Car Experts: Overheating? (1 Viewer)

[Todd Hochard]

Rapid changes in indicated temp can be due to a faulty gauge or temperature.
However, actual temp can also change like that. How so? If, for whatever reason, you are developing steam pockets in the cylinder head (which is where the sensor is), indicated temp can change rapidly. Steam pockets could be developing because:

1. Bad radiator cap.
2. Low coolant level.
3. water pump impeller is bad, and lacks sufficient pumping pressure.
4. Bad thermostat, causing localized boiling in the head.
5. System overheating, due to radiator clog or fan not working, in conjunction with older/worn parts in other parts of the cooling system, can cause this as well.

The rapid up-down is the formation, and subsequent collapse of the steam bubble.

Good luck. Remind your technician- an important rule of troubleshooting is, "Believe your indications." In order to accurately get to the bottom of the problem, take what you see at face value, until you can prove that the indication is not valid.

Todd

 

[Bry_DD]

had the same problem not so long time ago, when idling the temp goes up when driving the temp goes down. After flashing and changing the thermostat it was still overheating. so there's only one thing left is to change the radiator cap which i should've done in the first place so i did replaced it and it never overheat again.. i have a civic and i think it's the the cap.. replace the cap first then go from there.

 

[Ken Garrison]

Hell, I hadda replace the cap in mine because the gaskets on the old one were starting to break down. If I floored it, I can see water gushing outta the cap. Also, with the old one, I would open it up and the water can be seen way down there. Now with the new cap, when I open it, the water is right there. So, a new cap can make a difference.

 

[Sean Conklin]

Yep, it is a miniscule chance it is the radiator cap, Acura/Honda motors have a sealed cooling system and all air must be bled from the cooling system, but this doesn't sound like the symptoms.

From the way it was described, it is either the electric fan or one of it's sensing components, or a faulty gauge.

With a blown head gasket, you will see 1 of 2 or 3 things, a leakage of coolant onto the ground from an odd place, white steam from the exhaust, or you will lose compression into the cooling system causing excessive pressure which is identifiable by pulling the radiator cap off and revving it a little, if you see a geyser shoot out of the radiator this is whats happening. And I suppose an overheating condition could occur, but I doubt it, from the sound of the explaination.

 

[Sean Conklin]

Hell, I hadda replace the cap in mine because the gaskets on the old one were starting to break down. If I floored it, I can see water gushing outta the cap. Also, with the old one, I would open it up and the water can be seen way down there. Now with the new cap, when I open it, the water is right there. So, a new cap can make a difference.

That is some water pump, either that or it kinda sounds like you may have a little compression leaking into your cooling system.

 

[Greg_S_H]

Well, it turns out I had a minute crack in the plastic housing right where the hose attaches to the radiator, and it was allowing coolant to slowly seep out. So, I had to get a whole new radiator. After the installation, the guy ran the car for a long time out in the heat (yesterday or the day before was the first 100º day down here) and the needle never budged from the normal position. So, it seems everything's "cool" now, so to speak. Of course, I'll keep my eye on it, but the good news is there didn't seem to be any damage done.

 

[Ken Garrison]

That is some water pump, either that or it kinda sounds like you may have a little compression leaking into your cooling system.

Oh no. I mean, the gasket on the old radiator cap was BAD. VERY BAD. I'm not loosing anymore water with the Bars Leak in my system. Ever have a water pump blow up and break off the shaft while moving 70 MPH down the freeway? This happened when my dad was driving my van at the time. I didn't have my license yet. The repairs turned into an engine rebuild. It needed it anyway. And with the engine under your ass, we sure felt it. Felt like we hit something. KaBLAM! wrap wrap wrap, THUMP!! *back window fogs up* *Sam the Sham - Little Red Riding hood playing on the radio* *Dad cusses when he sees the needle off the scale* *All idiot lights are on* *Finally pull off freeway* *Van dies* *We coast through all the stop signs and park at a truck stop where we rented a room* Sounds kinda like fun, don't you think? Well, the repair was over $3800. Them sloabergoat dumbyshoes at Toyota didn't hook my cruise control back up either. I should demand a discount. Well, anyway, it sat in the shop for over a year until they let us fianace the repairs. My dad brought it home and he noticed a BIG difference in power. It used to lag on this one hill on the freeway. It don't anymore. Goes right over it at 70 MPH with no lag and no downshifting. After I replaced my coil, rotor, cap, plug wires, and spark plugs just last week, I notice even more power.

