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Discussion Starter · #1 ·
Have a 2008 dts . Was running slightly hot sometimes (1 tick above halfway and would cool back down with throttle or highway) changed the thermostat and did same thing . Started running a little hotter so I burped air again . Usually if started running hot in traffic or stop and go I could rev to 3k or give it some gas driving and it would cool right down . Now it keeps climbing . I checked radiator and seems to be hot on the passenger side cold on the driver side . Clogged? Copland it clean as a whistle .also I started noticing a ticking noise (like a lifter but I know it’s not the same on these) when I cold start it . Goes away with acceleration (or I think can’t hear it anyway ) but once car is hot as well if I start car and let idle it’s there . Minor tick not loud . I have no metal in the oil and also on the overheating issue coolant smells fine and no oil water mix . I think I can hear a minor exauhsted leak when cold starting as well. Any ideas ? I also have a slight shake in the front end when driving around 45+ Don’t really feel it in the steering wheel though. That is a symptom of the liver control arms where they bolt to the subframe bushing being bad isn’t it ? It minor but you can feel it and shakes passenger seat when driving . Anyway I bought this car cheap to fix and drive and I love it just want some input so I don’t spend unnecessary money on things . Has some other issues but these are the pressing ones currently . Car has 160k miles on it

Also fans are working fine I’ve had it on a good scanner comes on at proper temps and speeds and shuts of at correct temperatures
 

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2002 F55 STS, 2014 Explorer XLT, F-150s
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Coolant purge line clogged ? Should flow a steady stream into the surge tank at idle. No flow causes air pockets and water pump extremely low flow.

Clean the hollow bolt/nipple and the entire line.

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2002 F55 STS, 2014 Explorer XLT, F-150s
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Check the front wheels and tires for runout - any wobble and you get the "Seville Shimmy". Hub, rotor, and wheel mounting surfaces must be surgically clean and true. Lug nuts hand torqued to 100 lb/ft in an increasing star sequence.

32 psi ambient cold all around.

Sway bars, body mounting bushings, and end links.

Lower control arm bushings.
 

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2002 F55 STS, 2014 Explorer XLT, F-150s
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Because the thermostat is in the lower radiator hose return right at the water pump, if the pump was not pumping and the thermostat opened then some hot coolant would move to the upper radiator hose by convection, warming the passenger side of the radiator. A small amount of coolant flow would also warm the passenger side but, since our radiators are very efficient, the driver's side might not get perceptibly warm.

You should also have low or no cabin heat .......... that's the first circuit to airlock.

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Discussion Starter · #7 ·
Coolant purge line clogged ? Should flow a steady stream into the surge tank at idle. No flow causes air pockets and water pump extremely low flow.

Clean the hollow bolt/nipple and the entire line.

View attachment 591434
I did notice that it has little to no flow at idle in the surge tank. So could be the radiator is not bad then ? The old thermostat had a gasket like material on it and was missing a bunch maybe that clogged the Coolant purge ?
 

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'02 ETC 34,000 miles 2002 F55 STS 83,000 miles, 2016 Challenger SRT 392, 6 Sp.
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How long have you owned the car? It's possible someone put some stop leak tabs or some crap in there at some point. Cross your fingers they didn't. Tell us more about the ticking sound. That can be challenging to diagnose.
 

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Discussion Starter · #9 ·
How long have you owned the car? It's possible someone put some stop leak tabs or some crap in there at some point. Cross your fingers they didn't. Tell us more about the ticking sound. That can be challenging to diagnose.
Car sat for about 8 months before I bought it guy would start it once a month. No probably no chance of stop leak tabs in it guy always took it to the dealer and was an old guy who didn’t mind spending money on the right fix . What can help with figuring out the ticking sound ??

As in what info

Drive it from Fl to TN when I bought it and no issues except toward the end would run one tick up when I got off the interstate and cool back off on it’s own . Has slowly started becoming more of a problem until recently it goes to get hot most of the time . I forgot about the weep hole on these and I did notice when I changed the thermostat there was rubber pieces missing of the old one

