Minivan overheating

[Deleted]

Trying to think of all the pertinent/relevant information, I apologize in advance if I say too much or not enough!

We are extremely green with cars but are finding out we can change that one baby step at a time

So the vehicle in question is a 2002 pontiac montana. We bought it used a couple of years ago at a dealer so don't know all the history. Last year (around Father's day) we drove over a huge rock and this tore up the radiator I believe which we got fixed at the shop. Fast forward to last week. We have not had any overheating issues until on our way from New Mexico earlier this week. It started flashing the "coolant temperature hot" warning on the dash that's verbatim what the warning read and there was smoke from the hood. White/cloudy smoke. So we shut down the van, parked it at a gas station for an hour and that cooled it down and took away the warning when we started it back up an hour later and we drove home. Took it to the mechanic we've been frequenting for a year now and he said the van is on it's last legs and it could be anything from one mile to 30 miles but it will die due to a bad engine. 

While I was sharing my van woes with my friend he told me there was yet hope! He called his wife's grandfather who has been a mechanic for 55 years and together by looking at our van via skype they diagnosed it as a bad thermostat. They said if our coolant was oily/brown or if our oil was milky then it might be a head gasket. Our coolant looks green and doesn't look like there's oil mixed in it. Our oil is super low even though we're not due for an oil change for another 100 or 1000 miles so we're not able to tell if it's milky. So far the symptoms are such: the van when driven for around 5-10 minutes gets the oil needle (whatever the one on the far right is) up to the red zone gradually and once it reaches it or right before it will start to smoke under the hood. Once it's turned off it resets because it cools down I assume. Would a thermostat change fix this? My husband's work buddies furthermore told him a lot of them have just removed the thermostat and if the thermostat is the issue that will fix it and it won't harm the vehicle to drive it without a thermostat for a bit. All we'll lose is the ability to turn on the heat inside while the thermostat is removed. Is this true? 

Checked the prices here and the thermostats are just $10 so we don't mind replacing it if there's even a chance it would fix it, but then we were told to also try and replace the thermostat gasket (an O ring) and the hose as well which starts increasing the price for the fix, which we don't want to do if it's no chance it could be that/those things.

The reason I mentioned we replaced the radiator is because my friend mentioned that if there's water coming from the exhaust (which when we checked it was 24 degrees cold here and there was about half of a small cup full of water in droplets coming out of the exhaust) they said that could be one or more air pockets in the radiator that wasn't let out when the mechanic changed it last year. If this is the case then we need to find some valve and turn it and dump all the coolant I believe?

We have never even done an oil change ourselves but are willing to learn. If you have any thoughts/ideas please write it out as noob-friendly as possible lol. Thanks for reading!

[Deleted]

If I read this correctly I would start by adding some oil to the engine. Just because you are not due for an oil change does not mean that you should not check the oil level nor add oil as necessary.

Little oil in the engine and there is nothing to keep the moving parts lubricated.

No lubrication and those moving metal parts get hot.

Metal parts become hotter than they should, something will start to burn off. Probably what little oil is left and also coolant because the engine is hotter than normal.

Little to no oil in engine and gaskets (those little buggers that help to separate the oil and coolant that flow through the same engine at the same time) will start to dry out and become deformed. The head may even warp.

Deformity in the gaskets leads to leakage of the engines vital fluids (coolant and oil).

Your engine may be on its last leg. Especially if you have not maintained its oil level.

I was driving cross-country once and had a bit of an oil leak develop about half-way. I would just stop and purchase a good amount of oil and stop every 200 miles or so to add more oil and never let the level go below it needing about 1/2 of a quart. The car made it home, the engine was fine and I just changed the gasket on the oil pan.

Add some oil!!!!

