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My Half Case Seal Is Leaking


Texas Jim

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Took my DTS in for service on Monday.

I reminded the my service writer that it would soon be out of warranty...and to please look at EVERYTHING on the car and anything that needed to be fixed...FIX IT.

They replaced the right front headlight assembly...the right front TPMS sensor and a couple of other minor things.

He called me yesterday morning and told me the halfcase seal is leaking.

I went by there yesterday afternoon and they were waiting on the GMPP rep to come by and approve fixing it.

I was not expecting anything like this would need to be done.. :(

I was hoping the half case problem had been fixed... :(

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I agree that the frequent issue with the original design was fixed. Although surprising that you would have a half-case leak not impossible, so if confirmed and you get it fixed all good.

Bruce

2016 Cadillac ATS-V gray/black

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I agree that the frequent issue with the original design was fixed. Although surprising that you would have a half-case leak not impossible, so if confirmed and you get it fixed all good.

Very true...

I just don't like the idea of the engine being taken apart.

It has never needed oil added between changes... so this is a big surprise to me.

Evidently it just started leaking...but there are NO oil spots on my garage floor.

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I wonder if the fix lasts longer than the original gasket? This is disturbing to me as well. I always planned the next northstar I get will be an 02 or newer because of the headgasket and TCC problems. But apparently the half case seal will always be a problem. So still wonder if yours will be bad again in another 5 years?

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

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I wonder if the fix lasts longer than the original gasket? This is disturbing to me as well. I always planned the next northstar I get will be an 02 or newer because of the headgasket and TCC problems. But apparently the half case seal will always be a problem. So still wonder if yours will be bad again in another 5 years?

I also hope it does last a long time. :)

At this time.. I am planning on trading it some time later this year and getting another one.

Probably a 2010 CPO.

As far as the HG problem.. they made the biggest change to the headbolts in 2004.

I am very disappointed that it is leaking.

I HATE the idea of the block being cracked open.

It probably shouldn't bother me...but now I am not as confident in the engine as I was yesterday morning at this time... before I knew it was going to have to be opened up.

It must be a small leak... "AND" it must have just started.

The car has never needed oil added to it between changes and there are no oil drops on my garage floor.

Oh well... looks like I just have to deal with it.

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This really is disturbing. What comes to mind to me is, should the block now be timeserted.

Jim, I would have a look at it and see how badly its leaking. The fix may be worse than the problem for the longevity of your engine. I myself would be temped to let it seep, than take the engine apart and risk head gasket problems in the future as a result

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

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This really is disturbing. What comes to mind to me is, should the block now be timeserted.

Jim, I would have a look at it and see how badly its leaking. The fix may be worse than the problem for the longevity of your engine. I myself would be temped to let it seep, than take the engine apart and risk head gasket problems in the future as a result

The heads don't have to be pulled for a half case leak....DO THEY????????

NOW I am REALLY worried....... :( :(

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My service adviser said that they would probably just drop the cradle and tranny ... while using a special hoist to hold the engine and do the half case seal while engine is still in the car.

I didn't know it was possible to do it that way...

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This really is disturbing. What comes to mind to me is, should the block now be timeserted.

Jim, I would have a look at it and see how badly its leaking. The fix may be worse than the problem for the longevity of your engine. I myself would be temped to let it seep, than take the engine apart and risk head gasket problems in the future as a result

The heads don't have to be pulled for a half case leak....DO THEY????????

NOW I am REALLY worried....... sad.gifsad.gif

No they really don't, we had a tech IAN who used to do the case half from the bottom. But I would insist that they do not remove the heads if they invert the engine on an engine stand.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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This really is disturbing. What comes to mind to me is, should the block now be timeserted.

Jim, I would have a look at it and see how badly its leaking. The fix may be worse than the problem for the longevity of your engine. I myself would be temped to let it seep, than take the engine apart and risk head gasket problems in the future as a result

The heads don't have to be pulled for a half case leak....DO THEY????????

NOW I am REALLY worried....... sad.gifsad.gif

No they really don't, we had a tech IAN who used to do the case half from the bottom.

But I would insist that they do not remove the heads if they invert the engine on an engine stand.

Are you sure that's what you meant to say??

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Anotherwords, if they are able to invert the engine on a stand or do the case half in place, they should not need to remove the heads.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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They're not going to remove the heads. They will use the support fixture that will bolt to the strut towers to hold the engine in place and drop the transmission and cradle. Then the lower crankcase will be removed once the exhaust crossover is removed. Have them install new graphite donuts on the exhaust crossover connection and install a new oil manifold plate while they have it apart.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Here is a writeup by IAN, doing an AURORA from the bottom

http://www.caddyinfo.com/casehalf.htm

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Here is a writeup by IAN, doing an AURORA from the bottom

http://www.caddyinfo.com/casehalf.htm

Mike,

The 10th picture in that link shows the oil manifold plate. You can't see all the oil passages since it is installed on the upper crankcase though. A lot of times, this is leaking which makes it look like the oil pan gasket. Also, many times, a leak here is blamed in the case half.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Thanks Kevin, you and I have discussed that manifold a few times, thanks

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Well... back from the dealer.

