Solving a possible over heat.

[Blueberryyum02]

How's it going guys it's been awhile since I have posted but I'm always lurking in and out of the forum. Hope everyone's having a good year.

Now to business 2002 v8 I have been chasing a high speed fan issue while a/c is on. I have done all the usual things as for replacing all plastic new motor craft degas bottle wit brand new cap, dorman lasted me a year took a crap in my drive way was sent a new bottle it took a crap the same day I installed it so I went to motorcraft.

Problem solved.

I have bleed the system countless times, check the clamps on all hoses, found that the ones in the throttle body was loose bought new clamps for them two.

Today I was working on my Chrysler 5.7 changing the coolant hose and fan low speed stopped working so put a new assembly in.

I was filling it up while the engine was running and the first thing I notice was at temp wit the cap off it started to boil over.

So that got me to thinking I pop the hood on the ls let it run till it reached operating temp.

So I took the cap and let it run for 30 to 40 minutes

And not once did it boil over or begin to over heat.

Prior to this test

Have not seen it over heat

The fan ramps up loud and is rpm depended when the a/c is on.
A/c blows cold if I start it up wit temps below 70 degrees ambient
And goes hot if I give it gas.

And will not blow cold after that.

I'm lean towards a possible issue wit the thermostat, or the water pump I put on I want to say close to two years ago is getting weak.

All suggestion are appreciated.

 

[02LincLS]

Pressure test the cooling system and cap with one of those mitivac kits. It should hold 15 to 16 psi for 30 minutes with no pressure drop.

Ignore the AC for the moment. The car is overheating if the fan is that high. Verify with a $20 bluetooth obdII scanner and a free android app like torque.

Verify you have the right mixture of coolant/water with a specific gravity tester.

I just cleaned my radiator(s) that seemed okay, and it made a huge difference. Remove the hood latch plastic so you can see the top of the radiator. Remove the bottom air dams. Lightly tap the base of the radiator and the sand will just fall out. I pulled a few leaves out and a beach worth of sand. Lastly rinse it all out best you can without folding fins over. Blast it with a low pressure hose from both side until you stop seeing crud wash down the lower air dam.

I lowered my temps from a nominal 230 down to a nominal 212 from this alone. I believe 236 is where the fan starts to scream and not much warmer than that you risk head gasket/head.

 

[Blueberryyum02]

The thing is it only ramps up when the A/C is on. If I run it hard it never over heats and the fan remain at a low speed.

Cut the a/c on it goes on high, but the thing is and I forgot to mention in first post I don't think its high like over heating high. It ramps Up when I give it gas but at idle it's at its normal speed I have a scanner that pulls live data, on a test drive stop and go traffic, temp mid 80, it reads at 213F 216F.
Would have to find pressure tester to test if it holds pressure, I hear pressure bleed off when I unscrew the cap but noticed it does sound pretty weak like it has pressure but not as for the radiator cleaning that was the first thing I did when I notice the problem.

I think it's tied into the Ac


From a cold start 2 days sitting still if I start it regular fan blows on low speed.

Same scenario but before I turn it over hvac on auto the fan ramps up right at start up. If I shut the Ac system off then goes down to normal speed with in like 1 or 2 minutes.

That's why I think it has something to do with the Ac cause I have heard the fan running full speed when my water pump went out. it was loud this is more so like you only know it's high if I give it gas if not it sounds like the normal speed with the Ac on.

 

[Blueberryyum02]

I just went out and checked it now at 3 in the morning since my wife have to be at work, I went out to top up the coolant on the 300 and complete the repair by putting the engine cover on.


I checked the ls and noticed that the coolant level dropped in the degas bottle.

Just a hair pass that min line I didn't run it but when the sun comes up I think I'm going to re bleed it. By the coolant level dropping like it did I'm hoping it was air in the system that I didn't get out the last time I bleed it. This time I left the engine bleed open for a longer time during the warm, it never did get to a full stream, and I had the rpm up to around 1500 while leaving the air bleed open. I notice that it would spit out coolant and recess then blow out bubbles then recess.

Now that I think about it I had to retighten the bottom bolt on the water pump a few months back cause it leaked. When I turned it I got like three turns from ratchet before it tightened down. I bleed the system and think I did it to fast, so now I'll let it run for more than 15 20 minutes.

 

[joegr]

...
A/c blows cold if I start it up wit temps below 70 degrees ambient
And goes hot if I give it gas.
...

Repeat this exact sequence with the compressor switch off. Does the air coming out still get a lot hotter? If yes, then your DCCV is starting to fail. (It may also be leaking a little coolant.)

 

[RigsLS]

... 236 is where the fan starts to scream and not much warmer than that you risk head gasket/head.

~ and hoses popping, weak plastics will take a dump as well at that point.

... BUT we know this from previous forum experiences.

 

[milehighmikey]

I once had overcharged my 2000's A/C and every time the A/C got used, the fan was at its highest speed. You may want to have that A/C pressure checked.

 

[Blueberryyum02]

Joe that's what got me stumped I'd tried that thinking it was the DCCV but the air from the vents do not get hot like if I was calling for heat.

 

[Blueberryyum02]

You know what that's the only thing I haven't done is had the Ac checked I was assuming when I had the compressor replaced they did that. But most shops just put back what was recovered when it's just a compressor replacement.