[gundog]

TRellis is right. You need to change your oil and filter at least every 7,000 miles and check your oil level weekly. Add oil up to the full mark every time your oil level reaches the ADD mark on the dipstick. By not doing so is the fastest way to destroy your engine. Lets take a look at a few of your issues besides oil. Change the thermostat and gasket. If you take the thermostat out....well, you just did 99% of the work just drop the new one in. Your radiator hoses wear over time and will collapse. But, I would start with replacing the thermostat and test drive to see if this solved the issue. In the winter without a thermostat you will freeze and by the way always use a antifreeze/water mix in your radiator and never strait water. Your friend is (for a better word) mistaken. The water coming out of your exhaust is NORMAL forget that nonsense. NOW, get you oil changed or at least fill it up and change out the thermostat, add 50/50 mix of antifreeze and don't forget to add some antifreeze to your overflow container. Lastly, if you do find that you have water in your oil (creamy colored oil) or there is a thick layer of oil in your radiator...take it to a GM dealer as it could be something simple like a PCV valve. Good luck.

[spacecase0]

TRellis,
very well said,

also most owners manuals of the cars tell you to check the oil every time you get gas or once a week, whatever might apply...
hardly any one does that,
even with a new car, if you fail to do that, and it breaks from low oil, it is your fault, and no one else is going to pay for it.
I know a few people to loose engines from not checking often enough. (they almost always say, "but it never lost oil before")

[Deleted]

I would change the oil and filter, right there, do not start it again until done. Drain the oil in a clean pan, pour into a glass or clear plastic jug, let it settle and see if there is water on the bottom, oil floats. Check antifreeze, if full start and run, see if it gets hot again. Could be so low on oil it gets hot, if it did, who knows how much damage was done. If no oil in antifreeze or water (antifreeze) in oil, head gasket may still hold. How far from gas station to home?

Let us know what you find out....James

[Deleted]

Gas station is within a couple of miles. My husband is going to get some oil to pour in. Watched YT videos on an oil change on a Chevy Ventura which I believe has the same body as our van, looks like if we remove one lug nut the oil will drain out the bottom side. Will wait to do that in the morning and will try to do it in a clear oil pan so we can observe and report back. Will of course do this before we pour the new oil in Thanks!

gundog, I misspoke. My friend and his wife's grandpa actually said the same thing when we skyped. For how much water it was and how cold it is here right now that it was normal. Prior to skyping they thought it could be an air pocket, I figured it was worth mentioning to get a second opinion, I see you agree with them!

[hermitjohn]

I have owned many clunkers in my life. I've had some that to be reliable, you check oil and coolant EVERY morning in driveway before starting the vehicle. And do visual inspection of hoses/belts. It sucks, but if you wanted to drive and not walk, you did it. My ex wife refused to do it so unless I did it, she would just let car destroy itself, no matter how financially painful it made things. Caused some big fights. She'd do it cause she figured eventually I'd agree to go into debt to buy a new car... Apparently didnt realize I would sooner walk than go into debt. Notice the use of the prefix "EX".... Now most reasonable vehicles, not clunkers like I had, you check oil and coolant when you get gasoline. Everytime! You definitely dont wait until the little lights come on, that usually means its too late and you are royally screwed especially on the delicate modern high tech engines. I always spent the money to put actual gauges in my clunkers, not rely on the idiot lights. It nearly always was money well spent. My ex of course wouldnt look at gauges or pay attention to the idiot lights so... She really should found rich guy that traded new cars when ash tray was full, or whatever the modern equivalent is, maybe the floor mats get soiled or there is a squished bug on the windshield.

[Deleted]

Well we know to check both frequently now

So we put oil in. The oil in it is brown colored and not milky or watery or anything. After putting the oil in drove it about 2 miles and the issue is still there. The temperature needle on the far right climbs and will get into the red zone if we don't shut it off, there is white smoke under the hood still. When we checked the coolant the entire reservoir which was full 3 days ago was empty last night so we put more 50/50 mix in. Our friend told us to try changing the thermostat so going to spend a few hours doing that today and see what happens.

[hermitjohn]

Several possible causes. Is the coolant level still up in radiator? If not, look for leaks. If lucky leaky hose or leaky radiator or bad radiator cap or weeping water pump. If unlucky, blown head gasket. Blown head gasket doesnt necessarily mean there will be water in oil or oil in water, depends where the gasket blew, might blew to outside without intersecting with cylinder or oil passage. Brown is not super descriptive of oil. Is it nice clear golden brown like oil coming fresh from bottle or muddy brown like sludge.

