[20grand]

I have to do this on my Deville in the AM. It drives and rides nice but after a while at idle the gauge will increase and cold air kicks through the vents. After I rev the rpms real high, the gauge comes back down and then I have heat. I also checked the tank and she's nice and full. Was thinking maybe a faulty thermostat but will check the lines before I pull that out.

 

[Submariner409]

Re: Overheating please help!!

The surge tank should not be "nice and full". Proper coolant level, checked cold only, is just about at the tank midseam.

There is a COLD FULL legend molded into the top of the surge tank. Next to it is a flat arrow that runs across the tank top and down the side - it points to just about the seam line.

As advised, check the purge line and water crossover bolt/nipple for blockage. Your symptoms are classic for that.

............. and, if you see fairly constant bubbles in the surge tank with the engine running, there is a good chance of one or both head gaskets failing due to pulled head bolts.

 

[Ranger]

Re: Overheating - 2002 Eldorado

A faulty thermostat won't cause the heater to blow cold. That's caused by air in the cooling system getting into the heater core.

Here are the two ends of the purge line.

 

[20grand]

Going out to check now. Will let you know what I find out. Would a little movement in the tensioner be an issue?

 

[Submariner409]

Re: Overheating - 2002 Eldorado

Going out to check now. Will let you know what I find out. Would a little movement in the tensioner be an issue?

The water pump drive belt tensioner should keep that belt tight and be absolutely quiet. No bouncing back and forth. BUT if the belt is intact and the water pump is turning that's probably not the problem - a frozen pump or tensioner pulley bearing would wreak havoc in less than 30 seconds.

20grand, You hijacked the OP's Eldorado thread. Your Deville - what year ? Post it and I'll move the replies to your post into a new thread.

 

[20grand]

Checked the water pump belt and it's about split. Must be the pully itself that's splitting it. There is some play in the tensioner as well.

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The water pump drive belt tensioner should keep that belt tight and be absolutely quiet. No bouncing back and forth. BUT if the belt is intact and the water pump is turning that's probably not the problem - a frozen pump or tensioner pulley bearing would wreak havoc in less than 30 seconds. 20grand, You hijacked the OP's Eldorado thread. Your Deville - what year ? Post it and I'll move the replies to your post into a new thread.

2003 Deville. Was hoping my overheating problem might've helped him if I figured something out. But if I figure something out, I'll reach out to him just in case. I'm going to put a block test on it again to see what I find.

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I also have steady stream from purge line at the tank end. Is it necessary to check at the opposite end by the engine?

 

[Submariner409]

Re: Overheating - 2002 Eldorado

The coolant purge line flows from the water crossover nipple to the surge tank. If you have flow at/into the tank, it's good to go.

 

[Submariner409]

Replace that tensioner pulley - yesterday !!!!

The cover is held by two 10mm nuts on long hex headed studs and a bolt into the water crossover pad. The entire tensioner assembly itself is held by those 2 long studs. You can replace the pulley only by removing the center bolt. Use a small crescent wrencdh on the formed lug on the tensioner arm to lever it toward the firewall to remove tension. Have fun replacing the belt. NAPA.

 

[20grand]

I'm doing this right, right?

 

[20grand]

It's pretty snug and I'm turning the bolt on the left towards to firewall. It's really tight but doesn't seem to be moving. There's a lot of pressure and in afraid of breaking something.

 

[MoistCabbage]

A little bit of grease on the friction points on the tool will make it easier to turn.

 

[20grand]

I'm sorry, I'm turning the bolt on the right towards the firewall, which is tightening the tool.

 

[Submariner409]

If that tool has a slot and slides onto the groove in the steel pulley hub, then turning the bolt to the right will pull the pulley off the cam extension. ............ and it will be TIGHT. Wait 'till you go to press it back on with the other tool.

Why are you removing the drive pulley ? If that plastic pulley and its belt grooves are not messed up you don't need to remove it. The tensioner is what seizes, THEN destroys that big plastic drive pulley.

My picture is of the tensioner assembly, not the drive pulley.

 

[20grand]

The drive pulley is in pretty bad shape. It seems like it's tearing the belt apart. I got it with a bad belt, replaced the belt about 20 miles or so ago and it's already split in the middle. The car wants to overheat here and there and the tensioner has quite a bit of play in it.

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The drive pulley is what needs to be removed. It seems like there's a thousand pounds of pressure there. Almost seems like I would need a breaker bar to assist turning it.

 

[rodnok01]

I would hit with PB Blaster. Press on pulleys can be a bitch sometimes. You can try to rap on the tool with hammer with pressure on might jar it loose and may take a while of soaking and rapping. Heat would work but seal directly behind that pulley.

 

[Submariner409]

If that tensioner pulley is loose or seized I would suspect that first. The drive pulley doesn't look THAT bad. And, did you use a flashlight to make sure the belt was correctly positioned on the water pump pulley ?

Otherwise, remove the pulley puller and hit the hub with a shot of PB Blaster overnight - PB wet rag wrapped around the small hub. You get too carried away and damage the intake cam extension or oil seal and you got troubles.

That pulley should pull off with effort - not Herculean effort.

 

[20grand]

So I cleaned up the pully and put the belt back on along with a new thermostat. It ran really well for about 20 minutes with no overheating. Then the hot air in the cabin turned cold and the gauge went up. When I would rev it to 3k rpm the gauge would go down and I'd get hot air out of the vents. But as soon as it dropped to 700, the gauge goes up and the hot air turns cold. I reved it 3 or 4 times to try and get any air out of the coolant system might've gotten in the line but still the same ol. I also put a block test on it and the fluid stays blue. The gauge goes up but goes one notch short of the top. Does any of this sound familiar?

 

[Submariner409]

Sure does. The system is purging itself of air and gases - after the engine cools to almost ambient, check the surge tank level - half full is correct. One of these start-runs-stops the system will fart a big bubble and the heater core will fill, leaving you a half quart or so low.

 

[20grand]

Thanks Sub. I'll check her first thing in the AM. This is a pretty nice Deville I came across. 95k and really clean inside. Watching the big game tonight?

 

[Submariner409]

Watching the big game tonight?

Basketball ?? Nope. Bb is wasted on me. Maybe yesterday's playoff between Spieth, Walker, Holmes.