time serts

[Scotty]

I don't disagree with you at all. I have been hearing about NS problems for at least 5 years, first from a Caddy mechanic, that advised against buying a NS. I have 77K, so I am due for this problem myself. I hope that GM has fixed this problem and that this happens less going forward. There has to be a way to avoid this problem.

I am not an engineer but what I would like to see is a timesert like device molded into the block when the block mold is made so that the head bolts are not screwed into aluminum but into a timesert type of device that has an exterior that is intertwined with molten aluminum and therefore a permanent part of the block. I wonder if GM has attempted to accomplish that?

[BMWburner]

I’m starting to develop a certain level of paranoia on the head gasket issue. I’m well aware that are less than a quarter of Northstar owners have ever had a problem and there are a host of Northstar vehicles out on the road with over 200K on the clock without engine trouble. However, my question is this; how bad is bad? Are we talking a mild lack of compression, and power output, or an engine that won’t run? I hear of these head gasket leaks and wonder what to expect. Hopefully nothing, but I’d like to know what symptoms other members experienced before they got the bad news. I also agree with statements made about engine replacement. If I had head gasket trouble, I’d be shopping for a new engine. I don’t doubt that a well maintained Northstar would run forever, but for three to four thousand dollars I’d want a virgin power plant, not a Timesert job.

Just curious,

–Ben

[Scotty]

I’m starting to develop a certain level of paranoia on the head gasket issue.  I’m well aware that are less than a quarter of Northstar owners have ever had a problem and there are a host of Northstar vehicles out on the road with over 200K on the clock without engine trouble.  However, my question is this; how bad is bad?  Are we talking a mild lack of compression, and power output, or an engine that won’t run?  I hear of these head gasket leaks and wonder what to expect.  Hopefully nothing, but I’d like to know what symptoms other members experienced before they got the bad news.  I also agree with statements made about engine replacement.  If I had head gasket trouble, I’d be shopping for a new engine.  I don’t doubt that a well maintained Northstar would run forever, but for three to four thousand dollars I’d want a virgin power plant, not a Timesert job.

Just curious,

–Ben

Less than a quarter? It's much less. I would say in the real world we are talking about less than 5%. Even on this board the figure is about 14% based on a survey we did, but I think its a lot better overall. Once this problem occurs you will not be able to drive it, you will loose coolant and it will over heat. Furthermore, unless you were going to purchase a brand new engine doing the timesert job is a better idea if you ask me I don't believe you are going to get a new engine for $3K to $4K.

I was reluctant to post my comments above, I hope I didn't alarm you..

[growe3]

I’m starting to develop a certain level of paranoia on the head gasket issue. I’m well aware that are less than a quarter of Northstar owners have ever had a problem and there are a host of Northstar vehicles out on the road with over 200K on the clock without engine trouble. However, my question is this; how bad is bad? Are we talking a mild lack of compression, and power output, or an engine that won’t run? I hear of these head gasket leaks and wonder what to expect. Hopefully nothing, but I’d like to know what symptoms other members experienced before they got the bad news. I also agree with statements made about engine replacement. If I had head gasket trouble, I’d be shopping for a new engine. I don’t doubt that a well maintained Northstar would run forever, but for three to four thousand dollars I’d want a virgin power plant, not a Timesert job.

Just curious,

–Ben

The normal (?) mode of failure is coolant is pulled in through a small opening in the head gasket. Although the amount pulled in is small, it is done thousands of times per minute. You can easily burn a gallon or more of coolant in 30-40 minutes of freeway driving.

The strange thing is the car usually still runs great, with all of that coolant going through the engine.

-George

[growe3]

I am not an engineer but what I would like to see is a timesert like device molded into the block when the block mold is made so that the head bolts are not screwed into aluminum but into a timesert type of device that has an exterior that is intertwined with molten aluminum and therefore a permanent part of the block.  I wonder if GM has attempted to accomplish that?

I asked bbobynski that same question a couple of years ago. The response was it would be prohibitive to do that in the assembly line.

I don't agree with that assessment, and I think it would be the way to go. I think that GM feels that since the failures are usually to "second" owners, and the problem doesn't manifest itself until high mileage, they didn't want to do anything to raise the cost of building this engine. A shame.

-George

[tommysls]

To increase your odds of not having head gasket problems, make sure you change your coolant well before the 5 year, 100,000 miles that gm states that the coolant is good for.

Dexcool eats right thru those gaskets when it gets old.

[KHE]

I asked bbobynski that same question a couple of years ago. The response was it would be prohibitive to do that in the assembly line.

I don't agree with that assessment, and I think it would be the way to go. I think that GM feels that since the failures are usually to "second" owners, and the problem doesn't manifest itself until high mileage, they didn't want to do anything to raise the cost of building this engine. A shame.

-George

To add, the failure rate of the head bolt holes was so low that the extra cost of insert casting the time serts into the block could not be justified from a business case standpoint.

[KHE]

To increase your odds of not having head gasket problems, make sure you change your coolant well before the 5 year, 100,000 miles that gm states that the coolant is good for.

Dexcool eats right thru those gaskets when it gets old.

Where did you get this information??? DexCool's corrosion inhibitor package does not deplete over time so it is able to go 5 years/100K without incident.

The old green silicated coolant needed to be changed every two years as the silicated corrosion inhibitors depleted over time. The coolant could be completely void of corrosion inhibitors but still look new all while it was rotting the head gaskets.