But yea try the cheapest stuff first. Could well be a non-opening thermostat or a bad radiator cap or bad hose. But on the modern aluminum engines, it always seems to be head gasket or warped/cracked head. Sometimes a manifold gasket. If its a water pump, they not only leak but as coolant wipes out the bearing, they get really noisy too.

I truly hate working on modern cars with all the junk piled up in interlocking layers like a chinese puzzle and you need to be double jointed with hands the size of a pixie. Its like the engineers that designed the stuff truly hate mechanics and doityourself owners. Though I know in actuality, they are just following orders of the corporate bean counters and doing it so its as cheap as possible to assemble in as small of a package as possible. New car buyers rarely think about ease and cost of repairs.

[Deleted]

The oil is muddy brown and sludgy looking. There were a few drops underneath the van but not enough leaked (from what we can see on the ground) to compensate for what's missing (almost full reservoir to empty reservoir in 3 days time after driving 2 miles).

I know what you mean about being double jointed and having tiny hands lol. On our van there are tons of people who say it's almost impossible to get to the bottom bolt that holds the thermostat housing unless you either have tiny hands with a 13mm curved wrench (socket wrenches don't fit), if not you have to remove the throttle body and other components you wouldn't normally have to. So I get you there. The thermostat wasn't there and just arrived a few minutes ago, so while my husband was on the way to pick it up, I spent the time taking my acrylic nails off since that part seems to be the biggest time consumer. Here's to hoping these small hands can get that bottom bolt off!

[Deleted]

We used this YT video www.youtube.com/watch?v=ZgLWR1dCXRM as our referral point for changing our thermostat. When we got down the thermostat housing, we could not get the first lug nut on the "top". It's in a weird angle and our socket wrench, while it wraps around it, can't get it to loosen unless we're at a 90 degree angle, which can't do because of other things in the way. From feeling around it seems the problematic bottom lug nut holding the thermostat housing is missing so this one lug nut on the top is all that's standing between replacing our thermostat. When we couldn't get it out after about half an hour of trying, we decided to take the throttle body off since lots have stated this makes accessing the lug nut on the t-stat housing much easier. For this we used this YT video www.youtube.com/watch?v=qHaBs6vnZPQ as our source. We removed every lug nut he said to (again some are missing) and our throttle body won't even budge. We couldn't move the black bracket at the top (with the two lug nuts which we removed) either which he seems to do without disconnecting the hoses/throttle/cruise control lines from it. So far our only idea is to try to use WD40 to loosen things (lug nut/throttle body). The part where the t-stat sits appears to be completely black. We tested our t-stat with the boiling-water-over-stove-top test, and it "opens" and "closes" fine, so we are hopeful cleaning out the t-stat area and putting in a new one, might fix the overheating issue. Any suggestions on how to get the one lug nut off?

[hermitjohn]

If all bolts/nuts removed from throttle body, most likely its held on by age and a petrified gasket. A rubber mallet is handy in such situations. If you dont have that, a short piece of 2x4 to give it a little bump might help. Dont overdo the persuasion.... dont want to break anything. Dont hit it with steel hammer. If it doesnt quickly release, check and check again for any missed bolts or nuts holding it on. It really is easy to miss one. Too much persuasion with a bolt still tightened means you probably will break piece off the casting.

If its missing bolts and nuts, not a good sign. Means some ham fisted wannabe mechanic has been messing with it who really didnt give a hoot, he was into shortcuts.

Its worth having a good selection of socket extensions and swivels. Several different length extensions and at least one swivel. The cheaper swivels tend to be little too loose. With socket in place they tend to flop. You can correct that by wrapping electric tape around the swivel joint couple times. It will have enough give so swivel will let socket go on at an angle, but keep it from flopping over to one side making it hard to get socket onto bolt. Better swivels will be tighter and may have a spring. But cheap one wrapped with bit tape or maybe piece old inner tube be just fine. I have tried using two swivels at same time, to get to hard to access bolt, but its really iffy thing.

Here is and example of cheap set of swivel joints. www.harborfreight.com/3-pc-universal-joint-socket-adapter-set-67869.html You can also buy swivel sockets with swivel joint built into each socket, though I have never seen a particular advantage over a universal swivel joint extension. Guess a little more compact...

