94 STS-need answers

[charmin]

I recently purchased a 94 STS with 92k miles on it. First Caddy I ever owned. I have a few questions some may be able to help me with.
So here goes:

1.) The third brake. 2/3 of the thing doesn't light up. Only the passenger side 1/3rd section does. Anyone ever had this trouble and guide me to fix???
I heard they burn out and are expensive... But it IS something I can live without. Thaught maybe if it all wasn't burnt out, it may be repairable...

2.) I would like to change the coolant over to Dexcool. Anyone ever done this before?
I have also heard that the N*s' have trouble with air pockets after one messes with the coolant for thermostat changes or what-have-you, leading to overheating troubles... Is this true????
My 01' Monte SS(n.a. 3800) has a bleader bolt in the top of the thermostat housing to aid in ridding the system of air during service, but it isn't a pressurized system like the N*... Haven't found any bleaders in this engine...

3.) This question may seam kinda silly, but my STS coolant temp runs a little high. I was watching it the other day, and while driving, it hovered between 204-219. When it hit 219, I polled over. It didn't throw a message on or anything to tell me it was overheating, and the engine was running normal and the hoses didn't seem to be burning hot... I know most cars dont overheat till they hit @240-245, but this was kinda odd to me. Do they all run this warm???

4.) Today I placed an order with Strutmasters for the complete passive conversion kit. Has anyone here ever installed this system and could shed some light on what I should do with the air ride stuff that I will no longer need after I intall this kit?
Also, how hard is the kit to install?

Any help on these issues would be great!!
Thanks in advance.
John

 

[MAC1]

2.) I would like to change the coolant over to Dexcool. Anyone ever done this before?
I have also heard that the N*s' have trouble with air pockets after one messes with the coolant for thermostat changes or what-have-you, leading to overheating troubles... Is this true????
My 01' Monte SS(n.a. 3800) has a bleader bolt in the top of the thermostat housing to aid in ridding the system of air during service, but it isn't a pressurized system like the N*... Haven't found any bleaders in this engine...

It is not recommended to switch over to Dexcool if your cooling system calls for regular green coolant. If your Northstar calls for regular green coolant, that's what you should continue to use. This question was posed to a Cadillac engineer and he said to leave it alone. If you search this topic you will likely find the discussion regarding Dexcool vs. green coolant.

The Northstar should purge air by itself. You will probably find the radiator drain plug on the left (driver) side under the lower hose connection. It can be accessed by removing the air filter box. Have you checked the coolant condition? If you want to drain it, go ahead. But you need only drain the radiator and replace with 50/50 water/coolant mixture and sealer unless the coolant has been neglected, in which case, drain then fill with distilled water and drain it again from the radiator. You can do this a few times. If the coolant is good, then drain the radiator once and replace with 50/50. Do the same thing once a year and you will be fine. Your Northstar is not running hot. (See below)

3.) This question may seam kinda silly, but my STS coolant temp runs a little high. I was watching it the other day, and while driving, it hovered between 204-219. When it hit 219, I polled over. It didn't throw a message on or anything to tell me it was overheating, and the engine was running normal and the hoses didn't seem to be burning hot... I know most cars dont overheat till they hit @240-245, but this was kinda odd to me. Do they all run this warm???

The Northstar will run on average between 196-225, which is when the electric fan will automatically kick on. If driving in traffic and not moving, the temperature will slowly increase to the 225F level or even higher before the fan activates. Once moving, it should drop quickly depending on the outside temperature and driving conditions to 196-207. Depending on how your driving, it could hover in the 212-217 area or higher. It just depends on what factors the engine is operating under. At any rate, based on what you said, your Northstar is not running too hot. If coolant temperature reaches the 255F, a warning light will be activated and/or you may hear an audible alarm indicating the temperature is too high. If this happens the Northstar will activate "LIMP HOME" mode, which will cause the engine to deactivate firing on all 8 cylinders and to alternate firing groups of four cylinders for a predetermined number of cycles to prevent engine damage, enabling your vehicle to be driven to a service center.

Since the Northstar is an aluminum engine, it is very important to maintain coolant in order to prevent corrosion and overheating that could damage the engine. Also, if coolant is not maintained, it could cause the head gaskets to fail.

 

[charmin]

Hey, Thanks for the advice!
I don't know if the antifreeze has ever been changed, I'd have to guess not, so I'd like to drain it and replace it. Sounds like green stuff will be going back in. I have heard it is something that should be on a maintanence schedule for any N* equipped vehicle, but this car was VERY well taken care of apearance wise(outside/interior), but not so on the mechanical things. I Have to replace all the rotors/pads, struts, shocks, tires, plugs/wires, and fluids/filters...Basically, all the general maintanance stuff that needs replaced on any 100K mile car...
It also idles very high sometimes. Like 2500 RPM's . I took it to my uncles shop today and dropped it off so he could fix that and weld up the exhaust someone replaced(cobbled) onto it. He is also checking out all the other suspension(ball joints/wheel bearings, etc.), because I am getting my conversion kit from Strutmaster, tomorrow. I wanna make sure its all tight before I get it aligned...
I can't wait to get in this thing. I've had it 4 days now and am really getting the itch to drive it. They are pretty nice cars. Gotta get everything right on it first, though...

 

[MAC1]

The high idling could be caused by a number of things, but the throttle linkage and throttle opener needs to be cleaned from time-to-time.

As far as wires, don't waste time replacing things that aren't broken. I still have my original wires and my '94 Eldorado has 204,000 miles and still idles like a top. The Northstar generally does not even call for maintenance until it reaches 100,000 miles.

You should replace spark plugs with ACDelco/OEM platinum plugs. If ball joints need to be replaced, buy ACDelco. Be forewarned about aftermarket parts--They are often not worth the money.

As far as brakes, it's fine to buy quality aftermarket brakes as specs are generally acceptable in comparison to OEM. Same with Air filters and other minor parts. However, you should stick with ACDelco when it comes to oil filters. ACDelco parts are test to insure they meet your car's requirements. The same cannot be said for aftermarket parts. Some oil filters are advertised to filter better than others; however, be aware that these filters often allow a lot of oil bypass of unfiltered oil because the filtration system is not up to specs. This is not a problem with ACDelco since their filters are tested in GM cars to insure they meet performance requirements.

Below are a couple of sites that sell discounted ACDelco parts:

Rockauto.com

GMpartsdirect.com

I have only purchased from Rockauto and give them two thumbs up so far. I have not purchased from GMpartsdirect but, from what I have read, their customer service is not that great.

 

[ALBUNDY]

You might want to purchase a factory service manual if your going to be doing your own repairs. I tell you its worth its weight in gold. The chilton & haynes manuals are a total waist of money when it comes to the N*.

 

[charmin]

Funny that you mention the manual... This car was ropoed at one time, and I purchaced it at an auction, and it didn't even come with an owners manual, so there are a lot of things I do not know about the car. I didn't even get a fob!.. but these things aren't hard to find...
anyone got any spares they wanna part ways with???

 

[ALBUNDY]

You can go on the Cadillacowners.com site and print out an owner's manual. What I was referring to was the Factory Service/Repair Manual. Check ebay or Helms.com.

 

[charmin]

Thanks for the tip!