What would cause my car to run in the middle and near the red? all the shrouds are fine and the radiator only has a few bent fins.. It over heated almost ( i shut it off) on my way to the post office the other day. I pulled over and waited 2 hours and then took it home and flushed the system. I was on my way to the post office which is only right down the street.. I was driving for maybe about 7 or 8 minutes + some idling... Night time its fine.

 

wonder if you have a bad water pump. Also, I wonder if you had some air in your water lines

 

car ran cold as can be before I took the motor out. I just had the water pump off to do the water pump drive shaft seal too and it spun fine and seemed ok. I just added some conditioner to the system(supposed to lube oil pump).. how can I tell if the water pump is bad?

 

Did you bleed the coolant lines? are your fans coming on? do they come on w/ AC/defrost?

 

i know this subject has been beat to death but... A "bad" waterpump will not cause an overheat unless the seals are leaking or it is flat not spinning. For it to go "bad" the only real thing that can happen is the bearings go, that would cause a leak or the fins com off of the impeller, and i am quite sure you would know that. It sounds like the thermostat may need replaced or you have trapped air. Again subjects that get beaten here on a daily basis. If you myst satify yourself if the pump went "bad" pull off the bolts on the front of the pump and look at the impeller, if it is has all the fins and don't move around it is good. If you can spin it the drive shaft for the WP is not engaged with the cam driven gear / shaft. Be aware you should replace the pump cover oring but i have gotten by one wime with reusing the old one.

Overheating can be caused by other thins as well, timing, plugged cat and so on.

 

I would say that you have air in the lines since you just got done putting coolant in there after the rebuild. If you arent sure how to blead the lines correctly, go to shoebox's web page and read that article on how to properly drain and fill coolant. Not saying you dont know how to do it but seems like this could be it since it was fine before and now you have a problem.

Brandon

 

I know how to bleed the system.. I think it may be the timing.. Im not sure.. ill have to hook it up to a computer and check it.. I have a tune from pcm for less.. It should be good.. bryan knows what he is doing.. Only have pcmforless till i get it dyno tuned..

 

can you touch the radiator when the temps are high? if you can come within an inch or so of it then you need to replace the thermostat.

 

Have you checked the coolant resevoir. As you all know, our cars run on a pressurized system and if the resevior tank is too full or not full enough, it can cause the intermitant problems you are having.
Reason I said that is because my car was doing the same thing.
Since I now have the correct amount of coolant in the resevior, I have no more "running hot or almost running hot" problems.
I hope this helps

-Tim

 

Dude it's still over heating on you ????? It's has to be timing..Did you change the thremstat again after the one I gave you ?

 

Check to see if your fans are coming on ?

-Shannon

 

Borrow a coolant system pressure tester from auto zone and check the cap and system

 

Some causes of overheating and some ways i can think of to check them:
1. Thermostat not working correctly.
-Replace thermostat.
2. Not enough pressure / and or Antifreeze in the coolant mix.
- Not enough pressure and not enough antifreeze may cause your system to boilover internally. This creates bubbles which prevents some coolant from contacting the metal surface, which then causes more heat and more bubbles. This will often result in coolant boiling out of the system.
- Replace Cap
- Check mixture isn't too diluted (30/70 is the most I would go although it's debatable).
3. Low Coolant
-See if waterpump is leaking.
-See if there is coolant in the passenger footwell caused by a leaking heater core.
(You'd probably have noticed that already though).
-Check resevoir, check radiator when COLD.
4. Clogged Cat.
-Just happend to me. Car ran a bit hotter with a clogged cat. When the "clog" got real bad car ran real crappy and ran a good bit hotter. (Didn't overheat though)
5. Obstruction on the RAD or Fans not coming on.
- See if fans go on
6. Obstruction in the RAD.
- Not sure how to check that...
7. Air in system
- Bleed till water comes out the lower bleed screw, then do that with the upper bleed screw.