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More coolant woes

3023 Views 35 Replies 8 Participants Last post by  Yaemish
Two weeks ago I replaced all the gaskets on the coolant cross over. A few days after I was still hearing air bubbles but the guys in the forum told me to be patient. Today I was driving and the engine made it all the way to the red, flashed a message that the engine was hot and the AC has been stopped. I pulled over and turned it off, sat until the gauge made it 3/4 the way to normal operating temp and started back up. The temp continued to go down.

In the week prior to replacing the cross over gaskets the engine would sometimes move a little past normal operating temp, stay there for a minute and then go back to normal. It again started doing th is last week.

I'm not leaking coolant, but I did see some coming from under the radiator cap. A small turn of the cap released a ton of air, for a good two minutes. Would this be the symptom of a bad cap?
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Did coolant leak from the tube coming off of the coolant reservoir neck?

Since these cars are known for their head gasket issues, have you performed a block test?

You can also check the purge line and see if that is clogged. Sometimes that can be clogged causing air to stay stuck in the system. I am not familiar with where it hooks up in the 2001, but there should be a small tube that runs into the coolant tank. Follow that to where it connects to the engine. Unhook it and clean it out. Make sure coolant flows from it with the engine running.
I haven't done the check on the head gaskets for over a year. I cleaned the purge line when I did the crossover. I think It is the cap, there was a little coolant around it prior to me relieving the pressure.
Two weeks ago I replaced all the gaskets on the coolant cross over. A few days after I was still hearing air bubbles but the guys in the forum told me to be patient. Today I was driving and the engine made it all the way to the red, flashed a message that the engine was hot and the AC has been stopped. I pulled over and turned it off, sat until the gauge made it 3/4 the way to normal operating temp and started back up. The temp continued to go down.

In the week prior to replacing the cross over gaskets the engine would sometimes move a little past normal operating temp, stay there for a minute and then go back to normal. It again started doing th is last week.

I'm not leaking coolant, but I did see some coming from under the radiator cap. A small turn of the cap released a ton of air, for a good two minutes. Would this be the symptom of a bad cap?
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chances are you have air trapped in the cooling system -

check the PURGE LINE for a constant - gentle - flow of coolant -
with the engine idling -
Have you topped off the coolant after the gasket job as needed after the first few drives?
Yes, I topped it off. I probably have 300 miles on the car since replacing the gaskets. It doesn't look like the coolant level is dropping, there are not puddles under the car. I went through and made sure that the 8 bolts holding the crossover on were tight. I also double checked all the host clamps. Yesterday I replaced the radiator cap but have only driven 20 minutes, there is still air but maybe it is from the bad cap.

The purge line seemed fine. I did clean it all out when I did the crossover. I also replaced the gasket on the waterpump housing when I reinstalled it. My radiator is maybe 18 months old, so I don't think that there are any cracks taking in air or leaking coolant. I'll rent the little pump to check for exhaust in the surge tank, I still have the solution left form the last time that I did the test.
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I haven't yet had time to do the head gasket test; maybe tomorrow. I have a little more info that may help with diagnosis. The car registered that it was 32 degrees this evening. The heat was on automatic at 72 and I was getting was cool air.

Thinking back to pre-gasket failure, I had put the coolant tabs in to help me make it until the weather warmed up so I could perform the cross over job. After I did that, I was getting the temp rising problem almost to a full notch and then it would quickly go back to normal. Does that help with diagnosis?
If your purge line is clear, sealant tabs are not clogging it.
If you are getting any heat at all, the heater core is not clogged.
Heat stops because "air" is getting into the cooling system and when the "air" gets to the heater core, there is no hot coolant to transfer heat to the cabin.
It does not look promising.
Great news! I did the block test and the coolant changed from blue to yellow. I suppose I will put some tablets in it to get a few days or weeks of useful life out of it. I always assumed that when it happens, I would just buy a new car. Right now, I think every car is way overpriced and I don't want to buy one. I managed to do the coolant cross-over job, that is probably my limit in terms of skill. I wouldn't be able to pull off the head gasket job would I?
The tablets aren't going g to help with an HG issue.

