: 1999 Seville OVERHEATING



benmack
03-16-09, 12:45 PM
I bought a 99 seville in Jan. with 108,000 miles. I drove to Kansas City, MO from Wisconsin two days after I bought it (moved). The car drove fine. The first weekend I drove downtown the car overheated. I found some threads online that say it is the head gasket. I brought the car to a cadillac dealership and they said "yes it is the head gasket". I brought the car to another place and they ran a test (mixed some liquid with the coolant and did not see a color change) and found not to be a head gasket. This mechanic stated there is nothing wrong with the head gasket and replaced the fan sensore and sent me on my way. One week later I drove downtown and the temp has from the middle about an 1/8 inch (about 3/4 of the gauge). After it raised it went back down after about a minute. When I pull off from a stop light I can hear air bubbles. I need help and hoping this is an easy fix before I drive it back to WI to the dealership to get fixed.

Any help PLEASE!!!!

JimD
03-16-09, 04:02 PM
There is an air purge line that begins at a hollow bolt above the water pump cover and flows through the throttle body and terminates at the top of the coolant reservoir. Be 100% certain that line is flowing a slow steady trickle of coolant by removing the rubber hose from the top of the reservoir with the engine at idle (cold engine!!).

If there is no coolant flow, locate and remove the blockage.

Once the air is purged from the system, you can expect the coolant level in the reservoir to drop a little so keep an eye on the level. Once again, with a cold engine.

benmack
03-16-09, 07:12 PM
I took your advice Jim and checked for blockage. The coolant was flowing good and fast. The noise (water bubbles) is coming from the console. Any other options or thoughts?????????

Submariner409
03-16-09, 07:20 PM
Has to be in the heater core....they can be a PITA to purge of all air bubbles. Try a few judicious high rpm moderate accelerations in gear position 2. Let the engine run up to the 1 - 2 shift with moderate throttle and then ease it up to over 5000 rpm and let it coast back down. Watch the temp gauge (it probably won't move) and do it again. Let the car cool, and maintain the coolant level at about halfway up the tank, cool.

benmack
03-16-09, 08:54 PM
It will make the bubbling sound even when in park and i raise the RPM's, I can start to hear it at about 2000 RPM's. Do you think the heater core needs to be replaced or is there a way to bleed the system (if brought into a mechanic). I need to try and figure out if it is worth driving back to WI (still under warranty) from Kansas City, MO or pay to get fixed here.

Eldo1953
03-16-09, 09:03 PM
If you still have warranty I would take it back imo.

Destroyer
03-16-09, 09:45 PM
yeah, change the water pump, check the purge line, change the t stat and do all of what everyone is telling you to do. After you get done wasting all that time and money................it'll be the head gaskets. I'm rarely wrong on this. ;)

benmack
03-16-09, 10:07 PM
Thats is what I am guessing it is after everything I have read. Is there a reason when I had the dye test done it showed nothing?

Ranger
03-16-09, 10:31 PM
Maybe they did the test wrong. You can't do it after you add fresh coolant or it will give a false negative. From what you are saying I doubt you'll make it to Wisc. Your symptoms do not sound promising I hate to say.

benmack
03-16-09, 10:38 PM
That's what I am afraid of. Towing is not in the warranty. I am trying to eliminate everything so I am 100% confident in spending the money to get the car back to WI.

Ranger
03-16-09, 10:45 PM
Read the warranty closely and talk to them first. Some warranties have loopholes. I'd hate to see you go through the trouble and expense to get it back up here only to have them say oops, sorry.

benmack
03-16-09, 10:53 PM
I read it upside down and backwords. Have been dealing with them since the end of Jan. The only way they will fix it is if I bring it up there or they will send me a check for $2500 to get it fixed here but the cheapest I have found is $3500 after taxs.

ryannel2003
03-16-09, 10:59 PM
You're very lucky to have a warranty that covers HG's. Most people are left to pay the $3500 to get them fixed. Oh btw, make sure that warranty includes timeserting. Most don't, and if the car isn't timeserted it will fail again.

Ranger
03-16-09, 11:04 PM
Yeah, even if you have to foot the Timeserts out of your own pocket, DO IT.

benmack
03-17-09, 10:01 AM
Is there something I can do to make sure they fix the hg? I don't want to bring it all the way up there and have them do the same die with coolant test and tell me it's not the hg.

