Northstar Engines and System Technical Discussion Discussion, Timesert or not? in Cadillac Engine Discussion; Hi all, thank's for a great forum!
I'm a lucky owner of a sts-93 with N*, maybe not so lucky ...
I'm a lucky owner of a sts-93 with N*, maybe not so lucky now The engine have run great all the time but now it losing coolant! I did a compression test and find out that cylinder number 2 had low compression, about 3bar. All other cylinders had between 9,5-10bar. It is probably a blown head gasket so I must replace it! I have read many topics about Timesert but it is very hard(impossible) to find them here in Sweden. The question is, is it always necessary to use Timesert even if all the threads are in good contition?
I think most of the people here that have removed their older N* cylinder heads have found damaged block threads and didn’t have a choice as to installing the time-serts. I know when I removed the heads on my 1997 N* several of the head bolts carried the block threads out during there removal. You need the time-sert kit to repair any of the head bolts female block threads that are damaged even if it is only one bolt hole, so you do one, you might as well do them all while you are in there. IMHO even if you were lucky enough to remove the head bolts and the block threads remained intact they could yet fail during reassembly. If I were you I would just plan on time-serting all twenty head bolt holes if in fact the head gasket is proven to be the problem. The cylinder leak down test would appear to be the preferred test for a leaking head gasket. Did you email time-sert http://www.timesert.com/ and inquire as to the purchase and shipping of their repair kit?
The older the engine and/or the higher the miles, the more and more like that if you don't have to do a Time-sert to day you will very soon and tearing down an engine and putting back together really stress the threads. They don't get stronger with age and use that is for sure. With your engine being a 93 I would certainly do the Time-serts. I am doing a 94 now and all the head thread were good and looked good but I did them anyway because of all I had read and I am glade I did and they worked well but when tightening the mains down today one of those failed and they seldom do, so I think that is an strong indicator that the head threads could have gone at any time and probably would have in a few hundred or thousand miles after having gone throught the additnal stress of being reused. Don't trust them - Time-sert them, and do all the head threads.
Make sure to order enough serts the kit dosen't come with enough to do both heads.