help overheating

[zadam123]

My mechanic fixed my thermostat housing a few days ago cause it was leaking and now my car is overheating he also replace my thermostat. My car is not leaking now and has antifreeze and im not stuck in traffic. And my fan is working. Any ideas what is could be. evey 10 minutes i have to pull over to let it cool down

[jdm monkey]

bad thermostat (not opening)

[zadam123]

That's what I thought but mechanic do.t think so. Is there anyway to test that? I know changing it is a big job

[jdm monkey]

The only way to test it is to take the thermostat out let it sit in water until it boils and check if it opens.
Another possibility is a bad water pump.

[Grif]

Another possibility is a bad water pump.

I was thinking water pump as well, but the only time ie ever had one of those go bad (not in the VX) you knew it!! It made one hell of a noise.

[Marlin]

Another problem is the fan clutch. My fan still worked when it was running. The easiest way to check is to try and spin the fan with the truck off, it should not wiggle and be difficult to turn. If its easy to do it, or it wiggles, the clutch is bad.

[PK]

We can eliminate the fan clutch if the engine is still overheating while you are in free flowing traffic.
The air flow through the radiator eliminates the need for the fan.

Sounds like thermostat or water pump, or richard head mechanic left a rag or plug in one of the galleries while he was working on the engine.

Be careful or it will cost you a motor.

PK

[Grif]

Did a quick search here, seems if the engine is running lean it can cause overheating as well? Most reports indicate a throwing the CEL for a lean condition as well. Is the check engine light on?

If the lean condition is the cause, then some reports indicate cleaning the MAF sensor will rectify the issue.

I dunno, just throwing that out.

[zadam123]

I was thinking water pump as well, but the only time ie ever had one of those go bad (not in the VX) you knew it!! It made one hell of a noise.

Thanks for the input.no noise was made just noticed the air conditioner was starting to blow out hot and look at that temperature and it was hott. Here's another question i have a 1 hour ride home would it be better for me to go a little faster or to drive slower to keep the temperatures down?

[zadam123]

Also how hard is it take out the thermostat. does anyone have a step by step. i heard it's a big job

[lasturbo]

Another problem is the fan clutch. My fan still worked when it was running. The easiest way to check is to try and spin the fan with the truck off, it should not wiggle and be difficult to turn. If its easy to do it, or it wiggles, the clutch is bad.

I agree with Marlin, it may be a fan clutch failure or very weak. You need this to pull the air through the radiator. Did you check it yet?? I know this because mine was starting to run higher than normal on the temp guage and when I replaced the fan clutch, fixed it!!

Here was my thread on the fan clutch help I asked for FYI:
http://www.vehicross.info/forums/showthread.php?t=16221&highlight=fan+clutch

[zadam123]

I just checked the fan clutch and it doesn't wiggles an is not real easy to spin. So i don't blow out my motor what is the hottest i should let the temperature run before i pull over to let it cool off middle,3 quarters or up to the first line by the h? Also does the fan have two speeds ybecause it seems like it's spinning but not real real fast

[Marlin]

I just checked the fan clutch and it doesn't wiggles an is not real easy to spin. So i don't blow out my motor what is the hottest i should let the temperature run before i pull over to let it cool off middle,3 quarters or up to the first line by the h? Also does the fan have two speeds ybecause it seems like it's spinning but not real real fast

I am still sticking to the idea that the clutch is bad or going bad. Mine appeared to work just fine, but under any torque it was slipping, and my temp would get hot, even when driving.

As for speed, the RPMs are more important than actual speed. The lower the RPMs, the less combustion, therefore less heat generated. I would NOT run your AC, as a matter of fact, running the heat on full will help reduce the engine heat, but as long as it isn't in the red, you should be ok. You can also crack the hood, cut a hole in the hood;) I would change the oil after this problem is solved, if it has run hot a little bit, your oil will start to break down. No worries, don't drive it in the red, get it home, should be no problems, I have over heated mine a few times on the trail. Another trick the ZU guys showed me, and this will determine if its the fan, pop the hood, with the truck in park, rev the engine to about 2-3k rpms manually at the throttle body. If the fan isn't sucking a bunch of dirt out of the radiator, your fan isn't working, mine is like a hurricane under the hood when I do that and you can drop temp back to 170 in less than a minute.

