For the past month my 98 Deville has been leaking coolant. At first it was leaking from the radiator every time I shut off the engine and I had to fill it back up every time I left the house. Now that I have a radiator on order it's still leaking but thereleaks aren't visible. I take a look under my hood everyday and there are still no visible leaks but I figured it has to be going somewhere. The only spots I've seen in my driveway is right under the drivers side door between thedrivers sidefront tire. My guess for the radiator leak was because my engine was running hot and had to relive itself some way or another.My coolant temp these days are between 210-215 degrees.

Also my service stability system comes up on the messages on my computer every now and again. I thought it may have been because it's time to service my brake padsbecauseit comes on sometimeswhen Ihit thebrakes.

 

I didn't even see 1 question in there

 

Here's what I think they are:

Q1. What would cause a puddle of coolant to form between my left front tire and drivers door seam?

Q2. Is an operating temperature of 210 to 215 degrees ok?

Q3. When I hit my brakes the "Service Stability System" mesasage appears, what might cause this?

Does this about sum it up Stallsduke?

 

Q1. I don't know.......FLCaddytech any idea.

Q2. Normal range is 180 to 200 degrees per owner's manual.

Q3. ABS sensor.

 

Yeah you guys got me aboutnot aksing anyquestions. I had just woken upfrom working nightswhen I wrote that. I remember when I first bought the car my coolant temp used to be around 202 degrees. I was wondering if me needing to clean that EGR valve and the throttle that we talked about in my first post might have something to do with it. I read somewhere that a clogged EGR will make it run a little hot.Tell me what youthink?

Willthe new radiator help my car run cooler? I had a coolat problemon my chevy capriceand it was the radiator fans. I checked the fans on the radiator yesterday and they seem to work fine. As for the leak I continue to find behind my driver side tire... I don't know if that'sthe problem. It's the only visible leak I can find pertaining to anything. I put some radiator seal in itto hold me off until I got my new radiator andit's not leaking from the side of the radiator anymore.

I checked the water pump and there areno leaks there and I checked all of my hoses and everything else seems to be working as advertised. SoI don't think it's the water pump.

As for the "Service Stability System" message... I think it's because my pads are in dear need of changing.

So tell me what do you guys think?

 

EGR - for sure a problem there will make the engine run hotter. It is not uncommon for the passages and pipes to get clogged with carbon. This is what I wrote before:

The EGR system is a bit tricky but you can clean it too. The system on your 98 Deville has the valve which is on the drivers side of the engine on the intake. It has a series of pipes and passages that carry the exhaust gases from the exhaust manifold to the intake manifold and back into the combustion process. These pipes and passages can get clogged up with carbon and when the valve is carboned up and the passages are too your car will run like S**T. This sound crazy but to clean the pipes and pasages you need to make a tool to ream them out....a coat hanger would work on the pipes. The valve itself is probably easier to just change. For passages and the valve a Carb/Throttle body cleaner would work. Blocked EGR passages will also make the car run hot and could affect indivudal spark plugs by overheating them and lead to early failure or degrading. The Italian Tune Up helps clear carbon build up. Devilles get babied and the Northstar is a high performance engine, meant to be flogged.

Radiator - Any maintenance on the cooling system will help. The radiator change will give you a chance to clean and flush the entire system and put in fresh coolant. Change the Thermostat while you are at it.As for your leak, it is possible that the drain for the climate control system is on the drivers side behind the wheel and ahead of the door seam. I have seen a puddle under mine now you mention it but it is just water for me and I assumed it was the drain.

Stability System - since it uses the ABS system you are probably right is your pads need replacing.

 

Not likely. the computer is very sensitive to egr problems and will almost always set a check engine light long before you notice any problems from it.

212-220 deg F is perfectly normal temps around town. 200 is average on the highway. With the A/C on it will run a little cooler because the fans run constantly. A partially clogged radiator can cause temps to rise above normal.
So will being low on coolant.
If you have a crack in the radiator replace it before it leaves you stranded. Many times Dexcool dries up before it ever reaches the ground and you don't see the leak as a puddle under the car.
I'm not familiar with any leak that would leave a puddle near the drivers door. The heater hoses are the closest thing i can think of.


It's not the pads. You need to know what code is set to diag this further.

 

Well I flushed out my coolant system anddrove my car around for a couple of days with just water in the radiator. Today my low coolant light came back on and I searched for leaks and saw nothing. My radiator should be here in a few days. Hopefully that will fix my msytery leak. Then once I take care of my EGR problem and clean my pistons and rings... I'll give you guys an update and let you know how everything went.