Recommended Posts

Hello,

Fellow Caddy enthusiasts! New member here... Actually, this is my first post ever(Hopefully it's in the right place :unsure:) ! Anyway, I am posting this because I've been having some issues with the coolant system on a 98 STS... O.k. So, I AM aware of the head-gasket failure on this car and that was the first thing that I had diagnosed; It was done by a professional mechanic, GM certified(if that matters)! Also, tried to have the shop flush the radiator/coolant system... The rest of the work I did myself!? I'm NOT a mechanic but, I am fairly sensible and know my way around a wrench pretty well. Here is a list of what I did myself: Changed 1. Thermostat, 2. Water pump, 3. Radiator & 2 main hoses, 4. Reservoir tank and Pressure Cap ! Before taking the car apart it ran HOT but, i did have a small amount of circulation and the heater(defrost) blew hot air... After putting everything back together it feels like there is NO circulation in the two big radiator hoses at all; And they eventually get very hot and start to swell under pressure! Also, I can turn the Defrost setting on and the car NO longer blows hot air. Only cold! That's car idling 20-25 mins. at a time and heating up to about 3/4 the way up on the temp gauge... Which makes sense if it's not circulating. So, my question is, "What have I overlooked?" or "Is there anywhere I can access the coolant system diagram for this particular vehicle?" I have read about the water-pump pulley and a "crossover" hose(not sure where that's located) but, is there anything else? Is there any extremely small hoses or ports that I may need to check? I tried to be as thorough as possible?! But, if you have any questions or advice feel free to reply! Any help would be GREATLY appreciated! So, If anyone has any ideas please let me know! Thanks in advance!!

Share this post


Link to post
Share on other sites

Did you check the purge line that runs from "The bolt with a hole in it" to the surge tank ??

It "MUST" flow coolant or it "WILL" overheat.


Posted Image

Share this post


Link to post
Share on other sites

Document ID# 158416

1998 Cadillac Seville

Cooling System Description

General Description

The cooling system maintains proper engine temperature under all operating conditions. When the engine is cold, coolant in the radiator does not circulate, allowing for faster engine warm-up.

The thermostat remains closed until the engine reaches the proper operating temperature. Once the engine reaches normal operating temperature, the thermostat opens, and the coolant circulates through the crossflow radiator in order to keep the engine from overheating.

The cooling system includes the following components:

A radiator

A radiator surge tank and pressure cap

2 electric engine cooling fans

A thermostat and housing

A coolant pump

All related hoses

Cooling System Circulation

In the Northstar cooling system, the coolant pump takes coolant from the radiator and passes the coolant through the thermostat on the inlet side of the coolant pump. The coolant enters the block at the rear of the engine from the water crossover, then the coolant is routed through the cylinder heads back to the water crossover. At this point the coolant has four possible routes:

The radiator

The heater core

The throttle body heater circuit

The generator cooling circuit

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.