: Headgaskets And "time-serts"!?

04-28-08, 09:35 PM
Is there anyone on here that knows anything about these Repair Kits as far what kind of if any success rate they have is with regards to repair of HeadGaskets in the NorthStar engine from 93 thru 97? Second or in addition to that, aside from properly maintaining a good grade of coolant, would anyone think that applying a "TIME-SERT" kit to an engine "before" a Headgasket has started to fail, would provide any additional proctection against failure or even prolonged Headgasket life?? Thanks.

04-29-08, 12:10 AM
They have a very high success rate.

If the HG hasn't failed you may not have to timsert the block. The reason it's recommended is a couple (possibly 3) people have had a good appearing thread fail on torquing the bolts after replacing gaskets. There are people that did HG's and didn't timesert the block. I'm sure some people replaced blocks because they didn't know about timeserts.

If you timesert an engine before the HG's fail you will replace the HG's and a bunch of other gaskets when you reassemble the engine. You will be doing all the work before failure and you might never have had the HG's fail.

All HG's will eventually fail. It might be early, it might be very late. Some people reported over 250,000 miles. I'm sure a lot of them outlast the life of the car.

04-29-08, 12:44 PM
I am not sure what you are asking. If I were replacing a pre 2000 engine with another pre 2000 engine, I would insert the block and change all the gaskets and seals while the engine was out of the car. I say this because I replaced a 97 N* with a blown HG with another '97 N*, and 2 years later, the rear main seal and oil pan gasket were leaking, and the HGs blew. By that time, I had found this forum and learned from zonie and others about the causes and way to correct the problems. If I had known what to do, I would have repaired the first engine instead of replacing it, but if you need to replace an engine that is not repairable, I say do the repairs on the replacement engine before you install it.

04-29-08, 08:31 PM
First let me say "Thank you" for replying to my post and offering what knowledge and experience you have to my question. Now you said you didn't know exactly what it was that I was asking, in short I wanted to know whats the "Best" preventive measures towards avoiding HG failure or the various steps that I can take to "extend" the life of a HG in a NS* engine. I know from other answers on here that maintaining a very good grade of Coolant and changing it regularly goes along way, but I came across this site describing the "Time-Serts" repair kits as an "alternative" towards replacing the block and I wanted to know if based on the fact that part of the reason HG fail so commonly in NS* engines is because its an ALUMINUM block if installing a "TIME-SERT" to begin with, would help prolong the life if HG above the normal time frame that they tend to fail?!?!?

04-29-08, 09:01 PM
You have it right. Cooling system maintenance and prayer are about all you can do. Timeserting it BEFORE a failure is a waste of time as it requires the same amount of work as replacing the HG's, so IF they fail, THEN Timsert when you do the repair.

04-29-08, 09:13 PM
joez...........Sort of a convoluted "horse before the cart" deduction. IF GM had known that the porosity of the aluminum block castings in the mid - late 90's Northstars was going to cause early head bolt retention failures, then none of the blocks would ever have made it to the consumer. .......Problem is, the fault began to show up in the 2001 - 2002 calendar year after running changes had been made to the N* tooling, so there was no going back to a total recall because the failure rate was still within the normal manufacturing tolerances for a mass-produced item. NOW, the true extent of the problem is becoming known, so we see more and more head bolt failures.

The Timesert or Norm's insert method of block repair seems to be an acceptable alternative to block replacement. So far, so good. There is no good engineering reason to pre-insert a production line aluminum automobile part based on modern metallurgy.

Now, if we could get 10,000 people to form a class action suit against GM for negligence and deceit in marketing a known defective assembly, then there might be a ray of hope for those who have suffered expense and inconvenience due to poor engineering.

04-30-08, 12:16 AM
I've posted this story a few times but here it is again...

A group of guys at work were sitting around and talking about failed head gaskets. I walked in on the middle of the conversation and asked if they were talking about Caddy's, they looked at me and said "Caddy's have head gasket problems too?????" True story, none of them were talking about Caddy's. Other GM's have problems, Ford had a recall back a few years.

Head gaskets were a problem when I was a professional mechanic many years ago. I've also recounted realizing that some of the valve jobs being done were actually head gasket failures where coolant did not leak into the oil. We always did a valve job, primarily as CYA, so the valves were blamed even if there was no problem with them.

04-30-08, 03:27 PM

I think that it is possible that it is the head gasket that fails first, perhaps only slightly, but that allows the coolant and corrosive exhaust gases to degrade the aluminum threads in the block. Next, the bolts let go and then the exhaust gases enter the cooling system and displace the coolant and force it out the surge tank and THEN the massive overheating occurs.

This is just a theory based on my experiences and what I have observed.

If I am correct, inserting the block when new as a preventative measure would not really help. It would also mean that, unless there was a change in the design of the head gaskets, that 2000+ FWD N*s will eventually have widespread head gasket problems. I know they made some changes to the bolt lengths and pitch, but if it is the head gasket that fails first, then those changes will not really solve the issue. I know we haven't seen a lot of failures in head gaskets for the 2000 and later engines, but maybe it is just a matter of time? I think AJ has suggested that perhaps the open deck is at least part of the problem. I hope I am wrong and that head gaskets on the 2000+ N*s will NOT be a problem, since I just got a 2000 DTS as a hand me down. I still like my '97 ETC which i have owned since new. After all the effort to repair the head gaskets, I am having a hard time making the decision to sell it - I don't really need 4 cars for 2 drivers...... or do I?


05-01-08, 01:53 AM
I don't really need 4 cars for 2 drivers...... or do I?

If two of them are Cadillacs I'd hang on to the other two cars for spares. My Dodge has logged more miles in the past 3 months than it has in the past 3 years while my STS is OIA.

05-01-08, 02:33 PM
Yeah, chubbyranger, that's kind of what I was thinking also. I hate to get rid of a car and then have one of the remaining stolen or totaled or somehow out of commission. And I do like all four cars and can afford to own them all. I think I'll just keep all 4 for now, and get rid of one if I feel differently in the future. The other thing is my GM Mastercard rebate will max out in 2 1/2 years, so I will probably buy a new car then - I will get the maximum rebate of $3,500 off, so it is pretty compelling to buy a car at that point. I think I will get something better on gas.

05-11-08, 10:32 PM
joezaier56, Tateos and Ranger can be the best two people to talk to, my car would not be on the road if it was not for these guys. take all their advise and you can do the job.

05-12-08, 04:05 AM
"Thanks"! I really appreciate the feed back and the info!!!

05-13-08, 06:14 PM
Thanks for the kudos Joe!