BTW, how much HP and Torque you think I got with a 2.0 Liter 4 cylinder engine? I'm just curious. BTW, it CAN turn over gravel, if that helps.

 

[Sean Conklin]

Ken,
What do you mean turn over in gravel?
Thats some story, I would say you are around 90-100 HP with 150 ft. lbs. of torque, roughly.
Greg, It seem to me that a little crack would cause it too overheat on idle, unless you were dangerously low on coolant, I would be a little skeptical that they didn't rip you off, it could have been a $5.00 sensor causing the fan not to work. Hopefully I am wrong, and probably am, I am glad your back on the road!

 

[Ken Garrison]

I mean, I can step on the gas and it'll throw gravel all over. I did lay a little rubber on the pavement yesterday. I was getting outta my driveway, decided to test my power, so I stepped on it from a dead stop, threw gravel all over, then when I got on the pavement, it squealed a little and I was off. It's gotta have at least 110 HP. Well, I'll have to find somebody in town with a dyno and test my power and find out ways to improve it.

 

[Sean Conklin]

Hehehe, are we talking about a Toyota Van? Yes you could be at 110 HP, sure, that would be trick to soup up a Toyota van, cool sleeper!

 

[Greg_S_H]

Well, Sean, I neglected to mention this before because I didn't want to muddy the waters, but I had been experiencing a leak for about a week before the event that prompted this thread. I first noticed a strong syrupy smell, and the reserve bottle was almost empty. I filled it up, and it began very slowly emptying. Some leak stopper seemed to help, but then it began emptying again (very, very slowly). Like I said at first, when the needle was all the way to the right, the coolant level was fine, the engine did not seem overly hot, there was no steam, no smell (other than that damn syrupy stench), nothing to indicate an overheating engine. Plus, when I turned the key just enough to engage the needles again, it returned to normal.

So, the mystery of the hyperactive needle has not been solved, but I had to get the leak fixed anyway. My family has been visiting this mechanic for over 20 years now, so I trust him. But, I am still a little nervous about the needle situation. Hopefully, it won't pop up again.

(Of course, now you guys feel like a doctor dealing with a patient who neglected to reveal a few key symptoms. I'm sorry about that.)

 

[Ken Garrison]

The engine is pretty easy to work on once that passenger seat is removed and the panel underneath it. On my Toyota Van that is. I understand a lot of vehicles in Japan still use this design. Such as the Toyota Town Ace. OMG, I've seen pictures of the Town Ace. Same shape and design as my van, but it's VERY NICE. THAT's how a van should be built. Because Japan's streets are so small, is that the reason why a lot of their vans have the front wheels under your ass for better manuverability? I'm impressed I can make turns tighter than my dad's lumina can. It was a very bad idea to mention my van at the LS1.com website. Lot of dickheads over there. Excuse my French. I told them I have my great friends at HTF to be with and I don't need them. What a bunch of jerks! As you can tell, I really like my van. I can haul a lot of stuff in the back with both seats removed. It's pretty versatile. OH, and if the passengers in the middle seat wanna get comfortable, there's my engine they can rest their feet on. Now what OTHER van can do that? Someday, when I get a good job, I'm gonna have some major body work done to her. It's got some rust. I also wanna new stereo system and my cruise control fixed, no thanks to Uhlman Toyota in Chehalis, Washington who screwed it up after they rebuilt my engine. Napa told me it's gonna cost around $500 to $700 to replace my A/C pump and convert it to the new freon crap and charge it up. So, I'll have that done also. To save on labor, I'm gonna remove that passenger seat and the panel underneath it. Then when they are done fixing my A/C, I'll put it back together myself. That should save a LOT. Labor is pretty high on Toyota Vans for that reason.