Ranger
03-17-09, 11:02 AM
Test it again or have a cylinder pressure test done to confirm it. It should not be hard to diagnose to be sure before hauling it back up north.

benmack
03-18-09, 03:29 PM
If it is the hg, would it overheat all the time? I tried to get it to overheat last night by driving around for about an hour (fast, stop and go, everything) and I only got the temp to raise about and 1/8 inch and then it went back down after about a minute but the gurgling water sound seems to be getting louder/worse.

Ranger
03-18-09, 04:13 PM
Usually in the early stages of a HG failure it will overheat under a load, a hill climb or WOT.

benmack
03-18-09, 06:15 PM
I have not had the car overheat under a load yet. Everytime has been in stop and go traffic or at stop lights. I drove from Kansas City tothe middle of Iowa about a month ago and I did not have any problems. The temp was chilly on the way there but 50's on the way back. I also drive the car to work and back and anywhere I need to go without it overheating (unless I get in stop and go traffic). Whats is the gurgling noise that I hear? Can the be part of the problem?

Submariner409
03-18-09, 06:31 PM
What is your definition of "overheating" ? Where on the picture is your idea of "overheating" ?

benmack
03-18-09, 06:59 PM
It will raise up to about 5/8 to 6/8. What is that girgling noise and how much $$ at a mechanic to fix?

Ranger
03-18-09, 07:39 PM
The gurgling noise is air in the heater core.

What is 5/8 to 6/8? Where on that dial in temps listed?

benmack
03-18-09, 08:05 PM
210 - 225 degrees is what it raised to then goes back down. When it raises it takes about 4 seconds to get that high, then after a minute or so (depends everytime) it goes back down. It completley overheated once where I had to pull over. I hooked it up to a computer and did not get anything back.

Should I be worried about the gurgling?
Thanks for all the help!

Ranger
03-18-09, 08:15 PM
The gurgling COULD be an indication of a problem if the purge line is clear.

Mark C
03-18-09, 08:20 PM
If you don't have the A/C on or heater in Defrost mode the fans don't come on until the temperature gets to 225, and then only one starts. Two fans run in fast mode at 238 degrees. Did the car overheat (steam out of the surge tank) or did the DIC tell you to idle engine or stop the engine?

benmack
03-18-09, 08:30 PM
I popped the hood and there was steam and also coolant boiled out of the cap. I let it cool and made it to a gas station and added more coolant. I then made it all the way home (about 15 minutes) without the temp gauge raising. I have had the fan sensor replaced and now it raises to about the 225 mark if I am driving downtown otherwise it is fine.

Ranger
03-18-09, 08:38 PM
Just drive it and keep an eye on it. IF it is the HG, it will let you know in due time.

Submariner409
03-18-09, 08:53 PM
What is the coolant level in the surge tank, cold. Empty, 1/2 full, or at the top ??? No questions this time: answers only.

benmack
03-18-09, 09:14 PM
It is full, just to the top of where the divider is. There is room left for expansion.

Ranger
03-18-09, 09:21 PM
:hmm:

benmack
03-18-09, 10:11 PM
I'm running out of ideas, I sure would hate for the HG to go in 6 months after my warranty is done.

Ranger
03-18-09, 10:19 PM
Well, if that is what you are worried about have the coolant tested again and/or a cylinder leak down test done.

benmack
04-06-09, 11:46 AM
I had another die test done and the color did change but it took about 30 minutes. The mechanic told me the reason it took so long is because it is a small leak. Does this sound like an accurate assumption? I am just trying to make sure the guy isn't trying to buffalo me :)

mikelawson
04-07-09, 07:51 PM
Unfortunately, you have a blown head gasket. I have repaired over 20 of these and all have the same symptoms as yours. I repair these for 1500 + parts, so if they only pay 2500, I could get you repaired for less than that, with a warranty. I'm in Ky, which might pose some issues, but you can email me if you have additional questions about your car. Mikelawson@ctky.com.

Mike

shea
08-15-11, 04:59 AM
right i just got mine and i just replace the radiator the water pump and the thermostat and its still over heating and when it does get hot i have no hot air or cold neither so i think i have a air pocket in it somewhere but I've tryed bleeding it out is there some other or special way to do so??

Submariner409
08-15-11, 08:44 AM
right i just got mine

This is a heck of a way to say "Welcome Aboard !!!!!!..............:welcome:"

Before buying the car you needed to do some testing.........You now have a LOT of homework to do. If you have replaced most of the cooling system and the engine still overheats, then you have big problems. 1999 is the worst year for Northstars with blown head gaskets. Where did you buy the car, did you pay close to dealer Blue Book retail for it, and is/was there any warranty ??