An HG job is way up the totem pole from a crossover gasket job. Engine has to come out for starters.
If the car is "toast" I would recommend trying Dura-Seal. I have used it in my 2003 SLS and so far its worked fine. I have put several thousand miles on it with no problems. There really isn't much to lose as in my case the head gasket job would cost about what the car is worth. I did a block test on my engine before adding the Dura-Seal and it turned from blue to yellow in about 2 seconds. Now, nothing....it stays blue in-diffidently.
If the car is "toast" I would recommend trying Dura-Seal. I have used it in my 2003 SLS and so far its worked fine. I have put several thousand miles on it with no problems. There really isn't much to lose as in my case the head gasket job would cost about what the car is worth. I did a block test on my engine before adding the Dura-Seal and it turned from blue to yellow in about 2 seconds. Now, nothing....it stays blue in-diffidently.
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total waste of money -

due to the nature of the problem -
mechanic-in-a-can products can't possibly work on pulled head bolts -

if it "did work" in your engine -
you probably never had the problem -
Maybe I am in denial. I just did the crossover and part of me feels like the problem stems from that and is not the HG. I just did the test again, it seems like there is some color change but maybe more green than yellow. If it is the HG, would it being going back and forth with the engine temperature. Today when I was driving home, the temp jumped up two notches; then just as fast as it rose, it went back to normal operating temp. It is building a lot of pressure under the cap though. I relieve the pressure, it is fine. I also just did the test on the purge line, it is sputtering.

To recap...
Mid Feb - loose coolant from failed crossover gasket. I see the leak at the back of the engine.
Mid Feb - Add six tablets to the hose going to the water pump. The leak immediately stops. I do not hear any air and am hoping to make it to warm weather so I can repair.
Late Feb - Everything is still working just like it should. No problems.
March 1st week - I drive an hour. While stuck in traffic I notice that the temp sometimes jumps up on notch and then goes back. It will run for 20 minutes before seeing the problem again. No air in system.
March 2nd week - The seal fails and I loose coolant while pulling into my driveway. I have a nice two days to work on it and I replace the cross over gaskets.
March 3rd week - I still hear the air in the system and very rarely I see the temp jump up one notch and then back down.
April 1st week - Engine gets really hot, almost hits the red. Lots of pressure. Once pressure is relived it goes back down to normal and I can drive without problem for a few days.
April 2nd week - Replace radiator cap. I thought it was helping but I still hear water in the system.
Today - Temp goes up two notches and then falls back down to normal halfway into a 15 minute drive home. It didn't have any problems on the way into work. I was going on the back roads and up hills when it happened. I drove to work on the highway.
- The purge line is sputtering a bit and the block test changed color a bit. Not as yellow as when I put the tester up to the exhaust pipes.
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One of the crossover gaskets in pre '00 engines can allow exhaust gasses into the cooling system via s the EGR passage. Maybe it was damaged/defective?

IIRC, TP had his block crack after it was studded. Not that that helps, but may be a possibility as opposed to the studs pulling.
The gaskets looked pretty standard. There were pre-2000 ones that came in the kit but they obviously weren't used. When the HG goes, does it overhead then return to normal?
Yes, in the beginning, but as it gets worse it will simply overheat and not cool back down.
HG failure is a progressive disease.
I wouldn't be able to pull off the head gasket job would I?
Sure, why not. What do you have to lose? It is a straightforward job, just take your time. I did not even require an FSM.
I'm reading up about MoistCabbage's suggestion of it possibly being related to a gasket failure allowing exhaust form the EGR in. I found a comment on YouTube of all places, someone said that the regular block test could be a false positive since a gasket can allow gases into the coolant. He goes on to say that they only guaranteed test is a proper "cylinder leak test". I'm hoping that it is just the gasket since I didn't start hearing all the air until after I did the crossover.

I found a picture of a 2001 Seville engine with the crossover removed. See the yellow port just above the part circled in red? I don't remember replacing a gasket there and it is right where the EGR is connecting. This top gasket is also the one that eventually failed causing the massive coolant leak that started all this.


I think I screwed up. This is the kit I bought and I need to go back and check to see what gaskets I have that are left over. On this portion of the engine I used the basic rectangular gaskets that look like they fit there. Should I have used the one with the extra circular portion on it? The long and the short of it are that the circle in the image above, didn't get a gasket.

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That is a universal kit for the different generations of Northstar. You should have gaskets left over. The wrong gaskets will not physically fit, so I do not see how you could have made a mistake in that regard.
I need to figure out if it is worth while to fix it. I have an intermittent P0741 and I have to repaint the rear wheel wells each spring because it keeps rusting through. There isn't any car out there that to me, seems like it is worth the asking price.
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