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Chris

2007 DTS Overheating - Bad pump or something else?

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Hi All,

I haven't been on the forums for a while - life has been busy, and the DTS has been running great (around 105k miles)!

Until tonight.

I pulled into the driveway after a 25 minute drive home (80°F ambient temperature), windows down (A/C off), I got the message "AC off due to high engine temp" or something similar. After I turned off the car, both rad fans continued to run for a couple minutes.

After dinner, I went back outside and noticed coolant under the driver's side of the car (approximately below the water pump). I plugged in my OBDLink MX and turned on the ignition to check for codes - nothing showed, and coolant temp around 160 as reported by the OBD dongle. I turned on the car and verified that the pump belt was in tact and driving (it was), the temperatures quickly rose to 220 (fans on), and I shut off the car shortly after. I'd also cranked the heat in the car but the air didn't feel hot at all.

Based on the location of the coolant dripping, I initially assumed the pump was bad, but when I searched for info on failed pumps, most posts talk about a broken belt.

There appears to be coolant in the surge tank but I haven't opened it yet.

Do you have any advice to help me troubleshoot this issue?

Thanks,

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-Chris

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First off what a beautiful car that is.

When was the coolant last changed?

Can you confirm it is coming from the water pump? rather than one of the hoses on that side. 

Hopefully it is not the crossover gaskets. If it is the waterpump they are not too bad to do. 


GM FAN FOREVER

Nice, clean, luxury= fine automobile

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What year ? 06-11 they changed the waterpump design an removing the entire pump housing ! It’s bolted to the back side .

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20 hours ago, rockfangd said:

First off what a beautiful car that is.

When was the coolant last changed?

Can you confirm it is coming from the water pump? rather than one of the hoses on that side. 

Hopefully it is not the crossover gaskets. If it is the waterpump they are not too bad to do. 

Thanks!

I'm not sure when the coolant was last changed... I've had the car for 3 years and haven't changed it (bad, I know).

I've removed the air dams/covers and will try and see what is leaking when I get home tomorrow.

20 hours ago, barczy01 said:

What year ? 06-11 they changed the waterpump design an removing the entire pump housing ! It’s bolted to the back side .

2007. It may have been changed, but is in the same position (front driver side of engine).


-Chris

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Yes but the pump is now on those years 06-11 bolted on the back side the the crossover has to be removed

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What was the result of checking the coolant level in the tank?

Was the coolant low?

Did you get a low coolant message on the dash?

I have had thermostats go bad and stick closed

The location of that leak could also be a radiator end tank

Check your water pump belt and tensioner, I think I see red deposits by your tensioner pulley indicating that the pulley bearing might be a problem 


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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Last night I topped up the coolant it took almost 3/4 gallon - I filled it, turn on car, shut off, refill, etc.. Once full, I put on the rad cap and left the hood open and idled the car.

I turned on the heat and it was definitely blowing hot air while warming up.

Once the coolant temperature approached 200°F, I could feel heat through the upper hose to the rad, proving that the thermostat and water pump are working. At 221°F, the fans came on, and temperatures started falling after 223°F.

No drips visible last night.

 

I did the same test today with similar results (but also some drips) and believe I have two problems:

Electrical - According to AllDataDIY, the rad fans are supposed to turn on low at 'approximately' 202°F, and high at 220°F. Mine didn't turn on at all until 221°, but I'm not sure if they were running in high or low speed. The fans are operated with three relays in the under-hood fuse box:

"R1 (MINI) COOL/FAN 1" - 4 prong Hella 12193614 / 3614

"R2 (MINI) COOL/FAN" - 5 prong Hella 12193612 / 3612

"R7 (MINI) COOL/FAN 2"  - 4 prong Hella 12193614 / 3614

I swapped the R2 relay with an identical relay for the wipers - both relays ran the wipers, and neither caused the fans to run at 200-220°F. Any ideas, or is Alldatadiy wrong with respect to proper operation?

When running the AC, both fans run and temperatures stay stable (when parked) at around 207°F.

 

Drips - Coolant is dripping from the left (driver side) of the rad somewhere. The foam between the AC and coolant rad is wet at the far driver side, and there is a drip visible - see photo. I'll put the car back up on ramps on the weekend, but any suggestions on the source or how to get to it?

 

Thanks

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Edited by Chris

-Chris

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21 hours ago, barczy01 said:

Yes but the pump is now on those years 06-11 bolted on the back side the the crossover has to be removed

Ah, I see what you are saying... yes, that would not be fun!

9 hours ago, BodybyFisher said:

What was the result of checking the coolant level in the tank?

Was the coolant low?

Did you get a low coolant message on the dash?

I have had thermostats go bad and stick closed

The location of that leak could also be a radiator end tank

Check your water pump belt and tensioner, I think I see red deposits by your tensioner pulley indicating that the pulley bearing might be a problem 

See above post... I couldn't quote you before for some reason.

Coolant was extremely low (3/4 gallon), but was still present at the bottom of the tank. No low coolant messages on the DIC. I think you are right about location of the leak at side of the rad.

I don't see any signs of leaking at water pump belt/tensioner - the red in the photos is an exposed wire and some brown residue that shows up red in the photo... really good eye!


-Chris

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Do you have the ability to check the codes?

If not some autoparts places will read the codes for you.  Post all P codes here.  The cooling fan relays and engine temp sensor will set codes.  

Keep in mind that the cooling fans will operate differently with the AC on verses the AC off.

Don't parts replace, codes will guide you.  Find the leak.  I have found these radiators leak at the end tanks via cracks and where the cross ribs attach to the sides.  If you have a leak through that hole its a good chance the radiator has a leak.  


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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Very likely the tank on that side has cracked.

The 90s ones would usually leak on the other side.

It could also be between the tank and the main, pretty common as well


GM FAN FOREVER

Nice, clean, luxury= fine automobile

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I've left the lower cover off and been driving, but no more drips - because of this, I'm having a hard time finding the crack location. I'll keep monitoring.

Once I'm able to get the trouble codes read, I'll post back.

Thanks for the help so far!!


-Chris

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Inspect the plastic tank on the radiator for swelling and cracks.

Then inspect the crimps that crimp the plastic tank to the radiator itself. 

Any sign of leak there means that under pressure there is leakage


GM FAN FOREVER

Nice, clean, luxury= fine automobile

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14 hours ago, Chris said:

I've left the lower cover off and been driving, but no more drips - because of this, I'm having a hard time finding the crack location. I'll keep monitoring.

Once I'm able to get the trouble codes read, I'll post back.

Thanks for the help so far!!

The best way to find a leak is to pressurize the system with dye in it.  See if you can rent a cooling system pressure tester.  Pump it up to 18 psi and watch for leaks.  

Autozone rents one

https://m.autozone.com/loan-a-tools/loaner-pressure-tester-adapters

 


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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