coolnesss Posted September 26, 2012 Report Share Posted September 26, 2012 Help, my head bolts came loose on a 2002 ETC. My trusty mechanic doesn't know enough to fix it. Does anyone know a tech in the LA Area who does? THANKS Link to comment Share on other sites More sharing options...
KHE Posted September 26, 2012 Report Share Posted September 26, 2012 How do you know the head bolts came loose? What diagnostics have been done to pinpoint the cause? Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
coolnesss Posted September 26, 2012 Author Report Share Posted September 26, 2012 It's been low-grade heating up for a year - often to 230, 235 before it cools back down, which it does fairly quickly. The heating/cooling cycle is irrational with respect to weather and driving conditions. But, lately, it started misfiring badly and has a bad coolant leak that I couldn't see the source of on cursory inspection, but is coming from further back than the radiator area. I took it to a reputable shop. Mechanic tried a new coil pack, and it didn't fix the misfire. Then he inspected the spark plugs on the front head, and they've got coolant on them. And the magic question - are the Northstar Performance studs still preferred over time-serts? Thanks! Link to comment Share on other sites More sharing options...
KHE Posted September 26, 2012 Report Share Posted September 26, 2012 Never knew Northstar Performance studs were preferred over Timeserts. I used Timeserts in my engine and they have held up just fine. There seems to be a pattern when the headgaskets let go, it is usually the rear cylinder bank. I think yours is the first one to have the front bank go. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
coolnesss Posted September 26, 2012 Author Report Share Posted September 26, 2012 Kevin, it's been a little while since I read the head gasket posts in depth, but I think I remember that the Northstar Performance studs were getting great reviews on here. But, water on the plugs is a definitive symptom of a head gasket failure, isn't it? Anyway, I've located a shop by calling a local Cadillac-only parts man, and he has great confidence in a father/son shop in the valley called Caesar Restorations, and they talk the right talk, so I'm going to take the car to them. They want in the range of 3 grand for the job, and they looked at the Northstar Performance website and liked what they saw. They've done about 20 of the time-sert jobs with no be-backs. So, now, all I have to do is decide whether to use time-serts or the Northstar Performance studs. Help!!! and Thanks!!!!! Link to comment Share on other sites More sharing options...
airmike Posted September 27, 2012 Report Share Posted September 27, 2012 coolnesss, if you have not already, read the patience thread, before going the stud route. I would not go that way again, although I love the studs etc,.. Not stated in that thread, I just recieved a gasket set today, packaged in rock auto packing. No other parts and I haven't opened that box to see what all is in it. Link to comment Share on other sites More sharing options...
coolnesss Posted September 27, 2012 Author Report Share Posted September 27, 2012 Yikes, sounds like a problem exists with Jake. I sent him an email asking him about lead time from order to ship-out - we'll see if he replies. Thanks Bill Link to comment Share on other sites More sharing options...
KHE Posted September 27, 2012 Report Share Posted September 27, 2012 Timeserts are the factory repair. The thing I do not like on the stud repair is Northstar Performance has a different torque spec. than the factory spec. They use a straight torque value vs. the initial torque and angle method. The torque/angle method is much more consistent since it takes friction out of the equation and results in more consistent clamping. As long as the shop Timeserts all 20 head bolt holes, it should be fine. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
airmike Posted September 27, 2012 Report Share Posted September 27, 2012 Kevin I don't intend to start a debate here. I am not a scientist or mechanic of any kind, so I am really just curious, want to learn. It would seem to me that the weakest part of the head clamping system would be the aluminum and the fact that the bolts have to turn inside the threads. Once the studs are in, wouldn't the stress be on the steel threads of the stud and the nut? (studs would not have to twist in the threads) I am under the impression that the failed time serts are from the aluminum that is drilled, being degraded, most likely from excessive heat. Maybe an unprofessional person such as myself would be able to get away with studs, vs time serts, not knowing when the block is unusable? In any case that was my thinking when I decided to use the studs. Another thought is that I would not have to junk the block if the aluminum was somewhat degraded. Maybe I should have asked these questions before I ever started this, but hopefully its informative for the next guy down the line, which I assume will be many. Link to comment Share on other sites More sharing options...
KHE Posted September 27, 2012 Report Share Posted September 27, 2012 Kevin I don't intend to start a debate here. I am not a scientist or mechanic of any kind, so I am really just curious, want to learn. It would seem to me that the weakest part of the head clamping system would be the aluminum and the fact that the bolts have to turn inside the threads. Once the studs are in, wouldn't the stress be on the steel threads of the stud and the nut? (studs would not have to twist in the threads) I am under the impression that the failed time serts are from the aluminum that is drilled, being degraded, most likely from excessive heat. Maybe an unprofessional person such as myself would be able to get away with studs, vs time serts, not knowing when the block is unusable? In any case that was my thinking when I decided to use the studs. Another thought is that I would not have to junk the block if the aluminum was somewhat degraded. Maybe I should have asked these questions before I ever started this, but hopefully its informative for the next guy down the line, which I assume will be many. There will be a clamp load on the threads (tension) regardless of what type of fastener is used (Stud or Timesert). The Timesert is steel as are the headbolts so torquing them is not an issue with ripping threads out of the block since it is not the Timesert that turns in the block. The block is drilled & tapped, then a Timesert (with Loctite) is installed and the installation tool swages it into polace to lock it mechanically. If the block is degraded (which is very rare) either fastener system (studs or Timeserts) would be compromised. If the block is degraded, there won't be chips when drilling them but rather powdery aluminum. GM developed the Timesert not as a field repair but as part of the validation of the Northstar engine design. The non-Timeserted block is fine for one installation but in validation testing, there was a need to change out heads on the test engines. That changeover necessitated a thread repair and thus the Timesert was developed. Since the Timesert was already developed, it was the obvious choice for the field repair. When using non-factory sanctioned repair procedures, remember YOU are now doing the validation testing. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
airmike Posted September 28, 2012 Report Share Posted September 28, 2012 Thats a great response Kevin, and I thank you. Definitely should have asked that a long time ago. Link to comment Share on other sites More sharing options...
coolnesss Posted October 6, 2012 Author Report Share Posted October 6, 2012 For future searchers, the men doing my head work are at Cesars Restoration in Reseda 818 776 1212. It's a father/son operation, and they work mostly on Cadillacs, from frame-off restorations to mere oil changes. They're doing the head job for 3200 box, which is 1-2 grand less than I was quoted at every other place I called. They've done 20 or so of these. The shop is clean, organized, and the father and son are both happy guys. The father is an old-school kind of guy who says he loves working on cars. It seems to be his passion rather than just his job. I'll have more to say when the job is done. Link to comment Share on other sites More sharing options...
coolnesss Posted October 15, 2012 Author Report Share Posted October 15, 2012 It's Done. The car runs great. Thanks all for your input. Link to comment Share on other sites More sharing options...
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