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Z_Drifter_87
03-02-2009, 09:16 PM
Alright, I've had my radiator cleaned cause it was clogged. A new 160 thermostat. and new hoses. The car seems to heat up to about 200 degrees. The gauge marks on top of the "L" on "NORMAL". And there is alot of pressure on the upper radiator hose on the resovoir. Now a mechanic is tellin me that its a head gasket. Is that true??? I really need some help here. I would greatly appreciate it. And by the way, I have a 1997 Cobra. Thnx for the help and replies.

cobrabitn
03-02-2009, 10:13 PM
If you have air bubbles coming to the top of your coolant level in your radiator then you may have a blown gasket. Remove the radiator cap and see if air bubbles come up to the top.

Philcsag1
03-02-2009, 10:53 PM
you need to bleed all the air out of the system to get it to properly cool

You need to remove the plug in the crossover tube while filling the engine with coolant.

the engine will come upt to 227 degrees then the fan will turn on

the fact that you put a160 thermostate in will not change that.

Phil

Z_Drifter_87
03-03-2009, 02:17 AM
you need to bleed all the air out of the system to get it to properly cool

You need to remove the plug in the crossover tube while filling the engine with coolant.

the engine will come upt to 227 degrees then the fan will turn on

the fact that you put a160 thermostate in will not change that.

Phil

Ok, so normal operating temp is around 220? Would you recommend that i go with a higher temp thermostat? Also would i remove the plug in the crossover tube while its on and add water through there or the resovoir??

Z_Drifter_87
03-03-2009, 02:19 AM
If you have air bubbles coming to the top of your coolant level in your radiator then you may have a blown gasket. Remove the radiator cap and see if air bubbles come up to the top.

Now would the bubbles be coming out where the plug for the crossover tube is is, or where the resovoir cap is?

Z_Drifter_87
03-03-2009, 11:20 AM
So let me ask you all another question, Are my sensors for the temp sensor and temp sender out since my gauge is marking really hot??

cfradam
03-03-2009, 03:45 PM
I would recommend that you go with the stock thermostat. the 160 is most likely not allowing the rad to do its job efficiently enough if it doesn't stop the flow long enough to cool properly.

the cross over tube is just to let trapped air out of the system, and not to fill. if you let the air out a few times over a couple of heat cycles, you should not see anymore. if you do continue to see bubbles from either the cross over or the reservoir then you might have a head gasket problem

the idiot gauges that Ford put in these cars is very inaccurate. you may want to find someone that has another mechanical temp gauge you can hook up to get an accurate reading and go from there. a hot garage wont cause any gauge problems since its reading the water and not the ambient air.

Mystic_Cobra
03-03-2009, 11:21 PM
The thermostat probably isn't helping or hurting you but it will make the engine run better if you put a stock 192 back in it.
We've had this discussion many times with these cars. Unless the car is spewing coolant, IT'S NOT OVERHEATING.
What makes you think it is overheating? A stupid Ford gauge pointing to L means nothing. Pressure in the radiator hose? That's normal. First step is to get a real aftermarket gauge. Find a gauge pod you like. Analog or digital...doesn't matter. Mechanical or electric...doesn't matter. Just get a good gauge. I used the crossover tube plug/fitting and recommend it. In case you haven't heard, the oil pressure gauge doesn't actually do anything either.

Z_Drifter_87
03-04-2009, 02:08 AM
All of the posts that everyone has responded with really help me alot. I just had one more question. What is the temperature supposed to continually be at? Especially on a normal day, like down here in the valley, it reaches the high 80's and low 90's. Should it be at around 220?? I didnt use a mechanical gauge, but i have this laser gun that is very accurate and it seems to stay between 190 and 205 degrees. Is that normal or is that hot??

