AllExperts > Automotive 
Search      
Automotive
Volunteer
Answers to thousands of questions
 Home · More Automotive Questions · Answer Library  · Encyclopedia ·
More Automotive Answers
Question Library

Ask a question about Automotive
Volunteer
Experts of the Month
Expert Login

Awards

About Us
Tell friends
Link to Us
Disclaimer

 
 
 
 
About Sean Halliday
Expertise
general auto repair,japanese,bmw,mercedes.I DO NOT work on automatic transmissions.Manual transissions i install clutches only.Many people ask me to diagnose noises from their cars,unfortunately i cannot do this unless i hear it.As you appreciate,vehicles can and will make a variety of noises.I DONT UPGRADE or fit aftermarket performace kits,parts,chips,only replacement parts.

Experience
40 years experience on all general auto repair.

 
   

You are here:  Experts > Industry > Transportation and Logistics > Automotive > Radiator/Coolant pressure problem

Automotive - Radiator/Coolant pressure problem


Expert: Sean Halliday - 9/17/2008

Question
QUESTION: I have an 87 Saab 900-no turbo...Replaced the thermostat, but pressure is still building up in the Reservoir and leaking out of the cap. car also overheats.  I checked hose placement. can't think of anything else to do ?  any suggestions or comments.

ANSWER: Sounds like a leaking head gasket.You will need to have the head checked by a shop for a leak down test.Only a shop can do this and blown head gasket is the only cause of built up pressure in the cooling system.

---------- FOLLOW-UP ----------

QUESTION: would air coming up through the hose's into the reservoir be from the head gasket also ...almost look's like the coolant is boiling..

ANSWER: Yes,thats the symptoms for a leaking gasket.The gasket blows across the water jackets and the compression from the piston leaks into the cooling passages.

---------- FOLLOW-UP ----------

QUESTION: Is there any less expesive problems it could be? Air lock ?


Answer
Its the only possible cause as these are the symptoms of a blown head gasket.Air lock will not do this as it would only cause the car to run hot and not bubble the coolant like you said.Leak down test for a 100% verification of this will tell you this is the case.

Add to this Answer    Ask a Question



  Rate this Answer
   Was this answer helpful?
Not at allDefinitely              
   12345  

     
About Us | Advertise on This Site | User Agreement | Privacy Policy | Help
Copyright  © 2008 About, Inc. About and About.com are registered trademarks of About, Inc. The About logo is a trademark of About, Inc. All rights reserved.