 

[Sean Conklin]

Well if your mechanical at all. I would keep the van and soup it up a little, why not? I soup everything up though. Thats just me.
There are Dodge 4 cyl. turbo minivans running 12 and 13 second quarter mile times, believe me that is a sight to behold.
It would be fun to haul some ass in a minivan!

 

[Todd Hochard]

So, the mystery of the hyperactive needle has not been solved

Is it still doing it? If not, then the mystery probably is solved. See my previous post re: steam bubbles.
I've seen these EXACT symptoms, caused by low coolant level, in an '83 Civic I fixed for a friend (I'm not a professional car mechanic, just an able enthusiast).

Todd

 

[Ken Garrison]

I should install one of them K&N filters next time my filter needs to be changed. That has been said to raise my power a little. I'm kinda curious about them Tornado gizmos they've been advertising on TV. But some people say it does more harm than good. But I WOULDN'T mind getting one of THESE. It has you install on the throttle that will activate it when you floor it, say, like to pass some slow assed moron in front of you. Also, it would be great for getting up to speed when going on the freeway. I did manage to get more power after I replaced my coil, rotor, cap, plug wires and spark plugs. I got the Bosch Platinums. After a little retiming, I manage to squeeze a little more power.

 

[Greg_S_H]

Todd,

I haven't driven enough this weekend to be absolutely certain, but the mechanic ran it and didn't see the needle move, nor have I the few times I did drive. I like your theory, though, and if I get an opportunity, I'll run it by him and see what he thinks. For now, though, it looks like you're right and the problem's solved. Knocking on wood.

 

[Dennis Nicholls]

Well, it turns out I had a minute crack in the plastic housing right where the hose attaches to the radiator, and it was allowing coolant to slowly seep out. So, I had to get a whole new radiator.

Modern cars have a plastic/aluminum radiator. The plastic parts tend to break down after about 6-8 years. They do this to save weight. If you surf the web you should be able to find an all-metal radiator so this won't happen again. Sorry to give you this advice "too late" as it were.

You will notice that the plastic parts start out black in color and turn green or whitish when they start to break down. A good indicator to think about getting an all-metal replacement.

I got an all-metal brass radiator for my 1992 Miata for about $180. Add in all new hoses (9 of them!) and I spent about $250 for parts for a MAJOR cooling system tune-up. I spent about 4 hours changing things out - time well spent.

Coolant is toxic to pets. Fix your cooling system problems before you poison your or a neighbor's kitty.

 

[Brad_V]

I should install one of them K&N filters next time my filter needs to be changed. That has been said to raise my power a little. I'm kinda curious about them Tornado gizmos they've been advertising on TV. But some people say it does more harm than good. But I WOULDN'T mind getting one of THESE. It has you install on the throttle that will activate it when you floor it, say, like to pass some slow assed moron in front of you. Also, it would be great for getting up to speed when going on the freeway.

Oh man, all that stuff is so much crap. It's a restriction in your intake more than anything and will reduce power. All of those tornado things and everything else -- crap. This one says, "Get 1psi instantly!" Even IF it worked right, which it won't, 1psi is usually 10 horsepower on a good day. For that same $300 you can get a small nitrous kit.

The worst ones yet are the bozos on ebay and places selling the big electric blowers and saying they are turbochargers. The things are actually marine air blowers used on boats and things. Like a leaf blower. But they even *look* like a turbocharger. Sort of. People are paying over $200 for the stupid things on ebay. Some of the car groups I'm on got wind of them and email the ebay bidders when we can to let them know what it really is, (as well as provide a link to a marine page that sells them for boats), but I'm sure there are people out there still buying them.

Oh, the K&N is ok, though. Won't be a big gain by itself, but certainly won't hurt except for maybe letting a little more dirt through. The dirt thing has been debated many times.