Need Tech Help: Overheating 95 Cobra

[Brant]

Hi All....

I've got a bone-stock 1995 Cobra with 13,000 miles on it.

Over the years I've noticed a cooling problem with the car, but not being a tech-head myself, I haven't a clue as to what the problem is. I'm hoping someone here can give me some informed advice before I turn the dealer loose on the car.

During even moderately warm days (~70's) when the tempature of the car will rise....in stop and go traffic it doesn't take long for the engine to heat up. When the tempature guage goes past center, I can hear the fan click on.

However....at that point I will get such a noticible decrease in horsepower that its something that just *cannot* be considered normal. I mean put the car into gear and get it rolling (I've stalled it a couple of times even giving it liberal throttle) and putting my *foot to the floor* will result in the car going....nowhere.

Its as though the motor is completely retarding the fuel supply. It also means that it takes several full seconds to get the car up to speed enough to shift out of 1st and into 2nd.

The key here however is that there is no "Power" at all when I'm doing this. I actually FEAR the day I am on an incline stopped with the heating "low power" condition happening.

I do notice the whine of the fuel-pump when I turn the car over, but nothing else unusual.

When the car gets going...say 2nd gear around 2500RPM or so, all of a sudden I'll feel the power "kick back in"...ie: and usually its not a smooth transition......this is going to sound silly but:

<vrrrrrroooooooommmm><VROOM><VRRROOOOOOOOOOOOOM>
and then I'm off like normal WOT would be 3000rpm, 3500, etc.

The problem is that from a dead stop it takes awhile to get going, and merging into traffic on a hot summers day can get one killed if their mustang is poking up the onramp trying to merge.

I am going to take the car to the dealer near me within the next few weeks as the weather here in CT is starting to heat up a bit. I'm telling him "Turn it over, let it idle till it heats up, then take it for a spin"...hopefully they'll see what I mean.

Obviously this problem has never occurred with any of my other cars......none of my other cars have that much heat fluctuation as this mustang does....

So....anyone....does this ring a bell? Something I should tell the dealer/tech to consider when I bring it in? Thanks everyone.

NOte: Please see my other posting on this board regarding mods.
Thanks again!

[Coupe5oh]

When i was replacing my t-stat, i found that my old one was in pieces? my car ran hot only on certain occasions, i fixed that with a new radiator, 160 stat, and electric fan, (dang police cars were supposed to have improved cooling..yea right) Start with something simple as the t-stat, look into getting an aluminum radiator, check your oil for water and make sure you didnt lose a gasket.

Also the cobra computer sux, when you stomp on the gas does it happen to take 7 seconds to really pick up? Definately do the grs like you posted, you will enjoy the car more, with 373 you will enjoy it more, and gas mileage wont suffer real bad, but it will some.

Also if you really want to pick up some power swap the computer for an older a9l, the fuel and timing curves are way more aggressive, but if you just drive it normal, the cobra ecu wont hurt.

[whiterod]

brant, definatley go with the 3.73's first. This is definately one of the biggest bang for the buck. they shouldn't cost as much as you predicted. If you look in summit or visit their website you will find the fms gears for 189.00 or so. Someone should be able to put them in for about 200-250. Next look at pulleys, for 100 bucks or so you can pick up 8-10 hp. Advance the timing if you haven't already to about 14 deg or so. Put in a k&n. then go with the exhaust of your choice. these are just a few ideas if you have any questions, just ask, nothing to be ashamed about. and look, most of these mods you can do yourself. just start buying some 5.0 magazines and MM&FF and you will learn alot in their tech articles. also purchase a haynes or chiltons' and you will save yourself a ton of money not having labor costs involved. Just for example when i bought my heads i called a shop just to see how much it would cost to get them installed, they replied $1000 bucks, man that is about what i payed for the heads!!! good luck

[whiterod]

sorry i meant to my last post in your other post

[DRASTiK]

It's possible that you have some sort of blockage in your coolant passages. A piece of a gasket, or a broken thermostat. It's also very possible that your thermostat just isn't opening like it should.

When you fire it up cold, and drive it how you usually do, does it heat up kinda gradual and then once it hits a certain temp on the gauge, start to heat up faster?

I'd do as suggested above and spend the few (less than 10) dollars and replace the thermostat. It's not difficult at all and it's cheap. That may fix it for you right there.

