1990 Seville, having a few problems

[Michelle]

Hi, I just purchased a 1990 Seville. I am new to Cadillac's and seem to be having a few problems. I would appreciate any input anyone may have. 1st thing, the car runs hot. It hasnt over heated, but it is hot. The highet I have seen the coolant temp go it about 223. When it was this hot I noticed the smell of antifreeze. I turned the defrost on high and watched the temp drop to 188-192 with no smell of coolant. I am thinking that the thermostat is not opening up. I can squeeze the top hose on the radiator a little. It's not soft. But I can squeeze it a bit when the car is running. The anifreeze overflow tank is at the correct level and clean. The carpet under my dash is not wet.. and I can not see any thing leaking.

2nd is my as$ end is low, I have to take it real slow going up inclines as it will rub against the pavement a bit. And the 3rd problem is low refridgerant. There are only 103 k miles on the car. The interior is a beautiful dark blue and in great condition. There are a few dings in the body and a little bit of rust starting to peek through. But want to get things straigtend out mechanically before I fix any cosmetic things. I have priced new tires and will be purchasing them this week.

Here are the diagnostic codes I pulled up..

Current -

B447

History-

E046

E098

B120

B121

B127

B446

B447

B552

ECM?

No Sir Codes..

And a few pictures of my baby...

Thanks a bunch,

Michelle

[BodybyFisher]

Welcome aboard. You did a lot a diagnostics, good job

That is a beauty, it looks like my 91 Seville a lot, I had a 4.9.

I do not believe that you are having an overheating problem at all and everything that you described appears normal, the hose will be hard at normal operating temp and soft when the car is cool

You should DRAIN and REFILL your cooling system however if you are NOT sure when it was serviced last however, you use GREEN coolant it should be changed every 24K miles or 2 years religiously and you NEED to use the GM COOLING SUPPLEMENT TABLETS.

[BodybyFisher]

Here is where you can look up your codes

http://myweb.accessus.net/~090/dtcobd1.html#pcm

EO46 - P046 (E046) .................................. Right to Left Bank Fueling Difference, this sounds like a possible vacuum leak, how does the car run/idle

P098 (E098) .................................... High RPM P/N to D/R Shift Under ISC, what is your RPM in DRIVE, with your foot on the brake?

B447 ....................... Very Low A/C Refrigerant Condition Warning [A/C Clutch]

[Michelle]

Thanks for your reply BodybyFisher. I will get back to you with the rpm in drive. The car idles a little rough. I don't know how to describe it. The steering wheel shakes a bit. Just a little bit though. No stalls or anything like that.

In regard to the coolant temp. What is normal? I saw 223 and nearly had a cardiac. Then there was the smell of coolant that just made things worse.. Am I freaking out for nothing? I am going to have my boyfriend flush it today and see what happens. Can I get the GM supplement tablets at any autoparts store?

Thanks,

Michelle

[jlinde]

I have observed the codes E091 and E098 as history codes in my friends 90 and 92 STS cars

and I believe it is nothing really to worry about -maybe something about idle and selecting drive...

After changing all the injectors in the 90 STS it started to run on all 8 and it also passed emission

without any problem and is just running beatiful and strong but the E046 showed up after a while

pointing to some fault like spark plugs, cables or oxy sensors but they are all new. We have not done any more investigating on this fault though so we will do the idle learn and check the cars fuel consumption to find out if it is

using any more gas compared to earlier. I have not checked if the oxy sensors voltage can be checked during driving as it can be done for the northstar.

/Jan L

[adallak]

Hi, I just purchased a 1990 Seville. I am new to Cadillac's and seem to be having a few problems. I would appreciate any input anyone may have. 1st thing, the car runs hot. It hasnt over heated, but it is hot. The highet I have seen the coolant temp go it about 223. When it was this hot I noticed the smell of antifreeze. I turned the defrost on high and watched the temp drop to 188-192 with no smell of coolant. I am thinking that the thermostat is not opening up. I can squeeze the top hose on the radiator a little. It's not soft. But I can squeeze it a bit when the car is running. The anifreeze overflow tank is at the correct level and clean. The carpet under my dash is not wet.. and I can not see any thing leaking.

