Northstar engine overheated i repaired problem now runs like it did when it was hot can barely drive it now. has error message service Stability system

Service Stability System Message The message center displays the service stability system message when any one of many VSES-disabling DTCs is set. The EBCM sends a serial data message to the IPC requesting this display.
It means there is a problem an till you get it fixed the stability control system is disabled ! ( EBCM ) electronic brake control module Has detected a problem an set a DTC - diagnostic trouble code in it's memory an had the message displayed !
Vehicle Stability Enhancement System (VSES)
The vehicle stability enhancement system (VSES) provides added stability during aggressive maneuvers. Yaw rate is the rate of rotation about the vehicle's vertical axis. The VSES is activated when the electronic brake control module (EBCM) determines that the desired yaw rate does not match the actual yaw rate as measured by the yaw rate sensor.
The desired yaw rate is calculated by the EBCM using, primarily, the following inputs.
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The position of the steering wheel

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The speed of the vehicle

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The lateral, or sideways acceleration of the vehicle

The difference between the desired yaw rate and the actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. When a yaw rate error is detected, the EBCM attempts to correct the vehicle's yaw motion by applying brake pressure to one or more of the wheels. The amount of brake pressure which is applied varies, depending on the correction required. The engine torque may be reduced also, if it is necessary to slow the vehicle while maintaining stability.
VSES activations generally occur in turns during aggressive driving. When braking during VSES activation, the pedal may pulsate. The brake pedal pulsates at a higher frequency during VSES activation than during ABS activation.


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Do you have the Northstar engine? If so, there is an issue with head bolts pulling threads. Clues are periodic overheating. Look for exhaust in the cooling system. What happens is under load the compression gases push coolant out, and then you get overheat.
Pressure test the cooling system, there is a small hose that runs from the engine to the coolant tank, sometimes that plugs and air gets trapped. Some models suffer water pump impeller failure, easy to check with a special removal tool.
The head bolt issue is EXTREMELY expensive to fix correctly. Essentially you need to time-sert the bolt holes, and to do that you need to give a bare block to the machine shop.... Real bummer as the repair typically exceeds what is reasonable to invest in the vehicle, thereby rendering the vehicle useless.
I did repair mine, because I really liked the car.This issue should not happen.

Try to flush and fill with new fluid to get the passageways free of sediment.

Or, try to see if the fans are coming on at the right speed at operating temperature. May require new fans/relays/wiring to fix this problem.

I have a 1997 Cadillac Deville that was overheating its Northstar engine and it required service amounting to about $700.00 or so from an auto electric shop, but afterwards it ran cooler.

Good luck on this repair.

Suggest you look on the drivers side of the engine in the front, there is a black metal guard that covers a pulley that drives the water pump. Make sure the belt is not broken and that the water pump turns freely. Have the cooling system checked for exhaust gases, That is the way to check for blown head gaskets. Is there any coolant in the oil? The Northstar engine is designed to shut down cylinders one at a time to protect itself when overheating. Hope this will help you.

It is probably a head gasket issue if you have replaced the thermo and the pump and it still overheats. You probably can drive it 15 minutes or so and then the gauge starts soaring towards overheat shortly there after. Under completely normal driving conditions. Northstar engine's actually don't overheat not from bad head gaskets (they aren't the defect issue) but the inferior bolts holding the heads to the block. The bolts have been found to be pulling out of the Northstar's soft aluminum block(this is the actual problem but it's blamed on the gaskets). Causing spaces between the block, gaskets and the head that allows hot exhaust air to seep into the coolant flow chambers. This why your have coolant bubbling out of the top of the overflow valve under the hood after only short drives. Under normal operation the engine is literally boiling it's own water supply. The head bolt issue is a design flaw by GM and one that leads to a great number of Northstar engines being crippled at well under 100K miles of driving. Only remedy is to have both heads pulled off the engine, the head bolt replaced with new gasket and you're all set. Bad new very labor intensive whcih = a several thousand dollar repair. I had it happen to my 1998 Concourse Deville. I feel your pain.

hi,

are you familiar with the northstar engine?
first generation northstars are notorious for this kind of thing..
the engine is prone for metal fatigue/ warping of the heads, and stripped out head bolts, do you have documentation and service history for it?
these engines need a good mechanic to inspect and replace head bolts which strip out and need fixing. I will post a link at the bottom
once the engine is repaired correctly it should last a good long time
have it fixed correctly. I think someone has turned up the idle knob in an attempt to get the coolant flowing quicker to keep it cool.
its worth repairing if you have the money..

jm

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/976-overheating-northstar.html

There is no need to purge the air out of the cooling system as it is self purging on the northstar engine.
The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank or trace the hose further back until you locate the blockage.

the useual problem with this engine is the head gasket leaking, that sounds like what is going on with your Northstar.

Dude KravCar i seriously want to thank you for helping me fix my car!!@! i have a 1995 Oldsmobile Aurora Northstar 4.0 V8 and i came across your response to someone who was having an overheating problem with their Northstar Engine.....you commented for them to remove and inspect one of the purge lines to bleed out the air........ now after countless hours in my garage and wrongful diagnosis from a repair shop i finnaly have my engine running back fine after reading your response......thanx dude