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1996 Deville
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142 Posts
Discussion Starter #1
While I was in the middle of doing the crossover gaskets on my 96 deville I came across a good amount of oil in the intake manifold, so I decided to take it off and clean it out. When I got it off I looked down all the runners to make sure I got all the crap off the valves when to my surprise the #4 piston had a nice lil puddle of coolant. I had to move the car so I put things back together and started it up.

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I drove around for a while without issue the did a block test. I know at this point I blew a gasket but I had done the block test about 10 times since fall and never got a positive result. This time was no different I got a no exhaust gasses in the cooling system. Oh well doesn't matter now.

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I have a million questions to ask of this forum in the next few weeks but I will start with some essentials. Is northstar performance still the studs to go with?
Are the felpro Headgaskets adequate?
My engine runs smooth and gas mileage is good should I be looking at any of the timing guides or tensioners?
I will want to do the oil pan and half seal. What is the correct RTV and do I need new girdle bolts?

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It is a 1996 base deville with just over 300,000 miles.
 

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If you're getting a pass on the block test, and if you're having no HG failure symptoms, I would not worry about it. For 93-99, failed crossover gaskets could introduce coolant into the intake.

Why are you keep block testing it if it's showing no symptoms?
 

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1996 Deville
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142 Posts
Discussion Starter #3
The reason I ran the block test was around thanksgiving I had my rad hose pop off and I lost all my coolant. I filled it back up and ran a pressure test and all the crossover gaskets were leaking but it seemed to be losing more coolant than it was leaking. that is why I ran the test in the first place. Since then I had a bottle of fluid and the tester so I would just do it when I had the hood open topping off the coolant. How would coolant get from the crossover to the intake?
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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In that engine the EGR gas passage is right in the same gasket/flange as the upper right water crossover head connection.

A faulty gasket (and they DO fail - witness the misery of changing them, posted in here several times) could easily allow pressurized EGR gas into the coolant - or vice versa - with subsequent carryover to the EGR passages.

The EGR setup was changed on later engines.
 

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1996 Deville
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142 Posts
Discussion Starter #5
If that were the case coolant getting into the EGR flow or exhaust gas in the coolant would that mean a positive result on the block test might not necessarily mean a head gasket. And if I am getting coolant ingested thru the EGR system it should show up in all cylinders that are on the intake stroke when the engine is at rest.
 

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2004 Deville
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275 Posts
While I was in the middle of doing the crossover gaskets on my 96 deville I came across a good amount of oil in the intake manifold, so I decided to take it off and clean it out. When I got it off I looked down all the runners to make sure I got all the crap off the valves when to my surprise the #4 piston had a nice lil puddle of coolant. I had to move the car so I put things back together and started it up.

----------

I drove around for a while without issue the did a block test. I know at this point I blew a gasket but I had done the block test about 10 times since fall and never got a positive result. This time was no different I got a no exhaust gasses in the cooling system. Oh well doesn't matter now.

----------

I have a million questions to ask of this forum in the next few weeks but I will start with some essentials. Is northstar performance still the studs to go with?
Are the felpro Headgaskets adequate?
My engine runs smooth and gas mileage is good should I be looking at any of the timing guides or tensioners?
I will want to do the oil pan and half seal. What is the correct RTV and do I need new girdle bolts?

----------

It is a 1996 base deville with just over 300,000 miles.
I cannot answer your question on if you have a blown head gasket or not.

But, FelPro is fine. I used it for my head gasket job and I am sure many others have as well.

One member did timing guides, but they were very worn. You will know once you get that far.

Not sure on the girdle bolts, but it is recommended on the forums to use UltraGrey RTV. I think others have used high temp black as well.

Food for thought, my car passed a block test until the purge line was clear. Once I cleared it, that allowed the exhaust gases to be pushed into the coolant tank where the test takes place. That is worth looking into.

Worst case your car will overheat. You will know when it happens, and then you have a decision to make.
 
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