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Discussion Starter #2
Re: DHS Deville heads and gaskets pulled

The mobile app on the iphone has some issues, but here are more photos of the project. 20150516_170324_resized_1.jpg 20150516_170335_resized_1.jpg 20150516_170415_resized_1.jpg image1 (8).JPG image2 (4).JPG
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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Re: DHS Deville heads and gaskets pulled

Your gaskets don't look as bad as some ones I've repaired, but a leak is a leak.

To bulletproof the repair, I would use studs and a multi layered steel head gasket.
 

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Discussion Starter #4
See that's what confuses me. I've been using the inserts from Norm on my hg's. Not the studs...This one didn't look as bad as the last one we did. There was gasket trash stuck in the motor though. I just got a felpro gasket set for the repair. With new head bolts, inserts and gaskets, I'm hoping to be good.

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98eldo32v said:
Your gaskets don't look as bad as some ones I've repaired, but a leak is a leak. To bulletproof the repair, I would use studs and a multi layered steel head gasket.
You don't use the inserts?
 

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Re: DHS Deville heads and gaskets pulled

Inserts are good. I just feel the effort involved in drilling and tapping, just make one unified repair.

With the inserts you're still tightening a bolt back into something you just threaded in. I guess it boils down to what one prefers.

If I have to do it, it's studs all the way.

A fel pro set will be fine for most repairs. All the cars I've done I've used fel pro sets.

My Eldorado will get the MLS gaskets on the heads......

Good luck....

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Did you remove the bumper bar and cover on that deville?
 

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Discussion Starter #6
98eldo32v said:
Inserts are good. I just feel the effort involved in drilling and tapping, just make one unified repair. With the inserts you're still tightening a bolt back into something you just threaded in. I guess it boils down to what one prefers. If I have to do it, it's studs all the way. A fel pro set will be fine for most repairs. All the cars I've done I've used fel pro sets. My Eldorado will get the MLS gaskets on the heads...... Good luck.... ---------- Did you remove the bumper bar and cover on that deville?
I have two others to do. Maybe I'll try the studs on the next repair. How much are you paying for studs? Sounds like an easier method. No tapping and drilling sounds great.

We didn't remove the bumper bar or cover.
 

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Re: DHS Deville heads and gaskets pulled

Actually you still have to drill and tap because the lower end of the stud is larger in diameter and has coarser thread pitch.

I have the northstar performance studs for my car. The ones I've repaired I informed the customers of the northstar performance and the Carroll Cadillac customs studs. I felt most customers opted for the CCC studs because of the price factor.

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I believe Northstar performance has an economy kit now, but I feel you should get all the necessary bits and taps in one kit.
 

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Discussion Starter #8
98eldo32v said:
Actually you still have to drill and tap because the lower end of the stud is larger in diameter and has coarser thread pitch. I have the northstar performance studs for my car. The ones I've repaired I informed the customers of the northstar performance and the Carroll Cadillac customs studs. I felt most customers opted for the CCC studs because of the price factor. ---------- I believe Northstar performance has an economy kit now, but I feel you should get all the necessary bits and taps in one kit.
I see. So you feel the inserts are just as good? When you do yours, do you drop them from the bottom? I saw some people doing them still in the car but seems almost impossible.

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98eldo32v said:
Actually you still have to drill and tap because the lower end of the stud is larger in diameter and has coarser thread pitch. I have the northstar performance studs for my car. The ones I've repaired I informed the customers of the northstar performance and the Carroll Cadillac customs studs. I felt most customers opted for the CCC studs because of the price factor. ---------- I believe Northstar performance has an economy kit now, but I feel you should get all the necessary bits and taps in one kit.
Are there any gaskets that you reuse?
 

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Re: DHS Deville heads and gaskets pulled

I've pulled the motors both ways and I'll rather remove it from the top.

That whole sub frame deal is tolerable when you have a lift and some dollies and a nice size shop. If you have limited space and area, not to say you can't drop it from the bottom but why?

Would you dislocate your jaw to pull a tooth? No, you'd go directly to the tooth. Only in rare cases you have to dislocate a jaw to get a tooth. RARE cases.

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Ironically, mostly all the gaskets are reusable to some extent, use discretion though.

This isn't motor you want to redo too many things twice.
 

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Discussion Starter #10
98eldo32v said:
I've pulled the motors both ways and I'll rather remove it from the top. That whole sub frame deal is tolerable when you have a lift and some dollies and a nice size shop. If you have limited space and area, not to say you can't drop it from the bottom but why? Would you dislocate your jaw to pull a tooth? No, you'd go directly to the tooth. Only in rare cases you have to dislocate a jaw to get a tooth. RARE cases. ---------- Ironically, mostly all the gaskets are reusable to some extent, use discretion though. This isn't motor you want to redo too many things twice.
Well I hope I won't be pulling any teeth or putting together my own jaw, usually it's the other guy lol. But this is our second one. Ill have to do some more research on pulling it from the top. Id rather do it that way. Gotta crawl before you walk tho.
 

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Re: DHS Deville heads and gaskets pulled

You are absolutely correct.

Good luck....
 

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White Diamond '03 DHS (with DTS floor shift)
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Re: DHS Deville heads and gaskets pulled

Here are some pictures I took. Looks like this spot was the problem.
I'll never understand why GM used this damned open deck design. Have they learned nothing in near 100 years of motor building? Probably would never have been plagued with this HG problem if they had built these motors the way God intended (the old fashioned way -CLOSED DECK).
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Re: DHS Deville heads and gaskets pulled

In the picture of the cylinder with the compromised fire ring - what was your assessment of the adjacent head bolts and the corresponding block threads when pulled ?

I'll bet the open deck design had something to do with the casting process. Big mistake.

This thread sort of belongs in Engines; Northstar.
 

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Discussion Starter #15
Ranger said:
I'll never understand why GM used this damned open deck design. Have they learned nothing in near 100 years of motor building? Probably would never have been plagued with this HG problem if they had built these motors the way God intended (the old fashioned way -CLOSED DECK).
I hear you. The gasket seemed to be eaten through and corroded or melted in places too. I'm thinking spot in the close up picture above was one of the places it was failing.
 

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Re: DHS Deville heads and gaskets pulled

:noidea: I'm sure someone, somewhere has, but I've never heard of it.
 

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Discussion Starter #19
They get pretty caked up inside. Since I had it off for a few days I thought I'd take it down to get it cleaned out but from your response it sounds like a no.
 

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