Mystic_Cobra
03-04-2009, 07:21 AM
220 is starting to get hot but again, unless it is spewing out coolant or not running right, it's NOT OVERHEATING. With a 192 thermostat, the temp should stay above 192. That's it's job. 195-205 is perfectly normal. 220 is still not too hot but I would say 230 is pushing it. I think the the high speed on the fan doesn't even come on until 230. When I first started road racing, my coolant temp would slowly creep up during the session. After about 5 or 6 laps, the temp would go past 230 and then I would slow down and let it cool for a lap. I've seen temps around 240 on track and still not had it spew coolant or act up. But that's definitely too hot.
Also, your laser temp gauge isn't the most accurate gauge either. Sure it is accurate at measuring surface temps but you don't know what the temp is on the inside.
Cover all the basics first:
1. Get a real gauge.
2. Make sure everything on the car is working properly (two speed fan, no leaks, flush the system, right coolant/water mix, add water wetter, etc)
3. Then think about mods to fix things (bigger radiator, manual fan switch, etc)

Z_Drifter_87
03-06-2009, 04:40 AM
Well i bought a new autometer water temp gauge and it shows that it doesnt go over 180. So i think everything is fine. I'll keep everyone posted. Thanks alllloootttttt!!!

Mystic_Cobra
03-07-2009, 01:09 PM
Glad to see she's running cool. Let's see what happens after the spring and summer temps roll in and you start crankin the AC. Even my car runs cool in the winter (and I have no cooling fan). :D

Not sure if you care about emissions or fuel economy but, in general, these things will run better if the engine is up to operating temperature (192). That's why they put the 192 thermostat in there.

Mr. Snake Car
03-12-2009, 04:12 PM
I'm sorry, but it's an SVT Cobra, not a Geo Metro. It's not a bad guage. I question the need for an aftermarket anything on a Cobra for proper function!!

Your gauges are fine. Please fill and burp the water skirt through the plug in the crossover tube in front of the engine as stated above or via the maintenance manual. This will fill the overflow tank (no idea) and ensure the system has all the fluid it needs. Do not (can't) fill the system through the overflow tank.. Use coolant as it raiss the boiling point of water and fill thus reduce the pressure on the system. Anything beyond that would require specific symptoms.
Blown head asket could manifest as air or oil in the coolant.

side note...160 is kinda cool...engines like the heat! 190 is fine and below the boiling point of water (212) which is increased by the radiator cap and the coolant!

The thermostat probably isn't helping or hurting you but it will make the engine run better if you put a stock 192 back in it.
We've had this discussion many times with these cars. Unless the car is spewing coolant, IT'S NOT OVERHEATING.
What makes you think it is overheating? A stupid Ford gauge pointing to L means nothing. Pressure in the radiator hose? That's normal. First step is to get a real aftermarket gauge. Find a gauge pod you like. Analog or digital...doesn't matter. Mechanical or electric...doesn't matter. Just get a good gauge. I used the crossover tube plug/fitting and recommend it. In case you haven't heard, the oil pressure gauge doesn't actually do anything either.

Mystic_Cobra
03-12-2009, 09:26 PM
I'm sorry, but it's an SVT Cobra, not a Geo Metro. It's not a bad guage. I question the need for an aftermarket anything on a Cobra for proper function!!

Your gauges are fine. Please fill and burp the water skirt through the plug in the crossover tube in front of the engine as stated above or via the maintenance manual. This will fill the overflow tank (no idea) and ensure the system has all the fluid it needs. Do not (can't) fill the system through the overflow tank.. Use coolant as it raiss the boiling point of water and fill thus reduce the pressure on the system. Anything beyond that would require specific symptoms.
Blown head asket could manifest as air or oil in the coolant.

side note...160 is kinda cool...engines like the heat! 190 is fine and below the boiling point of water (212) which is increased by the radiator cap and the coolant!

I guess this all depends on how you define "proper function".
I'm not sure how much experience you have with these cars, but the gauges ARE a known problem.
1. The oil pressure gauge is connected to a switch. When the oil pressure goes above 6 psi, yes, that's SIX psi, the gauge pops up to normal and stays there. That is NOT how a gauge is supposed to work. Years ago, customers complained about the gauges moving around too much so Ford turned the OP gauge into a fancy idiot light.
2. These cars are known for running hot and overheating, especially the 96s. There was a TSB on fixing them. The water temp gauge has a range that says " N O R M A L " on it. There have been tons of threads on the internet over the last 12 plus years about these 4.6 DOHCs running hot. Do you know the water temp when the gauge needle points at N? How about R? How about L? I do, because I have a real gauge with real numbers (not to mention the digital gauge as a backup). If you actually want to know what the water/coolant temp is in the engine, you need a real gauge with real numbers on it.

As for "normal" water temp? Here's a few tidbits.
1.The factory thermostat is set to open at 192. That means the thermostat keeps the radiator from cooling the water until the temp reaches 192.
2.The electric fan has two modes-high and low. High speed isn't activated until the AC is turned on OR until the water temp reaches 230.
That tells me that "NORMAL" water temp would be roughly from 192 to 230 degrees. Most people know that 230 is too hot. I'd agree with that. I have had my water temp go well over 230 and not boil over. But I've had my share of boil overs, too.

No, the Cobra is not a Geo Metro. But it isn't perfect either. :thumbsup:

Mr. Snake Car
03-13-2009, 10:23 AM
I see your point! I, of course, was speaking in general terms meaning that R was operating temp and anything over that would be of increasing concern.

I recently (last week) boiled my coolant spinning my tires in the snow. I got stuck got IN MY PARKING LOT of all places after trying to get to work...I wonder what the temp was there..if I recall (I was so freaked my the smoke and smell that my wits were actually somewhere outside my head) the needle was over the L about at the first thin red hash.

In the past, I have noticed the needle on my guage creep to L with a new thermostat and have susupected old radiator. It's not right to have poorly functioning cooling systems after the SVT did such a nice job with the engine.

Z_Drifter_87
03-16-2009, 01:26 AM
I seem to understand everyones points of view. I put a new 160 thermostat, Had the radiator rodded out and cleaned, New Water Pump, New Hoses, DUAL 12 inch Fans, and a New Autometer Electric Water Temp Gauge. On the Expressway, the temp is at about 175; At idol it reaches about 195. Now when i'm driving on the expressway going bout 65 mph, the exit and drive "In Town", on a hot day, hot being in the 90's, it gets to 210. I want it to run cold all the time. And when i say that, i mean, below 180 all the time. What do i need to make that possible?? Bigger Radiator? And what if it is a Head Gasket problem?? Thats my biggest concern. And by the way, Where do i fill the fluid??? if not through the crossover tube, then where??

cobrabitn
03-16-2009, 07:22 PM
Water Wetter! :D

cfradam
03-16-2009, 10:40 PM
its going to be hard to have the motor run that temp when the engineers designed it to run at almost 200 for optimum operation and emissions. its not impossible but maybe just a little ambitious.

Adam

Z_Drifter_87
03-17-2009, 12:06 AM
Water Wetter sounds good. Along with Distilled water, right??? along with bout a half gallon of antifreeze? And where exactly do i fill the fluid at??

Mystic_Cobra
03-17-2009, 12:12 AM
Why do you want it to run cold all the time? The engine is designed to run around 190-200 degrees.
How often does it boil over?

puzzle13
03-17-2009, 05:31 PM
Skip the water wetter! It is useless if you use a 50/50 mix of antifreeze & water. Use distilled water. The lowest thermostat you need is a 180 degree one! As others have said ... 160 degrees is too cold and I really doubt you could get it to stay down there. With a temperature guage in the bottom of my block, a lower thermostat, and other mods it still runs around 185 and that is good. The only way to actually know the temperature is to get a guage with a sensor in the block or get a AeroForce Interceptor Scan Guage. This guage reads actual numbers off the Ford sensors. You can read coolant temperature, Boost, intake temp, down tube intake temp, etc. They are expensive, but you don't need to install other sensors.

cobrabitn
03-17-2009, 08:40 PM
Even with a 50/50 mix, water wetter will lower the temps. I cannot answer about distilled water. :p

Mystic_Cobra
03-17-2009, 10:49 PM
Water wetter will make it run cooler, but you're not going to notice below 200. It's ideal for engines where you can't run coolant (like race cars) bc it also has anti-corrosion additives.
Distilled water isn't going to make it run cooler, it keeps minerals from building up inside the cooling system.

Z_Drifter_87
03-18-2009, 05:42 AM
Its never actually boiled over.... not even once. I'll move up to the 180 thermostat and do another flush. As i fill the liquid, where do i fill it at???

Mr. Snake Car
03-28-2009, 11:54 PM
crossover tube plug.