Check the purge line for steady flow - with the engine cold, remove the line from the nipple at the reservoir top side and hold it in the open filler neck. Have an assistant start the engine and let it idle. No flow and, YES, you have air trapped in the main cooling system. Clean out the purge line and the metal bolt/nipple at the rear side of the thermostat housing/water pump cover. If the purge line is totally clogged it can be replaced by a proper sized length of reinforced fuel line from any parts store. BUT, if it IS totally clogged, the chances of someone having poured some sort of block sealer in the engine are very good - and that's NOT good for you - $$$$.$$

You should do a cylinder block test for exhaust gas in the airspace over the coolant in the reservoir - proper coolant level is halfway up in the reservoir, cold. www.sjdiscounttools.com/lis75500.html (http://www.sjdiscounttools.com/lis75500.html)

shea
08-17-11, 01:15 AM
yeah but my car i will get half way hot then it will go for about an hour then get hot very quick??

shea
08-17-11, 01:22 AM
do u think my reservoir cap isn't holding all 15 psi's ?

shea
08-17-11, 01:26 AM
i got it from lujacks with no warranty for 5,999

ternstes
08-17-11, 06:31 AM
I would test the coolant for exhaust gases before doing anything else.

Ranger
08-17-11, 11:47 AM
do u think my reservoir cap isn't holding all 15 psi's ?
Possible, but not probable. Any radiator shop can test the cap for you.

89falcon
08-18-11, 09:06 PM
Possible, but not probable. Any radiator shop can test the cap for you.

Or you can just buy a new one CHEAP.....

Destroyer
08-22-11, 08:16 PM
This is an old thread. I'm sure the car has been junked by now. :)

edb150
08-27-11, 11:14 PM
My shop has successfully repaired 98 Cadillacs with bad head gaskets, most had new water pumps, radiators, hoses, and fans etc etc. by the time they got to me. Unfortunately its usually the head gaskets. I have seen a couple that the test showed good but still had blown head gaskets. I have only tested 5 cars with the test as most are easily diagnosed without the test. Whoever fixes it make sure it gets inserts or studs or it will be time wasted. Not to mention money wasted.:tisk:

xxxxxxxxxxxxxxxRawben
09-07-11, 01:41 PM
Mark

89falcon
09-07-11, 01:57 PM
My shop has successfully repaired 98 Cadillacs with bad head gaskets, most had new water pumps, radiators, hoses, and fans etc etc. by the time they got to me. Unfortunately its usually the head gaskets. I have seen a couple that the test showed good but still had blown head gaskets. I have only tested 5 cars with the test as most are easily diagnosed without the test. Whoever fixes it make sure it gets inserts or studs or it will be time wasted. Not to mention money wasted.:tisk:

Mine got a new overflow reservoir (the first thing to go)...then a water pump......two hoses.....then radiator.....then heater (a fun and messy failure....)...then another hose......so I didn't bother with the "test"....pulled the engine...and upon pulling the heads, the failure was OBVIOUS.

I think my failure happened over a pretty long period of time...it didn't just fail massively one day.....symptoms just got worse...and worse and worse...

Ranger
09-07-11, 09:38 PM
I think my failure happened over a pretty long period of time...it didn't just fail massively one day.....symptoms just got worse...and worse and worse...

That's the norm. They never fail catastrophically. It's a long, slow painful death.

ChuckDog
08-24-12, 03:06 PM
Good evening; Guys i just got threw re-doing a 1999 Cad. Seville STS semi complete cooling system that is redoing the water pump housing gasket, therm. replace, radiator new out the box, coolant temp. sensor,100% antifreeze not 50/50.
But every time i drive it on the highway it shows half gauge, after getting off the highway and driving about 3mins. it starts to climb in temp. 6mins. off highway its running hot, my fan are coming on both of them, but it still rises in temp., but it seems that as long as i'm on the highway it never passes half gauge.
Can someone guide me in the right direction away from the DealerShip?__.:devil:

Ranger
08-24-12, 09:14 PM
:welcome:

Guide you to where? Diagnosis or repair?

