Mazda 6 Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Anyone please help!!! I have just replaced the water pump and thermostat in my 2004 Mazda 6. Did the repairs by the book, but my engine continues to overheat. The A/C and cooling fans all work great. I am stubbed as to what else could be causing the overheat problem.
 

·
Super Moderator
Joined
·
9,080 Posts
explain the problem first.

you overheat everyday? at idle, long drives, short drives? overflow tank looks good? water level is good?
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
After adding the coolant I let the car idle to operating temperature, until the cooling fans start. I then run it at 2500 rpms for five minutes, after about four minutes the car begins to overheat. I have checked all the hoses for leaks and there is nothing. The coolant level always stays at the full mark. At idle the engine as not overheated, but it does when any demand is put onto it.
 

·
Super Moderator
Joined
·
9,080 Posts
same issues before and after the tstat change? did you let it run for a bit with the cap off the rad as well to help eleviate concerns of air trapped in the system?

how are you monitoring when it overheats? if you say it starts overheating after 4min, does the dial start to move at that point? typically that dummy dial doesn't do squat until it's VERY hot, so unless you are about to shoot steam all over it stays still. i've run super hot on the track and it never moved, had a leak in a hose and running low, went from normal to full tilt in 5 sec.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #5
The thermostat was bad to begin with. I have ran with the cap off. After the 4-6 minutes the temp dial starts rising. When I ran with the cap off there was heavy steam after about 2 and continued until the needle moved. Is there a temperature sensor that may have gone bad too? Everything seems to be working fine; no leaks or clogs.
 

·
Registered
Joined
·
9 Posts
First of all, running without the radiator cap lowers the boiling point of your cooling system. This is bad. You boil your coolant faster that way. Second, have you tried replacing the radiator cap with a new one? If that goes bad you will also overheat. If that doesn't work, I would flush your cooling system by opening the drain plug and running clean water through it, then filling it back up with FL22 Mazda coolant. Hope this helps!

-Lawrence
 

·
Registered
Joined
·
1,610 Posts
Not sure if you're filling the radiator or the overflow tank? Try pouring the water directly into the radiator. Sitting still with no load, it should take a while for the engine to get hot enough to boil water. With the Rad cap removed, you should be able to see water moving if you shine a flashlight in the rad. Another good test is to turn on the heater. If the heater is blowing HOT air, you should have water circulating throughout the system.

My overheating issue turned out to be a head gasket... I also replaced the WP and Tstat, but noticed I was blowing a bit of white smoke on cold starts and was getting occasional mis-fire CELs due to coolant in the cylinders. :( On a cold engine, remove the plugs and turn the engine over. If you see or smell a mist of antifreeze, you've got coolant leaking into a cylinder or 2 which is probably a gasket issue... (Get a friend to help so you can watch the first few turns of the engine. ;) )
 

·
Registered
Joined
·
3 Posts
did you ever figure out what was causing urs to overheat? i have my gf that is doing the exact same it will run normal at idle but under load it overheats i have changed the tstat so far
 

·
Registered
Joined
·
140 Posts
You probably need to bleed the air out the system, best way I found to do this is to unbolt the resvr and pull it up as high as possible until bubbles start forming. I.guess pull up and tilt and start adding coolant. Sometimes when theres a big air pocket the coolant needs help flowing into the motor

Sent from my LG-P999 using AutoGuide.Com Free App
 

·
Registered
Joined
·
4 Posts
04 Mazda 6 V6

Hello everyone,
My daughter has an 04 Mazda 6-V6 and from what I'm told it overheated today so went to check it out and the (L) shaped heater hose connector with 3 inlets/outlets coming out of it broke in several places. It looks to me like it had a lot of pressure on it and exploded. I found a new one for 21.40 so purchased it and installed it out on the highway where she broke down. I slowly poured antifreeze until it wouldn't take anymore fluid. I started it up to see if it would take anymore fluid and it didn't but temp gauge started running really close to the hot side. We let it cool off and added just a little more coolant but it kept wanted to over heat. The antifreeze inside the coolant bottle was warm but there was no hot air coming through the vents. I can't see that the water pump is leaking or bad. I plan on replacing the thermostat tomorrow. Anyone have any suggestions on what could be wrong. I checked the oil and didn't see any water in the oil so I've ruled out a cracked head gasket. I hope anyway.
Respectfully,
Johnny767
 
1 - 11 of 11 Posts
Top