[Ascinder]

Another thing to try at least for this time of year would be to drain the antifreeze and just run straight water to get it home. The reason for having antifreeze at all is just to prevent it from freezing(clever name huh?) and to help prevent rust. Water by itself is a far superior coolant and would help keep your engine cooler in the meantime. I would also point out that that in my experience, any time you have weird/bad symptoms occurring right after somethings been worked on, it usually as a cause of that work. Most mechanics will tell you the "oh it's not that" story because obviously it would make them look bad to admit they screwed up, and 99% of the time the customer won't force the issue and make them correct their work. It also gives them more business since they're now working on "some new problem".

[zadam123]

Another trick the ZU guys showed me, and this will determine if its the fan, pop the hovod, with the truck in park, rev the engine to about 2-3k rpms manually at the throttle body. If the fan isn't sucking a bunch of dirt out of the radiator, your fan isn't working, mine is like a hurricane under the hood when I do that and you can drop temp back to 170 in less than a minute.

Should i try this on a cold Modor or let it warm up a little bit also how do i know if it's sucking dirt from rad. Do I just open the cap and look for bubbles is that what you mean?

[rowhard]

just noticed the air conditioner was starting to blow out hot and look at that temperature and it was hot.

did this just happen once? what you describe here is the ac freezing up and that will cause overheating. If you were stuck in traffic and running the ac, that will happen

[zadam123]

happend a couple of times. if i keep it at aroud 50 mph i can last a half hr from start befor i have to pull over and let it cool down. at least thats what happend today with no traffic

[zadam123]

Well the mechanic said it was the clutch fan even though it didn't spin freely 4 me when I spun it or seem loosening . He said it is not spinning fast enough when the temperature gets hot.I guess well wait and hope this is the problem. Total is 175

[lasturbo]

I assume that is parts and labor cuz I got my fan clutch for under 90 bucks with a lifetime warranty. At least u are fixed now!!!!:bwgy:

[Marlin]

Should i try this on a cold Modor or let it warm up a little bit also how do i know if it's sucking dirt from rad. Do I just open the cap and look for bubbles is that what you mean?

For the sake of others, doesn't matter if truck is hot or not, you can actually feel the air from the fan blowing across the engine, it is really like a hurricane in there, at least with the torque cool fan clutch. Nothing to do with the radiator or anything. If you have any dirt or whatnot in the radiator externals, the fan will suck it through.

[zadam123]

At least u are fixed now!!!!:bwgy:

WRONG! He replaced the fan clutch with the aftermarket one ( when you guys said it sounds like a semi you werent kidding) so i throw on the ac and head home and 20 minutes later its still overheating WTF! i turned off the ac and it cooled down to like half way maby a little more so I called him back and he is trying to tell me it may be my head gasket.

I thought if a head gasket goes the car looses power and smoke comes from the exhaust. I am tired of this guessing game, im out $600. Is there anyway it can be a themostat, he told me if it was no good it would get hot really fast which it dont.

[tom4bren]

Another thing to try at least for this time of year would be to drain the antifreeze and just run straight water to get it home. The reason for having antifreeze at all is just to prevent it from freezing(clever name huh?) and to help prevent rust. Water by itself is a far superior coolant and would help keep your engine cooler in the meantime.

Not true. Anti-freeze is a magic elixer. It lowers the freezing point of the solution but it also raises the boiling point. The heat exchange factor could be as you say but if he's already prone to overheating, then he could actually overheat quicker if the water starts to boil.

I've never experienced it but was told that the vanes on the water pump can erode over time. On that tid-bit of info I changed the water pump on the Eclipse when I was having overheating issues. It was fine but it was time to replace the timing belt anyway so I didn't get too pissed.