[Deleted]

You have a intake manifold gasket problem.

[Deleted]

hermitjohn, you were right there was a nut in the back that we couldn't see. Got that off and were able to get the throttle body off, which let us remove the thermostat housing and replace the tstat. When everything was said and done (it took us about 7 hours yesterday) and we fired up the van it now starts and then dies. Keeps starting but dies after a minute. We checked and rechecked everything and everything is put back in and in the spot it was before. What would make a vehicle that was running prior to replacing a bad tstat now not run at all? From googling it seems an anti-theft kicked in when we took the electrical sensors off and putting them back on "reset" the anti-theft. This is causing the engine to stall due to the anti-theft. Our mechanic said (last year) he noticed the anti-theft was making it so the engine was only firing on three cylinders instead of 6 so he disabled it. Did we re-enable it? We tried two YT fixes for resetting the anti-theft, no dice. Car is starting with no problem but dies one second later. Has oil, coolant and gas. We're stumped.

@fixitguy, would that exhibit the symptoms of starting and dying immediately now?

[hermitjohn]

Luckily I havent had the pleasure of the anti theft carp mandated on OBD2 stuff. My newest is a 94 with old OBD1. And its bad enough. But I have read about OBD2 theft stuff, especially about the $$$ chipped keys required. Just seems like a money making gotcha thing, especially on older high mile vehicles that nobody is going to steal anyway.

If it wasnt for possibility of some anti theft garbage, I would say you have an air leak. Did you use new gasket or some sealant on the throttle body when you reinstalled it? At least smear some grease on old gasket before clamping it down? Comfortably Numb was mentioning on my Ranger thread that OBD2 has some positives in diagnosing problems, so sure somebody here lot more fluent in OBD2 than me, that can guide you. I keep thinking in terms of mechanical problems, not computer problems. And I keep wanting to solve problems like they were in a pre-computer era vehicle only with strange new control gizmos. Wrong way to think about it as computer interconnects everything, then modifies the game if you make changes, so you end up playing whack a mole chasing your own tail.

Best advice I can give is to look at repair forums specializing in your make and model vehicle. Usually very similar vehicles, make, model, year, have similar problems. I would never guessed a vacuum controlled fuel pressure regulator was such an important gizmo on my Ranger until I started running across it mentioned on Ranger/Explorer forum as common problem on my year Ranger. When I found some previous owner had disconnected vacuum line to it and plugged the ports, BINGO... See back in carburetor era, fuel pressure regulators only used on race cars with high flow/pressure pumps. Dont think I ever seen one used on stock factory carburetor car.

[Deleted]

Thanks for your input hermitjohn, I will definitely try to suss out some forums that discuss my issues. So far from just perusing them it seems the most common thing for chevys and pontiacs (same body from 97-02 I believe) is this darn anti-theft thing. But I will try to find a few and actually register and post my questions there as well, that was a great idea thanks

What is OBD2 again?

[hermitjohn]

On Board Diagnostics, 2nd generation.  Basically its your engine's computerized control system.

There is an aftermarket system called Megasquirt that you can program.  I personally thought that was cooler name.

[Deleted]

Mar 26, 2016 2:30:22 GMT hermitjohn said:

On Board Diagnostics, 2nd generation.  Basically its your engine's computerized control system.

There is an aftermarket system called Megasquirt that you can program.  I personally thought that was cooler name.

lol was that supposed to be helpful and funny or just the latter? If just the latter, mission accomplished I have never heard of that system name on our van so no idea what to do with this info.

[hermitjohn]

Seriously there is an aftermarket engine control computer system called Megasquirt that you can program it to run your computerized fuel injection engine the way you want (in states that dont test emissions no doubt). Its third party aftermarket product, so no you wont find it on your average street car. Its intended for the hotrodder crowd, though I think high school kid that traditionally just wanted to slap a huge double pumper Holley and a chrome air cleaner on his small block chevy, get 5mpg, and pretend he has a race car, isnt really going to be up to the task.

en.wikipedia.org/wiki/MegaSquirt

[Deleted]

okay will check that out thanks!