overheating

[transparentdsm]

hey everyone, so i got 138 running and staying on and got all the wiring worked out for the rad sensor and the fans. now that everything is running and working the car overheats when idling in the driveway. so i thought lets try taking the thermostat out and use the fans through the harness, still overheats. let it cool down and figure ok let do this with the fans hardwired to just be on, nope, still overheats. when i put this motor in i flushed the rad out and it seemed to flow water fine, could it be a clogged rad or does anyone have any other ideas. i just dont want to go spending money for no reason, but im thinking redo my whole cooling system may be my only option.

 

[mikus]

If your fans are coming on & pointed the right way, and your thermostat is opening, you have a circulation problem.

Is this overheating based on temp gauge, do you have any hard temp numbers? What's been done to this car, since it last was able to keep temp?

 

[desant78]

just to throw out options, my logger would read close to normal temps when cold, but as it warmed up it became high, real fast.

My problem was in the wiring, food for thought! Good luck!

 

[transparentdsm]

i have V3 full and thats where my numbers are coming from. i always turned it off before it went above 240. it gets up to 219 stays there for about 10 minutes then jumps to 224, 232 then 240 wthin 4 minutes after that. the car has 8,000 miles on a rebuild motor w/ stock bottom end, MLS head gasket, 3 angle valve job, evo8 springs, retainers, cams and rockers, evo3 gt 16g, 780cc injectors, full throttle FPR, FP manifold, two slim fans, 3 inch exhaust, evo8 front mount with 2.5 piping, running SD, double platinum plugs and 8mm wires. stock radiator, stock sensors(i think the originals). the last time the car ran without overheating is unknown to me as i bought the car with rod knock and it never ran long enough to heat up with the old motor.

 

[desant78]

^shane I was getting the same number. One of the leads going to my coolant temp sensor was not the proper one. I believe the manual calls for a wire based on colors, and I had the right-ish colors. Upon inspection, my ground wasn't a ground, even though the right color (I thought) then I did some inspecting, and found in the same part of the harness a wire that was the correct wire. Both looked like the same color to me, but testing I found only one was a proper ground.

Good luck!

click

^link to old thread of my problem.

 

[transparentdsm]

maybe i should start with getting a water temp gauge.... ugh, so frustrated right now, ive spent like 3 days dealing with crap.

 

[transparentdsm]

no the gauge in the dash goes up and past the middle, its not a wiring issue. the water starts to boil. i know im overheating for real.

 

[DynastyLCD]

Shane.... if its a circulation problem, and you don't have a clogged heater core or any other blockage, i'd check the water pump. it could be possible that the blades have worn away. another good thing to check would be to pressure test it and see if it's getting air in the system somehow.

 

[Fish]

Start with a pressure test, if no leaks are found check the water pump. If you can get someone to help, you can remove a heater hose and have them start the car for a few seconds. If a LOT of water comes out you are good, if it just sort of dribbles out you need a new water pump. Sort of a messy way to check it but it works very well. Good luck.

 

[transparentdsm]

^ thank you, thats where ill start tomorrow. do you know what hose i would want to take off to check this?

 

[Fish]

As long as the heater core isn't plugged it doesn't matter. Make sure the engine is cold too before you do this. You also might want to put a catch pan under the car. It only takes a few seconds to make a huge mess all over your driveway.

 

[turbowop]

If he removes a heater hose, a lot of water/coolant is going to come out anyway since those hoses are well below the highest water level. You should be able to see coolant flowing just by removing the radiator cap.

 

[transparentdsm]

thank you very much, ill do it first tomorrow. if i drive the car around it doesn't overheat.

 

[Fish]

This is how i've checked all the water pumps I have ever replaced at work. It is the only way I know of to be 100% certain. Its generally hard to see water flowing through the radiator, at least for me. And when I took off the heater hoses on my car to back flush the heater core I didn't lose that much coolant so I figured he wouldn't either.

 

[transparentdsm]

well because i have no thermostat in right now im going to try wop's way first as that involves me losing zero coolant. if i see nothing moving then ill remove the hose and see what happens.

 

[prove_it]

How old is the radiator? You may have a block series of passages. Also can the airflow through the radiator easily?

 

[Gizmovr4]

[quote name=transparentdsm - if i drive the car around it doesn't overheat.



Since the car doesnt overheat while driving I would recomend you check the direction the fans are moving the air - since they are aftermarket there is a good chance someone wired them the wrong way.

My car after the installation of an aftermarket fan was doing the same thing.In my car the fans were installed inside the engine bay. Turns out that the fan was pushing the hot engine bay air thru the radiator instead of pulling cool air thru it. In essence the hot air from the turbo was being pushed thru the radiator. Please make sure that they are wired correctly. The easiest way to check is by placing a sheet of paper in front of the radiator if the paper gets sucked to the radiator when the fans are on you have it correct this is if you have the fans mounted inside the engine bay(air is being sucked thru the radiator). If the fans are between the intercooler and radiator you can place the sheet of paper in the engine bay if it does not get stuck to the radiator you have it wired correctly. If you reverse the wires going to the fan it will spin the opposite direction.

Hope this helps.

 

[transparentdsm]

Quoting prove_it:
How old is the radiator? You may have a block series of passages. Also can the airflow through the radiator easily?



this is what im thinking, im not sure on the age of the rad, when i pulled the rad for the engine swap i ran water through it, the water moved through it ok, or so i thought.

Nelson - i have the fans wired correctly, when i first started to troubleshoot this problem i couldn't even get the fans to turn on once the car got warm and after about 5 hours of tracing wires i fixed that problem. not it just wont cool the car off. it has to be a bad water pump, clogged rad or clogged heater core. everything else is new within the last 10,000 miles, even the water pump on has 10,000 miles on it.

on a side note, went to start up my durango today to do some things and sure enough after about 2 minutes of idling the water pump froze up. /ubbthreads/images/graemlins/rofl.gif so today mission is to get that swapped out and the durango running and ready to sell. /ubbthreads/images/graemlins/grin.gif

afterwards im going to have me a few /ubbthreads/images/graemlins/beer.gif

 

[prove_it]

When your running your car and it's overheating turn on the heater to full speed full hot on the vents. See how hot the air is. That will tell you if the core is plugged. Cold air=bad core hot air= good core.

It's my experience that a plugged heater core will not cause overheating as the coolant will bypass the core if plugged. Coolant will still circulate through the system. If your pump was bad then it would heat up while driving too, (these engines will not air cool themselves). Since your overheating at idle you need to check for proper fan operation. What temp do the fans come on? Also are they running full speed. Best test is to see if a piece of paper will hold to the front of your radiator with the fan on. If it stays good, if it won't hold then there is your issue.

My guess is that you either have an air bubble in the coolant system or the fans are not able to transfer enough heat.

You said when the car is moving it doesn't have any issue with cooling at all, right? Do you still have the AC condenser? The fins on the radiator or condenser may be full of bugs and dirt not allowing airflow at idle. You will still feel air coming from the back of the fan as it will pull air from around the radiator.

Also what kind of slim fans are they? Hayden fans at part store won't move enough air and will cause overheating.

 

[Fish]

Hey, sorry but I misread your origional post and thought you changed the thermostat, not completely removed it. So turbowop is right and you should be able to see coolant flowing if you remove the radiator cap.

Also if you think it might be the fans not pulling enough air you can spray the radiator core with a garden hose and see if it lowers your temp. Hope this helps.