite a bit

sounds like a fan clutch issue

my radiator had a sever leak. i ordered a new one with a new thermostat online and while waiting for it to come in was putting about a gallon n half or 2 gallons of antifreeze a day. the heater quit working while i was waiting for the new radiator to come in. i replaced the radiator and thermostat and drove it around 30 miles, it wasnt running as cool as normal but wasnt exactly overheating. after the 30 mile drive home antime i drove it it would overheat. i replaced the thermostat again, and let it run on a slope to make sure all air was out of the heater core. now as it warms up heat comes from the vents but once i turn the heater on high after a minute or 2 the air goes cold again, the motor itself is still running hotter than normal but not overheating at this time. my thoughts are that if i backflush the heater core that seams to be clogged and try and to unclog it that my cooling system will return to normal and cool correctly.

There is a good chance that will help the heater work better, but I'm worried about the engine running cooler. Have you checked for head gasket leaks? Have you flushed out the engine block?

there is radiator fluid leaking down the front of the oil pan so im going to assume head gasket. time to send it to a shop. thank you for your time.

What does it mean when the coolant in the coolant container is boiling? Boiling happened after the car was turned off, the a/c had been running prior. No boiling when car was turned off and the a/c had not been running.

Check coolant level and thermostat if okay -could be coming from the fan clutch check its operation cold and hot

Engine Cooling problem
2001 Chevy Blazer 6 cyl Four Wheel Drive Automatic

My car is overheating pretty bad. The heating doesnt wanna work at times but when it does the engine cools off. Today my car overheated and shut off and now its mis firing. Do I just need to change my thermostat.

lot of things can cause overheating, check out our page on this issue at https://www.2carpros.com/first_things/engine_over_heats.htm

Hi i have a 2001 chevy blazer that is overheating i tried replacing the thermostat but that didn't solve it. it gets to the check gauges light within about 3 to 5 minutes. any ideas what could be causing it

What's important to know here is: Does it get hot sitting still? Does it only get hot while you're driving it. 3 to 5 minutes is pretty quick to get hot. If it only gets hot when you start driving it, most likely it's the radiator. It'll be stopped up. It'll cool enough at idle but the strain of driving it will heat it up too fast for the partial radiator to cool it off. If it gets hot idling, it could be a number of things. Like I said, 3 to 5 minutes is pretty quick. Are you sure it's actually getting THAT hot. Air pockets in the cooling system will cause inaccurate readings on the guage. Rule that out first. Now, with it cool and no pressure on the upper hose, remove the radiator cap. If it uses a pressure cap on an overflow reservoir, remove it. Wherever you add coolant. Top it off with water and start the engine. Observe the coolant. Don't stand over it though because I'm expecting it to start shooting water out. It sounds like you may have a blown head gasket. If compression from the cylinder is getting into the cooling system, the circulation will be greatly interrupted, thus causing rapid overheating. If it doesn't shoot water out, watch it, along with the guage and see what the coolant does. Make sure it starts circulating. When the thermostat opens, the level will drop in the radiator some and start moving. If the water pump is working, that is. On rare occasions, I've seen the impellers on the water pump worn down due to lack of maintenence on the cooling system. Dirty water, over a period of time, will errode the impellers off of the water pump. Try raising the RPMs to about 1500 while observing the coolant. (cap still off).. see if it starts to circulate more water or see if it starts to cool off some. Enough for now. Repost if needed... I'll keep trying if none of this works..

I just bought this truck and it is overheating. I have changed the thermostat and got a powerflush and it still overheats when you are sitting in traffic with the a/c on. What can I do?