Overheating issue

[grantii]

Hi,
I'm relatively new to this site. I own a '98 Catera. I've recently had nearly $5000 of work done to the engine, cooling systems and suspension - and the car is still not right. The latest thing is this, when the car has been sitting for a while upon turning it over there is a very loud fan noise that goes off and stays on for about 1 good minute. it'll shut itself off, then come back on again for a few more seconds then go off. It sounds like the fan you'd hear when you car is getting hot. The second thing I'm noticing is that the car will routinely stay above 1/2 mark on the temperature. It gets up to the mark between 1/2 and 3/4 and then it'll start to cool, but only if I'm driving faster than 40 mph. If I'm doing under that, it will sometimes get up to the 3/4 mark before it cools. I am not used to a car getting that hot before it cools. My last car was a chrysler, and it never made it to 1/2, it always stayed at the 1/4 mark. Cadillac is saying that this is normal for the car to get that hot before cooling. Is this true, for those who own a catera. I've never known a car to heat that hot before it decided to cool off.

One last thing, when it gets that hot and I've reached my destination and turn the car off, there is a whining noise emminating from the hood, sounding like something is caught in some fan, like there should be a fan on, but the pully that works it is just spinning on the belt and the belt isn't moving kinda noise. It will do this anywhere from a minute up to three minutes before it finally dies out. Cadillac again is saying that this is normal. I don't buy it, but in the city I'm in, no other mechanic wants to deal with the engine on this car, citing that it's too complicated to repair or diagnose.

Has anyone experienced this? If you have or haven't do you know what might be causing this? What should I be looking for? What under the hood is getting ready to fail?

Please help me try to nip this in the bud before it escalates into something major or rest my mind on this issue to say that its truly normal - which i just cant fathom.

Please email me at grantger@msu.edu or use the instant messenger icons above to give me your opinions of what's going on.

Thank you!!

[AllenPacla]

Well from my experience with the car, all the things you mentioned are normal for the car. The noise that you hear when you do a cold start is the air compressor of the Secondary Air Injection system of the car, you can search on this forum on what this system is for. And about the heat the car is generating, it's normal for the car but many of us here believe that it's a flaw causing a lot of other problems like electrical problems, which the car has a ton of. I have just installed an external oil cooler to add to the OEM system and my car is a lot cooler now compared to before. And the last thing you mentioned, I don't know for sure, but I hear that noise as well after shutting off the car. I thought that it could be the fan extending its function to cool the car. The car has a control on how long a delay you want before the car completely shuts off power to the car. It's a dial on the switch for the fog lights. I don't know if you notice, but there is a delay before the headlights shuts off when you turn the ignition to off. You can set this to turn off immediately or up to three minutes if I am not mistaken. I guess it has something to do with the noise you're saying which stays on for three minutes. I could be wrong on this last one though, I guess somebody else could confirm on this.

[guardian]

The gauge action you describe says this to me:

Replace the thermostat.

This might help and it might not. But it's not an expensive fix to try.

And after the old 'stat is out, check it to see if it's the right one for the car. It might not be, or it might just be "tired".

Good luck.

And remember, when trying to fix a car or anything else, always attack the simple stuff first. Then work your way up in complexity, but only if you must.

[AllenPacla]

I don't think that the reading that he gets from his temperature gauge warrants a replacement. Because, from my experience, when the temperature gets to 3/4, the fan will start to run at full speed, thus the lowering of the temperature you notice. The fan just run at half speed if I am not mistaken when the temperature gets past the half way mark. That's why in my car right now that it has the added external cooler, even half speed of the fan is more than enough to keep the temperature at bay.

[AllenPacla]

And when you are driving faster than 40mph, naturally, you are getting natural air being blown into the radiator keeping the temperature from reaching the 3/4 level in the gauge. And just like you said, once it hits 3/4 it starts to cool down suddenly, and again, that's the fan running at full speed causing the falling of the temperature.

[grantii]

I'm sorry if I sound paranoid, but this car has cut really deeply into my savings account and i'm trying to catch things before they die. I'm almost to the point where I get physically sick when I have to take this car back to cadillac for yet another repair. Now I've had the oil cooler replaced on this car and the coolant lines - something to that nature. It's all a blur, but I remember the price tag being over $2000! I know that I'm over my head with this car, but i'm at the point I don't have money to buy another, so I gotta keep this one on the road as much as possible.

As far as the external oil cooler....where should I look for one of those, and how much are those? Also, I have considered changing the thermostat on this car, but advance auto wants nearly $50 for the damn thing. My chrysler was barely 10 for it's 'stat. But it's ok....this car is prepping me for when I finally buy a foreign car...so i'm not trippin too hard. Where is the 'stat on this car and how difficult is it to change? Same with the oil cooler....how and where does that get installed?

Thanks for all your help!

[guardian]

I'm really sorry to hear of the extraordinary problems you have had to endure.

In light of what you just wrote, full disclosure is obviously called for here:

While I continue to believe the thermostat could be problematic, I, too, would NEVER have guessed it is a fifty dollar fix. I honestly had no clue. And while I do not question your statement of the cost, I am astonished!

Bottom line you need wiser, more able, counsel on this problem than I can offer. You need real expertise.

I truly wish you every success with your Catera, and better fortune in the future than you have had in the past.

[Elo]

Though I will say this...

When my Catera gets warmed up (2000 non-sport model), the temp. gauge sits at 50%... No more, no less...

And when I shut the car off, the fans continue to spin for about a minute... Then they shut off... So that's normal...

-Elo

[SgtDriggs]

I have a 98 with 70,000 miles and the temp gauge has never went above the half way point. Maybe I'm just lucky. The only thing that I have noticed temp wise is when I start from a cold start. The rpm soar pretty high before switching gears but that is only temporarily until the engine warms up. I wish I could be of some help but I too have only learned about this car from the repairs that I have had (coolant sensor which replaced the whole reservoir, power steering reservoir, oil pan gasket, strut bushings, tires because of inner wear in the front). I do know that my car was serviced for some recalls which the GM dealership has noted. During the recall the timing belt was changed as this was included. I would suggest anyone to take their catera and get the free work done if not already. Atleast you get a free timing belt.

[guardian]

Originally Posted by Elo

Though I will say this...

When my Catera gets warmed up (2000 non-sport model), the temp. gauge sits at 50%... No more, no less...

And when I shut the car off, the fans continue to spin for about a minute... Then they shut off... So that's normal...

-Elo

Elo, thanks. That's pretty much what I would expect and tends to confirm my thinking a little.

When a 'stat sticks it opens late and wide and there is a RUSH of cold water from the radiator which takes the high needle down relatively abruptly. You appear not to be seeing this action.

When the 'stat is operating correctly it opens more gradually and the needle does not overshoot and then undershoot . . . . it just slowly rises until equilibrium is reached at the thermostat's setpoint.

This is pretty much what you seem to be reporting, if I've understood you correctly . . . . . but this is not what the OP was reporting.