2nd is my as$ end is low, I have to take it real slow going up inclines as it will rub against the pavement a bit. And the 3rd problem is low refridgerant. There are only 103 k miles on the car. The interior is a beautiful dark blue and in great condition. There are a few dings in the body and a little bit of rust starting to peek through. But want to get things straigtend out mechanically before I fix any cosmetic things. I have priced new tires and will be purchasing them this week.

Here are the diagnostic codes I pulled up..

Current -

B447

History-

E046

E098

B120

B121

B127

B446

B447

B552

ECM?

No Sir Codes..

And a few pictures of my baby...

Thanks a bunch,

Michelle

Your Seville is fine. Clear the codes and drive it for a while. If you put it in Neutral and press the gas pedal you will get E098 for sure. Ignore all the codes. The fans will not even turn on unless you get 226F. The fans will bring it down to some 212F. Do not get paranoid, just drive. As for rough idle, it could be old injectors. Measure the resistance of the injectors on two common connectors (one per fuel rail). They should be in the ballpark of 17 ohms. The resistance should be measured between vertical pairs of pins. If there are injectirs with with lower data, replace all of them. I'm doing that job next week, will share my experience.

[BodybyFisher]

Thanks for your reply BodybyFisher. I will get back to you with the rpm in drive. The car idles a little rough. I don't know how to describe it. The steering wheel shakes a bit. Just a little bit though. No stalls or anything like that.

In regard to the coolant temp. What is normal? I saw 223 and nearly had a cardiac. Then there was the smell of coolant that just made things worse.. Am I freaking out for nothing? I am going to have my boyfriend flush it today and see what happens. Can I get the GM supplement tablets at any autoparts store?

Thanks,

Michelle

No, don't worry about 223 at all. However, I ask you WHEN did you see 223?, stop and go traffic? You will need to locate the smell of coolant, I needed to replace my radiator on my 91, the side tanks are plastic (as they are on ALL cars these days), and they develop stress cracks as they age, you won't see coolant (until the cracks are bad) and what happens is that you SMELL coolant, as the coolant vaporizes when it hits the atmosphere.

DEFINATELY put in the cooling supplement, you can get it at a GM dealer, or you can get the BARS cooling supplement tablets at an auto parts supply, JUST USE the TABLETS and DO NOT let anyone talk you out of using them or to use any other stuff. I personally would get to a GM dealer and buy the GM version.

Your reaction to seeing 223 is normal, we all have freaked out, till we understand the NORMAL ranges, my 91 has been up to 240 in summer traffic, once you discover what the smell is, you will be fine.

You might change the thermostat and radiator cap, and check the hoses. Let the car warm up, and about 217 degrees, and your cooling fans should start up, look at them for strong rotation, I had a bad fan motor and had to replace it..

Keep posting your findings, we have a lot of 90 4.5 knowledge here. I am hoping someone chimes on on your fueling difference, it could be a bad injector and that would cause your roughness. Don't use injector cleaner, the next time you take a long trip, use TECHRON, and drive it through...

[Ed Hall]

Here is where you can look up your codes

<a href="http://myweb.accessus.net/~090/dtcobd1.html#pcm" target="_blank">http://myweb.accessus.net/~090/dtcobd1.html#pcm</a>

EO46 - P046 (E046) .................................. Right to Left Bank Fueling Difference, this sounds like a possible vacuum leak, how does the car run/idle

P098 (E098) .................................... High RPM P/N to D/R Shift Under ISC, what is your RPM in DRIVE, with your foot on the brake?

B447 ....................... Very Low A/C Refrigerant Condition Warning [A/C Clutch]

EO46 could also mean a defective O2 sensor. Go into the onboard computer and read the O2 sensor values as you're driving down the road.

Your car looks nice. It looks like it could use a pair of new rear struts. The rear struts have air bladders which get old and start to leak. A new pair would solve the sagging in the rear.

[Michelle]

Thanks for all your replies!

