@

Friday, January 27, 2012

Heater blows intermittently and temp gauge goes erratic?

This query was asked by my customer for his ford expedition vehicle.
In his case the thermostat was replaced,but still the same problem is getting noticed.


As per this details the possibilities that can cause such problem is as follows :-----
The problem  is very likely trapped air in the cooling system due to the fact the cooling system wasnt bled properly during the thermostat replacement and trapped air will cause the heater to be intermittent as well as the gage to read erratic. It will also cause the overheat code to set because it caused it to overheat. I would start with having the cooling system bled once again nd then be sure its top off to completely full.

Flushing the cooling system will not hurt anything no matter how many miles on the engine and in fact will likely help. Providing there where no leaks since the thermostat was replaced I still suspect you had trapped air and flushing and bleeding should take care of it if this is the case.But if flushing is not helping then, It is also possible the new thermostat was defective and possibly did stick shut. For no more than they cost it might be a good idea to replace it again just to be sure .


If you notice any rough idle and cold start problems then there is one more possibility to be checked.
That is CHT (cylinder head temp sensor).

It is possible if the CHT (cylinder head temp sensor) wasnt reading right, I would get the overheating issue resolved first and see it this issue returns. Engine temp can and does effect engine running.

This details will help.
Thanks.
See below latest solved car problems :----

All types of car overheating problems and troubleshooting?

Car freeze overnight and started overheating while driving?

http://technoanswers.blogspot.com/2012/01/car-freeze-overnight-and-started.html

Car heater blowing warm, but not hot air?

http://schematicsdiagram.blogspot.com/2011/12/car-heater-blowing-warm-but-not-hot-air.html

Engine Overheats and heater blowing cold?


Car overheats and Air blows hot at idle?


Buick Century overheating?

Car runs hot in Traffic?


Car engine Overheats and transmission starts slipping?

Replacing Heater Water Control Valve on Honda Vehicles?

http://howtobyme.blogspot.com/2011/12/replacing-heater-water-control-valve-on.html

How to replace heater core for All car models?

Click the link below:---

How to Flush Heater Core?


How to Remove Heater Core on 2008 Honda Odyssey?

Honda Heater Core Replacement?

------------

Temperature gauge keeps fluctuating up and down close to red?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-keeps-fluctuating-up.html




@