: Need help - going to see a 98 Seville STS on Sat, what do I check?



Jad
01-17-08, 01:39 PM
Hello all,

First time poster here, been lurking a bit...need your suggestions/tips!

I'm going on Saturday to look at a 1998 Seville STS w/ 148,00 kms (91k miles). Owner says it needs brakes (not sure if all or what yet), but otherwise that it's good and a daily driver.

My question is what specifically should I be asking or checking when I see the car? My concerns are with the suspension and head gasket as those seem to be the big $$$ items?
I will also be having a mechanic check it out...it is worthwhile to do a hydrocarbon test on the coolant?

Please let me know if there is any specific to Cadillacs/Seville STS's that I should be checking or asking the owner about.

Really appreciate your time!
Jad

Submariner409
01-17-08, 05:44 PM
Lots of history and writing. Pop a brew and go back to Day One in both the Seville and N* Performance forums and start reading. To type it all out here would take hours. Once you get reader's cramp from that, wade into the tech tips forum, and the tech archives at the top of the main page (black area under "CadillacForums.com") ^^.

Take the VIN to a Cadillac dealer and see if they will give you the GM database list for the car recalls/warranty work.

Ranger
01-17-08, 06:13 PM
Ask when and how often the coolant was changed. Make sure it does not over heat. Especially after some WOT treatment. Pull the DTC's.

Jad
01-17-08, 08:49 PM
Thanks Ranger, for the practical and specific advice that I can use when I see the car.

The OE temp for these cars is 180 degrees (right?), should the car stay at that temp for the most part during the test drive?

Ranger
01-17-08, 09:02 PM
No. Normal operating temperature is 205-215. The gauge should be at the 12:00 position. Should pretty much stay there. Some people report some minor fluctuation, but nothing more than 1 tick.

Check the Tech Tips section and print the sticky on how to pull the DTC's.

zonie77
01-17-08, 09:09 PM
submariner's good advice

:yeah:

Initially the HG's only fail under load, so find some hills or do a couple of on ramps in quick succession,

Other than that make sure you drive it pretty far, put a gallon of gas in it. Get out and shut it off, walk around it, get back in and drive. Do that a few times so you start to get used to it. Then if something's acting up you are more likely to notice it. You are also more likely to notice any body flaws.

Jad
01-17-08, 10:31 PM
Thanks again Ranger, and zonie.

I'll keep that temp range in mind, does the gauge show actual degrees or just watch for it to stay at 12:00 position?

Read the article on DTC's, thanks.

I'll try to put it through some stress and see what the temp does...

On a side note, what is the general opinion of those "Thermagasket" products on this board? ( http://www.rxauto.com/northstar-kits.html ) Do they work? Also, what do you think of this excerpt from the Thermagasket website:

"Important Notice:

The cooling fans on the Northstar come on between 210 and 218 degrees which is way too late, especially if you have compromised the head gaskets and head bolts by overheating the system. It is advised to install one of our adjustable fan switches so that you can adjust the temperature that the fans come on to 180-190 degrees for the overall well being of your engine."

Thanks guys!

CadillacSTS42005
01-18-08, 12:15 AM
biggest tip ever
search

05devilledave
01-18-08, 09:43 AM
If all we need to do is search, then mine as well take the "new thread" button off the website. Dont spend hours melting your brain searching dude, feel free to ask and have people answer for you. One thing I would check is highway vibration, like 65-75mph, see if she shimmys like a parkinsons patient, or glides smooth like glass. Also, smell the exhaust and see if it smells sweet, like coolant. Check the idle RPM, should be 650-750 or so, not like 800-1200, or more. Lastly Id check for leaks, I.E. main seals, tranny leaks, engine case leaks. Good luck!!:D

Jad
01-18-08, 10:03 AM
If all we need to do is search, then mine as well take the "new thread" button off the website. Dont spend hours melting your brain searching dude, feel free to ask and have people answer for you. One thing I would check is highway vibration, like 65-75mph, see if she shimmys like a parkinsons patient, or glides smooth like glass. Also, smell the exhaust and see if it smells sweet, like coolant. Check the idle RPM, should be 650-750 or so, not like 800-1200, or more. Lastly Id check for leaks, I.E. main seals, tranny leaks, engine case leaks. Good luck!!:D

THANK YOU DAVE. I was starting to wonder what the hell kinda message board this is...I mean, there's a time and place for reading up, which I will do...but right now I just need some quick advice.

I will check all those things, great tips..thanks! Will post back on Saturday to let you know how it went.

Submariner409
01-18-08, 10:52 AM
In the late 90's - on N* series, the thermostat begins to open at 188 degrees and is fully open at 206. No temperature numbers, just tick marks. 12:00 is about 210, normal operating temperature. The car is going to warm up to at least 200 no matter how many fans you put in there. The existing system is a lot smarter than the aftermarket sellers would have you believe. Waste of money to have your fans run for no reason. As an aside, don't get creative with the thermostat, either. These engines have a design temperature operating range, and to try and run it at 180 will play hob with engine control and emissions settings.

One of the advantages of doing extensive searches in threads of concern is the ability to see multiple answers to the same problems, weigh the results, and discard the suggestions of people who don't know what they're talking about. You would also find quite a bit on your aftermarket fan question. You will find a Seville temperature gauge with actual temperatures digitized onto the pic.

Jad
01-18-08, 03:44 PM
In the late 90's - on N* series, the thermostat begins to open at 188 degrees and is fully open at 206. No temperature numbers, just tick marks. 12:00 is about 210, normal operating temperature. The car is going to warm up to at least 200 no matter how many fans you put in there. The existing system is a lot smarter than the aftermarket sellers would have you believe. Waste of money to have your fans run for no reason. As an aside, don't get creative with the thermostat, either. These engines have a design temperature operating range, and to try and run it at 180 will play hob with engine control and emissions settings.

One of the advantages of doing extensive searches in threads of concern is the ability to see multiple answers to the same problems, weigh the results, and discard the suggestions of people who don't know what they're talking about. You would also find quite a bit on your aftermarket fan question. You will find a Seville temperature gauge with actual temperatures digitized onto the pic.

Thanks for the tips and info....I understand what you're saying about searches, and I have been doing those today, seeing similar threads to mine. Will continue checking more stuff out.

Destroyer
01-20-08, 11:34 PM
"Need help - going to see a 98 Seville STS on Sat, what do I check?"

Check your bank account and see if you have sufficient funds to fix the car when it breaks. :alchi: