99 GTP Overheating PLEASE HELP!! URGENT!!

[EviLette]

Okay, so my GTP is doing some weird stuff. I think it's probably the water pump, but let me give you the information.

 

When not in motion, the car's temp gauge climbs pretty quickly. I haven't redlined it yet, but it's gotten close. As soon as I start moving again, the temp drops almost instantly. If you are crusing at say 40mph down a long stretch, it will slowly climb. Once you've stopped, and accelerated again, it will cool back down. This leads me to believe the thermostat is operating properly, and it seems as though the water pump is only cooling effectively when the RPMs are higher.

 

Does this sound like a water pump to you guys?

Edited December 16, 2012 by EviLette

[Galaxie500XL]

I've seen failed cooling fans do this, too...and by failed, I don't always mean not running. If not enough air is being moved by a dying cooling fan, this can happen.

 

I'm guessing though, you've checked the fan--when it gets really hot, are both fans running?

[EviLette]

I honestly hadn't thought about that. I know I am constantly running my heat on full blast as hot as it will go to try and help get some of the heat out of the system. Honestly, it's always dark when this happens, and I don't have a damn underhood light. Things have been hectic lately, I'm just trying to keep everything moving smoothly lol.

 

Thanks for the input. I will definitely check this out!

[GtpKo]

Also check coolant level and bleed thoroughly.

[Galaxie500XL]

Just turn on the air conditioner...that should force the fan to come on right away, when you have daylight to actually see in there..

 

Once temps get into the 50's, the compressor should turn on, which forces the cooling fan to come on, too. If the fan doesn't come on, or is barely moving any air, you've got an idea where the problem is. General rule of thumb, if the fan is running, you should feel a breeze a good ways back toward the firewall. if you practically have to stick your hand right behind the fan to feel a breeze, it's toast, and the fan motor will need to be replaced.

 

I honestly hadn't thought about that. I know I am constantly running my heat on full blast as hot as it will go to try and help get some of the heat out of the system. Honestly, it's always dark when this happens, and I don't have a damn underhood light. Things have been hectic lately, I'm just trying to keep everything moving smoothly lol.

 

Thanks for the input. I will definitely check this out!

[Addicted to eaton]

Stucky t-stat when you rev it up to move. It moves the water more causing it to open

[AL]

I had a cracked coolant elbow cause this

[EviLette]

I swapped out the T-Stat and started bleeding the system earlier. I topped off the radiator and filled up the overflow (which was nearly empty, and though the rad didn't take a lot of coolant, there was still some room.) Now that I am bleeding the system, the only bleeder valve I am finding is on top of the t-stat housing, and I had it open for probably 5-10 minutes and it's still shooting out more air. I have yet to see a steady stream of coolant, and I had to shut the car down to cool off. My secondary fan never kicked on, but it will come on when the a/c is turned on so it still operates.

[EviLette]

I've seen failed cooling fans do this, too...and by failed, I don't always mean not running. If not enough air is being moved by a dying cooling fan, this can happen.

 

I'm guessing though, you've checked the fan--when it gets really hot, are both fans running?

 

How hot are you calling 'really hot' as in hot enough for the secondary to kick on?

[EviLette]

The secondary fan kicked on a couple clicks above 160, so that's not the issue.

 

I let it cool off and bled it again and sat there for a couple minutes with no coolant coming out, only air. It sputters and spits, has plenty of range to throw coolant out but there has yet to be a nice steady stream.

 

Am I doing this wrong?

 

Also, I didn't know if the person who had it previously put dex 3 or dex 4 in it, and it looks like there is a ton of sealer in the system. I will have to flush it at a later point, but right now I just want ot try and bleed it out to see if that will help the issue at all. As much air as I am finding in the system it stands to reason it would, since it's moving coolant and the fan is kicking on.

 

O'Reilly recommended the "universal" coolant becuase I didn't know which type was in there. Is this a bad thing? My boyfriend is trying to tell me that it won't bleed the air out of the system with universal......

[95 vert]

It'll bleed regardless of the type of coolant used. Universal is ok.

When bleeding the system, engine off, bleeder open, fill radiator till fluid comes out the bleeder.

Close bleeder, put rad cap on, run engine till t-stat opens (upper rad hose hot to touch). Let it

cool off for a bit, take rad cap off (make sure there's no pressure first by squeezing upper hose)

open bleeder and top off radiator with coolant if needed.

This should get you damn close to a bled system. At this point, make sure your overflow is topped off.

Run vehicle to see if you still have problems.

Hope this helps

[EviLette]

This is one of the first times I have had someone tell me to bleed the car with the system OFF.

 

I have the sneaking suspicion that air is all through the system, including the heater core, so will this still be effective to get air out of the entire system, or just the radiator to the t-stat?

[alec_b]

That will do the whole system.

 

Top gear Top Tip: If you can, jack the front of the car up, making the radiator neck the highest point on the engine. Air will naturally move towards the top of the cooling system. Bleed it engine cool and off using the procedure above. Should work great!

[Schurkey]

It'll bleed regardless of the type of coolant used. Universal is ok.

When bleeding the system, engine off, bleeder open, fill radiator till fluid comes out the bleeder.

Close bleeder, put rad cap on, run engine till t-stat opens (upper rad hose hot to touch).

1. Bleeder(s) open, begin to fill rad. Bleeder(s) may spit some coolant.

 

2. Radiator must be FULL when the cap goes on. Close bleeder(s). Turn on heater, set temperature as high as it goes.

 

3. Start engine, allow it to idle. As soon as the engine starts, I'd crack open the bleeder(s) and begin expelling air again. Bleeder(s) will eventually show only liquid, no air--unless cylinder pressure is leaking into cooling system.

 

4. Overflow bottle to the full mark, so when the engine cools down, there's coolant in the bottle to be drawn back into the rad.

 

Let it cool off for a bit, take rad cap off (make sure there's no pressure first by squeezing upper hose)

open bleeder and top off radiator with coolant if needed. This should get you damn close to a bled system.

If the bleeder is higher than the rad cap, you've just pulled air back into the system.

 

"I" would run the engine, open the bleeder, expel as much air as possible. If the bleeder doesn't ever stop expelling air, you've got a defective head gasket or a cracked casting. Bleeding coolant doesn't take forever.

 

At this point, make sure your overflow is topped off.

Run vehicle to see if you still have problems.

Hope this helps

Yep, the last thing done is to verify coolant level in the overflow tank, and run the engine to open the thermostat and turn on at least one cooling fan. If that's done in the shop or driveway, that's best--easier to see that the cooling fan is on. Otherwise, an appropriately-long test drive.

 

ARE YOU SURE THERE'S ONLY ONE BLEEDER? My 3.4 has two; haven't worked on a 3.1 in a couple of years.

Edited December 17, 2012 by Schurkey

[95 vert]

3800-one bleeder on the t-stat housing. Doesn't have the second one like the 3100/3.4

[EviLette]

1. Bleeder(s) open, begin to fill rad. Bleeder(s) may spit some coolant.

 

2. Radiator must be FULL when the cap goes on. Close bleeder(s). Turn on heater, set temperature as high as it goes.

 

3. Start engine, allow it to idle. As soon as the engine starts, I'd crack open the bleeder(s) and begin expelling air again. Bleeder(s) will eventually show only liquid, no air--unless cylinder pressure is leaking into cooling system.

 

4. Overflow bottle to the full mark, so when the engine cools down, there's coolant in the bottle to be drawn back into the rad.

 

 

If the bleeder is higher than the rad cap, you've just pulled air back into the system.

 

"I" would run the engine, open the bleeder, expel as much air as possible. If the bleeder doesn't ever stop expelling air, you've got a defective head gasket or a cracked casting. Bleeding coolant doesn't take forever.

 

 

Yep, the last thing done is to verify coolant level in the overflow tank, and run the engine to open the thermostat and turn on at least one cooling fan. If that's done in the shop or driveway, that's best--easier to see that the cooling fan is on. Otherwise, an appropriately-long test drive.

 

ARE YOU SURE THERE'S ONLY ONE BLEEDER? My 3.4 has two; haven't worked on a 3.1 in a couple of years.

 

This is the exact method I used, except that I didn't open the bleeder (other than to get it broke loose - i had to have the man break loose the t-stat housing bolts) until the car was warm and as stated, I am working on the 3800 S/C in this endeavor.

 

I ended up with a massive toothache and had to lay down and lost the last of my daylight yesterday. I had a bunch of stuff to do, and spent most of the day driving the car. I would watch it warm up, and then I could visibly see (particularly on the highway) where the T-Stat opened and the temp dropped. Never once did the car get to 210 on the gauge today. I am not at all confident that I purged all of the air out of the system, but maybe it was enough to get me by. The car seems to be cooling much better now, and I was all over Wichita - on the highways and on normal roads. The way it had been cooling before, it would have overheated. I even got stuck at a train and it seemed to operate normally. As I said, enough to limp by. I see a coolant system flush in the very near future.

 

We are already in the market for a compression tester, as it's something we need to check out on my new bike, and on my '92 SE, so I guess it's time to cough up the 25 bucks and get it. LOL

 

Thanks for your help, guys. I really appreciate it.

[Schurkey]

You've run the engine enough to get to normal operating temperature, the 'stat has opened and the system has stabilized.

 

Open the hood, start the engine from cold. Crack the bleeder screw--you'll probably have a stream of coolant with no bubbles. If so, great. If just a few bubbles, before getting a steady stream of coolant, OK. Steady bubbles is trouble. Close bleeder.

 

Shut off engine. Engine has not run long enough to warm up. Verify that radiator hoses are still squeezeably soft.

 

Pop rad cap, inspect coolant level. Should be completely full, or so close as to not make a difference.

 

Verify that overflow bottle is at Full Cold mark (not Full Hot mark)

 

Shut hood. Drive car. You're finished unless you had steady bubbles at bleeder or continue to have overheating issues.