And no circulation in tank
 

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'02 ETC 34,000 miles 2002 F55 STS 83,000 miles, 2016 Challenger SRT 392, 6 Sp.
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There are a lot of things that could cause a ticking, tapping sound. Carbon deposits on the pistons, exhaust or vacuum leaks, piston slap (although that usually goes away when the engine reaches normal operating temperature) bad pulleys or tensioners, valve train issues, etc.I had a very annoying ticking sound for a few years on my 2002 STS. Turned out to be coming from the primary accessory belt. Must have had a gouge or fray or something that was ticking against a pulley or something every time it made a revolution. Do you drive the snot out of the car normally or baby it? These engines are meant to be driven......hard. If you don't, carbon deposits can build up on the top of the pistons and then, as I understand it, make a ticking sound as they reach TDC. I haven't been on the forums for a while and I'm not very familiar with the new format but there used to be a section of notes written by Cadillac engineers. There was quite a bit about keeping the N* clean and happy with WOT (wide open throttle) runs. Maybe Sub or someone will chime in and tell you, (and me) where they are now. If you doubt that could be the issue, I'd trying to isolate exactly where the sound is coming from as a starting point.
 

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Discussion Starter · #11 ·
I run it pretty good . I live in the boonies and like the handling for a big car . I also change oil with dexos5/30 every 3k miles I will look tmmro and try and locate the noise area . I do think it’s developing an exhaust leak though if I’m hearing right . Just slightly and usually when cold . I have asked a few shops and I get tired of that “just throw Lucas in it or mmo “ answer or that’s a gn. I am very picky on things and like my car quite and running well

as to carbon build up I could not tell you my opinion on that . The car has 160k miles and everything is clean. I have noticed oil is a little darker now though
 

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2010 DTS
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I did notice that it has little to no flow at idle in the surge tank.
Little flow is OK. Rev the engine and it should increase. The main point is that the purge line is open.


What can help with figuring out the ticking sound ??
Use a stethoscope. It'll make pin pointing it MUCH easier.


There are a lot of things that could cause a ticking, tapping sound. Carbon deposits on the pistons,
"Cold Carbon Rap" only lasts for less than 60 seconds or so and was more prevalent on the pre-2000's.
 

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Discussion Starter · #13 ·
Thanks for the feedback it’s very appreciated. I can’t remember on the flow I am going to check it this morning . Is it possibly it will flow for a bit then clog up and stop?
 

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Please read Post #3 again and follow the advice given, i.e.: Clean out the hollow bolt/nipple and the entire purge line. Yes, the thermostat rubber seal ring and plate covering sometimes disintegrates and can clog the small passages in the heater core and purge nipple/line.

You get off the Interstate and stop, the temp will tick up a tad as the latent engine heat passes off to the coolant. It will either cool on its own or, if the temp gets to the SLOW fan run point the fans will come on, cool the engine, and shut off. Fans cycle on and off in warm weather with stalled or slow traffic. Fans run in SLOW any time some A/C compressor function is called for - like A/C or DEFROST.

Thermostat with rubber seal ring and rubber plate coating. The poppet valve is immaterial as the 'stat is in the RETURN (lower radiator) hose and flow pushes AGAINST the poppet, not behind it. Post #7. You can just barely see the edge of the poppet at about 5:30 in the pic -


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Discussion Starter · #15 ·
just checked the flow . Just started the car and it is POuring back into the rest our at idle

What should I do next? I have a new radiator for the car should I install it or do you recommend something different. Again all of the input is greatly appreciated guys
 

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Discussion Starter · #19 ·
I let it idle for a half an hour ran the ac and even put it in park to lower rpms with parking break on after replacing cap . Temp did not budge . I couldn’t drive it as I was blocked in and didn’t have the keys to the vehicle blocking it. No coolant loss after idling either . I also held it at about 2500-3k rpm for a few minutes at a time as well . No coolant smoke out of exhaust . Seems better . But sometimes it would stay at normal temp at idle before and go up after driving nice or hard after I got into town with traffic .

Ok so this is the second cap I’ve bought and now it’s not running hot . Let idle for a little bit (30) min with ac on then drove it a little bit a few pills and was doing fine . I pulled into work and let it idle for a minute and it climbed just a tad bit not even to first tick above halfway . Gave it some gas came right back down but then check engine came of and I’m not sure for what or why it would still go up . Had it in stop and go traffic and all . And gave it a good run down the road and it was perfectly fine ... I’ll have to run codes later I REALLY hope this thing doesn’t have head gasket issues ....

A few pulls not pills*
 

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2006 DTS perf
2006 DTS Performance Lux III
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If it was a head gasket it wouldn't be normal now like it is. The later Northstar engines don't have the head gasket issue like the earlier engines. The coolant tank cap is a common issue on the DTS. You should be good. But make sure you don't mix the coolant with the green coolant in these cars. Use only what cadillac says.
 
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