For diagnosis first check the purge line. If that's clear get a block test kit. You can borrow one from AutoZone. Run the test per the instructions to check for exhaust gases in the surge tank. Being a '99 I would not get my hopes to high though. Unfortunately, like many people you probably wasted a lot of money, time and effort throwing parts at it hoping one will stick.

Submariner409
08-25-12, 01:24 PM
.......... and 100% coolant freezes and boils at a lower temperature than the recommended 50/50 mix, and 100% coolant DOES NOT remove as much heat per liquid volume as 50/50. The various "water wetters" will not do a thing for you, so forget that, too.

As Ranger posted, you need to do a thorough cooling system diagnosis and stop throwing parts at it.

Here is approximately the temperatures you're looking at (the tick marks on the earlier 130 degree sweep gauge correspond to the ticks on this gauge). The notations are not applicable to Northstar cooling sysems after 2005.

Rick777888
10-07-16, 01:59 AM
Should the purge line pump water into the purge tank with a steady flow or with a pulsing action?

Submariner409
10-07-16, 08:02 AM
Fairly steady flow at idle, increasing in volume as rpm is raised. Spits and sputters that clear up shortly after engine start is a small air pocket being purged. Constant sputtering, with bubbles, is not good. No flow is not good.

A pulsating flow with no bubbles is probably OK, but flow should smooth out as engine rpm is increased.

...........remember - correct coolant level in the surge tank is half full, cold. Don't check/adjust level with the engine any more than barely warm.

Welcome to the Funny Farm!! You must have your site viewing preferences set to "View oldest posts/threads first". This thread had been dead for 4 years.

Ranger
10-07-16, 10:59 AM
Should the purge line pump water into the purge tank with a steady flow or with a pulsing action?
The important thing is that the line is clear and flows coolant. The flow rate is irrelevant.

Paul London
10-11-16, 01:02 PM
Fairly steady flow at idle, increasing in volume as rpm is raised. Spits and sputters that clear up shortly after engine start is a small air pocket being purged. Constant sputtering, with bubbles, is not good. No flow is not good.

A pulsating flow with no bubbles is probably OK, but flow should smooth out as engine rpm is increased.

...........remember - correct coolant level in the surge tank is half full, cold. Don't check/adjust level with the engine any more than barely warm.

Welcome to the Funny Farm!! You must have your site viewing preferences set to "View oldest posts/threads first". This thread had been dead for 4 years.

but there's life in the old thread yet: it's helped me 'cos it gave info. I'd not seen elsewhere.

Replacing the pressure cap (NOT cheap here) stopped the water coming out of the surge tank & then replacing the 'stat meant the bottom hose felt only a little cooler than the top one (whereas before it was barely warm) that leaves the purge line (following Sub's advice elsewhere not to throw money/parts at it) which clearly needs attention: before I did the 'stat it spluttered (like a domestic faucet after the supply been interrupted) but afterwards - nothing! (at least at idle). I know now what I have to do (although removing the airbox &, it seems, the MAF sensor, to get at the "other" end out in the street, in the dark won't be a lot of fun) AND what, having cleared/by-passed any blockage, I should expect.

Submariner409
10-11-16, 01:15 PM
If your engine has the coolant-heated throttlebody, those are known to clog and cause purge flow issues.

Bypass the TB circuit and replace the entire purge line with proper sized reinforced rubber fuel line from a parts house. Screw-type band clamps. Be careful wth that plastic surge tank nipple.

Coolant heated throttlebody ???? Theory says that, with the throttle blade almost closed - idle speeds - the rapid expansion of the air on the vacuum side of the throttle blade can cause ice formation on cool, humid mornings. Heat the throttle bore. Old carburetor stuff - the heat riser - did that as well as assured cold fuel atomization. But we have port fuel injection. Our throttlebody is bolted to an aluminum water crossover so it naturally heats as the coolant does so. Heated throttlebody = redundant, and it lasted only 2 years or so.

Paul London
10-13-16, 01:21 PM
If your engine has the coolant-heated throttlebody, those are known to clog and cause purge flow issues.

Bypass the TB circuit and replace the entire purge line with proper sized reinforced rubber fuel line from a parts house. Screw-type band clamps. Be careful wth that plastic surge tank nipple.

Coolant heated throttlebody ???? Theory says that, with the throttle blade almost closed - idle speeds - the rapid expansion of the air on the vacuum side of the throttle blade can cause ice formation on cool, humid mornings. Heat the throttle bore. Old carburetor stuff - the heat riser - did that as well as assured cold fuel atomization. But we have port fuel injection. Our throttlebody is bolted to an aluminum water crossover so it naturally heats as the coolant does so. Heated throttlebody = redundant, and it lasted only 2 years or so.

