[usethetorque]

Hi fellow Catera owners,

I apologize in advance if I am posting this thread in the wrong spot. About two months ago, I purchased my 2001 Cadillac Catera Sport Package. I thought that all was going well with the car after getting a wheel bearing replaced, and then I realized that coolant was leaking from the car. I pulled open the oil cap, and noticed a yellow mustard colored paste. From research on Google, I concluded that the paste was most likely coolant mixing with the oil.

I have taken the car to a shop, at which the mechanic concluded that the problem is most likely a blown head gasket. As I am relatively new to cars, I did a bit of Googling around at which point, I came across this forum.

Here are the tests that I have done so far:

-used a radiator pressure tester to determine that the reservoir does not indeed holder pressure
-visually checked the dipstick and determined that the oil is not a milky color
-checked behind the car for white smoke behind the exhaust pipe (there was none)
-looked for bubbles in the coolant reservoir after turning off the engine (there were none)

I obtained some records for the vehicle from a local Cadillac dealership and also pulled Carfax and Auto Check to obtain more records.

Here are some of the highlights from what was done between 2001 and 2004 (from my perspective):

11/2001: Pipes, Fuel and Evaporative Emission Control - Front - Center Canister - Replace (12,983 miles)

05/2003: Valve, Hot Water Vacuum Control - Replace (31,366 miles)

07/2003: Cooler, Engine Oil - Replace (33,659 miles)

07/2003: Valve, Hot Water Vacuum Control - Replace (33,659 miles)

10/2003: Shift linkage adjusted and serviced

12/2003: Water pump and any or all pulleys replaced (37,000 miles)

01/2004: Oxygen sensor replaced (37,552 miles)

03/2004: Hoses, Power Steering, Hydraulic - Pressure - Replaced (38,822 miles)

06/2004: Belt, Primary Accessory Drive - Replaced (38,910 miles)

07/2004: Oil Pan Replaced (38,955 miles)

10/2004: Engine Oil Pressure Replaced (43,846 miles)

------------ (8 years of service records not yet obtained)

07/2012: Relay Switch installed, Ignition Coil an d Platinum Plugs Installed

09/2013: Pulley for Serpentine Belt Installed


My primary question is what I can do to tell if it is the head gasket that needs to be replaced rather than a different part such as a heater control valve. Thank you.

usethetorque

 

[jjportia]

Hello and welcome to a love hate relationship in the automotive world. Patience is probably the most valuable asset to owning one of these. Money and/or mechanical skills are the next most important. I personally have found this forum coupled with my years in the car business (mostly the service side) invaluable to owning a Catera.

First off I saw no mention of the current mileage of your Catera. Time and or quality of some parts may require repeated replacement. I saw the oil cooler/ heat exchanger has been replaced. A head gasket can have 3 possible leaks....external, oil/coolant. Internal, oil/coolant that would give telltale signs in either the coolant tank leaving a milky residue or dipstick/oil filler cap again milky residue. Internal once again but with a running issue, either engine misfire or steam in the exhaust. You ruled out several of these issues in your description already so I would narrow down where the external leak is coming from. In the Cartera's engine bay things can be quite cramped. Make sure connections are not leaking or freeze/expansion plugs are not leaking before jumping into the head gasket replacement. The heater control/bypaas valve is at the rear of the engine bay, and would show the leak at the rear of the engine almost over the front of the transmission. Misdiagnosis has been the cause of much money spent on repairs or replacing a car that I've witnessed over the years. Also a main cause for disgruntled former Catera ownership.

 

[usethetorque]

Hi jjportia,

Current odometer: 118,750 miles

Thank you for your quick reply. I took the car into a mechanic, and he stated that he sees two leaks on the bottom side of the engine (that he concludes are the head gasket leaking). I agree with you, that a misdiagnosis would be very expensive. The antifreeze is still disappearing from the coolant reservoir, but I have not found the location where it is going to. I went ahead and ordered a code reader from Amazon so that I can hook it up and try to pull codes from the engine (if this helps).

How would I diagnose whether the heater control/bypass valve is leaking on the Catera? This would be a lifesaver from a cost stand point. Also, do you know what size of external torx I need to take off the top of the engine. I have a socket set and a few torque wrenches that should help with the rest of the job. I found a Feel Pro head gasket set for $250 from Autozone and a Victor Reinze set for $371. Is there a substantial difference in quality between these two head gasket sets that justifies the price difference? Thank you for your help and thoughts.

 

[jjportia]

A code reader is a valuable tool for most cars today. However it won't be any help for a coolant leak.
The heater control valve is at the rear of the engine, so if it was leaking you would more than likely see coolant under the car at the center (side to side) at the base of the windshield if you can picture that position.

You need to pinpoint the exact spot you find it and follow the traces upward to it's driest point. Remember water flows to the lowest point, but in the case of
the cooling system pressure can also change the direction as well. Also, if the leak has been happening for a length of time you may also see a whitish crusty residue in the area of the leak. A pressure tester hooked up and applying about 12-15 pounds of pressure should make the leak visible.

The less expensive head gasket kit is not a German kit, but should still be fine. I personally (my opinion) prefer better quality parts whenever possible, it is not always an option but I use factory parts as often as possible.

 

[elvin315]

A Block Test will verify if it's a head gasket leak. Kits are available between $25 - $50.

http://www.blockchek.com/instructions.htm