I saw the temp climb to 223 while the car was stopped in traffic. I guess I worried for nothing. Now that I know that these Caddys run hot I am more at ease with my purchase. Also I contacted the seller and he assured me AGAIN that everything was fine with the cooling system. But there must be a leak somewhere in order for me to smell the coolant. So I am going to bring the car back to the seller sometime this week. He works in a garage and he said he would try to find the problem for me. I trust the kid. He is the lil brother of a friend.

I'll check the o2 readings and talk with him about the rough idle as well. I couldnt really put my finger on a reading for the rpm, I have a lead foot. Going 30-40 mph the rpm ranged from 1200 to 2400 in stop and go traffic. I have yet to bring her onto the highway..

I will definately have to do something about the sag in the rear too. Maybe the kid can do that job for me. Thanks again for all your replies, I'll keep in touch!

Michelle

p.s I'll get some techron on my next fill up and see if it helps. Should I fill with chevron or just get the bottled additive?

[KHE]

I will definately have to do something about the sag in the rear too.

Looking at the pictures of your car, I don't see the rear end sagging at all - the gap between the rear tire and the wheel well molding in the back looks the same as the front.

[adallak]

Thanks for all your replies!

I saw the temp climb to 223 while the car was stopped in traffic. I guess I worried for nothing. Now that I know that these Caddys run hot I am more at ease with my purchase. Also I contacted the seller and he assured me AGAIN that everything was fine with the cooling system. But there must be a leak somewhere in order for me to smell the coolant. So I am going to bring the car back to the seller sometime this week. He works in a garage and he said he would try to find the problem for me. I trust the kid. He is the lil brother of a friend.

I'll check the o2 readings and talk with him about the rough idle as well. I couldnt really put my finger on a reading for the rpm, I have a lead foot. Going 30-40 mph the rpm ranged from 1200 to 2400 in stop and go traffic. I have yet to bring her onto the highway..

I will definately have to do something about the sag in the rear too. Maybe the kid can do that job for me. Thanks again for all your replies, I'll keep in touch!

Michelle

p.s I'll get some techron on my next fill up and see if it helps. Should I fill with chevron or just get the bottled additive?

A plastic T on the top of engine (heater valve) is a known source of leaks. They develop tiny cracks. You cannot see anything under normal conditions, but if you open the hood up and increase RPM up to 3000-3500 by hand (holding up the throttle lever) you may see a leak (if the T is cracked). Same procedure upplies to such areas of 4.9 engine as water pump gasket, heater pipes, hoses/connections, radiator hoses/connection as as well as radiator plastic end tanks. If the radiaotor has never been changed it is probably time to replace it as those end tanks crack sooner or later. Mine did a few years ago.

[BodybyFisher]

Use Chevron, if you have it near you.. If you plan to take a long trip, use the Techron so that it blows through quickly and so that it does NOT sit in the tank.

Take a look at your side tanks on your radiator, look for steam and white sediment. Put you nose on each side of the radiator and smell for coolant.

[Michelle]

I will definately have to do something about the sag in the rear too.

Looking at the pictures of your car, I don't see the rear end sagging at all - the gap between the rear tire and the wheel well molding in the back looks the same as the front.

Hi KHE, when I had my daughter (who is pregnant) and her 250 lb b/f get in the car the rear end draggged as we started to up a slight incline, lol..I mean it was bad..I had to have the b/f get out and walk..... I am thinking about replacing the rear air suspension with rear conversion strutmasters. Any thoughts on this? Has anyone here ever done this?

Michelle

[Michelle]

Use Chevron, if you have it near you.. If you plan to take a long trip, use the Techron so that it blows through quickly and so that it does NOT sit in the tank.

Take a look at your side tanks on your radiator, look for steam and white sediment. Put you nose on each side of the radiator and smell for coolant.

