tgowen

95 seville sts

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i have an 95 seville sts. I replaced the water pump, the thermostat, and the cooling fans, and im still overheating. not a head gasket oil looks fine, not blowing any smoke out of tail pipe. what and where is the air purge line located, and if there is air in the cooling system will it really overheat lie that

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You say "not a head gasket, oil looks fine". Are you assuming that if you had a bad head gasket you would have coolant in your oil?

If you are, that is an incorrect assumption. You can have a bad head gasket and NOT have coolant in your oil

There are two hoses on the top of the coolant tank, an overflow and a second hose. Follow the second hose across to the engine to where it enters the engine, (should be near the throttle body), that is the purge line.

To test the purge line, gently pull that hose off the top of the coolant tank and let it hang, with the engine COOL

Go and start the engine dont race it, let it idle

Go and look at the purge line that is hanging, coolant should flow.... that is where air comes out of the cooling system when you fill it. AND YES, if there is AIR in your cooling system the water pump will cavitate and not pump coolant and you WILL overheat

Have you checked to see if your cooling system holds pressure and the cap is good? how is the water pump belt? do the cooling fans work? have you changed the thermostat?

Tell us what you find


Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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if there is air in the cooling system will it really overheat lie that

You bet.

When you do the purge line check that BBF suggested, open the surge tank cap and stick the purge line inside. That way you'll recover the coolant and won't make a mess.

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hey thanks for the info. going to try it today after work, and i was

assuming, lol. now when i let it run the temp climbs up to about 220, when i

give it a little gas it comes down a few degrees. does it still sound like

an air in the system problem? hopefully

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Ok so I am foreman at a scrap yard, and 1 year ago an older gentleman drove this gorgeous gold seville sts on the scale. Yes he ws scrapping it, all because he ws having overheating issues(wich are now solved thanks to you all) and the rear subframe connecting the rear wheels together was snapped. So i bought the car for scrap price, little under 500...lol...picked up a new rear end for 150...ive got a grand total of about 1,000 (including what i paid for the car) into the car. theres not one spec of rust or scratches on the car. the only thing i have left to do is replace the windshield, bleed the brakes, get an alignment, tune-up, oil change, and then take it to a detailer.

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220 degrees does not sound like a problem, what is your outside temp.

Does it get above 220 degrees?

Normal is 195 to 205 at highway speeds but it will rise a bit from that in the summer

In traffic depending upon the outside temp it will range from 217 to 228

With the AC off, you will see higher temps, as the fans don't run at full speed, and they will cycle on and off, off at 217 and on at 228. On very hot days in traffic, I have seen higher temps up to 245 in heavy traffic, which is ok, if you cooling system is good and you have at least a 50/50 coolant mix.

Now, if your cooling system leaks pressure due to leaks even small leaks the temps will be higher,


Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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thank you all again for your tips and suggestions. blowing out the air purge line did the trick. at idling the temp stays at 207-208. almost done.

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thank you all again for your tips and suggestions. blowing out the air purge line did the trick. at idling the temp stays at 207-208. almost done.

Glad that fixed your problem...:yupi3ti:

I am assuming that you blew air thru the purge line into the engine...

If you did, whatever was clogging the purge line may come back and clog it again.

If this happens, follow the purge line to the engine... it connects to a HOLLOW BOLT...

REMOVE the hollow bolt and remove the obstruction there...

Blowing backwards thru the purge line is usually only a temporary fix.

Whatever is blocking it needs to be removed from the system.


Posted Image

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OH NO......

WHO TOLD YOU TO BLOW ANYTHING??????????? I said COME BACK with the results of your TEST, nothing else

Explain exactly what you did


Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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If you did, whatever was clogging the purge line may come back and clog it again.

Most likely it was sealant tab residue and will be chopped up by the water pump impeller. I wouldn't be overly concerned about it.

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