Dave

[Casper5.0]

I had the worst time finding the cooling problem with mine when i first got it and it turned out to be the ECT sensor. The ECT controls the fan as well as timing and fuel tables in the computer. The ECT is located on the front passenger side of the intake and is screwed into a black coolant passage. If yours is bad, as mine was your car will run like crap and the fan won't come on at the right time causing your car to overheat. If the fan doesn't come on until halfway across the gauge there's definately a problem, it should come on at about the "O" on your gauge. I hope this fixes your problem i know how frustrating this is, i had the same problem.......

RYAN

[Godslayer]

I agree with the ECT suggestion. That will usually throw a code though. Do you get any check engine light?

[Casper5.0]

I didn't get a check engine light, but it could trigger it on your car.......

RYAN

[86StangGT]

Hey Brant, i have a 95 Cobra also, damn I love that car. It ran a 14.2 @99 bone stock with the temperature gauge reading very hot. I've done some mods to it now and can't wait to get it to the track and throw some ice on the intake. Well I don't have any problems with that car but my old 86 GT was overheating on me a few months ago. Once it got hot it would run like crap, I had no idea what it was, I thought it was a head problem of something. I had already changed the thermostat so I didn't think I would ever find the problem. Lo and behold I said let me check the coolant, and that was my problem. I added about 2 qts. of water into the radiator and my problem was fixed. Basically the things you can do before you bring it somewhere is check the coolant level and change the thermostat, if it still runs hot then I would have it checked out.

[Brant]

Hmmm..if that ECT..err..sensor controls timing and fuel that might definately be a consideration...

Like I said, imagine flooring the car...and having it just go as if you were at 1/2 or 1/4 throttle until it hit more than 2400 RPM or so..after that all of a sudden (if you kept your foot down) the car would "Leap" into action....as though a computer was retarding the fuel flow and then suddenly letting it go once air starting getting to the motor as you accellerated...or something.

Yeah, the stock cobra gauge is pretty vague..but the fan doesn't come on until its more than past the 1/2 way point. normally the car runs to the left of center....on warm days int he center, but as soon as I get stuck in traffic or make alot of stop and go's...all of a sudden it drifts over to hot...and then the power all but disappears. The longer I am stuck in traffic or driving stop and go, the worse the problem gets..again, on warm and hot days. In the fall/spring it usually wont heat up that bad...but it does it a little bit.

The reason I have to get this problem fixed is because last year I tried merging onto a highway after being in stop n go traffic..got stopped on the onramp.....and then had to merge fast....and the car just sort of wouldn't get going...almost got rear-ended by a dude in a really big Tahoe who no doubt was wondering what NumbNutz was behind the wheel of a Cobra and was doing 35 merging onto the highway

I'm printing out this list and will take it to the dealer to say "check this, this, this".

PS: There's plenty of coolant in the radiator...AND I'm running a bottle of Redline in there.......

[LX XLR8R]

have you cecked your FP when it does this..my car used to do something very simular off the idle when my FP was going bad..after i changed it all was well..but my car would die after about an hour of driving then you have to let it sit and then it was better

[sn95gt19]

have you had any work done on the cooling system, like heater core, or radiator replacement, cause when you replace those there are air pockets that stay in there and when it hits one of these the car will run hot until revved up. as for your other prob. i have the same prob with my 95gt when i floor it the car seems to have to power but then it will suddenly "kicks in" when i bought my car my mass air was bad and i replaced that and it made a world of difference, i have had 3 mass airs go bad one in every one of my mustangs. the mass air will make it fall on its face when you floor it but it will go OK when your at part throttle. this most likely isnt your prob. but its a suggestion if nothing else works.

[Brant]

No, no work was done......when I first bought the car I had it in for service and mentioned the overheating problem, naturally...they found nothing...and I dismissed it as new-owner jitters.....maybe it was normal for the car to behave that way.

This time I'm going back with a detailed explanation of the problem.....I'll even tell them how to re-create it...and I'll provide them a list of these possible solutions I've received here...now I know its not normal for the car to behave that way...sensors..MAF....fuel pump..etc.

[jimberg]

I'd start with the thermostat. It's the cheapest thing to fix. The computer could be sensing the heat via the ECT and backing off timing. If that doesn't fix it, replace the ECT.

Replace your radiator cap also.