There are no Chevron stations in MA nor are there any Texaco stations near me. Lol..Last Sunday I filled up using premium unleaded from Hess and added a bottle of Techron. I don't know if it helped. But it sure was an expensive fill. 8 bucks for the bottle of Techron and 59.00 to fill my tank. We took a trip to the beach. The tank is almost empty again . I think the only thing I don't like about this car is having to use the premium unleaded. My father(who was a Ford mechanic for half his life) says in this day and age he doesn't believe that putting 87 octane in the tank will harm my caddy nor hinder it's performance. Any thoughts on this?

Still no coolant leaks and the coolant smell while idling hot seems to have disappeared. I am still waiting on the seller to get it into the garage where he works. He broke his arm last week.

[KHE]

I will definately have to do something about the sag in the rear too.

Looking at the pictures of your car, I don't see the rear end sagging at all - the gap between the rear tire and the wheel well molding in the back looks the same as the front.

Hi KHE, when I had my daughter (who is pregnant) and her 250 lb b/f get in the car the rear end draggged as we started to up a slight incline, lol..I mean it was bad..I had to have the b/f get out and walk..... I am thinking about replacing the rear air suspension with rear conversion strutmasters. Any thoughts on this? Has anyone here ever done this?

Michelle

It sounds like the leveling control system is not working... With the ignition in the ON position, lean/sit on the rear bumper and after a few seconds, you should hear the compressor run and the car should level out. If not, you need to determine why the compressor is not activating. I would do this before replacing the rear shocks.

Use Chevron, if you have it near you.. If you plan to take a long trip, use the Techron so that it blows through quickly and so that it does NOT sit in the tank.

Take a look at your side tanks on your radiator, look for steam and white sediment. Put you nose on each side of the radiator and smell for coolant.

I think the only thing I don't like about this car is having to use the premium unleaded. My father(who was a Ford mechanic for half his life) says in this day and age he doesn't believe that putting 87 octane in the tank will harm my caddy nor hinder it's performance. Any thoughts on this?

When the tank is close to empty, try a half tank of regular. If the engine does not ping, then you can probably get away with running regular. If it pings, fill it up with premium. The next tank, try a half tank of mid grade and repeat the test. Pinging will damage the engine over time so if the engine pings, go to the next highest octane until it doesn't ping.

If it pings on 87 and 89, the other option is to retard the timing a few degrees and then it will run on regular but at the expense of fuel economy and performance. In other words, your cost per mile could be less with regular vs. premium.

[Michelle]

It sounds like the leveling control system is not working... With the ignition in the ON position, lean/sit on the rear bumper and after a few seconds, you should hear the compressor run and the car should level out. If not, you need to determine why the compressor is not activating. I would do this before replacing the rear shocks.

Hi KHE, Thanks for getting back to me . I read up a bit more on this and I do think that a little more investigation is warranted before I decide to go ahead and replace anything. So I did exactly what you said. I put the key and and turned it to the on position. I heard the compressor come on so I sat on the bumper for a few seconds and nothing happened. The compressor just kept on running. One thing that I do notice that the drivers side is lower then the passenger side and I can feel it when the road is a little rough. There is also a bit of rattle back there on the left.

I wish the guy who sold it to me would get back to me soon. I can't stand driving it the way it is.

When the tank is close to empty, try a half tank of regular. If the engine does not ping, then you can probably get away with running regular. If it pings, fill it up with premium. The next tank, try a half tank of mid grade and repeat the test. Pinging will damage the engine over time so if the engine pings, go to the next highest octane until it doesn't ping.

If it pings on 87 and 89, the other option is to retard the timing a few degrees and then it will run on regular but at the expense of fuel economy and performance. In other words, your cost per mile could be less with regular vs. premium.

Thanks for everything : ) I will try this lil experiment out and see if I can hear any pinging.

Michelle

[KHE]

If the compressor runs and the rear does not level out, there is a leak in the air lines, compressor head, or the shocks themselves. You will need to trace the lines from the compressor to each shock looking for a leak. The lines are plastic and about 1/8" in diameter. Pay close attention where the line comes near moving suspension components. Spray soap water on the lines and look for foaming at the site of a leak. Spray the lower boots on the shocks as well as where the air lines connect to the shocks.

If you find a leak in the line, a repair splice is available at the dealer for $3.00.