Cadillac Owners Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Ive got a 2001 DHS. I never experienced any overheating problems until a month ago. I drove it about 10 miles, the alarm went off saying it was getting hot so I pulled over immediately and let it cool down. I noticed the water spurting from the upper rad hose, so I replaced it once the car cooled down. For about a week no more over heating problems. Then I drove it about 20miles and it started to get hot, about the 2oclock on temp hand. I stopped, let it cool down for an hour then drove it back with no issues for 2 weeks.

During this i was starting to think my thermostat was sticking, so I decided to change it. As soon as I change it the car starts running hot within 5 miles. I pulled over let it cool down and pulled the thermostat out. Started back home and ran hot in the same 5 miles.

Is there anything I could have done while changing out the thermostat to cause the instant overheating or is it just coincidence?
 

·
Registered
Joined
·
4,153 Posts
Check your purge line for proper coolant flow. It's located at the side of your surge tank - the 3/8 line that goes to the engine side - It should have steady flow with the engine running.

A Northstar will run hot with the thermostat installed backwards (possible) or without a thermostat. Also make sure that the hole on the thermostat goes to the 12 o' clock side, that is necessary for properly purging air.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
68,481 Posts
Please study the sticky posts in Northstar - cooling, fans, and gauges. Replace the thermostat - it is vital to proper cooling system operation.

Look in here, Seville, tech Tips and Northstar for threads on the "purge line" - that system which bleeds air and gases out of the coolant so the water pump sees "solid" coolant instead of bubbles which cavitates the water pump, stops pumping action and overheats the engine.

Purge line and the hollow bolt-nipple.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Ok thanks for the comments. I went ahead and put a new thermostat in. I pulled the purge line off the nipple at the reservoir and put it in the top of the tank and the flow of coolant wasnt steady it came in spurts. The car idled for a good 20minutes at normal running temp without ever going above, I drove it for less than half a mile and the temp started rising so I parked it. The local part stores said they arent allowed to sell me a tester kit to check my tank for exhaust in case of a blown head gasket.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
68,481 Posts
Bullshit. Most large parts chain stores "rent" the cylinder block exhaust gas test kit and sell you the chemical test fluid. Follow the instructions, don't try to make it better, and bubble the airspace over the coolant in the surge tank to test for exhaust gas components.
 

·
Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
·
86,785 Posts
I pulled the purge line off the nipple at the reservoir and put it in the top of the tank and the flow of coolant wasnt steady it came in spurts.
As long as you have flow, it is not clogged and not the problem.

The local part stores said they arent allowed to sell me a tester kit to check my tank for exhaust in case of a blown head gasket.
:histeric: :bsflag:
 

·
Registered
Joined
·
5 Posts
Discussion Starter #7
Ill go to a different parts store tomorrow. It was Advance Auto Parts that said something about they are only allowed to sell to licensed mechanics due to some environmental stuff.
 

·
Registered
Joined
·
4,153 Posts
This is about the only time Autozone will come in handy. Loan a tool is no questions asked there. You have to buy the fluid though, and make sure the fluid has strong blue color to it.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #10
ok went by Autozone and got the tester. I started the car up and let it run for several minutes to get to almost the normal temp its been running at. I did the test a few times since the bottle of testing fluid was decent sized. The tests stayed blue, the blue didnt always stay strong it did fade though. Then the last test I did the car had been running for awhile and the reservoir was probably close to boiling, I tested and the blue lost all of its color, didnt turn yellow but it wasnt blue either.
 

·
Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
·
86,785 Posts
Sounds like the early stages of a HG failure. Eventually as the overheating gets worse, it should turn yellow.
 

·
Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
Joined
·
19,275 Posts
ok went by Autozone and got the tester. I started the car up and let it run for several minutes to get to almost the normal temp its been running at. I did the test a few times since the bottle of testing fluid was decent sized. The tests stayed blue, the blue didnt always stay strong it did fade though. Then the last test I did the car had been running for awhile and the reservoir was probably close to boiling, I tested and the blue lost all of its color, didnt turn yellow but it wasnt blue either.
===============================
the blue liquid reacts to hydrocarbons -

the stronger the concentration -
the stronger the color change -

but mote -

ANY color change is a positive result -
and that is BAD news -
 

·
Registered
Joined
·
4,153 Posts
If coolant gets into the tester it will ruin the fluid. Close the surge tank cap, drive the car until the temp rises again, if it does, cool down and then test it again. You should get a definite reading.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
68,481 Posts
If coolant gets into the tester it will ruin the fluid..............................
You must then drain and wash the tester and hose, replace the pressure cap on the surge tank and go for a drive. A simple driveway warmup won't do it - unless the problem is so bad that the surge tank coolant is obviously bubbly. THEN re-sample the airspace over the coolant.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #15
I was kind of afraid it was a head gasket since its a rather common issue. My dad is wanting to throw money at it since he believes its just the radiator despite the block test i did.

Since spending the money on a head gasket job is out of the question, is there any particular "magic in a bottle" gasket sealer that can be used to prolong the life long enough to find another vehicle? Is it possible to remove the AC condenser so the radiator catches more air to help in cooling in the meantime?
 

·
Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
·
86,785 Posts
Pulling the condenser won't help unless it is clogged with dead bugs and restricting air flow to almost zero.

Some people have reported some success with some of those HG repairs-in-a-bottle. It might buy you a little time. :noidea:
 
1 - 19 of 19 Posts
Top