I don't know if the VX has a similar problem but some engines are prone to getting an air bubble right behind the thermostat. That air bubble keeps the thermostat from responding to the water temp & opening. You have to get a special tool (can't remember what it's called) that fits on the opening of the radiator in place of the cap and allows you to have extra anti-freeze above the level of the radiator. When the bubbles work their way out, the anit-freeze flows in to replace.

If you do replace your thermostat, make sure you get the kind that has the blow-by plug. Supposedly if your engine overheats, fluid will leak by enough to save your engine ... in theory. In reality, take a pair of pliers and pull that plug out before you install in in the engine. Also, install it with the hole at the highest level. It should allow any trapped air to flow through and solve that trapped air problem.

Now to qualify EVERYTHING I've said. I'm still having overheating problems with the Eclipse so I may be out in left field. I've isolated the problem down to a relay that controls the fan (it never comes on).

[Ascinder]

Antifreeze does raise the boiling point, but water is unmatched at absorbing and carrying heat away. It may boil over, but then all that's boiling over is water and you can just add more to get home for far cheaper and less environmental impact than boiling out your antifreeze. I wasn't telling him to run his VX on it, he just wanted something to help get him home with.

[jdm monkey]

WRONG! He replaced the fan clutch with the aftermarket one ( when you guys said it sounds like a semi you werent kidding) so i throw on the ac and head home and 20 minutes later its still overheating WTF! i turned off the ac and it cooled down to like half way maby a little more so I called him back and he is trying to tell me it may be my head gasket.

I thought if a head gasket goes the car looses power and smoke comes from the exhaust. I am tired of this guessing game, im out $600. Is there anyway it can be a themostat, he told me if it was no good it would get hot really fast which it dont.

Maybe the thermostat is only partially opening... who knows.

[Riff Raff]

I would also point out that in my experience, any time you have weird/bad symptoms occurring right after somethings been worked on, it usually as a cause of that work. Most mechanics will tell you the "oh it's not that" story because obviously it would make them look bad to admit they screwed up, and 99% of the time the customer won't force the issue and make them correct their work. It also gives them more business since they're now working on "some new problem".

ASCINDER--- Hmmm, now the total is up to $600 and continues to grow. You are dead-on target about the mechanic!!!

:_thinking:_confused

[PK]

WRONG! He replaced the fan clutch with the aftermarket one ( when you guys said it sounds like a semi you werent kidding) so i throw on the ac and head home and 20 minutes later its still overheating WTF! i turned off the ac and it cooled down to like half way maby a little more so I called him back and he is trying to tell me it may be my head gasket.

I thought if a head gasket goes the car looses power and smoke comes from the exhaust. I am tired of this guessing game, im out $600. Is there anyway it can be a themostat, he told me if it was no good it would get hot really fast which it dont.

Well, it certainly could be a head gasket, or a cracked head.
But that should have been the first thing your mechanic checked and eliminated.
The engine would only loose power if it is real bad.
And it would not blow smoke, only steam like when you first start up on a cold day.

1. Check for water in your oil. (Oil goes milky like creamed honey).
2 Remove radiator cap and run engine at idle, revving up and down a bit as you watch water in radiator.

If the oil is milky, or you see bubbles, or water squirts out, then the head or gasket is gone.

Good luck.

PK

[Marlin]

Antifreeze does raise the boiling point, but water is unmatched at absorbing and carrying heat away. It may boil over, but then all that's boiling over is water and you can just add more to get home for far cheaper and less environmental impact than boiling out your antifreeze. I wasn't telling him to run his VX on it, he just wanted something to help get him home with.

And with the extra antifreeze you have since it is no longer in your truck, you can feed that to your significant other as a calorie free sweetener!!! Sorry, just saw the news about the chick that killed her husband and then a few years later her boyfriend by feeding them antifreeze.

[tom4bren]

Antifreeze does raise the boiling point, but water is unmatched at absorbing and carrying heat away. It may boil over, but then all that's boiling over is water and you can just add more to get home for far cheaper and less environmental impact than boiling out your antifreeze. I wasn't telling him to run his VX on it, he just wanted something to help get him home with.