I verified that the oil manifold is also being replaced when they do the case half seal.

When the GMPP warranty guy was there yesterday...he also authorized the rear valve cover/ cam cover, gasket to be replaced.

It too was leaking.

AND.........Since it has a little over 93,000 miles on it...

I am having the coolant changed and the transmission fluid changed while it is in the shop.

That should be done at 100,000 miles anyway.

Then I don't have to take it back and have that done at a later date.

Hopefully this is the last time it will ever need to be there for anything other than oil changes.

I am more than a little disappointed that it has oil leaks in two different places and it is just barely 4 years old.

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Jim its 93000 hard highway miles. You have taken care of it well, but you say yourself that its not using oil, so I am sure this is seepage.

I am not making excuses at all, and you would hope that they would make seals and gaskets that lasted 100,000 miles at least for their own benefit of not having to repair this car now.

Did you see the car on the lift?, did you see the leak?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Jim its 93000 hard highway miles. You have taken care of it well, but you say yourself that its not using oil, so I am sure this is seepage.

I am not making excuses at all, and you would hope that they would make seals and gaskets that lasted 100,000 miles at least for their own benefit of not having to repair this car now.

Did you see the car on the lift?, did you see the leak?

I reckon I have to agree with you on the FAIRLY HARD miles... :D :D

And I do try to take care of it well.

But my 1980 Sedan DeVille was 21 years old and had well over 250,000 on it and didn't leak oil... dunno.gif

But I also realize, it wasn't a N* and was put together totally differently.

No...the DTS wasn't on the lift yet.

He had one in his stall that he just did a TIMESERTS on.

Mine is next to be worked on... probably in a couple of hours.

I may run back over there this afternoon to look at it.

PS... The 1980 also didn't turn 7000 RPM either...:D :D :D

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Its an innovative engine, maybe it's similar to the 4-6-8 that was ahead of its time as computers and sensors were not advanced enough, in the NS's case seal technology is not up to the task of sealing an aluminum block.

Maybe the bean counters won't allow for seal development or improvement, but if that is true, that is shortsighted, maybe seal technology is behind this engine's needs

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I always planned the next northstar I get will be an 02 or newer because of the headgasket and TCC problems.

The TCC is STILL a problem. I am getting the P0741 on a somewhat regular basis. I know of many others who are as well on '02 or newer cars.

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I think starting with the 2004 model year, they went back to a conventional lockup system rather than the VCC system but I am not sure.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I always planned the next northstar I get will be an 02 or newer because of the headgasket and TCC problems.

The TCC is STILL a problem. I am getting the P0741 on a somewhat regular basis. I know of many others who are as well on '02 or newer cars.

ahhhh. I keep moving up in years of which northstar I can buy again. After Jims problems I dont know if I should ever get another one. I can do alot of repairs but dont ever feel like dropping a cradle on my daily driver. And I cant afford super low mileage ones or ones with an existing warranty. Dont get me wrong I still think its a better, more advanced motor than about anything else out there but theres just a few repairs that cost so much. I dont know what GM's problem is. Maybe because its now government motors I dont know. A mechanic I know was telling me according to ALLDATA the new camaros already have 300 service bulletins and the new shelby mustangs have 3! <_< 2011 Caddy has 17

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

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Jim is getting the case half fixed under warranty. If the dealer did not point it out it is doubtful it would have ever been noticed. I would do the same thing (have it repaired under warranty if it were my car) but if it was not covered under warranty, I'd leave it. The case half leak rarely if ever drips to the ground.

My '96 SLS that I sold in October of last year had the case half seepage - it did not leak to the ground at all. I noticed it every time I changed the oil but there wasn't enough on there to even clean off. Oh, it had 148,000 miles and had the original headgaskets too. I am not in the least bit concerned about the reliability of my '05 Deville.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Just a quick note about my "TROUBLES... :)

My DTS has almost 100,000 on it.

It has never been ABUSED, but it "HAS" been DRIVEN... probably a little harder than most.

It is such a superb high speed highway cruiser.

I love the way it runs and performs... :yupi3ti:

So far, the powertrain has been totally FLAWLESS.

There is not one oil spot in my garage.

It was just minor SEEPAGE on both the halfcase seal and on the cam cover.

I have NEVER had to add oil between changes and I usually go 5000 to 7,000 miles between changes.

"I" didn't even know it was leaking.

If the service tech hadn't found it, I "STILL" wouldn't know it was leaking.

I am very particular with my car...but it seems like this was so minor...If it wasn't under warranty... I would not be having it fixed.

I "DO" still plan on buying another one...probably later this year...

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