Root Cause of Head gasket Failure and a Fix?

AJxtcman · #1 (**permalink**) 03-05-08, 07:50 AM

This is also on another forum.

Let me start out with an argument and please keep in mind I do this for a living. I have first hand experience and I am GM certified.
TimeSerts are a band aid and just make the bolt bigger in this case. Yes They just make the bolt bigger. This is a fact. They do not become a part of the block.

I have seen TimeSert inserts lock into an aluminum part, but that is not the case with the Northstar head bolt application.

If you have a brand new block. You removed the heads, then installed Timeserts, and then reinstalled the heads you may have just caused a premature failure. Just say the engine goes 80K and looses a head gasket for another reason (ran low on coolant) now when you remove the head bolts the inserts come out (this is typical) now what? GM doe not endorse any large or big inserts

This how they come out

This is a TimeSert insert If you notice it does NOT have a flange at the top or just a minor flange to seat it in place

This is a Norms insert. This will be another part of this discussion later.

This is the two of them side by side

AJxtcman · #2 (**permalink**) 03-05-08, 07:54 AM

We all don't agree on the statement that it just makes the bolt bigger yet, but I hope to give enough information to change that.
With the correct education most of us will come to an understanding.

Now on to the root causes.
#1 is the block and they did redesign it in 00. They also used a slightly different alloy blend. Well that has been what I have been told.

The 93 to 99 block have been known to leak coolant though the casting. Wait I have seen more leak oil than coolant.

This is a cross section

And another

One of the block I have in my garage had a leak after 3k from New. I repaired the by welding it, but I learned a lot about the root problem. It appeared that when the block was poured the aluminum splashed up the side. Then as the casting filled the part that splashed had started to cooled. The splashed part did not melt back into the casting. This block had a very small pin hole leak, but as I heated it a line formed. this line actually then grew into two parts with a grey substances in between. This was little waxy and it in part of the off gassing.

I have some pictures after it was fixed. :mellow:

AJxtcman · #3 (**permalink**) 03-05-08, 07:57 AM

If the treads come out like this I would say the a TimeSert will last.

The fact is that is a Main bolt and has NO thread locker on them

AJxtcman · #4 (**permalink**) 03-05-08, 07:57 AM

This is a head bolt hole and looks pretty good I can see the it is shiny and has no pits or erosion.

AJxtcman · #5 (**permalink**) 03-05-08, 07:58 AM

This is a head bolt hole that has pitting and erosion. IT WOULD NOT BE ACCEPTIBLE TO TIMESERT!

AJxtcman · #6 (**permalink**) 03-05-08, 07:59 AM

This bolt hole we will use for an example.

You can see some deep pits

Now I use the TimeSert drill and remove some material. OH no it is not shiny

The pits are still in the block.

AJxtcman · #7 (**permalink**) 03-05-08, 08:00 AM

This is a my 99 block that leaked. The casting looks good in the water jackets, but it still leaked.

This is the block that I showed drilling out above. I installed a TimeSert in that hole and it pulled out. This is the block after I installed Norm's inserts.

This is a lip on the top of the deck that must not be removed.

AJxtcman · #8 (**permalink**) 03-05-08, 08:01 AM

This is an area that is still bad. It is not in the bolt hole, but coolant leaked into the bolt hole from this area. I pressurize the hole and could see the air coming through the casting

AJxtcman · #9 (**permalink**) 03-05-08, 08:03 AM

What is it that the TimeSert is going to grip to?
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Some time in the 2003 production run GM switch from 11mm X 1.50mm bolts to 11 X 2.0 bolts. This is a much courser bolts and can grip better. I have not seen 1 failure yet.
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I will start in on the head gasket design flaws now.
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The block and head expand and contract in the heat cycles.
This leads to the head gasket bunching up in this area.

Because of this open area the head gasket will look like this.

This is an old picture of some of my Good parts. The collection has grown

AJxtcman · #10 (**permalink**) 03-05-08, 08:04 AM

This is the Deck of a 3.6L VVT engine from a CTS.
The deck is flat and the head gasket is a Multi Layer Metal gasket. I have no picture, but I will get them on Monday. Guess what. I have never seen a failure of a head gasket yet.

AJxtcman · #11 (**permalink**) 03-05-08, 08:05 AM

Quote:

Originally Posted by AJxtcman

What is it that the TimeSert is going to grip to?
.
.
.

Some time in the 2003 production run GM switch from 11mm X 1.50mm bolts to 11 X 2.0 bolts. This is a much courser bolts and can grip better. I have not seen 1 failure yet.
.
I will start in on the head gasket design flaws now.
.
.
.
.
.
The block and head expand and contract in the heat cycles.
This leads to the head gasket bunching up in this area.

Because of this open area the head gasket will look like this.

This is an old picture of some of my Good parts. The collection has grown

After looking at that you can see that the head gasket can shrink. This will cause a failure.

AJxtcman · #12 (**permalink**) 03-05-08, 08:06 AM

This is a block from a 4.4L S/C RWD Northstar. As you can see the block has a full deck.

This is the Multi Layer Metal head gasket that is used on a RWD Northstar

AJxtcman · #13 (**permalink**) 03-05-08, 08:09 AM

I have not installed timeserts in several block. I bet that I have rejected more 99 and prior than I have actually install TimeSerts in.

I installed TimeSerts in several 99 and prior blocks and had the inserts pull while torquing them (never left = never came back). I have had several come in that have been done by other tech's at the dealer. This is how I learned what will hold and what will not.

We have a 00 in currently (2/5/2008) with Head gaskets out. Long story, but I will post pictures

AJxtcman · #14 (**permalink**) 03-05-08, 08:10 AM

Some history
03/12/2003 @ 46998 miles: COVER AND/OR GASKETS, COOLANT PUMP - REPLACE
03/26/2004 @ 58428 miles: COVER AND/OR GASKETS, COOLANT PUMP - REPLACE Not at are Dealer
01/30/2006 @ 74820 miles: J1190 - LOWER CRANKCASE SEAL/SEALANT REPLACEMENT

After the last repair listed. The customer went to another dealer and had the Coolant Cross-over resealed and had been over heated
The customer again stated having over heating issues last summer. He continued to drive it until now.

The front bank head bolts did not crack loose. I have not looked at the head bolts yet and inspected for any signs of aluminum. I will today. The Tech doing the job installs all 20 inserts when he has a failure.

As you can see the material is shiny.

This is a shot of the chips. They are chips and not powder. They are shiny

This is a picture of the TimeSert alignment fixture. It has collected minor amount of smaller chip/powder this is not shiny, but it is not like some blocks. On the really bad blocks the drill goes in easy and when you pull the bit out the material you removed is all powdery. Like dust.

So this 2000 block will hold the TimeSerts

AJxtcman · #15 (**permalink**) 03-05-08, 08:12 AM

I JUMPPED SOME POST HERE
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I strongly endorse Norm's inserts. I feel that they are the best thing in most cases for a 99 and prior block. I know of a couple of issues with Norm's kit. It is not that big of a deal. It is not the product, but it does not use a stop collar. This means that the insert may not be set in the same location. If you take your time you can make sure that they all stop in the same location. I am used to the TimeSert kit, so I had two that did not stop at the proper distance. I just let the loctite set and I was good.