DHP PCM Causing overheating?

[hass]

Okay, so I'm having some annoying, very annoying overheating problems.

It will only overheat from a cold start.
When it starts cold, it will run the gauge up to 240ish then I shut it off.
Once and a while I can't get to the side of the road fast enough and it pegs 250-260 [the red]

I shut the car off, and let the fans cool it down [the auto fan turn on after it's turned off]

Then I turn it to ON, then OFF... So the fans turn back on.
Once it hits 210-220, I restart the car, then it runs fine.

Replaced the Tstat [to a 180 degree]
Replaced the LIM
Flushed Coolant

[all within ~100 miles]

Now, the only thing that I added recently before this started happening, was the DHP PCM.
I did that about 2-3 weeks before all this started happening.
Would the PCM cause this?

Or would it just be air pockets in the coolant?
I lose coolant everytime it over heats... It pours out of the overflow.
So I guess it does suck in air, but I refill it ASAP.

Just wondering :\

My father first suggested it...
Then a guy at a muffler store [I had the car pressure checked and what not, to look for a water pump leak/head gasket leak] said that could be it too.
but then again, another guy at the store also said that my fuse under the hood running to the amplifier could cause something like this.
So uhhh... I don't quite believe what he says.
lol :p
He didn't even know what it was. He just said that big thing over there can effect the car, then I told him.. and he was like oh yeah yeah, those can 'cause major problems blah blah.

Suggestions?
Put the stocker back in?

[SikMindz]

Check the radiator and reservoir cap for leaks.

[MilzyZ34]

Okay, so I'm having some annoying, very annoying overheating problems.

It will only overheat from a cold start.
When it starts cold, it will run the gauge up to 240ish then I shut it off.
Once and a while I can't get to the side of the road fast enough and it pegs 250-260 [the red]

I shut the car off, and let the fans cool it down [the auto fan turn on after it's turned off]

Then I turn it to ON, then OFF... So the fans turn back on.
Once it hits 210-220, I restart the car, then it runs fine.

Replaced the Tstat [to a 180 degree]
Replaced the LIM
Flushed Coolant

[all within ~100 miles]

Now, the only thing that I added recently before this started happening, was the DHP PCM.
I did that about 2-3 weeks before all this started happening.
Would the PCM cause this?

Or would it just be air pockets in the coolant?
I lose coolant everytime it over heats... It pours out of the overflow.
So I guess it does suck in air, but I refill it ASAP.

Just wondering :\

My father first suggested it...
Then a guy at a muffler store [I had the car pressure checked and what not, to look for a water pump leak/head gasket leak] said that could be it too.
but then again, another guy at the store also said that my fuse under the hood running to the amplifier could cause something like this.
So uhhh... I don't quite believe what he says.
lol :p
He didn't even know what it was. He just said that big thing over there can effect the car, then I told him.. and he was like oh yeah yeah, those can 'cause major problems blah blah.

Suggestions?
Put the stocker back in?


As long as your fans are functioning properly, the PCM shouldn't be causing your overheating issues. Did you purge all the air out of the system when you worked on the car? That could definately cause this. A blown headgasket can also pressurize the coolant system and send coolant out the overflow.

Make sure your fans work. Then make sure you have no air in the coolant system. if you feel like it, do a compression test or a coolant system pressure test.

[hass]

Check the radiator and reservoir cap for leaks.
No leaks of any kind when the car is sitting... When it's running, maybe... But none that I can visibly see.
The cap let's out a long pssshhhh noise anytime I remove it after the car has been running. and it's pretty tough to turn until that pssh noise stops.

As long as your fans are functioning properly, the PCM shouldn't be causing your overheating issues. Did you purge all the air out of the system when you worked on the car? That could definately cause this. A blown headgasket can also pressurize the coolant system and send coolant out the overflow.

Make sure your fans work. Then make sure you have no air in the coolant system. if you feel like it, do a compression test or a coolant system pressure test.

Yep, fans are functioning great.. the turn on right as they should. I managed to get all the air out, then somehow the coolant level dropped and it looks like air worked it's way back in.

When the engine starts to overheat, does it put coolant out of the overflow?

[SikMindz]

No leaks of any kind when the car is sitting... When it's running, maybe... But none that I can visibly see.
The cap let's out a long pssshhhh noise anytime I remove it after the car has been running. and it's pretty tough to turn until that pssh noise stops.



Yep, fans are functioning great.. the turn on right as they should. I managed to get all the air out, then somehow the coolant level dropped and it looks like air worked it's way back in.

When the engine starts to overheat, does it put coolant out of the overflow?

I would still have it pressure tested again. The crack in my radiator and reservoir cap were almost invisible to the eye but causing the pressure to be off when the car was running.

Yes to your question. At least it has everytime my car has overheated. ;crap

[MilzyZ34]

No leaks of any kind when the car is sitting... When it's running, maybe... But none that I can visibly see.
The cap let's out a long pssshhhh noise anytime I remove it after the car has been running. and it's pretty tough to turn until that pssh noise stops.



Yep, fans are functioning great.. the turn on right as they should. I managed to get all the air out, then somehow the coolant level dropped and it looks like air worked it's way back in.

When the engine starts to overheat, does it put coolant out of the overflow?

air doesn't work it's way back in, maybe you didn't get all the air out. (unless headgasket)

[hass]

Does every single screw have to be coated in silicone?

Or just the six in the lower section?

[AaronGTR]

Does every single screw have to be coated in silicone?

Or just the six in the lower section?


Which screws are you talking about? If you mean the lower intake manifold bolts, they aren't supposed to have any silicone on them. They are supposed to have red loctite.

There's no way the pcm is causing this issue, it's something mechanical. My first guess would be a faulty cap on the reservoir. Wouldn't be the first time one's gone bad. Could also be a leak somewhere else or a bad head gasket as has been suggested.