OK, now we're on the same page:)

I H8d Thermodynamics in college. I do remember about the caloric capacity of H2O. Thinking about Steam Tables still gives me a headache.

I still remember PV=mRT from that class as well.:)

[zadam123]

Does anyone know how much a head gasket should see if that is the problem?.
I think the oil looks fine As far as bubbles are you talking about the radiator Because when i took top off the rad. bubbles were coming up

[tom4bren]

Bubbles in your radiator is not a good thing. What was going on at the time is important though.

Was it just a couple of small bubbles or were they big bubbles that just kept coming?

Was the engine hot at the time?

Was the radiator full?

I recommend you start over with the basics. Start with the most basic first.

Check to make sure the radiator hoses are OK (you can even do that before replacing the thermostat). With the engine at operating temperature, make sure neither of the hoses have collapsed. It doesn't sound like that is what your problem is but check anyway.

Take the VX to a radiator shop & get the radiator flushed & pressure tested. They'll should be able to spot any potential problems if there are any.

Most often the thermostat is the problem. Even though it was just replaced, do it again & get an OEM replacement from Isuzu (they are almost always better than the aftermarket ones from the box stores).

[etlsport]

I think that what he is talking about is when taking the pressure cap of the radiator bubbles come up in the overflow tank. That is probably a good thing. Means that the radiator is holding pressure.

[tom4bren]

I didn't get that. It sounded like the bubbles were in the rad.

Flushing the radiator probably won't help but considering the age of the VX, it's not a bad idea.

I'm trying to think of anything, other than a blown head gasket that would cause those bubbles. Since his oil is clean, I'm kinda leaning away from the head gasket.

If the lower hose is collapsing when the engine gets hot, that could be restricting the flow to the point that it overheats (boils) and the bubbles are actually trapped air in the system that are just working their way out. Of course, if the thermostat is staying closed then the lower hose could still be collapsing even if there is nothing wrong with it.

http://www.dummies.com/how-to/content/how-to-troubleshoot-an-overheating-engine.seriesId-131604.html

Hey, it's a starting point.

[zadam123]

I took of the radiator cap While it still was hot The overflow tank started overflowing And some bubbles c.ame from the radiator 4 a second or 2. It doesn't look like any hoses collapsed. If it is the head gasket has anyone had it done and how much?

Is there any definite test to see if it's the head gasket,watter pump, thermostat, or even radiator. My mechanics guessing games are costing me a fortune

[Ascinder]

Almost sounds like the mechanic failed to completely bleed out any remaining air when he did the thermostat. Your system may be trying to purge it. Do what Tom said and take it to a radiator shop(not the mechanic) and tell them the story.

[tom4bren]

To test the head gasket, you can pick up a compression tester at your local auto parts store & check the compression on each cylender. That would be the first indicator but only if it's a major leak. You're better off taking it to a garage to get them to do it and to perform a bleed down test at the same time (not sure if the guage you pick up at auto parts will be adequate for that).

I'm still leaning towards the thermostat. It's not unheard of to get a bad one out of the box. If you do go that route, make sure they bleed the system like Ascinder mentioned. Does anyone know the procedure for that on our VX? Even though it's not easy on our beloved VXs, it is something you can do at home. That should save you a few $$$.

There is no test for the thermostat without removing it. Same for water pump. Radiator can be flushed & pressure tested.

I feel for you zadam. I replaced the thermostat twice on the Eclipse, the water pump & timing belt, 2 temp sensors ... all were fine. It appears that it's just a relay that's causing my problem. That's not your problem though since your fan is coming on (mine's not).

[zadam123]

the saga continues. drove my car to work today (45 min drive)without the ac on and no problems, gave it to the mechanic and he drove it around with the ac on and he said no problems and dont think head gasket is bad cause car runs strong, he said maby there was a bubble in the rad and now it good so i drove it home wiht ac on and after about 50 minutes it started heatin up again. now he thinks its the water pump cause there was a lot of corrosion in it when he fixed the housing..

sorry for all the qustions but if its the water pump wouldnt it leak and how can you test a water pump. im not paying for any more guesses.

thanks

adam

[tom4bren]

That's the problem. Usually when a water pump goes out, it starts leaking. But I've been told that it's not uncommon that the vanes erode eventually which just cuts down on it's ability to move the water. In that failure mode, it doesn't leak ... or make noise. Worst of all, the only way to tell if that's the problem is to remove it & inspect it. If you're going to go through all that trouble then you should replace it.