Forum site let me down again, almost finished reply yesterday when it froze - & at about the 3rd attempt to get cursor to move, the site just disappeared off the screen.

Oh well, here we go again: yup, knew that hence the current &, probably, final phase in tackling this problem. Of course you couldn't have known that, so it's not that I'm not grateful.

Had already printed off an enlarged copy of that diagram, to keep by me when I start dismantling. I now know I have the heated TB, because the line from the surge tank ends on a vertical pipe. I now also know where to be looking for the other end, to lead me to the infamous hollow bolt.

Couple of details though, how much pipe do I need to do the bye-pass job? I'd like to get it before I further disable the car & why do you say fuel line? Short of going to a truck dealer I'm going to have difficulty getting some with anything like that i.d. - 8 or 10mm seems to be about the norm here.

Submariner409
10-13-16, 03:59 PM
Reinforced rubber fuel line comes on large spools in many different ID sizes. Use a length of it - proper ID - and go straight from the hollow bolt/nipple over to the surge tank. Use screw-type band clamps - fuel line size.

Why reinforced fuel line??? Because it is tough and easily withstands any normal cooling system pressure.

5 second quick search ..........

https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=automotive+rubbber+fuel+line+hose

Paul London
10-14-16, 12:51 PM
As far as I know, it only comes in 6,8 &19mm ID here for automotive use, so, depending on what I can find, it looks like ordinary coolant pipe for me - & I'm certainly not going to buy a spool of it, I begrudge having to buy a metre, but I suspect that's the minimum.

Off to a restoration show in a couple of weeks (poor substitute for a weekend in LA - but there you go) so there'll be a couple of specialist traders there, I can wait that long now, so I'll see what i ca find.

You've mentioned clips before, not a fan of Detroit's staple fitting then (just as BMW & the French are latching on to them)?

Submariner409
10-14-16, 06:32 PM
The spring clips are just fine for assembly line work - problem is, they seem to lose "spring" over the years and do so even more when you use the correct tool or drilled pliers to remove/replace them.

I like fuel and coolant lines to be ......... secure.

Drilled pliers? Yep - use a vise and high speed drill+bit to groove a cheap pair of slip joint pliers. I have used this particular one since the late 50s. It also works for the type that is a single round spring with angled tips. Good for drum brake springs, too.

Paul London
11-01-16, 02:16 PM
The spring clips are just fine for assembly line work - problem is, they seem to lose "spring" over the years and do so even more when you use the correct tool or drilled pliers to remove/replace them.

I like fuel and coolant lines to be ......... secure.

Drilled pliers? Yep - use a vise and high speed drill+bit to groove a cheap pair of slip joint pliers. I have used this particular one since the late 50s. It also works for the type that is a single round spring with angled tips. Good for drum brake springs, too.

Guess I've been lucky, once I'd discovered how to remove replace them (the proper tool has only recently become available here - but at such a price), although access can be an issue, e.g. the heated TB connections.

Love those drilled pliers (all these years I've struggled with brake shoe springs - & the answer's so obvious!). So one pair of waterpump pliers (my spring clamp removal tool of choice) will soon have an appointment with a drill - & I'll be looking for a cheap pair of slip joints! (for when those just not enough room to wield those 10" WP pliers)

B-t-w, those screw clamps you favour, I assumed you meant the ones with the course thread that drives the free end of the band. But, then I wondered if you actually mean what we call fuel line clamps, i.e. the ones with the small set screw into a trapped nut at a tangent to the clamp (bit like those bent wire ones you'll know from '50's British cars); supposed to pull into a true circle - but only available in smaller sizes.

----------

Oh yes, back to the original story, got a metre length of heater hose (+ 2 clamps) for 2-odd at the weekend, so last night, removed the hollow bolt to clear it (didn't fancy poking what was blocking it back into the cooling system) only to find it wasn't blocked - but not a dribble came out of it's hole! Anyway, bypassed the heated TB, reassembled the air intake, topped off the water (antifreeze can come later, if I've finally cracked the problem!) Fired it up, left it idling but got called in for dinner, so never got up to temp. but that new piece of pipe was warm, so must have water flowing along it now - so perhaps the final piece of the problem was the TB! Might find out tonight :suspense: