: Headgasket - How long, how much?



eldorado1
04-27-04, 04:17 PM
I might have to swap my heads in the future here (if I can't find a cheap 96+ longblock), so my question is, how involved is changing out the headgaskets? From what I can tell, I can get both headgaskets (Felpro) for ~$19 ea, headbolts for $27, I already have the intake gaskets... Timesert kit ($???), anything else? Maybe valvecover gaskets... I've got the engine sitting in the garage right now, how long can I expect this job to take? One thing I'm worried about are the timing chains - how do I keep everything in time?

zonie77
04-27-04, 07:35 PM
The timing chains aren't that hard to reinstall. Important to have the manual.
The timesert kits are on ebay or here occassionally. You can do the timeserts in 6 hours, more or less depending on many things, but that'll be close.
Some people reuse the intake gaskets, I don't think it's worth a potential problem. The whole job should be 12 hours(my guess).

ShadowLvr400
04-27-04, 07:46 PM
Prepare for misery. Couple hundred for parts. I have the tools for the time serting now, will pass them for the same price I got them, let them become the site's pass around parts. ;) Thank Frank W on here for this. :) The redrilling for the bolts is a pain though, you're going to need a professional shop for all this. Figure over 1k for labor. Easily.

eldorado1
04-27-04, 08:37 PM
The redrilling for the bolts is a pain though, you're going to need a professional shop for all this. Figure over 1k for labor. Easily.
Why would I need a pro shop? Unless you just mean access to tools and what not, which I have. I just took a look at the service manual, and it seems like I'm going to need to pull the front cover to make sure I get everything timed correctly, no big deal. Is drilling the head bolt holes really that tough? I was planning on using a standard electric drill, as there's no way to get the block in my tiny drill press... Is that going to be a problem?

captcaddy
04-27-04, 09:00 PM
I changed my head gaskets with the engine still in the car on my 88 deville. It took me a week because of all the lines.

eldorado1
04-27-04, 09:05 PM
I changed my head gaskets with the engine still in the car on my 88 deville. It took me a week because of all the lines.
That's different though... 4.9? I've done a 350 once in the car, that was "fun"... I know what I'm getting myself into, just haven't worked on a northstar before.

zonie77
04-27-04, 11:32 PM
You can easily do this yourself. A few special tools are needed but you can get those easily. (torque angle meter, allen sockets, timesert kit). the timeserting process is easy and straightforward. The kit makes it almost foolproof. It's just a little tedious since you have 20 holes to do. A machine shop is not necessary. A 1/2" drill is needed.
Here's a writeup I did after doing one. i was gonna follow up with cleaning the heads and reassembly(which is pretty straightforward) but got busy on other stuff. Expect the lifters to be very noisy on startup but they'll quiet down in a minute or so.
http://cadillacforums.com/forums/showthread.php?t=5052

Lawrence
04-28-04, 03:01 AM
In addition to Zonie's list you'll need a 4" three jaw puller for the crank pulley, a pulley puller for the water pump pulley (I got one at Harbour freight for $10.00), a 12mmX85mm (correct me here if I'm wrong) bolt to re-install the crank pulley, the allen socket Zonie mentions is a 10mm hex bit drive, you'll need alot of long 3/8 drive extensions and/or wooble extensions for getting the exhaust bolts when removing/installing the engine, and if you don't already have one make sure you get a good telescoping magnet (invaluble for the torque converter bolts). Also if you buy a used Timesert kit, make sure you have Loctite 266 and cutting oil on hand for the job. Don't use anything else. Also have some high quailty harness tape on hand as you will likely need to repair/redo the wiring harness.

The Northstar is as easy as any engine I have ever worked on and so is the Timesert process, as Zonie said. The valve timing is about idiot proof, no problems there. Just line up the timing marks on the crank and intermediate sprockets, install the inner (left chain ?) first by lining up cam sprocket timing marks 90 degrees (straight up) to the head (valve cover) surface. On the exaust cam make sure the "E" is up, on the intake cam the "I" is up. Either way the camshaft to camshaft sprocket "locating pin" is up. Make sure all marks are lined up with the chains tight. Thats all there is to it.

Do use OEM head gaskets, about $45 ea which includes the head bolts. Make sure the gasket and mating surfaces are clean and dry of oil before/while installing. As a personal addition I used RTV around the bottom of the head bolt washer. The top of it is factory sealed. I noted oil down the head bolts when I removed them.

Also as George recommened to me, plan on replacing the HVAC cover while the engine is out. It deteriorates from the rear exaust manifold. I also had to do the inner metal box as well. And while there clean/service the AC evaporator. They get plugged up and can't be done with the engine in the car.

I personally would recommend all new lower oil seals as well. That one got me and I had to pull the engine again. Don't worry much about the valve cover seals, or any other seals that can be replaced later with the engine in the car unless they are obviously bad. On mine I had to replace the intake manifold gaskets as they were shrunken and dried out. At least the ones that contact the head.

One other thing. To be safe, prime the oil system before starting the engine. Do this by pulling the smaller of the two connectors on the drivers side of the coil pack. This cuts power to the ignition. Make sure the battery is fully charged. Crank the motor for two or three 60 second sessions. Reconnect the plug, start the engine and watch the DIC for a low oil pressure warning.

If you have the engine out already, you're already on the road home. Good Luck!

ShadowLvr400
04-28-04, 10:22 AM
It's been taking the shop here some 45 minutes per hole. The timesert I have is a heavy duty version apparently, with longer bolts, but I don't know. It's beyond my personal expertise.

dloch
04-28-04, 10:29 AM
It's been taking the shop here some 45 minutes per hole. The timesert I have is a heavy duty version apparently, with longer bolts, but I don't know. It's beyond my personal expertise.
I believe the timesert kit for the Northstar Head bolts are longer than the standard timeseters used elsewhere. I think it took me about 4 - 5 hours to do all 20 headbolt holes.

eldorado1
04-28-04, 10:40 AM
I have the tools for the time serting now, will pass them for the same price I got them, let them become the site's pass around parts. ;)
Hey Shadow, send me an email at ryan.h@excite.com about that kit when you're done with it... To everyone else, thanks for the (confidence boosting) information! This should be... umm... fun? :drinker

brad3378
04-28-04, 11:14 AM
well,
it looks like I just got burned on my last repair.
I diagnosed the front headgasket on my 98 Deville and fixed it - now the other one is blown. I REALLY wish I wouldn't have tried to save those last few dollars and just replaced both. This time I've got a car hoist in my tiny Dearborn garage so I'm going to drop the engine cradle.
Where are you guys finding head bolt / gasket sets for $50?
I could have sworn I paid $75+ at the Local Cadillac dealership.
I called the local Murray's, AutoZone, Napa, Pep Boys, and Auto Value stores and nobody could seem to find these in their computer.

Does anybody have Fel-Pro part number(s)?
I'm assuming the front and rear sets are different.

Lawrence
04-28-04, 11:29 AM
well,
it looks like I just got burned on my last repair.
I diagnosed the front headgasket on my 98 Deville and fixed it - now the other one is blown. I REALLY wish I wouldn't have tried to save those last few dollars and just replaced both.

OOOUCH! I have to admit, I did the dame thing. I replaced both head gaskets but didn't do the oil seals. It leaked and I pulled it again, uughh.


Where are you guys finding head bolt / gasket sets for $50?
I could have sworn I paid $75+ at the Local Cadillac dealership.
I called the local Murray's, AutoZone, Napa, Pep Boys, and Auto Value stores and nobody could seem to find these in their computer.

OEM headgaskets from www.partszoneonline.com are $47.00 a side including head bolts.

Lawrence
04-28-04, 11:31 AM
I believe the timesert kit for the Northstar Head bolts are longer than the standard timeseters used elsewhere. I think it took me about 4 - 5 hours to do all 20 headbolt holes.

Yes, me too. I don't see how you could make the job go 45 mins a hole, hmmm?

zonie77
04-28-04, 11:33 AM
There are online parts suppliers. www.gmpartsdirect.com , www.partszoneonline.com , wwwgmpartscenter.net .

There are more and I havn't ordered from any so i can't recommend a specific one. If you check part prices online you can ask your local dealer if he can match. I've had good luck with that.
You might try a regular auto parts store. Some of them discount prices to get all the business they can.

zonie77
04-28-04, 11:47 AM
We did a few holes in 5 min but the average is more like 10. I'd say the whole job (taping, reading instructions, cleaning up, everything) should be 5 hrs or less. A plate that covered the whole side would really cut the time down, as would having multiple 1/2" drills.

Shadowlvr, Have you been there watching them?

Brad, If I thought the front was the only blown gasket I would do it in the car too.

eldorado1
04-28-04, 12:50 PM
Everyone I know swears by the quality of FelPro gaskets... http://www.fel-progaskets.com It's what I used on my Camaro at least. Plus they're cheap :D Obviously the OEM ones aren't doing too well ;) j/k I know they revised them, but still... track record - 1 in 2.

brad3378
04-28-04, 04:16 PM
I don't think it's so much the quality of the gasket as much as a combination of Age/High Miles and thread damage in the block. My Northstar headgasket doesn't even look damaged, but I believe that the lack of headbolt tension created by damaged threads caused the leak.

When I replace the other headgasket tonight, I'm guessing that the headgasket will look normal but the threads in the block will need to be repaired.

As sick as it sounds, I kinda like working on these engines.

brad3378
04-28-04, 04:20 PM
I forgot to mention Cooling problems...

I bought my 98 Deville for a bargain price knowing that there was a headgasket problem. I recently found a receipt under the seat for a brand new radiator, so now I think I know the root cause of my headgasket problem.