BTW, even though I've been told that it's not uncommon, I've NEVER known anyone that has experienced that problem.

[lasturbo]

Well the mechanic said it was the clutch fan even though it didn't spin freely 4 me when I spun it or seem loosening . He said it is not spinning fast enough when the temperature gets hot.I guess well wait and hope this is the problem. Total is 175

Maybe the fan clutch was the ultimate cause and the subsequent damage to the vehicle continually getting hot is something else like the head gasket now or t-stat etc. Aluminum does not like to get too hot and/or the next weakest point goes. Good luck on your diagnosis.

BTW-I put a Hayden fan clutch and it is quiet. When I posted my thread, the group who had Torqflos seemed to like them but the drawback was they were loud so I tried the Hayden and was happy.

[zadam123]

Just wondering if theres a warrantee on a water pump since i know they should be replaced at 100,000 miles which mine was and now only has 40,000 miles on it? should it go this fast?

[IndianaVX]

I feel your pain.....why you ask? Because I'm having a lot of the same thing happening to me.
Here is what I know and what I've done.
I have replaced my thermostat, and am right now in the process of doing a step by step on how to replace it, including pictures!!
It is a big job, but if taken slowly, and pay attention, its not too bad of a job. But vx still overheats in town driving with ac on, and even with the heater on
It takes a lot to get it to cool down.
Befor replacing the thermo, my theory was. While driving, the resevour was filling all the way up with. Coolant, and then blowing the coolant out the top of resivour
Which then left me low on coolant. However, even after thermo replacement, and even when the engine isn't overheating, when I stop and shut the engine off, I hear the resivour bubbles, and it fills up to the top.
I replaced my orange coolant because it looked extremly dirty, and even had little tar ball looking things in it. This tar ball residue also stained my resivour. So with this in mind, I wonder if the lines in my radiator are also covered in this tar all residue, which would constrict the flow thru the radiator.
My mechanic buddy told me that the orange coolant breaks down luke that, and gets all mucky. So now I'm running the green coolant.
But I'm still overheating.
I also replaced my radiator cap, which I suggest you do also. If the cap is bad, nothing else works proper
Still overheating, and by overheating, in my case, I can drive for hours withac on and. At highway speed and not overheat, or even get high. But if there is a stoplight I have to stop for, within a minute, I am getting hot. Then its windows down, heater on full blast,
And then even at highway speeds, it does not cool down where it should be. This is the point where I. Think I'm loosing coolant thru the resivour. Because I am always low on coolant when I check it after I get home.
Sorry if this is hard to follow. With this blackberry, its like I'm typing on a postage stamp! Lol
Hard to stay cohesive.....
Something else you need to check is that you don't have a ton of debris on the front side of the radiator. It wouldn't take too many butterflys plastered on the front side to restrict the flow of air over the fins.
But that is where my next step is, and that is to replace the radiator.
I may need to check the fan clutch again. I had the water pump replaced a couple of years ago (or it was SUPPOSED to be repaced, I ought the pump) with my timing belt debackle.
I don't really know anymore. I am watching this thread closely. OH, my oil is not milky.
That's about all I got right now, get a new radiator cap. Its cheap, and easy to do, and you will probably be repacing the one that came with the truck.
Hopefully my mini novel may shake something loose in someones head and we can get this problem fixed.
I will try and finishthe thermostat replacement how to soon, so you can do that. The shop here wanted 500 to replace mine!

[zadam123]

I was suppose to take my carto the mechanic today when the temperature was hot . only problem was today it did not overheat. Maby because it's colder in the morning i drove it for 1 hour with a c on and no problems. It was about 74 thismornin and when overheated temp was 94 outside.